fs/ext4/super.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  linux/fs/ext4/super.c
0004  *
0005  * Copyright (C) 1992, 1993, 1994, 1995
0006  * Remy Card (card@masi.ibp.fr)
0007  * Laboratoire MASI - Institut Blaise Pascal
0008  * Universite Pierre et Marie Curie (Paris VI)
0009  *
0010  *  from
0011  *
0012  *  linux/fs/minix/inode.c
0013  *
0014  *  Copyright (C) 1991, 1992  Linus Torvalds
0015  *
0016  *  Big-endian to little-endian byte-swapping/bitmaps by
0017  *        David S. Miller (davem@caip.rutgers.edu), 1995
0018  */
0019
0020 #include <linux/module.h>
0021 #include <linux/string.h>
0022 #include <linux/fs.h>
0023 #include <linux/time.h>
0024 #include <linux/vmalloc.h>
0025 #include <linux/slab.h>
0026 #include <linux/init.h>
0027 #include <linux/blkdev.h>
0028 #include <linux/backing-dev.h>
0029 #include <linux/parser.h>
0030 #include <linux/buffer_head.h>
0031 #include <linux/exportfs.h>
0032 #include <linux/vfs.h>
0033 #include <linux/random.h>
0034 #include <linux/mount.h>
0035 #include <linux/namei.h>
0036 #include <linux/quotaops.h>
0037 #include <linux/seq_file.h>
0038 #include <linux/ctype.h>
0039 #include <linux/log2.h>
0040 #include <linux/crc16.h>
0041 #include <linux/dax.h>
0042 #include <linux/uaccess.h>
0043 #include <linux/iversion.h>
0044 #include <linux/unicode.h>
0045 #include <linux/part_stat.h>
0046 #include <linux/kthread.h>
0047 #include <linux/freezer.h>
0048 #include <linux/fsnotify.h>
0049 #include <linux/fs_context.h>
0050 #include <linux/fs_parser.h>
0051
0052 #include "ext4.h"
0053 #include "ext4_extents.h"   /* Needed for trace points definition */
0054 #include "ext4_jbd2.h"
0055 #include "xattr.h"
0056 #include "acl.h"
0057 #include "mballoc.h"
0058 #include "fsmap.h"
0059
0060 #define CREATE_TRACE_POINTS
0061 #include <trace/events/ext4.h>
0062
0063 static struct ext4_lazy_init *ext4_li_info;
0064 static DEFINE_MUTEX(ext4_li_mtx);
0065 static struct ratelimit_state ext4_mount_msg_ratelimit;
0066
0067 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
0068                  unsigned long journal_devnum);
0069 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
0070 static void ext4_update_super(struct super_block *sb);
0071 static int ext4_commit_super(struct super_block *sb);
0072 static int ext4_mark_recovery_complete(struct super_block *sb,
0073                     struct ext4_super_block *es);
0074 static int ext4_clear_journal_err(struct super_block *sb,
0075                   struct ext4_super_block *es);
0076 static int ext4_sync_fs(struct super_block *sb, int wait);
0077 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
0078 static int ext4_unfreeze(struct super_block *sb);
0079 static int ext4_freeze(struct super_block *sb);
0080 static inline int ext2_feature_set_ok(struct super_block *sb);
0081 static inline int ext3_feature_set_ok(struct super_block *sb);
0082 static void ext4_destroy_lazyinit_thread(void);
0083 static void ext4_unregister_li_request(struct super_block *sb);
0084 static void ext4_clear_request_list(void);
0085 static struct inode *ext4_get_journal_inode(struct super_block *sb,
0086                         unsigned int journal_inum);
0087 static int ext4_validate_options(struct fs_context *fc);
0088 static int ext4_check_opt_consistency(struct fs_context *fc,
0089                       struct super_block *sb);
0090 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
0091 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
0092 static int ext4_get_tree(struct fs_context *fc);
0093 static int ext4_reconfigure(struct fs_context *fc);
0094 static void ext4_fc_free(struct fs_context *fc);
0095 static int ext4_init_fs_context(struct fs_context *fc);
0096 static const struct fs_parameter_spec ext4_param_specs[];
0097
0098 /*
0099  * Lock ordering
0100  *
0101  * page fault path:
0102  * mmap_lock -> sb_start_pagefault -> invalidate_lock (r) -> transaction start
0103  *   -> page lock -> i_data_sem (rw)
0104  *
0105  * buffered write path:
0106  * sb_start_write -> i_mutex -> mmap_lock
0107  * sb_start_write -> i_mutex -> transaction start -> page lock ->
0108  *   i_data_sem (rw)
0109  *
0110  * truncate:
0111  * sb_start_write -> i_mutex -> invalidate_lock (w) -> i_mmap_rwsem (w) ->
0112  *   page lock
0113  * sb_start_write -> i_mutex -> invalidate_lock (w) -> transaction start ->
0114  *   i_data_sem (rw)
0115  *
0116  * direct IO:
0117  * sb_start_write -> i_mutex -> mmap_lock
0118  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
0119  *
0120  * writepages:
0121  * transaction start -> page lock(s) -> i_data_sem (rw)
0122  */
0123
0124 static const struct fs_context_operations ext4_context_ops = {
0125     .parse_param    = ext4_parse_param,
0126     .get_tree   = ext4_get_tree,
0127     .reconfigure    = ext4_reconfigure,
0128     .free       = ext4_fc_free,
0129 };
0130
0131
0132 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
0133 static struct file_system_type ext2_fs_type = {
0134     .owner          = THIS_MODULE,
0135     .name           = "ext2",
0136     .init_fs_context    = ext4_init_fs_context,
0137     .parameters     = ext4_param_specs,
0138     .kill_sb        = kill_block_super,
0139     .fs_flags       = FS_REQUIRES_DEV,
0140 };
0141 MODULE_ALIAS_FS("ext2");
0142 MODULE_ALIAS("ext2");
0143 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
0144 #else
0145 #define IS_EXT2_SB(sb) (0)
0146 #endif
0147
0148
0149 static struct file_system_type ext3_fs_type = {
0150     .owner          = THIS_MODULE,
0151     .name           = "ext3",
0152     .init_fs_context    = ext4_init_fs_context,
0153     .parameters     = ext4_param_specs,
0154     .kill_sb        = kill_block_super,
0155     .fs_flags       = FS_REQUIRES_DEV,
0156 };
0157 MODULE_ALIAS_FS("ext3");
0158 MODULE_ALIAS("ext3");
0159 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
0160
0161
0162 static inline void __ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags,
0163                   bh_end_io_t *end_io)
0164 {
0165     /*
0166      * buffer's verified bit is no longer valid after reading from
0167      * disk again due to write out error, clear it to make sure we
0168      * recheck the buffer contents.
0169      */
0170     clear_buffer_verified(bh);
0171
0172     bh->b_end_io = end_io ? end_io : end_buffer_read_sync;
0173     get_bh(bh);
0174     submit_bh(REQ_OP_READ | op_flags, bh);
0175 }
0176
0177 void ext4_read_bh_nowait(struct buffer_head *bh, blk_opf_t op_flags,
0178              bh_end_io_t *end_io)
0179 {
0180     BUG_ON(!buffer_locked(bh));
0181
0182     if (ext4_buffer_uptodate(bh)) {
0183         unlock_buffer(bh);
0184         return;
0185     }
0186     __ext4_read_bh(bh, op_flags, end_io);
0187 }
0188
0189 int ext4_read_bh(struct buffer_head *bh, blk_opf_t op_flags, bh_end_io_t *end_io)
0190 {
0191     BUG_ON(!buffer_locked(bh));
0192
0193     if (ext4_buffer_uptodate(bh)) {
0194         unlock_buffer(bh);
0195         return 0;
0196     }
0197
0198     __ext4_read_bh(bh, op_flags, end_io);
0199
0200     wait_on_buffer(bh);
0201     if (buffer_uptodate(bh))
0202         return 0;
0203     return -EIO;
0204 }
0205
0206 int ext4_read_bh_lock(struct buffer_head *bh, blk_opf_t op_flags, bool wait)
0207 {
0208     if (trylock_buffer(bh)) {
0209         if (wait)
0210             return ext4_read_bh(bh, op_flags, NULL);
0211         ext4_read_bh_nowait(bh, op_flags, NULL);
0212         return 0;
0213     }
0214     if (wait) {
0215         wait_on_buffer(bh);
0216         if (buffer_uptodate(bh))
0217             return 0;
0218         return -EIO;
0219     }
0220     return 0;
0221 }
0222
0223 /*
0224  * This works like __bread_gfp() except it uses ERR_PTR for error
0225  * returns.  Currently with sb_bread it's impossible to distinguish
0226  * between ENOMEM and EIO situations (since both result in a NULL
0227  * return.
0228  */
0229 static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
0230                            sector_t block,
0231                            blk_opf_t op_flags, gfp_t gfp)
0232 {
0233     struct buffer_head *bh;
0234     int ret;
0235
0236     bh = sb_getblk_gfp(sb, block, gfp);
0237     if (bh == NULL)
0238         return ERR_PTR(-ENOMEM);
0239     if (ext4_buffer_uptodate(bh))
0240         return bh;
0241
0242     ret = ext4_read_bh_lock(bh, REQ_META | op_flags, true);
0243     if (ret) {
0244         put_bh(bh);
0245         return ERR_PTR(ret);
0246     }
0247     return bh;
0248 }
0249
0250 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
0251                    blk_opf_t op_flags)
0252 {
0253     return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
0254 }
0255
0256 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
0257                         sector_t block)
0258 {
0259     return __ext4_sb_bread_gfp(sb, block, 0, 0);
0260 }
0261
0262 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
0263 {
0264     struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
0265
0266     if (likely(bh)) {
0267         ext4_read_bh_lock(bh, REQ_RAHEAD, false);
0268         brelse(bh);
0269     }
0270 }
0271
0272 static int ext4_verify_csum_type(struct super_block *sb,
0273                  struct ext4_super_block *es)
0274 {
0275     if (!ext4_has_feature_metadata_csum(sb))
0276         return 1;
0277
0278     return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
0279 }
0280
0281 __le32 ext4_superblock_csum(struct super_block *sb,
0282                 struct ext4_super_block *es)
0283 {
0284     struct ext4_sb_info *sbi = EXT4_SB(sb);
0285     int offset = offsetof(struct ext4_super_block, s_checksum);
0286     __u32 csum;
0287
0288     csum = ext4_chksum(sbi, ~0, (char *)es, offset);
0289
0290     return cpu_to_le32(csum);
0291 }
0292
0293 static int ext4_superblock_csum_verify(struct super_block *sb,
0294                        struct ext4_super_block *es)
0295 {
0296     if (!ext4_has_metadata_csum(sb))
0297         return 1;
0298
0299     return es->s_checksum == ext4_superblock_csum(sb, es);
0300 }
0301
0302 void ext4_superblock_csum_set(struct super_block *sb)
0303 {
0304     struct ext4_super_block *es = EXT4_SB(sb)->s_es;
0305
0306     if (!ext4_has_metadata_csum(sb))
0307         return;
0308
0309     es->s_checksum = ext4_superblock_csum(sb, es);
0310 }
0311
0312 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
0313                    struct ext4_group_desc *bg)
0314 {
0315     return le32_to_cpu(bg->bg_block_bitmap_lo) |
0316         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0317          (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
0318 }
0319
0320 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
0321                    struct ext4_group_desc *bg)
0322 {
0323     return le32_to_cpu(bg->bg_inode_bitmap_lo) |
0324         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0325          (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
0326 }
0327
0328 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
0329                   struct ext4_group_desc *bg)
0330 {
0331     return le32_to_cpu(bg->bg_inode_table_lo) |
0332         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0333          (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
0334 }
0335
0336 __u32 ext4_free_group_clusters(struct super_block *sb,
0337                    struct ext4_group_desc *bg)
0338 {
0339     return le16_to_cpu(bg->bg_free_blocks_count_lo) |
0340         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0341          (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
0342 }
0343
0344 __u32 ext4_free_inodes_count(struct super_block *sb,
0345                   struct ext4_group_desc *bg)
0346 {
0347     return le16_to_cpu(bg->bg_free_inodes_count_lo) |
0348         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0349          (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
0350 }
0351
0352 __u32 ext4_used_dirs_count(struct super_block *sb,
0353                   struct ext4_group_desc *bg)
0354 {
0355     return le16_to_cpu(bg->bg_used_dirs_count_lo) |
0356         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0357          (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
0358 }
0359
0360 __u32 ext4_itable_unused_count(struct super_block *sb,
0361                   struct ext4_group_desc *bg)
0362 {
0363     return le16_to_cpu(bg->bg_itable_unused_lo) |
0364         (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
0365          (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
0366 }
0367
0368 void ext4_block_bitmap_set(struct super_block *sb,
0369                struct ext4_group_desc *bg, ext4_fsblk_t blk)
0370 {
0371     bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
0372     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0373         bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
0374 }
0375
0376 void ext4_inode_bitmap_set(struct super_block *sb,
0377                struct ext4_group_desc *bg, ext4_fsblk_t blk)
0378 {
0379     bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
0380     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0381         bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
0382 }
0383
0384 void ext4_inode_table_set(struct super_block *sb,
0385               struct ext4_group_desc *bg, ext4_fsblk_t blk)
0386 {
0387     bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
0388     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0389         bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
0390 }
0391
0392 void ext4_free_group_clusters_set(struct super_block *sb,
0393                   struct ext4_group_desc *bg, __u32 count)
0394 {
0395     bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
0396     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0397         bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
0398 }
0399
0400 void ext4_free_inodes_set(struct super_block *sb,
0401               struct ext4_group_desc *bg, __u32 count)
0402 {
0403     bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
0404     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0405         bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
0406 }
0407
0408 void ext4_used_dirs_set(struct super_block *sb,
0409               struct ext4_group_desc *bg, __u32 count)
0410 {
0411     bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
0412     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0413         bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
0414 }
0415
0416 void ext4_itable_unused_set(struct super_block *sb,
0417               struct ext4_group_desc *bg, __u32 count)
0418 {
0419     bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
0420     if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
0421         bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
0422 }
0423
0424 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi, time64_t now)
0425 {
0426     now = clamp_val(now, 0, (1ull << 40) - 1);
0427
0428     *lo = cpu_to_le32(lower_32_bits(now));
0429     *hi = upper_32_bits(now);
0430 }
0431
0432 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
0433 {
0434     return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
0435 }
0436 #define ext4_update_tstamp(es, tstamp) \
0437     __ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi, \
0438                  ktime_get_real_seconds())
0439 #define ext4_get_tstamp(es, tstamp) \
0440     __ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
0441
0442 /*
0443  * The del_gendisk() function uninitializes the disk-specific data
0444  * structures, including the bdi structure, without telling anyone
0445  * else.  Once this happens, any attempt to call mark_buffer_dirty()
0446  * (for example, by ext4_commit_super), will cause a kernel OOPS.
0447  * This is a kludge to prevent these oops until we can put in a proper
0448  * hook in del_gendisk() to inform the VFS and file system layers.
0449  */
0450 static int block_device_ejected(struct super_block *sb)
0451 {
0452     struct inode *bd_inode = sb->s_bdev->bd_inode;
0453     struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
0454
0455     return bdi->dev == NULL;
0456 }
0457
0458 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
0459 {
0460     struct super_block      *sb = journal->j_private;
0461     struct ext4_sb_info     *sbi = EXT4_SB(sb);
0462     int             error = is_journal_aborted(journal);
0463     struct ext4_journal_cb_entry    *jce;
0464
0465     BUG_ON(txn->t_state == T_FINISHED);
0466
0467     ext4_process_freed_data(sb, txn->t_tid);
0468
0469     spin_lock(&sbi->s_md_lock);
0470     while (!list_empty(&txn->t_private_list)) {
0471         jce = list_entry(txn->t_private_list.next,
0472                  struct ext4_journal_cb_entry, jce_list);
0473         list_del_init(&jce->jce_list);
0474         spin_unlock(&sbi->s_md_lock);
0475         jce->jce_func(sb, jce, error);
0476         spin_lock(&sbi->s_md_lock);
0477     }
0478     spin_unlock(&sbi->s_md_lock);
0479 }
0480
0481 /*
0482  * This writepage callback for write_cache_pages()
0483  * takes care of a few cases after page cleaning.
0484  *
0485  * write_cache_pages() already checks for dirty pages
0486  * and calls clear_page_dirty_for_io(), which we want,
0487  * to write protect the pages.
0488  *
0489  * However, we may have to redirty a page (see below.)
0490  */
0491 static int ext4_journalled_writepage_callback(struct page *page,
0492                           struct writeback_control *wbc,
0493                           void *data)
0494 {
0495     transaction_t *transaction = (transaction_t *) data;
0496     struct buffer_head *bh, *head;
0497     struct journal_head *jh;
0498
0499     bh = head = page_buffers(page);
0500     do {
0501         /*
0502          * We have to redirty a page in these cases:
0503          * 1) If buffer is dirty, it means the page was dirty because it
0504          * contains a buffer that needs checkpointing. So the dirty bit
0505          * needs to be preserved so that checkpointing writes the buffer
0506          * properly.
0507          * 2) If buffer is not part of the committing transaction
0508          * (we may have just accidentally come across this buffer because
0509          * inode range tracking is not exact) or if the currently running
0510          * transaction already contains this buffer as well, dirty bit
0511          * needs to be preserved so that the buffer gets writeprotected
0512          * properly on running transaction's commit.
0513          */
0514         jh = bh2jh(bh);
0515         if (buffer_dirty(bh) ||
0516             (jh && (jh->b_transaction != transaction ||
0517                 jh->b_next_transaction))) {
0518             redirty_page_for_writepage(wbc, page);
0519             goto out;
0520         }
0521     } while ((bh = bh->b_this_page) != head);
0522
0523 out:
0524     return AOP_WRITEPAGE_ACTIVATE;
0525 }
0526
0527 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
0528 {
0529     struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
0530     struct writeback_control wbc = {
0531         .sync_mode =  WB_SYNC_ALL,
0532         .nr_to_write = LONG_MAX,
0533         .range_start = jinode->i_dirty_start,
0534         .range_end = jinode->i_dirty_end,
0535         };
0536
0537     return write_cache_pages(mapping, &wbc,
0538                  ext4_journalled_writepage_callback,
0539                  jinode->i_transaction);
0540 }
0541
0542 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
0543 {
0544     int ret;
0545
0546     if (ext4_should_journal_data(jinode->i_vfs_inode))
0547         ret = ext4_journalled_submit_inode_data_buffers(jinode);
0548     else
0549         ret = jbd2_journal_submit_inode_data_buffers(jinode);
0550
0551     return ret;
0552 }
0553
0554 static int ext4_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
0555 {
0556     int ret = 0;
0557
0558     if (!ext4_should_journal_data(jinode->i_vfs_inode))
0559         ret = jbd2_journal_finish_inode_data_buffers(jinode);
0560
0561     return ret;
0562 }
0563
0564 static bool system_going_down(void)
0565 {
0566     return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
0567         || system_state == SYSTEM_RESTART;
0568 }
0569
0570 struct ext4_err_translation {
0571     int code;
0572     int errno;
0573 };
0574
0575 #define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
0576
0577 static struct ext4_err_translation err_translation[] = {
0578     EXT4_ERR_TRANSLATE(EIO),
0579     EXT4_ERR_TRANSLATE(ENOMEM),
0580     EXT4_ERR_TRANSLATE(EFSBADCRC),
0581     EXT4_ERR_TRANSLATE(EFSCORRUPTED),
0582     EXT4_ERR_TRANSLATE(ENOSPC),
0583     EXT4_ERR_TRANSLATE(ENOKEY),
0584     EXT4_ERR_TRANSLATE(EROFS),
0585     EXT4_ERR_TRANSLATE(EFBIG),
0586     EXT4_ERR_TRANSLATE(EEXIST),
0587     EXT4_ERR_TRANSLATE(ERANGE),
0588     EXT4_ERR_TRANSLATE(EOVERFLOW),
0589     EXT4_ERR_TRANSLATE(EBUSY),
0590     EXT4_ERR_TRANSLATE(ENOTDIR),
0591     EXT4_ERR_TRANSLATE(ENOTEMPTY),
0592     EXT4_ERR_TRANSLATE(ESHUTDOWN),
0593     EXT4_ERR_TRANSLATE(EFAULT),
0594 };
0595
0596 static int ext4_errno_to_code(int errno)
0597 {
0598     int i;
0599
0600     for (i = 0; i < ARRAY_SIZE(err_translation); i++)
0601         if (err_translation[i].errno == errno)
0602             return err_translation[i].code;
0603     return EXT4_ERR_UNKNOWN;
0604 }
0605
0606 static void save_error_info(struct super_block *sb, int error,
0607                 __u32 ino, __u64 block,
0608                 const char *func, unsigned int line)
0609 {
0610     struct ext4_sb_info *sbi = EXT4_SB(sb);
0611
0612     /* We default to EFSCORRUPTED error... */
0613     if (error == 0)
0614         error = EFSCORRUPTED;
0615
0616     spin_lock(&sbi->s_error_lock);
0617     sbi->s_add_error_count++;
0618     sbi->s_last_error_code = error;
0619     sbi->s_last_error_line = line;
0620     sbi->s_last_error_ino = ino;
0621     sbi->s_last_error_block = block;
0622     sbi->s_last_error_func = func;
0623     sbi->s_last_error_time = ktime_get_real_seconds();
0624     if (!sbi->s_first_error_time) {
0625         sbi->s_first_error_code = error;
0626         sbi->s_first_error_line = line;
0627         sbi->s_first_error_ino = ino;
0628         sbi->s_first_error_block = block;
0629         sbi->s_first_error_func = func;
0630         sbi->s_first_error_time = sbi->s_last_error_time;
0631     }
0632     spin_unlock(&sbi->s_error_lock);
0633 }
0634
0635 /* Deal with the reporting of failure conditions on a filesystem such as
0636  * inconsistencies detected or read IO failures.
0637  *
0638  * On ext2, we can store the error state of the filesystem in the
0639  * superblock.  That is not possible on ext4, because we may have other
0640  * write ordering constraints on the superblock which prevent us from
0641  * writing it out straight away; and given that the journal is about to
0642  * be aborted, we can't rely on the current, or future, transactions to
0643  * write out the superblock safely.
0644  *
0645  * We'll just use the jbd2_journal_abort() error code to record an error in
0646  * the journal instead.  On recovery, the journal will complain about
0647  * that error until we've noted it down and cleared it.
0648  *
0649  * If force_ro is set, we unconditionally force the filesystem into an
0650  * ABORT|READONLY state, unless the error response on the fs has been set to
0651  * panic in which case we take the easy way out and panic immediately. This is
0652  * used to deal with unrecoverable failures such as journal IO errors or ENOMEM
0653  * at a critical moment in log management.
0654  */
0655 static void ext4_handle_error(struct super_block *sb, bool force_ro, int error,
0656                   __u32 ino, __u64 block,
0657                   const char *func, unsigned int line)
0658 {
0659     journal_t *journal = EXT4_SB(sb)->s_journal;
0660     bool continue_fs = !force_ro && test_opt(sb, ERRORS_CONT);
0661
0662     EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
0663     if (test_opt(sb, WARN_ON_ERROR))
0664         WARN_ON_ONCE(1);
0665
0666     if (!continue_fs && !sb_rdonly(sb)) {
0667         ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
0668         if (journal)
0669             jbd2_journal_abort(journal, -EIO);
0670     }
0671
0672     if (!bdev_read_only(sb->s_bdev)) {
0673         save_error_info(sb, error, ino, block, func, line);
0674         /*
0675          * In case the fs should keep running, we need to writeout
0676          * superblock through the journal. Due to lock ordering
0677          * constraints, it may not be safe to do it right here so we
0678          * defer superblock flushing to a workqueue.
0679          */
0680         if (continue_fs && journal)
0681             schedule_work(&EXT4_SB(sb)->s_error_work);
0682         else
0683             ext4_commit_super(sb);
0684     }
0685
0686     /*
0687      * We force ERRORS_RO behavior when system is rebooting. Otherwise we
0688      * could panic during 'reboot -f' as the underlying device got already
0689      * disabled.
0690      */
0691     if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
0692         panic("EXT4-fs (device %s): panic forced after error\n",
0693             sb->s_id);
0694     }
0695
0696     if (sb_rdonly(sb) || continue_fs)
0697         return;
0698
0699     ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
0700     /*
0701      * Make sure updated value of ->s_mount_flags will be visible before
0702      * ->s_flags update
0703      */
0704     smp_wmb();
0705     sb->s_flags |= SB_RDONLY;
0706 }
0707
0708 static void flush_stashed_error_work(struct work_struct *work)
0709 {
0710     struct ext4_sb_info *sbi = container_of(work, struct ext4_sb_info,
0711                         s_error_work);
0712     journal_t *journal = sbi->s_journal;
0713     handle_t *handle;
0714
0715     /*
0716      * If the journal is still running, we have to write out superblock
0717      * through the journal to avoid collisions of other journalled sb
0718      * updates.
0719      *
0720      * We use directly jbd2 functions here to avoid recursing back into
0721      * ext4 error handling code during handling of previous errors.
0722      */
0723     if (!sb_rdonly(sbi->s_sb) && journal) {
0724         struct buffer_head *sbh = sbi->s_sbh;
0725         handle = jbd2_journal_start(journal, 1);
0726         if (IS_ERR(handle))
0727             goto write_directly;
0728         if (jbd2_journal_get_write_access(handle, sbh)) {
0729             jbd2_journal_stop(handle);
0730             goto write_directly;
0731         }
0732         ext4_update_super(sbi->s_sb);
0733         if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
0734             ext4_msg(sbi->s_sb, KERN_ERR, "previous I/O error to "
0735                  "superblock detected");
0736             clear_buffer_write_io_error(sbh);
0737             set_buffer_uptodate(sbh);
0738         }
0739
0740         if (jbd2_journal_dirty_metadata(handle, sbh)) {
0741             jbd2_journal_stop(handle);
0742             goto write_directly;
0743         }
0744         jbd2_journal_stop(handle);
0745         ext4_notify_error_sysfs(sbi);
0746         return;
0747     }
0748 write_directly:
0749     /*
0750      * Write through journal failed. Write sb directly to get error info
0751      * out and hope for the best.
0752      */
0753     ext4_commit_super(sbi->s_sb);
0754     ext4_notify_error_sysfs(sbi);
0755 }
0756
0757 #define ext4_error_ratelimit(sb)                    \
0758         ___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state), \
0759                  "EXT4-fs error")
0760
0761 void __ext4_error(struct super_block *sb, const char *function,
0762           unsigned int line, bool force_ro, int error, __u64 block,
0763           const char *fmt, ...)
0764 {
0765     struct va_format vaf;
0766     va_list args;
0767
0768     if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
0769         return;
0770
0771     trace_ext4_error(sb, function, line);
0772     if (ext4_error_ratelimit(sb)) {
0773         va_start(args, fmt);
0774         vaf.fmt = fmt;
0775         vaf.va = &args;
0776         printk(KERN_CRIT
0777                "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
0778                sb->s_id, function, line, current->comm, &vaf);
0779         va_end(args);
0780     }
0781     fsnotify_sb_error(sb, NULL, error ? error : EFSCORRUPTED);
0782
0783     ext4_handle_error(sb, force_ro, error, 0, block, function, line);
0784 }
0785
0786 void __ext4_error_inode(struct inode *inode, const char *function,
0787             unsigned int line, ext4_fsblk_t block, int error,
0788             const char *fmt, ...)
0789 {
0790     va_list args;
0791     struct va_format vaf;
0792
0793     if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
0794         return;
0795
0796     trace_ext4_error(inode->i_sb, function, line);
0797     if (ext4_error_ratelimit(inode->i_sb)) {
0798         va_start(args, fmt);
0799         vaf.fmt = fmt;
0800         vaf.va = &args;
0801         if (block)
0802             printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
0803                    "inode #%lu: block %llu: comm %s: %pV\n",
0804                    inode->i_sb->s_id, function, line, inode->i_ino,
0805                    block, current->comm, &vaf);
0806         else
0807             printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
0808                    "inode #%lu: comm %s: %pV\n",
0809                    inode->i_sb->s_id, function, line, inode->i_ino,
0810                    current->comm, &vaf);
0811         va_end(args);
0812     }
0813     fsnotify_sb_error(inode->i_sb, inode, error ? error : EFSCORRUPTED);
0814
0815     ext4_handle_error(inode->i_sb, false, error, inode->i_ino, block,
0816               function, line);
0817 }
0818
0819 void __ext4_error_file(struct file *file, const char *function,
0820                unsigned int line, ext4_fsblk_t block,
0821                const char *fmt, ...)
0822 {
0823     va_list args;
0824     struct va_format vaf;
0825     struct inode *inode = file_inode(file);
0826     char pathname[80], *path;
0827
0828     if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
0829         return;
0830
0831     trace_ext4_error(inode->i_sb, function, line);
0832     if (ext4_error_ratelimit(inode->i_sb)) {
0833         path = file_path(file, pathname, sizeof(pathname));
0834         if (IS_ERR(path))
0835             path = "(unknown)";
0836         va_start(args, fmt);
0837         vaf.fmt = fmt;
0838         vaf.va = &args;
0839         if (block)
0840             printk(KERN_CRIT
0841                    "EXT4-fs error (device %s): %s:%d: inode #%lu: "
0842                    "block %llu: comm %s: path %s: %pV\n",
0843                    inode->i_sb->s_id, function, line, inode->i_ino,
0844                    block, current->comm, path, &vaf);
0845         else
0846             printk(KERN_CRIT
0847                    "EXT4-fs error (device %s): %s:%d: inode #%lu: "
0848                    "comm %s: path %s: %pV\n",
0849                    inode->i_sb->s_id, function, line, inode->i_ino,
0850                    current->comm, path, &vaf);
0851         va_end(args);
0852     }
0853     fsnotify_sb_error(inode->i_sb, inode, EFSCORRUPTED);
0854
0855     ext4_handle_error(inode->i_sb, false, EFSCORRUPTED, inode->i_ino, block,
0856               function, line);
0857 }
0858
0859 const char *ext4_decode_error(struct super_block *sb, int errno,
0860                   char nbuf[16])
0861 {
0862     char *errstr = NULL;
0863
0864     switch (errno) {
0865     case -EFSCORRUPTED:
0866         errstr = "Corrupt filesystem";
0867         break;
0868     case -EFSBADCRC:
0869         errstr = "Filesystem failed CRC";
0870         break;
0871     case -EIO:
0872         errstr = "IO failure";
0873         break;
0874     case -ENOMEM:
0875         errstr = "Out of memory";
0876         break;
0877     case -EROFS:
0878         if (!sb || (EXT4_SB(sb)->s_journal &&
0879                 EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
0880             errstr = "Journal has aborted";
0881         else
0882             errstr = "Readonly filesystem";
0883         break;
0884     default:
0885         /* If the caller passed in an extra buffer for unknown
0886          * errors, textualise them now.  Else we just return
0887          * NULL. */
0888         if (nbuf) {
0889             /* Check for truncated error codes... */
0890             if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
0891                 errstr = nbuf;
0892         }
0893         break;
0894     }
0895
0896     return errstr;
0897 }
0898
0899 /* __ext4_std_error decodes expected errors from journaling functions
0900  * automatically and invokes the appropriate error response.  */
0901
0902 void __ext4_std_error(struct super_block *sb, const char *function,
0903               unsigned int line, int errno)
0904 {
0905     char nbuf[16];
0906     const char *errstr;
0907
0908     if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
0909         return;
0910
0911     /* Special case: if the error is EROFS, and we're not already
0912      * inside a transaction, then there's really no point in logging
0913      * an error. */
0914     if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
0915         return;
0916
0917     if (ext4_error_ratelimit(sb)) {
0918         errstr = ext4_decode_error(sb, errno, nbuf);
0919         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
0920                sb->s_id, function, line, errstr);
0921     }
0922     fsnotify_sb_error(sb, NULL, errno ? errno : EFSCORRUPTED);
0923
0924     ext4_handle_error(sb, false, -errno, 0, 0, function, line);
0925 }
0926
0927 void __ext4_msg(struct super_block *sb,
0928         const char *prefix, const char *fmt, ...)
0929 {
0930     struct va_format vaf;
0931     va_list args;
0932
0933     if (sb) {
0934         atomic_inc(&EXT4_SB(sb)->s_msg_count);
0935         if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state),
0936                   "EXT4-fs"))
0937             return;
0938     }
0939
0940     va_start(args, fmt);
0941     vaf.fmt = fmt;
0942     vaf.va = &args;
0943     if (sb)
0944         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
0945     else
0946         printk("%sEXT4-fs: %pV\n", prefix, &vaf);
0947     va_end(args);
0948 }
0949
0950 static int ext4_warning_ratelimit(struct super_block *sb)
0951 {
0952     atomic_inc(&EXT4_SB(sb)->s_warning_count);
0953     return ___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),
0954                 "EXT4-fs warning");
0955 }
0956
0957 void __ext4_warning(struct super_block *sb, const char *function,
0958             unsigned int line, const char *fmt, ...)
0959 {
0960     struct va_format vaf;
0961     va_list args;
0962
0963     if (!ext4_warning_ratelimit(sb))
0964         return;
0965
0966     va_start(args, fmt);
0967     vaf.fmt = fmt;
0968     vaf.va = &args;
0969     printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
0970            sb->s_id, function, line, &vaf);
0971     va_end(args);
0972 }
0973
0974 void __ext4_warning_inode(const struct inode *inode, const char *function,
0975               unsigned int line, const char *fmt, ...)
0976 {
0977     struct va_format vaf;
0978     va_list args;
0979
0980     if (!ext4_warning_ratelimit(inode->i_sb))
0981         return;
0982
0983     va_start(args, fmt);
0984     vaf.fmt = fmt;
0985     vaf.va = &args;
0986     printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
0987            "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
0988            function, line, inode->i_ino, current->comm, &vaf);
0989     va_end(args);
0990 }
0991
0992 void __ext4_grp_locked_error(const char *function, unsigned int line,
0993                  struct super_block *sb, ext4_group_t grp,
0994                  unsigned long ino, ext4_fsblk_t block,
0995                  const char *fmt, ...)
0996 __releases(bitlock)
0997 __acquires(bitlock)
0998 {
0999     struct va_format vaf;
1000     va_list args;
1001
1002     if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
1003         return;
1004
1005     trace_ext4_error(sb, function, line);
1006     if (ext4_error_ratelimit(sb)) {
1007         va_start(args, fmt);
1008         vaf.fmt = fmt;
1009         vaf.va = &args;
1010         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
1011                sb->s_id, function, line, grp);
1012         if (ino)
1013             printk(KERN_CONT "inode %lu: ", ino);
1014         if (block)
1015             printk(KERN_CONT "block %llu:",
1016                    (unsigned long long) block);
1017         printk(KERN_CONT "%pV\n", &vaf);
1018         va_end(args);
1019     }
1020
1021     if (test_opt(sb, ERRORS_CONT)) {
1022         if (test_opt(sb, WARN_ON_ERROR))
1023             WARN_ON_ONCE(1);
1024         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
1025         if (!bdev_read_only(sb->s_bdev)) {
1026             save_error_info(sb, EFSCORRUPTED, ino, block, function,
1027                     line);
1028             schedule_work(&EXT4_SB(sb)->s_error_work);
1029         }
1030         return;
1031     }
1032     ext4_unlock_group(sb, grp);
1033     ext4_handle_error(sb, false, EFSCORRUPTED, ino, block, function, line);
1034     /*
1035      * We only get here in the ERRORS_RO case; relocking the group
1036      * may be dangerous, but nothing bad will happen since the
1037      * filesystem will have already been marked read/only and the
1038      * journal has been aborted.  We return 1 as a hint to callers
1039      * who might what to use the return value from
1040      * ext4_grp_locked_error() to distinguish between the
1041      * ERRORS_CONT and ERRORS_RO case, and perhaps return more
1042      * aggressively from the ext4 function in question, with a
1043      * more appropriate error code.
1044      */
1045     ext4_lock_group(sb, grp);
1046     return;
1047 }
1048
1049 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
1050                      ext4_group_t group,
1051                      unsigned int flags)
1052 {
1053     struct ext4_sb_info *sbi = EXT4_SB(sb);
1054     struct ext4_group_info *grp = ext4_get_group_info(sb, group);
1055     struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
1056     int ret;
1057
1058     if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
1059         ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
1060                         &grp->bb_state);
1061         if (!ret)
1062             percpu_counter_sub(&sbi->s_freeclusters_counter,
1063                        grp->bb_free);
1064     }
1065
1066     if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
1067         ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
1068                         &grp->bb_state);
1069         if (!ret && gdp) {
1070             int count;
1071
1072             count = ext4_free_inodes_count(sb, gdp);
1073             percpu_counter_sub(&sbi->s_freeinodes_counter,
1074                        count);
1075         }
1076     }
1077 }
1078
1079 void ext4_update_dynamic_rev(struct super_block *sb)
1080 {
1081     struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1082
1083     if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
1084         return;
1085
1086     ext4_warning(sb,
1087              "updating to rev %d because of new feature flag, "
1088              "running e2fsck is recommended",
1089              EXT4_DYNAMIC_REV);
1090
1091     es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
1092     es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
1093     es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
1094     /* leave es->s_feature_*compat flags alone */
1095     /* es->s_uuid will be set by e2fsck if empty */
1096
1097     /*
1098      * The rest of the superblock fields should be zero, and if not it
1099      * means they are likely already in use, so leave them alone.  We
1100      * can leave it up to e2fsck to clean up any inconsistencies there.
1101      */
1102 }
1103
1104 /*
1105  * Open the external journal device
1106  */
1107 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
1108 {
1109     struct block_device *bdev;
1110
1111     bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
1112     if (IS_ERR(bdev))
1113         goto fail;
1114     return bdev;
1115
1116 fail:
1117     ext4_msg(sb, KERN_ERR,
1118          "failed to open journal device unknown-block(%u,%u) %ld",
1119          MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
1120     return NULL;
1121 }
1122
1123 /*
1124  * Release the journal device
1125  */
1126 static void ext4_blkdev_put(struct block_device *bdev)
1127 {
1128     blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1129 }
1130
1131 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
1132 {
1133     struct block_device *bdev;
1134     bdev = sbi->s_journal_bdev;
1135     if (bdev) {
1136         ext4_blkdev_put(bdev);
1137         sbi->s_journal_bdev = NULL;
1138     }
1139 }
1140
1141 static inline struct inode *orphan_list_entry(struct list_head *l)
1142 {
1143     return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
1144 }
1145
1146 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
1147 {
1148     struct list_head *l;
1149
1150     ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
1151          le32_to_cpu(sbi->s_es->s_last_orphan));
1152
1153     printk(KERN_ERR "sb_info orphan list:\n");
1154     list_for_each(l, &sbi->s_orphan) {
1155         struct inode *inode = orphan_list_entry(l);
1156         printk(KERN_ERR "  "
1157                "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
1158                inode->i_sb->s_id, inode->i_ino, inode,
1159                inode->i_mode, inode->i_nlink,
1160                NEXT_ORPHAN(inode));
1161     }
1162 }
1163
1164 #ifdef CONFIG_QUOTA
1165 static int ext4_quota_off(struct super_block *sb, int type);
1166
1167 static inline void ext4_quota_off_umount(struct super_block *sb)
1168 {
1169     int type;
1170
1171     /* Use our quota_off function to clear inode flags etc. */
1172     for (type = 0; type < EXT4_MAXQUOTAS; type++)
1173         ext4_quota_off(sb, type);
1174 }
1175
1176 /*
1177  * This is a helper function which is used in the mount/remount
1178  * codepaths (which holds s_umount) to fetch the quota file name.
1179  */
1180 static inline char *get_qf_name(struct super_block *sb,
1181                 struct ext4_sb_info *sbi,
1182                 int type)
1183 {
1184     return rcu_dereference_protected(sbi->s_qf_names[type],
1185                      lockdep_is_held(&sb->s_umount));
1186 }
1187 #else
1188 static inline void ext4_quota_off_umount(struct super_block *sb)
1189 {
1190 }
1191 #endif
1192
1193 static void ext4_put_super(struct super_block *sb)
1194 {
1195     struct ext4_sb_info *sbi = EXT4_SB(sb);
1196     struct ext4_super_block *es = sbi->s_es;
1197     struct buffer_head **group_desc;
1198     struct flex_groups **flex_groups;
1199     int aborted = 0;
1200     int i, err;
1201
1202     /*
1203      * Unregister sysfs before destroying jbd2 journal.
1204      * Since we could still access attr_journal_task attribute via sysfs
1205      * path which could have sbi->s_journal->j_task as NULL
1206      * Unregister sysfs before flush sbi->s_error_work.
1207      * Since user may read /proc/fs/ext4/xx/mb_groups during umount, If
1208      * read metadata verify failed then will queue error work.
1209      * flush_stashed_error_work will call start_this_handle may trigger
1210      * BUG_ON.
1211      */
1212     ext4_unregister_sysfs(sb);
1213
1214     if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs unmount"))
1215         ext4_msg(sb, KERN_INFO, "unmounting filesystem.");
1216
1217     ext4_unregister_li_request(sb);
1218     ext4_quota_off_umount(sb);
1219
1220     flush_work(&sbi->s_error_work);
1221     destroy_workqueue(sbi->rsv_conversion_wq);
1222     ext4_release_orphan_info(sb);
1223
1224     if (sbi->s_journal) {
1225         aborted = is_journal_aborted(sbi->s_journal);
1226         err = jbd2_journal_destroy(sbi->s_journal);
1227         sbi->s_journal = NULL;
1228         if ((err < 0) && !aborted) {
1229             ext4_abort(sb, -err, "Couldn't clean up the journal");
1230         }
1231     }
1232
1233     ext4_es_unregister_shrinker(sbi);
1234     del_timer_sync(&sbi->s_err_report);
1235     ext4_release_system_zone(sb);
1236     ext4_mb_release(sb);
1237     ext4_ext_release(sb);
1238
1239     if (!sb_rdonly(sb) && !aborted) {
1240         ext4_clear_feature_journal_needs_recovery(sb);
1241         ext4_clear_feature_orphan_present(sb);
1242         es->s_state = cpu_to_le16(sbi->s_mount_state);
1243     }
1244     if (!sb_rdonly(sb))
1245         ext4_commit_super(sb);
1246
1247     rcu_read_lock();
1248     group_desc = rcu_dereference(sbi->s_group_desc);
1249     for (i = 0; i < sbi->s_gdb_count; i++)
1250         brelse(group_desc[i]);
1251     kvfree(group_desc);
1252     flex_groups = rcu_dereference(sbi->s_flex_groups);
1253     if (flex_groups) {
1254         for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1255             kvfree(flex_groups[i]);
1256         kvfree(flex_groups);
1257     }
1258     rcu_read_unlock();
1259     percpu_counter_destroy(&sbi->s_freeclusters_counter);
1260     percpu_counter_destroy(&sbi->s_freeinodes_counter);
1261     percpu_counter_destroy(&sbi->s_dirs_counter);
1262     percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1263     percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
1264     percpu_free_rwsem(&sbi->s_writepages_rwsem);
1265 #ifdef CONFIG_QUOTA
1266     for (i = 0; i < EXT4_MAXQUOTAS; i++)
1267         kfree(get_qf_name(sb, sbi, i));
1268 #endif
1269
1270     /* Debugging code just in case the in-memory inode orphan list
1271      * isn't empty.  The on-disk one can be non-empty if we've
1272      * detected an error and taken the fs readonly, but the
1273      * in-memory list had better be clean by this point. */
1274     if (!list_empty(&sbi->s_orphan))
1275         dump_orphan_list(sb, sbi);
1276     ASSERT(list_empty(&sbi->s_orphan));
1277
1278     sync_blockdev(sb->s_bdev);
1279     invalidate_bdev(sb->s_bdev);
1280     if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
1281         /*
1282          * Invalidate the journal device's buffers.  We don't want them
1283          * floating about in memory - the physical journal device may
1284          * hotswapped, and it breaks the `ro-after' testing code.
1285          */
1286         sync_blockdev(sbi->s_journal_bdev);
1287         invalidate_bdev(sbi->s_journal_bdev);
1288         ext4_blkdev_remove(sbi);
1289     }
1290
1291     ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1292     sbi->s_ea_inode_cache = NULL;
1293
1294     ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1295     sbi->s_ea_block_cache = NULL;
1296
1297     ext4_stop_mmpd(sbi);
1298
1299     brelse(sbi->s_sbh);
1300     sb->s_fs_info = NULL;
1301     /*
1302      * Now that we are completely done shutting down the
1303      * superblock, we need to actually destroy the kobject.
1304      */
1305     kobject_put(&sbi->s_kobj);
1306     wait_for_completion(&sbi->s_kobj_unregister);
1307     if (sbi->s_chksum_driver)
1308         crypto_free_shash(sbi->s_chksum_driver);
1309     kfree(sbi->s_blockgroup_lock);
1310     fs_put_dax(sbi->s_daxdev, NULL);
1311     fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
1312 #if IS_ENABLED(CONFIG_UNICODE)
1313     utf8_unload(sb->s_encoding);
1314 #endif
1315     kfree(sbi);
1316 }
1317
1318 static struct kmem_cache *ext4_inode_cachep;
1319
1320 /*
1321  * Called inside transaction, so use GFP_NOFS
1322  */
1323 static struct inode *ext4_alloc_inode(struct super_block *sb)
1324 {
1325     struct ext4_inode_info *ei;
1326
1327     ei = alloc_inode_sb(sb, ext4_inode_cachep, GFP_NOFS);
1328     if (!ei)
1329         return NULL;
1330
1331     inode_set_iversion(&ei->vfs_inode, 1);
1332     spin_lock_init(&ei->i_raw_lock);
1333     INIT_LIST_HEAD(&ei->i_prealloc_list);
1334     atomic_set(&ei->i_prealloc_active, 0);
1335     spin_lock_init(&ei->i_prealloc_lock);
1336     ext4_es_init_tree(&ei->i_es_tree);
1337     rwlock_init(&ei->i_es_lock);
1338     INIT_LIST_HEAD(&ei->i_es_list);
1339     ei->i_es_all_nr = 0;
1340     ei->i_es_shk_nr = 0;
1341     ei->i_es_shrink_lblk = 0;
1342     ei->i_reserved_data_blocks = 0;
1343     spin_lock_init(&(ei->i_block_reservation_lock));
1344     ext4_init_pending_tree(&ei->i_pending_tree);
1345 #ifdef CONFIG_QUOTA
1346     ei->i_reserved_quota = 0;
1347     memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1348 #endif
1349     ei->jinode = NULL;
1350     INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1351     spin_lock_init(&ei->i_completed_io_lock);
1352     ei->i_sync_tid = 0;
1353     ei->i_datasync_tid = 0;
1354     atomic_set(&ei->i_unwritten, 0);
1355     INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1356     ext4_fc_init_inode(&ei->vfs_inode);
1357     mutex_init(&ei->i_fc_lock);
1358     return &ei->vfs_inode;
1359 }
1360
1361 static int ext4_drop_inode(struct inode *inode)
1362 {
1363     int drop = generic_drop_inode(inode);
1364
1365     if (!drop)
1366         drop = fscrypt_drop_inode(inode);
1367
1368     trace_ext4_drop_inode(inode, drop);
1369     return drop;
1370 }
1371
1372 static void ext4_free_in_core_inode(struct inode *inode)
1373 {
1374     fscrypt_free_inode(inode);
1375     if (!list_empty(&(EXT4_I(inode)->i_fc_list))) {
1376         pr_warn("%s: inode %ld still in fc list",
1377             __func__, inode->i_ino);
1378     }
1379     kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1380 }
1381
1382 static void ext4_destroy_inode(struct inode *inode)
1383 {
1384     if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1385         ext4_msg(inode->i_sb, KERN_ERR,
1386              "Inode %lu (%p): orphan list check failed!",
1387              inode->i_ino, EXT4_I(inode));
1388         print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1389                 EXT4_I(inode), sizeof(struct ext4_inode_info),
1390                 true);
1391         dump_stack();
1392     }
1393
1394     if (EXT4_I(inode)->i_reserved_data_blocks)
1395         ext4_msg(inode->i_sb, KERN_ERR,
1396              "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
1397              inode->i_ino, EXT4_I(inode),
1398              EXT4_I(inode)->i_reserved_data_blocks);
1399 }
1400
1401 static void init_once(void *foo)
1402 {
1403     struct ext4_inode_info *ei = foo;
1404
1405     INIT_LIST_HEAD(&ei->i_orphan);
1406     init_rwsem(&ei->xattr_sem);
1407     init_rwsem(&ei->i_data_sem);
1408     inode_init_once(&ei->vfs_inode);
1409     ext4_fc_init_inode(&ei->vfs_inode);
1410 }
1411
1412 static int __init init_inodecache(void)
1413 {
1414     ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1415                 sizeof(struct ext4_inode_info), 0,
1416                 (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1417                     SLAB_ACCOUNT),
1418                 offsetof(struct ext4_inode_info, i_data),
1419                 sizeof_field(struct ext4_inode_info, i_data),
1420                 init_once);
1421     if (ext4_inode_cachep == NULL)
1422         return -ENOMEM;
1423     return 0;
1424 }
1425
1426 static void destroy_inodecache(void)
1427 {
1428     /*
1429      * Make sure all delayed rcu free inodes are flushed before we
1430      * destroy cache.
1431      */
1432     rcu_barrier();
1433     kmem_cache_destroy(ext4_inode_cachep);
1434 }
1435
1436 void ext4_clear_inode(struct inode *inode)
1437 {
1438     ext4_fc_del(inode);
1439     invalidate_inode_buffers(inode);
1440     clear_inode(inode);
1441     ext4_discard_preallocations(inode, 0);
1442     ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1443     dquot_drop(inode);
1444     if (EXT4_I(inode)->jinode) {
1445         jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1446                            EXT4_I(inode)->jinode);
1447         jbd2_free_inode(EXT4_I(inode)->jinode);
1448         EXT4_I(inode)->jinode = NULL;
1449     }
1450     fscrypt_put_encryption_info(inode);
1451     fsverity_cleanup_inode(inode);
1452 }
1453
1454 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1455                     u64 ino, u32 generation)
1456 {
1457     struct inode *inode;
1458
1459     /*
1460      * Currently we don't know the generation for parent directory, so
1461      * a generation of 0 means "accept any"
1462      */
1463     inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1464     if (IS_ERR(inode))
1465         return ERR_CAST(inode);
1466     if (generation && inode->i_generation != generation) {
1467         iput(inode);
1468         return ERR_PTR(-ESTALE);
1469     }
1470
1471     return inode;
1472 }
1473
1474 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1475                     int fh_len, int fh_type)
1476 {
1477     return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1478                     ext4_nfs_get_inode);
1479 }
1480
1481 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1482                     int fh_len, int fh_type)
1483 {
1484     return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1485                     ext4_nfs_get_inode);
1486 }
1487
1488 static int ext4_nfs_commit_metadata(struct inode *inode)
1489 {
1490     struct writeback_control wbc = {
1491         .sync_mode = WB_SYNC_ALL
1492     };
1493
1494     trace_ext4_nfs_commit_metadata(inode);
1495     return ext4_write_inode(inode, &wbc);
1496 }
1497
1498 #ifdef CONFIG_QUOTA
1499 static const char * const quotatypes[] = INITQFNAMES;
1500 #define QTYPE2NAME(t) (quotatypes[t])
1501
1502 static int ext4_write_dquot(struct dquot *dquot);
1503 static int ext4_acquire_dquot(struct dquot *dquot);
1504 static int ext4_release_dquot(struct dquot *dquot);
1505 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1506 static int ext4_write_info(struct super_block *sb, int type);
1507 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1508              const struct path *path);
1509 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1510                    size_t len, loff_t off);
1511 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1512                 const char *data, size_t len, loff_t off);
1513 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1514                  unsigned int flags);
1515
1516 static struct dquot **ext4_get_dquots(struct inode *inode)
1517 {
1518     return EXT4_I(inode)->i_dquot;
1519 }
1520
1521 static const struct dquot_operations ext4_quota_operations = {
1522     .get_reserved_space = ext4_get_reserved_space,
1523     .write_dquot        = ext4_write_dquot,
1524     .acquire_dquot      = ext4_acquire_dquot,
1525     .release_dquot      = ext4_release_dquot,
1526     .mark_dirty     = ext4_mark_dquot_dirty,
1527     .write_info     = ext4_write_info,
1528     .alloc_dquot        = dquot_alloc,
1529     .destroy_dquot      = dquot_destroy,
1530     .get_projid     = ext4_get_projid,
1531     .get_inode_usage    = ext4_get_inode_usage,
1532     .get_next_id        = dquot_get_next_id,
1533 };
1534
1535 static const struct quotactl_ops ext4_qctl_operations = {
1536     .quota_on   = ext4_quota_on,
1537     .quota_off  = ext4_quota_off,
1538     .quota_sync = dquot_quota_sync,
1539     .get_state  = dquot_get_state,
1540     .set_info   = dquot_set_dqinfo,
1541     .get_dqblk  = dquot_get_dqblk,
1542     .set_dqblk  = dquot_set_dqblk,
1543     .get_nextdqblk  = dquot_get_next_dqblk,
1544 };
1545 #endif
1546
1547 static const struct super_operations ext4_sops = {
1548     .alloc_inode    = ext4_alloc_inode,
1549     .free_inode = ext4_free_in_core_inode,
1550     .destroy_inode  = ext4_destroy_inode,
1551     .write_inode    = ext4_write_inode,
1552     .dirty_inode    = ext4_dirty_inode,
1553     .drop_inode = ext4_drop_inode,
1554     .evict_inode    = ext4_evict_inode,
1555     .put_super  = ext4_put_super,
1556     .sync_fs    = ext4_sync_fs,
1557     .freeze_fs  = ext4_freeze,
1558     .unfreeze_fs    = ext4_unfreeze,
1559     .statfs     = ext4_statfs,
1560     .show_options   = ext4_show_options,
1561 #ifdef CONFIG_QUOTA
1562     .quota_read = ext4_quota_read,
1563     .quota_write    = ext4_quota_write,
1564     .get_dquots = ext4_get_dquots,
1565 #endif
1566 };
1567
1568 static const struct export_operations ext4_export_ops = {
1569     .fh_to_dentry = ext4_fh_to_dentry,
1570     .fh_to_parent = ext4_fh_to_parent,
1571     .get_parent = ext4_get_parent,
1572     .commit_metadata = ext4_nfs_commit_metadata,
1573 };
1574
1575 enum {
1576     Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1577     Opt_resgid, Opt_resuid, Opt_sb,
1578     Opt_nouid32, Opt_debug, Opt_removed,
1579     Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1580     Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1581     Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1582     Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1583     Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1584     Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1585     Opt_inlinecrypt,
1586     Opt_usrjquota, Opt_grpjquota, Opt_quota,
1587     Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1588     Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
1589     Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
1590     Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1591     Opt_nowarn_on_error, Opt_mblk_io_submit, Opt_debug_want_extra_isize,
1592     Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1593     Opt_inode_readahead_blks, Opt_journal_ioprio,
1594     Opt_dioread_nolock, Opt_dioread_lock,
1595     Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1596     Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1597     Opt_no_prefetch_block_bitmaps, Opt_mb_optimize_scan,
1598     Opt_errors, Opt_data, Opt_data_err, Opt_jqfmt, Opt_dax_type,
1599 #ifdef CONFIG_EXT4_DEBUG
1600     Opt_fc_debug_max_replay, Opt_fc_debug_force
1601 #endif
1602 };
1603
1604 static const struct constant_table ext4_param_errors[] = {
1605     {"continue",    EXT4_MOUNT_ERRORS_CONT},
1606     {"panic",   EXT4_MOUNT_ERRORS_PANIC},
1607     {"remount-ro",  EXT4_MOUNT_ERRORS_RO},
1608     {}
1609 };
1610
1611 static const struct constant_table ext4_param_data[] = {
1612     {"journal", EXT4_MOUNT_JOURNAL_DATA},
1613     {"ordered", EXT4_MOUNT_ORDERED_DATA},
1614     {"writeback",   EXT4_MOUNT_WRITEBACK_DATA},
1615     {}
1616 };
1617
1618 static const struct constant_table ext4_param_data_err[] = {
1619     {"abort",   Opt_data_err_abort},
1620     {"ignore",  Opt_data_err_ignore},
1621     {}
1622 };
1623
1624 static const struct constant_table ext4_param_jqfmt[] = {
1625     {"vfsold",  QFMT_VFS_OLD},
1626     {"vfsv0",   QFMT_VFS_V0},
1627     {"vfsv1",   QFMT_VFS_V1},
1628     {}
1629 };
1630
1631 static const struct constant_table ext4_param_dax[] = {
1632     {"always",  Opt_dax_always},
1633     {"inode",   Opt_dax_inode},
1634     {"never",   Opt_dax_never},
1635     {}
1636 };
1637
1638 /* String parameter that allows empty argument */
1639 #define fsparam_string_empty(NAME, OPT) \
1640     __fsparam(fs_param_is_string, NAME, OPT, fs_param_can_be_empty, NULL)
1641
1642 /*
1643  * Mount option specification
1644  * We don't use fsparam_flag_no because of the way we set the
1645  * options and the way we show them in _ext4_show_options(). To
1646  * keep the changes to a minimum, let's keep the negative options
1647  * separate for now.
1648  */
1649 static const struct fs_parameter_spec ext4_param_specs[] = {
1650     fsparam_flag    ("bsddf",       Opt_bsd_df),
1651     fsparam_flag    ("minixdf",     Opt_minix_df),
1652     fsparam_flag    ("grpid",       Opt_grpid),
1653     fsparam_flag    ("bsdgroups",       Opt_grpid),
1654     fsparam_flag    ("nogrpid",     Opt_nogrpid),
1655     fsparam_flag    ("sysvgroups",      Opt_nogrpid),
1656     fsparam_u32 ("resgid",      Opt_resgid),
1657     fsparam_u32 ("resuid",      Opt_resuid),
1658     fsparam_u32 ("sb",          Opt_sb),
1659     fsparam_enum    ("errors",      Opt_errors, ext4_param_errors),
1660     fsparam_flag    ("nouid32",     Opt_nouid32),
1661     fsparam_flag    ("debug",       Opt_debug),
1662     fsparam_flag    ("oldalloc",        Opt_removed),
1663     fsparam_flag    ("orlov",       Opt_removed),
1664     fsparam_flag    ("user_xattr",      Opt_user_xattr),
1665     fsparam_flag    ("nouser_xattr",    Opt_nouser_xattr),
1666     fsparam_flag    ("acl",         Opt_acl),
1667     fsparam_flag    ("noacl",       Opt_noacl),
1668     fsparam_flag    ("norecovery",      Opt_noload),
1669     fsparam_flag    ("noload",      Opt_noload),
1670     fsparam_flag    ("bh",          Opt_removed),
1671     fsparam_flag    ("nobh",        Opt_removed),
1672     fsparam_u32 ("commit",      Opt_commit),
1673     fsparam_u32 ("min_batch_time",  Opt_min_batch_time),
1674     fsparam_u32 ("max_batch_time",  Opt_max_batch_time),
1675     fsparam_u32 ("journal_dev",     Opt_journal_dev),
1676     fsparam_bdev    ("journal_path",    Opt_journal_path),
1677     fsparam_flag    ("journal_checksum",    Opt_journal_checksum),
1678     fsparam_flag    ("nojournal_checksum",  Opt_nojournal_checksum),
1679     fsparam_flag    ("journal_async_commit",Opt_journal_async_commit),
1680     fsparam_flag    ("abort",       Opt_abort),
1681     fsparam_enum    ("data",        Opt_data, ext4_param_data),
1682     fsparam_enum    ("data_err",        Opt_data_err,
1683                         ext4_param_data_err),
1684     fsparam_string_empty
1685             ("usrjquota",       Opt_usrjquota),
1686     fsparam_string_empty
1687             ("grpjquota",       Opt_grpjquota),
1688     fsparam_enum    ("jqfmt",       Opt_jqfmt, ext4_param_jqfmt),
1689     fsparam_flag    ("grpquota",        Opt_grpquota),
1690     fsparam_flag    ("quota",       Opt_quota),
1691     fsparam_flag    ("noquota",     Opt_noquota),
1692     fsparam_flag    ("usrquota",        Opt_usrquota),
1693     fsparam_flag    ("prjquota",        Opt_prjquota),
1694     fsparam_flag    ("barrier",     Opt_barrier),
1695     fsparam_u32 ("barrier",     Opt_barrier),
1696     fsparam_flag    ("nobarrier",       Opt_nobarrier),
1697     fsparam_flag    ("i_version",       Opt_i_version),
1698     fsparam_flag    ("dax",         Opt_dax),
1699     fsparam_enum    ("dax",         Opt_dax_type, ext4_param_dax),
1700     fsparam_u32 ("stripe",      Opt_stripe),
1701     fsparam_flag    ("delalloc",        Opt_delalloc),
1702     fsparam_flag    ("nodelalloc",      Opt_nodelalloc),
1703     fsparam_flag    ("warn_on_error",   Opt_warn_on_error),
1704     fsparam_flag    ("nowarn_on_error", Opt_nowarn_on_error),
1705     fsparam_u32 ("debug_want_extra_isize",
1706                         Opt_debug_want_extra_isize),
1707     fsparam_flag    ("mblk_io_submit",  Opt_removed),
1708     fsparam_flag    ("nomblk_io_submit",    Opt_removed),
1709     fsparam_flag    ("block_validity",  Opt_block_validity),
1710     fsparam_flag    ("noblock_validity",    Opt_noblock_validity),
1711     fsparam_u32 ("inode_readahead_blks",
1712                         Opt_inode_readahead_blks),
1713     fsparam_u32 ("journal_ioprio",  Opt_journal_ioprio),
1714     fsparam_u32 ("auto_da_alloc",   Opt_auto_da_alloc),
1715     fsparam_flag    ("auto_da_alloc",   Opt_auto_da_alloc),
1716     fsparam_flag    ("noauto_da_alloc", Opt_noauto_da_alloc),
1717     fsparam_flag    ("dioread_nolock",  Opt_dioread_nolock),
1718     fsparam_flag    ("nodioread_nolock",    Opt_dioread_lock),
1719     fsparam_flag    ("dioread_lock",    Opt_dioread_lock),
1720     fsparam_flag    ("discard",     Opt_discard),
1721     fsparam_flag    ("nodiscard",       Opt_nodiscard),
1722     fsparam_u32 ("init_itable",     Opt_init_itable),
1723     fsparam_flag    ("init_itable",     Opt_init_itable),
1724     fsparam_flag    ("noinit_itable",   Opt_noinit_itable),
1725 #ifdef CONFIG_EXT4_DEBUG
1726     fsparam_flag    ("fc_debug_force",  Opt_fc_debug_force),
1727     fsparam_u32 ("fc_debug_max_replay", Opt_fc_debug_max_replay),
1728 #endif
1729     fsparam_u32 ("max_dir_size_kb", Opt_max_dir_size_kb),
1730     fsparam_flag    ("test_dummy_encryption",
1731                         Opt_test_dummy_encryption),
1732     fsparam_string  ("test_dummy_encryption",
1733                         Opt_test_dummy_encryption),
1734     fsparam_flag    ("inlinecrypt",     Opt_inlinecrypt),
1735     fsparam_flag    ("nombcache",       Opt_nombcache),
1736     fsparam_flag    ("no_mbcache",      Opt_nombcache), /* for backward compatibility */
1737     fsparam_flag    ("prefetch_block_bitmaps",
1738                         Opt_removed),
1739     fsparam_flag    ("no_prefetch_block_bitmaps",
1740                         Opt_no_prefetch_block_bitmaps),
1741     fsparam_s32 ("mb_optimize_scan",    Opt_mb_optimize_scan),
1742     fsparam_string  ("check",       Opt_removed),   /* mount option from ext2/3 */
1743     fsparam_flag    ("nocheck",     Opt_removed),   /* mount option from ext2/3 */
1744     fsparam_flag    ("reservation",     Opt_removed),   /* mount option from ext2/3 */
1745     fsparam_flag    ("noreservation",   Opt_removed),   /* mount option from ext2/3 */
1746     fsparam_u32 ("journal",     Opt_removed),   /* mount option from ext2/3 */
1747     {}
1748 };
1749
1750 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1751
1752 static const char deprecated_msg[] =
1753     "Mount option \"%s\" will be removed by %s\n"
1754     "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1755
1756 #define MOPT_SET    0x0001
1757 #define MOPT_CLEAR  0x0002
1758 #define MOPT_NOSUPPORT  0x0004
1759 #define MOPT_EXPLICIT   0x0008
1760 #ifdef CONFIG_QUOTA
1761 #define MOPT_Q      0
1762 #define MOPT_QFMT   0x0010
1763 #else
1764 #define MOPT_Q      MOPT_NOSUPPORT
1765 #define MOPT_QFMT   MOPT_NOSUPPORT
1766 #endif
1767 #define MOPT_NO_EXT2    0x0020
1768 #define MOPT_NO_EXT3    0x0040
1769 #define MOPT_EXT4_ONLY  (MOPT_NO_EXT2 | MOPT_NO_EXT3)
1770 #define MOPT_SKIP   0x0080
1771 #define MOPT_2      0x0100
1772
1773 static const struct mount_opts {
1774     int token;
1775     int mount_opt;
1776     int flags;
1777 } ext4_mount_opts[] = {
1778     {Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1779     {Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1780     {Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1781     {Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1782     {Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1783     {Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1784     {Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1785      MOPT_EXT4_ONLY | MOPT_SET},
1786     {Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1787      MOPT_EXT4_ONLY | MOPT_CLEAR},
1788     {Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1789     {Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1790     {Opt_delalloc, EXT4_MOUNT_DELALLOC,
1791      MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1792     {Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1793      MOPT_EXT4_ONLY | MOPT_CLEAR},
1794     {Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1795     {Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1796     {Opt_commit, 0, MOPT_NO_EXT2},
1797     {Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1798      MOPT_EXT4_ONLY | MOPT_CLEAR},
1799     {Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1800      MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1801     {Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1802                     EXT4_MOUNT_JOURNAL_CHECKSUM),
1803      MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1804     {Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1805     {Opt_data_err, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_NO_EXT2},
1806     {Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1807     {Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1808     {Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1809     {Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1810     {Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1811     {Opt_dax_type, 0, MOPT_EXT4_ONLY},
1812     {Opt_journal_dev, 0, MOPT_NO_EXT2},
1813     {Opt_journal_path, 0, MOPT_NO_EXT2},
1814     {Opt_journal_ioprio, 0, MOPT_NO_EXT2},
1815     {Opt_data, 0, MOPT_NO_EXT2},
1816     {Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1817     {Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1818 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1819     {Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1820     {Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1821 #else
1822     {Opt_acl, 0, MOPT_NOSUPPORT},
1823     {Opt_noacl, 0, MOPT_NOSUPPORT},
1824 #endif
1825     {Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1826     {Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1827     {Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1828     {Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1829                             MOPT_SET | MOPT_Q},
1830     {Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1831                             MOPT_SET | MOPT_Q},
1832     {Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1833                             MOPT_SET | MOPT_Q},
1834     {Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1835                EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1836                             MOPT_CLEAR | MOPT_Q},
1837     {Opt_usrjquota, 0, MOPT_Q},
1838     {Opt_grpjquota, 0, MOPT_Q},
1839     {Opt_jqfmt, 0, MOPT_QFMT},
1840     {Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1841     {Opt_no_prefetch_block_bitmaps, EXT4_MOUNT_NO_PREFETCH_BLOCK_BITMAPS,
1842      MOPT_SET},
1843 #ifdef CONFIG_EXT4_DEBUG
1844     {Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
1845      MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
1846 #endif
1847     {Opt_err, 0, 0}
1848 };
1849
1850 #if IS_ENABLED(CONFIG_UNICODE)
1851 static const struct ext4_sb_encodings {
1852     __u16 magic;
1853     char *name;
1854     unsigned int version;
1855 } ext4_sb_encoding_map[] = {
1856     {EXT4_ENC_UTF8_12_1, "utf8", UNICODE_AGE(12, 1, 0)},
1857 };
1858
1859 static const struct ext4_sb_encodings *
1860 ext4_sb_read_encoding(const struct ext4_super_block *es)
1861 {
1862     __u16 magic = le16_to_cpu(es->s_encoding);
1863     int i;
1864
1865     for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1866         if (magic == ext4_sb_encoding_map[i].magic)
1867             return &ext4_sb_encoding_map[i];
1868
1869     return NULL;
1870 }
1871 #endif
1872
1873 #define EXT4_SPEC_JQUOTA            (1 <<  0)
1874 #define EXT4_SPEC_JQFMT             (1 <<  1)
1875 #define EXT4_SPEC_DATAJ             (1 <<  2)
1876 #define EXT4_SPEC_SB_BLOCK          (1 <<  3)
1877 #define EXT4_SPEC_JOURNAL_DEV           (1 <<  4)
1878 #define EXT4_SPEC_JOURNAL_IOPRIO        (1 <<  5)
1879 #define EXT4_SPEC_s_want_extra_isize        (1 <<  7)
1880 #define EXT4_SPEC_s_max_batch_time      (1 <<  8)
1881 #define EXT4_SPEC_s_min_batch_time      (1 <<  9)
1882 #define EXT4_SPEC_s_inode_readahead_blks    (1 << 10)
1883 #define EXT4_SPEC_s_li_wait_mult        (1 << 11)
1884 #define EXT4_SPEC_s_max_dir_size_kb     (1 << 12)
1885 #define EXT4_SPEC_s_stripe          (1 << 13)
1886 #define EXT4_SPEC_s_resuid          (1 << 14)
1887 #define EXT4_SPEC_s_resgid          (1 << 15)
1888 #define EXT4_SPEC_s_commit_interval     (1 << 16)
1889 #define EXT4_SPEC_s_fc_debug_max_replay     (1 << 17)
1890 #define EXT4_SPEC_s_sb_block            (1 << 18)
1891 #define EXT4_SPEC_mb_optimize_scan      (1 << 19)
1892
1893 struct ext4_fs_context {
1894     char        *s_qf_names[EXT4_MAXQUOTAS];
1895     struct fscrypt_dummy_policy dummy_enc_policy;
1896     int     s_jquota_fmt;   /* Format of quota to use */
1897 #ifdef CONFIG_EXT4_DEBUG
1898     int s_fc_debug_max_replay;
1899 #endif
1900     unsigned short  qname_spec;
1901     unsigned long   vals_s_flags;   /* Bits to set in s_flags */
1902     unsigned long   mask_s_flags;   /* Bits changed in s_flags */
1903     unsigned long   journal_devnum;
1904     unsigned long   s_commit_interval;
1905     unsigned long   s_stripe;
1906     unsigned int    s_inode_readahead_blks;
1907     unsigned int    s_want_extra_isize;
1908     unsigned int    s_li_wait_mult;
1909     unsigned int    s_max_dir_size_kb;
1910     unsigned int    journal_ioprio;
1911     unsigned int    vals_s_mount_opt;
1912     unsigned int    mask_s_mount_opt;
1913     unsigned int    vals_s_mount_opt2;
1914     unsigned int    mask_s_mount_opt2;
1915     unsigned long   vals_s_mount_flags;
1916     unsigned long   mask_s_mount_flags;
1917     unsigned int    opt_flags;  /* MOPT flags */
1918     unsigned int    spec;
1919     u32     s_max_batch_time;
1920     u32     s_min_batch_time;
1921     kuid_t      s_resuid;
1922     kgid_t      s_resgid;
1923     ext4_fsblk_t    s_sb_block;
1924 };
1925
1926 static void ext4_fc_free(struct fs_context *fc)
1927 {
1928     struct ext4_fs_context *ctx = fc->fs_private;
1929     int i;
1930
1931     if (!ctx)
1932         return;
1933
1934     for (i = 0; i < EXT4_MAXQUOTAS; i++)
1935         kfree(ctx->s_qf_names[i]);
1936
1937     fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
1938     kfree(ctx);
1939 }
1940
1941 int ext4_init_fs_context(struct fs_context *fc)
1942 {
1943     struct ext4_fs_context *ctx;
1944
1945     ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
1946     if (!ctx)
1947         return -ENOMEM;
1948
1949     fc->fs_private = ctx;
1950     fc->ops = &ext4_context_ops;
1951
1952     return 0;
1953 }
1954
1955 #ifdef CONFIG_QUOTA
1956 /*
1957  * Note the name of the specified quota file.
1958  */
1959 static int note_qf_name(struct fs_context *fc, int qtype,
1960                struct fs_parameter *param)
1961 {
1962     struct ext4_fs_context *ctx = fc->fs_private;
1963     char *qname;
1964
1965     if (param->size < 1) {
1966         ext4_msg(NULL, KERN_ERR, "Missing quota name");
1967         return -EINVAL;
1968     }
1969     if (strchr(param->string, '/')) {
1970         ext4_msg(NULL, KERN_ERR,
1971              "quotafile must be on filesystem root");
1972         return -EINVAL;
1973     }
1974     if (ctx->s_qf_names[qtype]) {
1975         if (strcmp(ctx->s_qf_names[qtype], param->string) != 0) {
1976             ext4_msg(NULL, KERN_ERR,
1977                  "%s quota file already specified",
1978                  QTYPE2NAME(qtype));
1979             return -EINVAL;
1980         }
1981         return 0;
1982     }
1983
1984     qname = kmemdup_nul(param->string, param->size, GFP_KERNEL);
1985     if (!qname) {
1986         ext4_msg(NULL, KERN_ERR,
1987              "Not enough memory for storing quotafile name");
1988         return -ENOMEM;
1989     }
1990     ctx->s_qf_names[qtype] = qname;
1991     ctx->qname_spec |= 1 << qtype;
1992     ctx->spec |= EXT4_SPEC_JQUOTA;
1993     return 0;
1994 }
1995
1996 /*
1997  * Clear the name of the specified quota file.
1998  */
1999 static int unnote_qf_name(struct fs_context *fc, int qtype)
2000 {
2001     struct ext4_fs_context *ctx = fc->fs_private;
2002
2003     if (ctx->s_qf_names[qtype])
2004         kfree(ctx->s_qf_names[qtype]);
2005
2006     ctx->s_qf_names[qtype] = NULL;
2007     ctx->qname_spec |= 1 << qtype;
2008     ctx->spec |= EXT4_SPEC_JQUOTA;
2009     return 0;
2010 }
2011 #endif
2012
2013 static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
2014                         struct ext4_fs_context *ctx)
2015 {
2016     int err;
2017
2018     if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
2019         ext4_msg(NULL, KERN_WARNING,
2020              "test_dummy_encryption option not supported");
2021         return -EINVAL;
2022     }
2023     err = fscrypt_parse_test_dummy_encryption(param,
2024                           &ctx->dummy_enc_policy);
2025     if (err == -EINVAL) {
2026         ext4_msg(NULL, KERN_WARNING,
2027              "Value of option \"%s\" is unrecognized", param->key);
2028     } else if (err == -EEXIST) {
2029         ext4_msg(NULL, KERN_WARNING,
2030              "Conflicting test_dummy_encryption options");
2031         return -EINVAL;
2032     }
2033     return err;
2034 }
2035
2036 #define EXT4_SET_CTX(name)                      \
2037 static inline void ctx_set_##name(struct ext4_fs_context *ctx,      \
2038                   unsigned long flag)           \
2039 {                                   \
2040     ctx->mask_s_##name |= flag;                 \
2041     ctx->vals_s_##name |= flag;                 \
2042 }
2043
2044 #define EXT4_CLEAR_CTX(name)                        \
2045 static inline void ctx_clear_##name(struct ext4_fs_context *ctx,    \
2046                     unsigned long flag)         \
2047 {                                   \
2048     ctx->mask_s_##name |= flag;                 \
2049     ctx->vals_s_##name &= ~flag;                    \
2050 }
2051
2052 #define EXT4_TEST_CTX(name)                     \
2053 static inline unsigned long                     \
2054 ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)    \
2055 {                                   \
2056     return (ctx->vals_s_##name & flag);             \
2057 }
2058
2059 EXT4_SET_CTX(flags); /* set only */
2060 EXT4_SET_CTX(mount_opt);
2061 EXT4_CLEAR_CTX(mount_opt);
2062 EXT4_TEST_CTX(mount_opt);
2063 EXT4_SET_CTX(mount_opt2);
2064 EXT4_CLEAR_CTX(mount_opt2);
2065 EXT4_TEST_CTX(mount_opt2);
2066
2067 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
2068 {
2069     set_bit(bit, &ctx->mask_s_mount_flags);
2070     set_bit(bit, &ctx->vals_s_mount_flags);
2071 }
2072
2073 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
2074 {
2075     struct ext4_fs_context *ctx = fc->fs_private;
2076     struct fs_parse_result result;
2077     const struct mount_opts *m;
2078     int is_remount;
2079     kuid_t uid;
2080     kgid_t gid;
2081     int token;
2082
2083     token = fs_parse(fc, ext4_param_specs, param, &result);
2084     if (token < 0)
2085         return token;
2086     is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2087
2088     for (m = ext4_mount_opts; m->token != Opt_err; m++)
2089         if (token == m->token)
2090             break;
2091
2092     ctx->opt_flags |= m->flags;
2093
2094     if (m->flags & MOPT_EXPLICIT) {
2095         if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
2096             ctx_set_mount_opt2(ctx, EXT4_MOUNT2_EXPLICIT_DELALLOC);
2097         } else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
2098             ctx_set_mount_opt2(ctx,
2099                        EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM);
2100         } else
2101             return -EINVAL;
2102     }
2103
2104     if (m->flags & MOPT_NOSUPPORT) {
2105         ext4_msg(NULL, KERN_ERR, "%s option not supported",
2106              param->key);
2107         return 0;
2108     }
2109
2110     switch (token) {
2111 #ifdef CONFIG_QUOTA
2112     case Opt_usrjquota:
2113         if (!*param->string)
2114             return unnote_qf_name(fc, USRQUOTA);
2115         else
2116             return note_qf_name(fc, USRQUOTA, param);
2117     case Opt_grpjquota:
2118         if (!*param->string)
2119             return unnote_qf_name(fc, GRPQUOTA);
2120         else
2121             return note_qf_name(fc, GRPQUOTA, param);
2122 #endif
2123     case Opt_noacl:
2124     case Opt_nouser_xattr:
2125         ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "3.5");
2126         break;
2127     case Opt_sb:
2128         if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2129             ext4_msg(NULL, KERN_WARNING,
2130                  "Ignoring %s option on remount", param->key);
2131         } else {
2132             ctx->s_sb_block = result.uint_32;
2133             ctx->spec |= EXT4_SPEC_s_sb_block;
2134         }
2135         return 0;
2136     case Opt_removed:
2137         ext4_msg(NULL, KERN_WARNING, "Ignoring removed %s option",
2138              param->key);
2139         return 0;
2140     case Opt_abort:
2141         ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
2142         return 0;
2143     case Opt_i_version:
2144         ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
2145         ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
2146         ctx_set_flags(ctx, SB_I_VERSION);
2147         return 0;
2148     case Opt_inlinecrypt:
2149 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
2150         ctx_set_flags(ctx, SB_INLINECRYPT);
2151 #else
2152         ext4_msg(NULL, KERN_ERR, "inline encryption not supported");
2153 #endif
2154         return 0;
2155     case Opt_errors:
2156         ctx_clear_mount_opt(ctx, EXT4_MOUNT_ERRORS_MASK);
2157         ctx_set_mount_opt(ctx, result.uint_32);
2158         return 0;
2159 #ifdef CONFIG_QUOTA
2160     case Opt_jqfmt:
2161         ctx->s_jquota_fmt = result.uint_32;
2162         ctx->spec |= EXT4_SPEC_JQFMT;
2163         return 0;
2164 #endif
2165     case Opt_data:
2166         ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2167         ctx_set_mount_opt(ctx, result.uint_32);
2168         ctx->spec |= EXT4_SPEC_DATAJ;
2169         return 0;
2170     case Opt_commit:
2171         if (result.uint_32 == 0)
2172             ctx->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE;
2173         else if (result.uint_32 > INT_MAX / HZ) {
2174             ext4_msg(NULL, KERN_ERR,
2175                  "Invalid commit interval %d, "
2176                  "must be smaller than %d",
2177                  result.uint_32, INT_MAX / HZ);
2178             return -EINVAL;
2179         }
2180         ctx->s_commit_interval = HZ * result.uint_32;
2181         ctx->spec |= EXT4_SPEC_s_commit_interval;
2182         return 0;
2183     case Opt_debug_want_extra_isize:
2184         if ((result.uint_32 & 1) || (result.uint_32 < 4)) {
2185             ext4_msg(NULL, KERN_ERR,
2186                  "Invalid want_extra_isize %d", result.uint_32);
2187             return -EINVAL;
2188         }
2189         ctx->s_want_extra_isize = result.uint_32;
2190         ctx->spec |= EXT4_SPEC_s_want_extra_isize;
2191         return 0;
2192     case Opt_max_batch_time:
2193         ctx->s_max_batch_time = result.uint_32;
2194         ctx->spec |= EXT4_SPEC_s_max_batch_time;
2195         return 0;
2196     case Opt_min_batch_time:
2197         ctx->s_min_batch_time = result.uint_32;
2198         ctx->spec |= EXT4_SPEC_s_min_batch_time;
2199         return 0;
2200     case Opt_inode_readahead_blks:
2201         if (result.uint_32 &&
2202             (result.uint_32 > (1 << 30) ||
2203              !is_power_of_2(result.uint_32))) {
2204             ext4_msg(NULL, KERN_ERR,
2205                  "EXT4-fs: inode_readahead_blks must be "
2206                  "0 or a power of 2 smaller than 2^31");
2207             return -EINVAL;
2208         }
2209         ctx->s_inode_readahead_blks = result.uint_32;
2210         ctx->spec |= EXT4_SPEC_s_inode_readahead_blks;
2211         return 0;
2212     case Opt_init_itable:
2213         ctx_set_mount_opt(ctx, EXT4_MOUNT_INIT_INODE_TABLE);
2214         ctx->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
2215         if (param->type == fs_value_is_string)
2216             ctx->s_li_wait_mult = result.uint_32;
2217         ctx->spec |= EXT4_SPEC_s_li_wait_mult;
2218         return 0;
2219     case Opt_max_dir_size_kb:
2220         ctx->s_max_dir_size_kb = result.uint_32;
2221         ctx->spec |= EXT4_SPEC_s_max_dir_size_kb;
2222         return 0;
2223 #ifdef CONFIG_EXT4_DEBUG
2224     case Opt_fc_debug_max_replay:
2225         ctx->s_fc_debug_max_replay = result.uint_32;
2226         ctx->spec |= EXT4_SPEC_s_fc_debug_max_replay;
2227         return 0;
2228 #endif
2229     case Opt_stripe:
2230         ctx->s_stripe = result.uint_32;
2231         ctx->spec |= EXT4_SPEC_s_stripe;
2232         return 0;
2233     case Opt_resuid:
2234         uid = make_kuid(current_user_ns(), result.uint_32);
2235         if (!uid_valid(uid)) {
2236             ext4_msg(NULL, KERN_ERR, "Invalid uid value %d",
2237                  result.uint_32);
2238             return -EINVAL;
2239         }
2240         ctx->s_resuid = uid;
2241         ctx->spec |= EXT4_SPEC_s_resuid;
2242         return 0;
2243     case Opt_resgid:
2244         gid = make_kgid(current_user_ns(), result.uint_32);
2245         if (!gid_valid(gid)) {
2246             ext4_msg(NULL, KERN_ERR, "Invalid gid value %d",
2247                  result.uint_32);
2248             return -EINVAL;
2249         }
2250         ctx->s_resgid = gid;
2251         ctx->spec |= EXT4_SPEC_s_resgid;
2252         return 0;
2253     case Opt_journal_dev:
2254         if (is_remount) {
2255             ext4_msg(NULL, KERN_ERR,
2256                  "Cannot specify journal on remount");
2257             return -EINVAL;
2258         }
2259         ctx->journal_devnum = result.uint_32;
2260         ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2261         return 0;
2262     case Opt_journal_path:
2263     {
2264         struct inode *journal_inode;
2265         struct path path;
2266         int error;
2267
2268         if (is_remount) {
2269             ext4_msg(NULL, KERN_ERR,
2270                  "Cannot specify journal on remount");
2271             return -EINVAL;
2272         }
2273
2274         error = fs_lookup_param(fc, param, 1, &path);
2275         if (error) {
2276             ext4_msg(NULL, KERN_ERR, "error: could not find "
2277                  "journal device path");
2278             return -EINVAL;
2279         }
2280
2281         journal_inode = d_inode(path.dentry);
2282         ctx->journal_devnum = new_encode_dev(journal_inode->i_rdev);
2283         ctx->spec |= EXT4_SPEC_JOURNAL_DEV;
2284         path_put(&path);
2285         return 0;
2286     }
2287     case Opt_journal_ioprio:
2288         if (result.uint_32 > 7) {
2289             ext4_msg(NULL, KERN_ERR, "Invalid journal IO priority"
2290                  " (must be 0-7)");
2291             return -EINVAL;
2292         }
2293         ctx->journal_ioprio =
2294             IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, result.uint_32);
2295         ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
2296         return 0;
2297     case Opt_test_dummy_encryption:
2298         return ext4_parse_test_dummy_encryption(param, ctx);
2299     case Opt_dax:
2300     case Opt_dax_type:
2301 #ifdef CONFIG_FS_DAX
2302     {
2303         int type = (token == Opt_dax) ?
2304                Opt_dax : result.uint_32;
2305
2306         switch (type) {
2307         case Opt_dax:
2308         case Opt_dax_always:
2309             ctx_set_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2310             ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2311             break;
2312         case Opt_dax_never:
2313             ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2314             ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2315             break;
2316         case Opt_dax_inode:
2317             ctx_clear_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS);
2318             ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER);
2319             /* Strictly for printing options */
2320             ctx_set_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE);
2321             break;
2322         }
2323         return 0;
2324     }
2325 #else
2326         ext4_msg(NULL, KERN_INFO, "dax option not supported");
2327         return -EINVAL;
2328 #endif
2329     case Opt_data_err:
2330         if (result.uint_32 == Opt_data_err_abort)
2331             ctx_set_mount_opt(ctx, m->mount_opt);
2332         else if (result.uint_32 == Opt_data_err_ignore)
2333             ctx_clear_mount_opt(ctx, m->mount_opt);
2334         return 0;
2335     case Opt_mb_optimize_scan:
2336         if (result.int_32 == 1) {
2337             ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2338             ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2339         } else if (result.int_32 == 0) {
2340             ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN);
2341             ctx->spec |= EXT4_SPEC_mb_optimize_scan;
2342         } else {
2343             ext4_msg(NULL, KERN_WARNING,
2344                  "mb_optimize_scan should be set to 0 or 1.");
2345             return -EINVAL;
2346         }
2347         return 0;
2348     }
2349
2350     /*
2351      * At this point we should only be getting options requiring MOPT_SET,
2352      * or MOPT_CLEAR. Anything else is a bug
2353      */
2354     if (m->token == Opt_err) {
2355         ext4_msg(NULL, KERN_WARNING, "buggy handling of option %s",
2356              param->key);
2357         WARN_ON(1);
2358         return -EINVAL;
2359     }
2360
2361     else {
2362         unsigned int set = 0;
2363
2364         if ((param->type == fs_value_is_flag) ||
2365             result.uint_32 > 0)
2366             set = 1;
2367
2368         if (m->flags & MOPT_CLEAR)
2369             set = !set;
2370         else if (unlikely(!(m->flags & MOPT_SET))) {
2371             ext4_msg(NULL, KERN_WARNING,
2372                  "buggy handling of option %s",
2373                  param->key);
2374             WARN_ON(1);
2375             return -EINVAL;
2376         }
2377         if (m->flags & MOPT_2) {
2378             if (set != 0)
2379                 ctx_set_mount_opt2(ctx, m->mount_opt);
2380             else
2381                 ctx_clear_mount_opt2(ctx, m->mount_opt);
2382         } else {
2383             if (set != 0)
2384                 ctx_set_mount_opt(ctx, m->mount_opt);
2385             else
2386                 ctx_clear_mount_opt(ctx, m->mount_opt);
2387         }
2388     }
2389
2390     return 0;
2391 }
2392
2393 static int parse_options(struct fs_context *fc, char *options)
2394 {
2395     struct fs_parameter param;
2396     int ret;
2397     char *key;
2398
2399     if (!options)
2400         return 0;
2401
2402     while ((key = strsep(&options, ",")) != NULL) {
2403         if (*key) {
2404             size_t v_len = 0;
2405             char *value = strchr(key, '=');
2406
2407             param.type = fs_value_is_flag;
2408             param.string = NULL;
2409
2410             if (value) {
2411                 if (value == key)
2412                     continue;
2413
2414                 *value++ = 0;
2415                 v_len = strlen(value);
2416                 param.string = kmemdup_nul(value, v_len,
2417                                GFP_KERNEL);
2418                 if (!param.string)
2419                     return -ENOMEM;
2420                 param.type = fs_value_is_string;
2421             }
2422
2423             param.key = key;
2424             param.size = v_len;
2425
2426             ret = ext4_parse_param(fc, &param);
2427             if (param.string)
2428                 kfree(param.string);
2429             if (ret < 0)
2430                 return ret;
2431         }
2432     }
2433
2434     ret = ext4_validate_options(fc);
2435     if (ret < 0)
2436         return ret;
2437
2438     return 0;
2439 }
2440
2441 static int parse_apply_sb_mount_options(struct super_block *sb,
2442                     struct ext4_fs_context *m_ctx)
2443 {
2444     struct ext4_sb_info *sbi = EXT4_SB(sb);
2445     char *s_mount_opts = NULL;
2446     struct ext4_fs_context *s_ctx = NULL;
2447     struct fs_context *fc = NULL;
2448     int ret = -ENOMEM;
2449
2450     if (!sbi->s_es->s_mount_opts[0])
2451         return 0;
2452
2453     s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
2454                 sizeof(sbi->s_es->s_mount_opts),
2455                 GFP_KERNEL);
2456     if (!s_mount_opts)
2457         return ret;
2458
2459     fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
2460     if (!fc)
2461         goto out_free;
2462
2463     s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
2464     if (!s_ctx)
2465         goto out_free;
2466
2467     fc->fs_private = s_ctx;
2468     fc->s_fs_info = sbi;
2469
2470     ret = parse_options(fc, s_mount_opts);
2471     if (ret < 0)
2472         goto parse_failed;
2473
2474     ret = ext4_check_opt_consistency(fc, sb);
2475     if (ret < 0) {
2476 parse_failed:
2477         ext4_msg(sb, KERN_WARNING,
2478              "failed to parse options in superblock: %s",
2479              s_mount_opts);
2480         ret = 0;
2481         goto out_free;
2482     }
2483
2484     if (s_ctx->spec & EXT4_SPEC_JOURNAL_DEV)
2485         m_ctx->journal_devnum = s_ctx->journal_devnum;
2486     if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
2487         m_ctx->journal_ioprio = s_ctx->journal_ioprio;
2488
2489     ext4_apply_options(fc, sb);
2490     ret = 0;
2491
2492 out_free:
2493     if (fc) {
2494         ext4_fc_free(fc);
2495         kfree(fc);
2496     }
2497     kfree(s_mount_opts);
2498     return ret;
2499 }
2500
2501 static void ext4_apply_quota_options(struct fs_context *fc,
2502                      struct super_block *sb)
2503 {
2504 #ifdef CONFIG_QUOTA
2505     bool quota_feature = ext4_has_feature_quota(sb);
2506     struct ext4_fs_context *ctx = fc->fs_private;
2507     struct ext4_sb_info *sbi = EXT4_SB(sb);
2508     char *qname;
2509     int i;
2510
2511     if (quota_feature)
2512         return;
2513
2514     if (ctx->spec & EXT4_SPEC_JQUOTA) {
2515         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2516             if (!(ctx->qname_spec & (1 << i)))
2517                 continue;
2518
2519             qname = ctx->s_qf_names[i]; /* May be NULL */
2520             if (qname)
2521                 set_opt(sb, QUOTA);
2522             ctx->s_qf_names[i] = NULL;
2523             qname = rcu_replace_pointer(sbi->s_qf_names[i], qname,
2524                         lockdep_is_held(&sb->s_umount));
2525             if (qname)
2526                 kfree_rcu(qname);
2527         }
2528     }
2529
2530     if (ctx->spec & EXT4_SPEC_JQFMT)
2531         sbi->s_jquota_fmt = ctx->s_jquota_fmt;
2532 #endif
2533 }
2534
2535 /*
2536  * Check quota settings consistency.
2537  */
2538 static int ext4_check_quota_consistency(struct fs_context *fc,
2539                     struct super_block *sb)
2540 {
2541 #ifdef CONFIG_QUOTA
2542     struct ext4_fs_context *ctx = fc->fs_private;
2543     struct ext4_sb_info *sbi = EXT4_SB(sb);
2544     bool quota_feature = ext4_has_feature_quota(sb);
2545     bool quota_loaded = sb_any_quota_loaded(sb);
2546     bool usr_qf_name, grp_qf_name, usrquota, grpquota;
2547     int quota_flags, i;
2548
2549     /*
2550      * We do the test below only for project quotas. 'usrquota' and
2551      * 'grpquota' mount options are allowed even without quota feature
2552      * to support legacy quotas in quota files.
2553      */
2554     if (ctx_test_mount_opt(ctx, EXT4_MOUNT_PRJQUOTA) &&
2555         !ext4_has_feature_project(sb)) {
2556         ext4_msg(NULL, KERN_ERR, "Project quota feature not enabled. "
2557              "Cannot enable project quota enforcement.");
2558         return -EINVAL;
2559     }
2560
2561     quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
2562               EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
2563     if (quota_loaded &&
2564         ctx->mask_s_mount_opt & quota_flags &&
2565         !ctx_test_mount_opt(ctx, quota_flags))
2566         goto err_quota_change;
2567
2568     if (ctx->spec & EXT4_SPEC_JQUOTA) {
2569
2570         for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2571             if (!(ctx->qname_spec & (1 << i)))
2572                 continue;
2573
2574             if (quota_loaded &&
2575                 !!sbi->s_qf_names[i] != !!ctx->s_qf_names[i])
2576                 goto err_jquota_change;
2577
2578             if (sbi->s_qf_names[i] && ctx->s_qf_names[i] &&
2579                 strcmp(get_qf_name(sb, sbi, i),
2580                    ctx->s_qf_names[i]) != 0)
2581                 goto err_jquota_specified;
2582         }
2583
2584         if (quota_feature) {
2585             ext4_msg(NULL, KERN_INFO,
2586                  "Journaled quota options ignored when "
2587                  "QUOTA feature is enabled");
2588             return 0;
2589         }
2590     }
2591
2592     if (ctx->spec & EXT4_SPEC_JQFMT) {
2593         if (sbi->s_jquota_fmt != ctx->s_jquota_fmt && quota_loaded)
2594             goto err_jquota_change;
2595         if (quota_feature) {
2596             ext4_msg(NULL, KERN_INFO, "Quota format mount options "
2597                  "ignored when QUOTA feature is enabled");
2598             return 0;
2599         }
2600     }
2601
2602     /* Make sure we don't mix old and new quota format */
2603     usr_qf_name = (get_qf_name(sb, sbi, USRQUOTA) ||
2604                ctx->s_qf_names[USRQUOTA]);
2605     grp_qf_name = (get_qf_name(sb, sbi, GRPQUOTA) ||
2606                ctx->s_qf_names[GRPQUOTA]);
2607
2608     usrquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2609             test_opt(sb, USRQUOTA));
2610
2611     grpquota = (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) ||
2612             test_opt(sb, GRPQUOTA));
2613
2614     if (usr_qf_name) {
2615         ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2616         usrquota = false;
2617     }
2618     if (grp_qf_name) {
2619         ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2620         grpquota = false;
2621     }
2622
2623     if (usr_qf_name || grp_qf_name) {
2624         if (usrquota || grpquota) {
2625             ext4_msg(NULL, KERN_ERR, "old and new quota "
2626                  "format mixing");
2627             return -EINVAL;
2628         }
2629
2630         if (!(ctx->spec & EXT4_SPEC_JQFMT || sbi->s_jquota_fmt)) {
2631             ext4_msg(NULL, KERN_ERR, "journaled quota format "
2632                  "not specified");
2633             return -EINVAL;
2634         }
2635     }
2636
2637     return 0;
2638
2639 err_quota_change:
2640     ext4_msg(NULL, KERN_ERR,
2641          "Cannot change quota options when quota turned on");
2642     return -EINVAL;
2643 err_jquota_change:
2644     ext4_msg(NULL, KERN_ERR, "Cannot change journaled quota "
2645          "options when quota turned on");
2646     return -EINVAL;
2647 err_jquota_specified:
2648     ext4_msg(NULL, KERN_ERR, "%s quota file already specified",
2649          QTYPE2NAME(i));
2650     return -EINVAL;
2651 #else
2652     return 0;
2653 #endif
2654 }
2655
2656 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
2657                         struct super_block *sb)
2658 {
2659     const struct ext4_fs_context *ctx = fc->fs_private;
2660     const struct ext4_sb_info *sbi = EXT4_SB(sb);
2661     int err;
2662
2663     if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
2664         return 0;
2665
2666     if (!ext4_has_feature_encrypt(sb)) {
2667         ext4_msg(NULL, KERN_WARNING,
2668              "test_dummy_encryption requires encrypt feature");
2669         return -EINVAL;
2670     }
2671     /*
2672      * This mount option is just for testing, and it's not worthwhile to
2673      * implement the extra complexity (e.g. RCU protection) that would be
2674      * needed to allow it to be set or changed during remount.  We do allow
2675      * it to be specified during remount, but only if there is no change.
2676      */
2677     if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
2678         if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2679                          &ctx->dummy_enc_policy))
2680             return 0;
2681         ext4_msg(NULL, KERN_WARNING,
2682              "Can't set or change test_dummy_encryption on remount");
2683         return -EINVAL;
2684     }
2685     /* Also make sure s_mount_opts didn't contain a conflicting value. */
2686     if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
2687         if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
2688                          &ctx->dummy_enc_policy))
2689             return 0;
2690         ext4_msg(NULL, KERN_WARNING,
2691              "Conflicting test_dummy_encryption options");
2692         return -EINVAL;
2693     }
2694     /*
2695      * fscrypt_add_test_dummy_key() technically changes the super_block, so
2696      * technically it should be delayed until ext4_apply_options() like the
2697      * other changes.  But since we never get here for remounts (see above),
2698      * and this is the last chance to report errors, we do it here.
2699      */
2700     err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
2701     if (err)
2702         ext4_msg(NULL, KERN_WARNING,
2703              "Error adding test dummy encryption key [%d]", err);
2704     return err;
2705 }
2706
2707 static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
2708                          struct super_block *sb)
2709 {
2710     if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
2711         /* if already set, it was already verified to be the same */
2712         fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
2713         return;
2714     EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
2715     memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
2716     ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
2717 }
2718
2719 static int ext4_check_opt_consistency(struct fs_context *fc,
2720                       struct super_block *sb)
2721 {
2722     struct ext4_fs_context *ctx = fc->fs_private;
2723     struct ext4_sb_info *sbi = fc->s_fs_info;
2724     int is_remount = fc->purpose == FS_CONTEXT_FOR_RECONFIGURE;
2725     int err;
2726
2727     if ((ctx->opt_flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
2728         ext4_msg(NULL, KERN_ERR,
2729              "Mount option(s) incompatible with ext2");
2730         return -EINVAL;
2731     }
2732     if ((ctx->opt_flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
2733         ext4_msg(NULL, KERN_ERR,
2734              "Mount option(s) incompatible with ext3");
2735         return -EINVAL;
2736     }
2737
2738     if (ctx->s_want_extra_isize >
2739         (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE)) {
2740         ext4_msg(NULL, KERN_ERR,
2741              "Invalid want_extra_isize %d",
2742              ctx->s_want_extra_isize);
2743         return -EINVAL;
2744     }
2745
2746     if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DIOREAD_NOLOCK)) {
2747         int blocksize =
2748             BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2749         if (blocksize < PAGE_SIZE)
2750             ext4_msg(NULL, KERN_WARNING, "Warning: mounting with an "
2751                  "experimental mount option 'dioread_nolock' "
2752                  "for blocksize < PAGE_SIZE");
2753     }
2754
2755     err = ext4_check_test_dummy_encryption(fc, sb);
2756     if (err)
2757         return err;
2758
2759     if ((ctx->spec & EXT4_SPEC_DATAJ) && is_remount) {
2760         if (!sbi->s_journal) {
2761             ext4_msg(NULL, KERN_WARNING,
2762                  "Remounting file system with no journal "
2763                  "so ignoring journalled data option");
2764             ctx_clear_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS);
2765         } else if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DATA_FLAGS) !=
2766                test_opt(sb, DATA_FLAGS)) {
2767             ext4_msg(NULL, KERN_ERR, "Cannot change data mode "
2768                  "on remount");
2769             return -EINVAL;
2770         }
2771     }
2772
2773     if (is_remount) {
2774         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2775             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
2776             ext4_msg(NULL, KERN_ERR, "can't mount with "
2777                  "both data=journal and dax");
2778             return -EINVAL;
2779         }
2780
2781         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_DAX_ALWAYS) &&
2782             (!(sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2783              (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER))) {
2784 fail_dax_change_remount:
2785             ext4_msg(NULL, KERN_ERR, "can't change "
2786                  "dax mount option while remounting");
2787             return -EINVAL;
2788         } else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_NEVER) &&
2789              (!(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2790               (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS))) {
2791             goto fail_dax_change_remount;
2792         } else if (ctx_test_mount_opt2(ctx, EXT4_MOUNT2_DAX_INODE) &&
2793                ((sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) ||
2794                 (sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_NEVER) ||
2795                 !(sbi->s_mount_opt2 & EXT4_MOUNT2_DAX_INODE))) {
2796             goto fail_dax_change_remount;
2797         }
2798     }
2799
2800     return ext4_check_quota_consistency(fc, sb);
2801 }
2802
2803 static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
2804 {
2805     struct ext4_fs_context *ctx = fc->fs_private;
2806     struct ext4_sb_info *sbi = fc->s_fs_info;
2807
2808     sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
2809     sbi->s_mount_opt |= ctx->vals_s_mount_opt;
2810     sbi->s_mount_opt2 &= ~ctx->mask_s_mount_opt2;
2811     sbi->s_mount_opt2 |= ctx->vals_s_mount_opt2;
2812     sbi->s_mount_flags &= ~ctx->mask_s_mount_flags;
2813     sbi->s_mount_flags |= ctx->vals_s_mount_flags;
2814     sb->s_flags &= ~ctx->mask_s_flags;
2815     sb->s_flags |= ctx->vals_s_flags;
2816
2817     /*
2818      * i_version differs from common mount option iversion so we have
2819      * to let vfs know that it was set, otherwise it would get cleared
2820      * on remount
2821      */
2822     if (ctx->mask_s_flags & SB_I_VERSION)
2823         fc->sb_flags |= SB_I_VERSION;
2824
2825 #define APPLY(X) ({ if (ctx->spec & EXT4_SPEC_##X) sbi->X = ctx->X; })
2826     APPLY(s_commit_interval);
2827     APPLY(s_stripe);
2828     APPLY(s_max_batch_time);
2829     APPLY(s_min_batch_time);
2830     APPLY(s_want_extra_isize);
2831     APPLY(s_inode_readahead_blks);
2832     APPLY(s_max_dir_size_kb);
2833     APPLY(s_li_wait_mult);
2834     APPLY(s_resgid);
2835     APPLY(s_resuid);
2836
2837 #ifdef CONFIG_EXT4_DEBUG
2838     APPLY(s_fc_debug_max_replay);
2839 #endif
2840
2841     ext4_apply_quota_options(fc, sb);
2842     ext4_apply_test_dummy_encryption(ctx, sb);
2843 }
2844
2845
2846 static int ext4_validate_options(struct fs_context *fc)
2847 {
2848 #ifdef CONFIG_QUOTA
2849     struct ext4_fs_context *ctx = fc->fs_private;
2850     char *usr_qf_name, *grp_qf_name;
2851
2852     usr_qf_name = ctx->s_qf_names[USRQUOTA];
2853     grp_qf_name = ctx->s_qf_names[GRPQUOTA];
2854
2855     if (usr_qf_name || grp_qf_name) {
2856         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) && usr_qf_name)
2857             ctx_clear_mount_opt(ctx, EXT4_MOUNT_USRQUOTA);
2858
2859         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA) && grp_qf_name)
2860             ctx_clear_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA);
2861
2862         if (ctx_test_mount_opt(ctx, EXT4_MOUNT_USRQUOTA) ||
2863             ctx_test_mount_opt(ctx, EXT4_MOUNT_GRPQUOTA)) {
2864             ext4_msg(NULL, KERN_ERR, "old and new quota "
2865                  "format mixing");
2866             return -EINVAL;
2867         }
2868     }
2869 #endif
2870     return 1;
2871 }
2872
2873 static inline void ext4_show_quota_options(struct seq_file *seq,
2874                        struct super_block *sb)
2875 {
2876 #if defined(CONFIG_QUOTA)
2877     struct ext4_sb_info *sbi = EXT4_SB(sb);
2878     char *usr_qf_name, *grp_qf_name;
2879
2880     if (sbi->s_jquota_fmt) {
2881         char *fmtname = "";
2882
2883         switch (sbi->s_jquota_fmt) {
2884         case QFMT_VFS_OLD:
2885             fmtname = "vfsold";
2886             break;
2887         case QFMT_VFS_V0:
2888             fmtname = "vfsv0";
2889             break;
2890         case QFMT_VFS_V1:
2891             fmtname = "vfsv1";
2892             break;
2893         }
2894         seq_printf(seq, ",jqfmt=%s", fmtname);
2895     }
2896
2897     rcu_read_lock();
2898     usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2899     grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2900     if (usr_qf_name)
2901         seq_show_option(seq, "usrjquota", usr_qf_name);
2902     if (grp_qf_name)
2903         seq_show_option(seq, "grpjquota", grp_qf_name);
2904     rcu_read_unlock();
2905 #endif
2906 }
2907
2908 static const char *token2str(int token)
2909 {
2910     const struct fs_parameter_spec *spec;
2911
2912     for (spec = ext4_param_specs; spec->name != NULL; spec++)
2913         if (spec->opt == token && !spec->type)
2914             break;
2915     return spec->name;
2916 }
2917
2918 /*
2919  * Show an option if
2920  *  - it's set to a non-default value OR
2921  *  - if the per-sb default is different from the global default
2922  */
2923 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2924                   int nodefs)
2925 {
2926     struct ext4_sb_info *sbi = EXT4_SB(sb);
2927     struct ext4_super_block *es = sbi->s_es;
2928     int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2929     const struct mount_opts *m;
2930     char sep = nodefs ? '\n' : ',';
2931
2932 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2933 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2934
2935     if (sbi->s_sb_block != 1)
2936         SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2937
2938     for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2939         int want_set = m->flags & MOPT_SET;
2940         if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2941             m->flags & MOPT_SKIP)
2942             continue;
2943         if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2944             continue; /* skip if same as the default */
2945         if ((want_set &&
2946              (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2947             (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2948             continue; /* select Opt_noFoo vs Opt_Foo */
2949         SEQ_OPTS_PRINT("%s", token2str(m->token));
2950     }
2951
2952     if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2953         le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2954         SEQ_OPTS_PRINT("resuid=%u",
2955                 from_kuid_munged(&init_user_ns, sbi->s_resuid));
2956     if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2957         le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2958         SEQ_OPTS_PRINT("resgid=%u",
2959                 from_kgid_munged(&init_user_ns, sbi->s_resgid));
2960     def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2961     if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2962         SEQ_OPTS_PUTS("errors=remount-ro");
2963     if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2964         SEQ_OPTS_PUTS("errors=continue");
2965     if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2966         SEQ_OPTS_PUTS("errors=panic");
2967     if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2968         SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2969     if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2970         SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2971     if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2972         SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2973     if (sb->s_flags & SB_I_VERSION)
2974         SEQ_OPTS_PUTS("i_version");
2975     if (nodefs || sbi->s_stripe)
2976         SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2977     if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2978             (sbi->s_mount_opt ^ def_mount_opt)) {
2979         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2980             SEQ_OPTS_PUTS("data=journal");
2981         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2982             SEQ_OPTS_PUTS("data=ordered");
2983         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2984             SEQ_OPTS_PUTS("data=writeback");
2985     }
2986     if (nodefs ||
2987         sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2988         SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2989                    sbi->s_inode_readahead_blks);
2990
2991     if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2992                (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2993         SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2994     if (nodefs || sbi->s_max_dir_size_kb)
2995         SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2996     if (test_opt(sb, DATA_ERR_ABORT))
2997         SEQ_OPTS_PUTS("data_err=abort");
2998
2999     fscrypt_show_test_dummy_encryption(seq, sep, sb);
3000
3001     if (sb->s_flags & SB_INLINECRYPT)
3002         SEQ_OPTS_PUTS("inlinecrypt");
3003
3004     if (test_opt(sb, DAX_ALWAYS)) {
3005         if (IS_EXT2_SB(sb))
3006             SEQ_OPTS_PUTS("dax");
3007         else
3008             SEQ_OPTS_PUTS("dax=always");
3009     } else if (test_opt2(sb, DAX_NEVER)) {
3010         SEQ_OPTS_PUTS("dax=never");
3011     } else if (test_opt2(sb, DAX_INODE)) {
3012         SEQ_OPTS_PUTS("dax=inode");
3013     }
3014
3015     if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3016             !test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3017         SEQ_OPTS_PUTS("mb_optimize_scan=0");
3018     } else if (sbi->s_groups_count < MB_DEFAULT_LINEAR_SCAN_THRESHOLD &&
3019             test_opt2(sb, MB_OPTIMIZE_SCAN)) {
3020         SEQ_OPTS_PUTS("mb_optimize_scan=1");
3021     }
3022
3023     ext4_show_quota_options(seq, sb);
3024     return 0;
3025 }
3026
3027 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
3028 {
3029     return _ext4_show_options(seq, root->d_sb, 0);
3030 }
3031
3032 int ext4_seq_options_show(struct seq_file *seq, void *offset)
3033 {
3034     struct super_block *sb = seq->private;
3035     int rc;
3036
3037     seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
3038     rc = _ext4_show_options(seq, sb, 1);
3039     seq_puts(seq, "\n");
3040     return rc;
3041 }
3042
3043 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
3044                 int read_only)
3045 {
3046     struct ext4_sb_info *sbi = EXT4_SB(sb);
3047     int err = 0;
3048
3049     if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
3050         ext4_msg(sb, KERN_ERR, "revision level too high, "
3051              "forcing read-only mode");
3052         err = -EROFS;
3053         goto done;
3054     }
3055     if (read_only)
3056         goto done;
3057     if (!(sbi->s_mount_state & EXT4_VALID_FS))
3058         ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
3059              "running e2fsck is recommended");
3060     else if (sbi->s_mount_state & EXT4_ERROR_FS)
3061         ext4_msg(sb, KERN_WARNING,
3062              "warning: mounting fs with errors, "
3063              "running e2fsck is recommended");
3064     else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
3065          le16_to_cpu(es->s_mnt_count) >=
3066          (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
3067         ext4_msg(sb, KERN_WARNING,
3068              "warning: maximal mount count reached, "
3069              "running e2fsck is recommended");
3070     else if (le32_to_cpu(es->s_checkinterval) &&
3071          (ext4_get_tstamp(es, s_lastcheck) +
3072           le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
3073         ext4_msg(sb, KERN_WARNING,
3074              "warning: checktime reached, "
3075              "running e2fsck is recommended");
3076     if (!sbi->s_journal)
3077         es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
3078     if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
3079         es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
3080     le16_add_cpu(&es->s_mnt_count, 1);
3081     ext4_update_tstamp(es, s_mtime);
3082     if (sbi->s_journal) {
3083         ext4_set_feature_journal_needs_recovery(sb);
3084         if (ext4_has_feature_orphan_file(sb))
3085             ext4_set_feature_orphan_present(sb);
3086     }
3087
3088     err = ext4_commit_super(sb);
3089 done:
3090     if (test_opt(sb, DEBUG))
3091         printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
3092                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
3093             sb->s_blocksize,
3094             sbi->s_groups_count,
3095             EXT4_BLOCKS_PER_GROUP(sb),
3096             EXT4_INODES_PER_GROUP(sb),
3097             sbi->s_mount_opt, sbi->s_mount_opt2);
3098     return err;
3099 }
3100
3101 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
3102 {
3103     struct ext4_sb_info *sbi = EXT4_SB(sb);
3104     struct flex_groups **old_groups, **new_groups;
3105     int size, i, j;
3106
3107     if (!sbi->s_log_groups_per_flex)
3108         return 0;
3109
3110     size = ext4_flex_group(sbi, ngroup - 1) + 1;
3111     if (size <= sbi->s_flex_groups_allocated)
3112         return 0;
3113
3114     new_groups = kvzalloc(roundup_pow_of_two(size *
3115                   sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
3116     if (!new_groups) {
3117         ext4_msg(sb, KERN_ERR,
3118              "not enough memory for %d flex group pointers", size);
3119         return -ENOMEM;
3120     }
3121     for (i = sbi->s_flex_groups_allocated; i < size; i++) {
3122         new_groups[i] = kvzalloc(roundup_pow_of_two(
3123                      sizeof(struct flex_groups)),
3124                      GFP_KERNEL);
3125         if (!new_groups[i]) {
3126             for (j = sbi->s_flex_groups_allocated; j < i; j++)
3127                 kvfree(new_groups[j]);
3128             kvfree(new_groups);
3129             ext4_msg(sb, KERN_ERR,
3130                  "not enough memory for %d flex groups", size);
3131             return -ENOMEM;
3132         }
3133     }
3134     rcu_read_lock();
3135     old_groups = rcu_dereference(sbi->s_flex_groups);
3136     if (old_groups)
3137         memcpy(new_groups, old_groups,
3138                (sbi->s_flex_groups_allocated *
3139             sizeof(struct flex_groups *)));
3140     rcu_read_unlock();
3141     rcu_assign_pointer(sbi->s_flex_groups, new_groups);
3142     sbi->s_flex_groups_allocated = size;
3143     if (old_groups)
3144         ext4_kvfree_array_rcu(old_groups);
3145     return 0;
3146 }
3147
3148 static int ext4_fill_flex_info(struct super_block *sb)
3149 {
3150     struct ext4_sb_info *sbi = EXT4_SB(sb);
3151     struct ext4_group_desc *gdp = NULL;
3152     struct flex_groups *fg;
3153     ext4_group_t flex_group;
3154     int i, err;
3155
3156     sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
3157     if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
3158         sbi->s_log_groups_per_flex = 0;
3159         return 1;
3160     }
3161
3162     err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
3163     if (err)
3164         goto failed;
3165
3166     for (i = 0; i < sbi->s_groups_count; i++) {
3167         gdp = ext4_get_group_desc(sb, i, NULL);
3168
3169         flex_group = ext4_flex_group(sbi, i);
3170         fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
3171         atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
3172         atomic64_add(ext4_free_group_clusters(sb, gdp),
3173                  &fg->free_clusters);
3174         atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
3175     }
3176
3177     return 1;
3178 failed:
3179     return 0;
3180 }
3181
3182 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
3183                    struct ext4_group_desc *gdp)
3184 {
3185     int offset = offsetof(struct ext4_group_desc, bg_checksum);
3186     __u16 crc = 0;
3187     __le32 le_group = cpu_to_le32(block_group);
3188     struct ext4_sb_info *sbi = EXT4_SB(sb);
3189
3190     if (ext4_has_metadata_csum(sbi->s_sb)) {
3191         /* Use new metadata_csum algorithm */
3192         __u32 csum32;
3193         __u16 dummy_csum = 0;
3194
3195         csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
3196                      sizeof(le_group));
3197         csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
3198         csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
3199                      sizeof(dummy_csum));
3200         offset += sizeof(dummy_csum);
3201         if (offset < sbi->s_desc_size)
3202             csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
3203                          sbi->s_desc_size - offset);
3204
3205         crc = csum32 & 0xFFFF;
3206         goto out;
3207     }
3208
3209     /* old crc16 code */
3210     if (!ext4_has_feature_gdt_csum(sb))
3211         return 0;
3212
3213     crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
3214     crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
3215     crc = crc16(crc, (__u8 *)gdp, offset);
3216     offset += sizeof(gdp->bg_checksum); /* skip checksum */
3217     /* for checksum of struct ext4_group_desc do the rest...*/
3218     if (ext4_has_feature_64bit(sb) &&
3219         offset < le16_to_cpu(sbi->s_es->s_desc_size))
3220         crc = crc16(crc, (__u8 *)gdp + offset,
3221                 le16_to_cpu(sbi->s_es->s_desc_size) -
3222                 offset);
3223
3224 out:
3225     return cpu_to_le16(crc);
3226 }
3227
3228 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
3229                 struct ext4_group_desc *gdp)
3230 {
3231     if (ext4_has_group_desc_csum(sb) &&
3232         (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
3233         return 0;
3234
3235     return 1;
3236 }
3237
3238 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
3239                   struct ext4_group_desc *gdp)
3240 {
3241     if (!ext4_has_group_desc_csum(sb))
3242         return;
3243     gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
3244 }
3245
3246 /* Called at mount-time, super-block is locked */
3247 static int ext4_check_descriptors(struct super_block *sb,
3248                   ext4_fsblk_t sb_block,
3249                   ext4_group_t *first_not_zeroed)
3250 {
3251     struct ext4_sb_info *sbi = EXT4_SB(sb);
3252     ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
3253     ext4_fsblk_t last_block;
3254     ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
3255     ext4_fsblk_t block_bitmap;
3256     ext4_fsblk_t inode_bitmap;
3257     ext4_fsblk_t inode_table;
3258     int flexbg_flag = 0;
3259     ext4_group_t i, grp = sbi->s_groups_count;
3260
3261     if (ext4_has_feature_flex_bg(sb))
3262         flexbg_flag = 1;
3263
3264     ext4_debug("Checking group descriptors");
3265
3266     for (i = 0; i < sbi->s_groups_count; i++) {
3267         struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
3268
3269         if (i == sbi->s_groups_count - 1 || flexbg_flag)
3270             last_block = ext4_blocks_count(sbi->s_es) - 1;
3271         else
3272             last_block = first_block +
3273                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
3274
3275         if ((grp == sbi->s_groups_count) &&
3276            !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3277             grp = i;
3278
3279         block_bitmap = ext4_block_bitmap(sb, gdp);
3280         if (block_bitmap == sb_block) {
3281             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3282                  "Block bitmap for group %u overlaps "
3283                  "superblock", i);
3284             if (!sb_rdonly(sb))
3285                 return 0;
3286         }
3287         if (block_bitmap >= sb_block + 1 &&
3288             block_bitmap <= last_bg_block) {
3289             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3290                  "Block bitmap for group %u overlaps "
3291                  "block group descriptors", i);
3292             if (!sb_rdonly(sb))
3293                 return 0;
3294         }
3295         if (block_bitmap < first_block || block_bitmap > last_block) {
3296             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3297                    "Block bitmap for group %u not in group "
3298                    "(block %llu)!", i, block_bitmap);
3299             return 0;
3300         }
3301         inode_bitmap = ext4_inode_bitmap(sb, gdp);
3302         if (inode_bitmap == sb_block) {
3303             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3304                  "Inode bitmap for group %u overlaps "
3305                  "superblock", i);
3306             if (!sb_rdonly(sb))
3307                 return 0;
3308         }
3309         if (inode_bitmap >= sb_block + 1 &&
3310             inode_bitmap <= last_bg_block) {
3311             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3312                  "Inode bitmap for group %u overlaps "
3313                  "block group descriptors", i);
3314             if (!sb_rdonly(sb))
3315                 return 0;
3316         }
3317         if (inode_bitmap < first_block || inode_bitmap > last_block) {
3318             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3319                    "Inode bitmap for group %u not in group "
3320                    "(block %llu)!", i, inode_bitmap);
3321             return 0;
3322         }
3323         inode_table = ext4_inode_table(sb, gdp);
3324         if (inode_table == sb_block) {
3325             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3326                  "Inode table for group %u overlaps "
3327                  "superblock", i);
3328             if (!sb_rdonly(sb))
3329                 return 0;
3330         }
3331         if (inode_table >= sb_block + 1 &&
3332             inode_table <= last_bg_block) {
3333             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3334                  "Inode table for group %u overlaps "
3335                  "block group descriptors", i);
3336             if (!sb_rdonly(sb))
3337                 return 0;
3338         }
3339         if (inode_table < first_block ||
3340             inode_table + sbi->s_itb_per_group - 1 > last_block) {
3341             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3342                    "Inode table for group %u not in group "
3343                    "(block %llu)!", i, inode_table);
3344             return 0;
3345         }
3346         ext4_lock_group(sb, i);
3347         if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
3348             ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
3349                  "Checksum for group %u failed (%u!=%u)",
3350                  i, le16_to_cpu(ext4_group_desc_csum(sb, i,
3351                      gdp)), le16_to_cpu(gdp->bg_checksum));
3352             if (!sb_rdonly(sb)) {
3353                 ext4_unlock_group(sb, i);
3354                 return 0;
3355             }
3356         }
3357         ext4_unlock_group(sb, i);
3358         if (!flexbg_flag)
3359             first_block += EXT4_BLOCKS_PER_GROUP(sb);
3360     }
3361     if (NULL != first_not_zeroed)
3362         *first_not_zeroed = grp;
3363     return 1;
3364 }
3365
3366 /*
3367  * Maximal extent format file size.
3368  * Resulting logical blkno at s_maxbytes must fit in our on-disk
3369  * extent format containers, within a sector_t, and within i_blocks
3370  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
3371  * so that won't be a limiting factor.
3372  *
3373  * However there is other limiting factor. We do store extents in the form
3374  * of starting block and length, hence the resulting length of the extent
3375  * covering maximum file size must fit into on-disk format containers as
3376  * well. Given that length is always by 1 unit bigger than max unit (because
3377  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
3378  *
3379  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
3380  */
3381 static loff_t ext4_max_size(int blkbits, int has_huge_files)
3382 {
3383     loff_t res;
3384     loff_t upper_limit = MAX_LFS_FILESIZE;
3385
3386     BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
3387
3388     if (!has_huge_files) {
3389         upper_limit = (1LL << 32) - 1;
3390
3391         /* total blocks in file system block size */
3392         upper_limit >>= (blkbits - 9);
3393         upper_limit <<= blkbits;
3394     }
3395
3396     /*
3397      * 32-bit extent-start container, ee_block. We lower the maxbytes
3398      * by one fs block, so ee_len can cover the extent of maximum file
3399      * size
3400      */
3401     res = (1LL << 32) - 1;
3402     res <<= blkbits;
3403
3404     /* Sanity check against vm- & vfs- imposed limits */
3405     if (res > upper_limit)
3406         res = upper_limit;
3407
3408     return res;
3409 }
3410
3411 /*
3412  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
3413  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
3414  * We need to be 1 filesystem block less than the 2^48 sector limit.
3415  */
3416 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
3417 {
3418     loff_t upper_limit, res = EXT4_NDIR_BLOCKS;
3419     int meta_blocks;
3420     unsigned int ppb = 1 << (bits - 2);
3421
3422     /*
3423      * This is calculated to be the largest file size for a dense, block
3424      * mapped file such that the file's total number of 512-byte sectors,
3425      * including data and all indirect blocks, does not exceed (2^48 - 1).
3426      *
3427      * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
3428      * number of 512-byte sectors of the file.
3429      */
3430     if (!has_huge_files) {
3431         /*
3432          * !has_huge_files or implies that the inode i_block field
3433          * represents total file blocks in 2^32 512-byte sectors ==
3434          * size of vfs inode i_blocks * 8
3435          */
3436         upper_limit = (1LL << 32) - 1;
3437
3438         /* total blocks in file system block size */
3439         upper_limit >>= (bits - 9);
3440
3441     } else {
3442         /*
3443          * We use 48 bit ext4_inode i_blocks
3444          * With EXT4_HUGE_FILE_FL set the i_blocks
3445          * represent total number of blocks in
3446          * file system block size
3447          */
3448         upper_limit = (1LL << 48) - 1;
3449
3450     }
3451
3452     /* Compute how many blocks we can address by block tree */
3453     res += ppb;
3454     res += ppb * ppb;
3455     res += ((loff_t)ppb) * ppb * ppb;
3456     /* Compute how many metadata blocks are needed */
3457     meta_blocks = 1;
3458     meta_blocks += 1 + ppb;
3459     meta_blocks += 1 + ppb + ppb * ppb;
3460     /* Does block tree limit file size? */
3461     if (res + meta_blocks <= upper_limit)
3462         goto check_lfs;
3463
3464     res = upper_limit;
3465     /* How many metadata blocks are needed for addressing upper_limit? */
3466     upper_limit -= EXT4_NDIR_BLOCKS;
3467     /* indirect blocks */
3468     meta_blocks = 1;
3469     upper_limit -= ppb;
3470     /* double indirect blocks */
3471     if (upper_limit < ppb * ppb) {
3472         meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb);
3473         res -= meta_blocks;
3474         goto check_lfs;
3475     }
3476     meta_blocks += 1 + ppb;
3477     upper_limit -= ppb * ppb;
3478     /* tripple indirect blocks for the rest */
3479     meta_blocks += 1 + DIV_ROUND_UP_ULL(upper_limit, ppb) +
3480         DIV_ROUND_UP_ULL(upper_limit, ppb*ppb);
3481     res -= meta_blocks;
3482 check_lfs:
3483     res <<= bits;
3484     if (res > MAX_LFS_FILESIZE)
3485         res = MAX_LFS_FILESIZE;
3486
3487     return res;
3488 }
3489
3490 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
3491                    ext4_fsblk_t logical_sb_block, int nr)
3492 {
3493     struct ext4_sb_info *sbi = EXT4_SB(sb);
3494     ext4_group_t bg, first_meta_bg;
3495     int has_super = 0;
3496
3497     first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
3498
3499     if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
3500         return logical_sb_block + nr + 1;
3501     bg = sbi->s_desc_per_block * nr;
3502     if (ext4_bg_has_super(sb, bg))
3503         has_super = 1;
3504
3505     /*
3506      * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
3507      * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
3508      * on modern mke2fs or blksize > 1k on older mke2fs) then we must
3509      * compensate.
3510      */
3511     if (sb->s_blocksize == 1024 && nr == 0 &&
3512         le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
3513         has_super++;
3514
3515     return (has_super + ext4_group_first_block_no(sb, bg));
3516 }
3517
3518 /**
3519  * ext4_get_stripe_size: Get the stripe size.
3520  * @sbi: In memory super block info
3521  *
3522  * If we have specified it via mount option, then
3523  * use the mount option value. If the value specified at mount time is
3524  * greater than the blocks per group use the super block value.
3525  * If the super block value is greater than blocks per group return 0.
3526  * Allocator needs it be less than blocks per group.
3527  *
3528  */
3529 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
3530 {
3531     unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
3532     unsigned long stripe_width =
3533             le32_to_cpu(sbi->s_es->s_raid_stripe_width);
3534     int ret;
3535
3536     if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
3537         ret = sbi->s_stripe;
3538     else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
3539         ret = stripe_width;
3540     else if (stride && stride <= sbi->s_blocks_per_group)
3541         ret = stride;
3542     else
3543         ret = 0;
3544
3545     /*
3546      * If the stripe width is 1, this makes no sense and
3547      * we set it to 0 to turn off stripe handling code.
3548      */
3549     if (ret <= 1)
3550         ret = 0;
3551
3552     return ret;
3553 }
3554
3555 /*
3556  * Check whether this filesystem can be mounted based on
3557  * the features present and the RDONLY/RDWR mount requested.
3558  * Returns 1 if this filesystem can be mounted as requested,
3559  * 0 if it cannot be.
3560  */
3561 int ext4_feature_set_ok(struct super_block *sb, int readonly)
3562 {
3563     if (ext4_has_unknown_ext4_incompat_features(sb)) {
3564         ext4_msg(sb, KERN_ERR,
3565             "Couldn't mount because of "
3566             "unsupported optional features (%x)",
3567             (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3568             ~EXT4_FEATURE_INCOMPAT_SUPP));
3569         return 0;
3570     }
3571
3572 #if !IS_ENABLED(CONFIG_UNICODE)
3573     if (ext4_has_feature_casefold(sb)) {
3574         ext4_msg(sb, KERN_ERR,
3575              "Filesystem with casefold feature cannot be "
3576              "mounted without CONFIG_UNICODE");
3577         return 0;
3578     }
3579 #endif
3580
3581     if (readonly)
3582         return 1;
3583
3584     if (ext4_has_feature_readonly(sb)) {
3585         ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3586         sb->s_flags |= SB_RDONLY;
3587         return 1;
3588     }
3589
3590     /* Check that feature set is OK for a read-write mount */
3591     if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3592         ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3593              "unsupported optional features (%x)",
3594              (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3595                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
3596         return 0;
3597     }
3598     if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3599         ext4_msg(sb, KERN_ERR,
3600              "Can't support bigalloc feature without "
3601              "extents feature\n");
3602         return 0;
3603     }
3604
3605 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3606     if (!readonly && (ext4_has_feature_quota(sb) ||
3607               ext4_has_feature_project(sb))) {
3608         ext4_msg(sb, KERN_ERR,
3609              "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3610         return 0;
3611     }
3612 #endif  /* CONFIG_QUOTA */
3613     return 1;
3614 }
3615
3616 /*
3617  * This function is called once a day if we have errors logged
3618  * on the file system
3619  */
3620 static void print_daily_error_info(struct timer_list *t)
3621 {
3622     struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3623     struct super_block *sb = sbi->s_sb;
3624     struct ext4_super_block *es = sbi->s_es;
3625
3626     if (es->s_error_count)
3627         /* fsck newer than v1.41.13 is needed to clean this condition. */
3628         ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3629              le32_to_cpu(es->s_error_count));
3630     if (es->s_first_error_time) {
3631         printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3632                sb->s_id,
3633                ext4_get_tstamp(es, s_first_error_time),
3634                (int) sizeof(es->s_first_error_func),
3635                es->s_first_error_func,
3636                le32_to_cpu(es->s_first_error_line));
3637         if (es->s_first_error_ino)
3638             printk(KERN_CONT ": inode %u",
3639                    le32_to_cpu(es->s_first_error_ino));
3640         if (es->s_first_error_block)
3641             printk(KERN_CONT ": block %llu", (unsigned long long)
3642                    le64_to_cpu(es->s_first_error_block));
3643         printk(KERN_CONT "\n");
3644     }
3645     if (es->s_last_error_time) {
3646         printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3647                sb->s_id,
3648                ext4_get_tstamp(es, s_last_error_time),
3649                (int) sizeof(es->s_last_error_func),
3650                es->s_last_error_func,
3651                le32_to_cpu(es->s_last_error_line));
3652         if (es->s_last_error_ino)
3653             printk(KERN_CONT ": inode %u",
3654                    le32_to_cpu(es->s_last_error_ino));
3655         if (es->s_last_error_block)
3656             printk(KERN_CONT ": block %llu", (unsigned long long)
3657                    le64_to_cpu(es->s_last_error_block));
3658         printk(KERN_CONT "\n");
3659     }
3660     mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3661 }
3662
3663 /* Find next suitable group and run ext4_init_inode_table */
3664 static int ext4_run_li_request(struct ext4_li_request *elr)
3665 {
3666     struct ext4_group_desc *gdp = NULL;
3667     struct super_block *sb = elr->lr_super;
3668     ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3669     ext4_group_t group = elr->lr_next_group;
3670     unsigned int prefetch_ios = 0;
3671     int ret = 0;
3672     u64 start_time;
3673
3674     if (elr->lr_mode == EXT4_LI_MODE_PREFETCH_BBITMAP) {
3675         elr->lr_next_group = ext4_mb_prefetch(sb, group,
3676                 EXT4_SB(sb)->s_mb_prefetch, &prefetch_ios);
3677         if (prefetch_ios)
3678             ext4_mb_prefetch_fini(sb, elr->lr_next_group,
3679                           prefetch_ios);
3680         trace_ext4_prefetch_bitmaps(sb, group, elr->lr_next_group,
3681                         prefetch_ios);
3682         if (group >= elr->lr_next_group) {
3683             ret = 1;
3684             if (elr->lr_first_not_zeroed != ngroups &&
3685                 !sb_rdonly(sb) && test_opt(sb, INIT_INODE_TABLE)) {
3686                 elr->lr_next_group = elr->lr_first_not_zeroed;
3687                 elr->lr_mode = EXT4_LI_MODE_ITABLE;
3688                 ret = 0;
3689             }
3690         }
3691         return ret;
3692     }
3693
3694     for (; group < ngroups; group++) {
3695         gdp = ext4_get_group_desc(sb, group, NULL);
3696         if (!gdp) {
3697             ret = 1;
3698             break;
3699         }
3700
3701         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3702             break;
3703     }
3704
3705     if (group >= ngroups)
3706         ret = 1;
3707
3708     if (!ret) {
3709         start_time = ktime_get_real_ns();
3710         ret = ext4_init_inode_table(sb, group,
3711                         elr->lr_timeout ? 0 : 1);
3712         trace_ext4_lazy_itable_init(sb, group);
3713         if (elr->lr_timeout == 0) {
3714             elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) *
3715                 EXT4_SB(elr->lr_super)->s_li_wait_mult);
3716         }
3717         elr->lr_next_sched = jiffies + elr->lr_timeout;
3718         elr->lr_next_group = group + 1;
3719     }
3720     return ret;
3721 }
3722
3723 /*
3724  * Remove lr_request from the list_request and free the
3725  * request structure. Should be called with li_list_mtx held
3726  */
3727 static void ext4_remove_li_request(struct ext4_li_request *elr)
3728 {
3729     if (!elr)
3730         return;
3731
3732     list_del(&elr->lr_request);
3733     EXT4_SB(elr->lr_super)->s_li_request = NULL;
3734     kfree(elr);
3735 }
3736
3737 static void ext4_unregister_li_request(struct super_block *sb)
3738 {
3739     mutex_lock(&ext4_li_mtx);
3740     if (!ext4_li_info) {
3741         mutex_unlock(&ext4_li_mtx);
3742         return;
3743     }
3744
3745     mutex_lock(&ext4_li_info->li_list_mtx);
3746     ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3747     mutex_unlock(&ext4_li_info->li_list_mtx);
3748     mutex_unlock(&ext4_li_mtx);
3749 }
3750
3751 static struct task_struct *ext4_lazyinit_task;
3752
3753 /*
3754  * This is the function where ext4lazyinit thread lives. It walks
3755  * through the request list searching for next scheduled filesystem.
3756  * When such a fs is found, run the lazy initialization request
3757  * (ext4_rn_li_request) and keep track of the time spend in this
3758  * function. Based on that time we compute next schedule time of
3759  * the request. When walking through the list is complete, compute
3760  * next waking time and put itself into sleep.
3761  */
3762 static int ext4_lazyinit_thread(void *arg)
3763 {
3764     struct ext4_lazy_init *eli = arg;
3765     struct list_head *pos, *n;
3766     struct ext4_li_request *elr;
3767     unsigned long next_wakeup, cur;
3768
3769     BUG_ON(NULL == eli);
3770
3771 cont_thread:
3772     while (true) {
3773         next_wakeup = MAX_JIFFY_OFFSET;
3774
3775         mutex_lock(&eli->li_list_mtx);
3776         if (list_empty(&eli->li_request_list)) {
3777             mutex_unlock(&eli->li_list_mtx);
3778             goto exit_thread;
3779         }
3780         list_for_each_safe(pos, n, &eli->li_request_list) {
3781             int err = 0;
3782             int progress = 0;
3783             elr = list_entry(pos, struct ext4_li_request,
3784                      lr_request);
3785
3786             if (time_before(jiffies, elr->lr_next_sched)) {
3787                 if (time_before(elr->lr_next_sched, next_wakeup))
3788                     next_wakeup = elr->lr_next_sched;
3789                 continue;
3790             }
3791             if (down_read_trylock(&elr->lr_super->s_umount)) {
3792                 if (sb_start_write_trylock(elr->lr_super)) {
3793                     progress = 1;
3794                     /*
3795                      * We hold sb->s_umount, sb can not
3796                      * be removed from the list, it is
3797                      * now safe to drop li_list_mtx
3798                      */
3799                     mutex_unlock(&eli->li_list_mtx);
3800                     err = ext4_run_li_request(elr);
3801                     sb_end_write(elr->lr_super);
3802                     mutex_lock(&eli->li_list_mtx);
3803                     n = pos->next;
3804                 }
3805                 up_read((&elr->lr_super->s_umount));
3806             }
3807             /* error, remove the lazy_init job */
3808             if (err) {
3809                 ext4_remove_li_request(elr);
3810                 continue;
3811             }
3812             if (!progress) {
3813                 elr->lr_next_sched = jiffies +
3814                     (prandom_u32()
3815                      % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3816             }
3817             if (time_before(elr->lr_next_sched, next_wakeup))
3818                 next_wakeup = elr->lr_next_sched;
3819         }
3820         mutex_unlock(&eli->li_list_mtx);
3821
3822         try_to_freeze();
3823
3824         cur = jiffies;
3825         if ((time_after_eq(cur, next_wakeup)) ||
3826             (MAX_JIFFY_OFFSET == next_wakeup)) {
3827             cond_resched();
3828             continue;
3829         }
3830
3831         schedule_timeout_interruptible(next_wakeup - cur);
3832
3833         if (kthread_should_stop()) {
3834             ext4_clear_request_list();
3835             goto exit_thread;
3836         }
3837     }
3838
3839 exit_thread:
3840     /*
3841      * It looks like the request list is empty, but we need
3842      * to check it under the li_list_mtx lock, to prevent any
3843      * additions into it, and of course we should lock ext4_li_mtx
3844      * to atomically free the list and ext4_li_info, because at
3845      * this point another ext4 filesystem could be registering
3846      * new one.
3847      */
3848     mutex_lock(&ext4_li_mtx);
3849     mutex_lock(&eli->li_list_mtx);
3850     if (!list_empty(&eli->li_request_list)) {
3851         mutex_unlock(&eli->li_list_mtx);
3852         mutex_unlock(&ext4_li_mtx);
3853         goto cont_thread;
3854     }
3855     mutex_unlock(&eli->li_list_mtx);
3856     kfree(ext4_li_info);
3857     ext4_li_info = NULL;
3858     mutex_unlock(&ext4_li_mtx);
3859
3860     return 0;
3861 }
3862
3863 static void ext4_clear_request_list(void)
3864 {
3865     struct list_head *pos, *n;
3866     struct ext4_li_request *elr;
3867
3868     mutex_lock(&ext4_li_info->li_list_mtx);
3869     list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3870         elr = list_entry(pos, struct ext4_li_request,
3871                  lr_request);
3872         ext4_remove_li_request(elr);
3873     }
3874     mutex_unlock(&ext4_li_info->li_list_mtx);
3875 }
3876
3877 static int ext4_run_lazyinit_thread(void)
3878 {
3879     ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3880                      ext4_li_info, "ext4lazyinit");
3881     if (IS_ERR(ext4_lazyinit_task)) {
3882         int err = PTR_ERR(ext4_lazyinit_task);
3883         ext4_clear_request_list();
3884         kfree(ext4_li_info);
3885         ext4_li_info = NULL;
3886         printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3887                  "initialization thread\n",
3888                  err);
3889         return err;
3890     }
3891     ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3892     return 0;
3893 }
3894
3895 /*
3896  * Check whether it make sense to run itable init. thread or not.
3897  * If there is at least one uninitialized inode table, return
3898  * corresponding group number, else the loop goes through all
3899  * groups and return total number of groups.
3900  */
3901 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3902 {
3903     ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3904     struct ext4_group_desc *gdp = NULL;
3905
3906     if (!ext4_has_group_desc_csum(sb))
3907         return ngroups;
3908
3909     for (group = 0; group < ngroups; group++) {
3910         gdp = ext4_get_group_desc(sb, group, NULL);
3911         if (!gdp)
3912             continue;
3913
3914         if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3915             break;
3916     }
3917
3918     return group;
3919 }
3920
3921 static int ext4_li_info_new(void)
3922 {
3923     struct ext4_lazy_init *eli = NULL;
3924
3925     eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3926     if (!eli)
3927         return -ENOMEM;
3928
3929     INIT_LIST_HEAD(&eli->li_request_list);
3930     mutex_init(&eli->li_list_mtx);
3931
3932     eli->li_state |= EXT4_LAZYINIT_QUIT;
3933
3934     ext4_li_info = eli;
3935
3936     return 0;
3937 }
3938
3939 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3940                         ext4_group_t start)
3941 {
3942     struct ext4_li_request *elr;
3943
3944     elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3945     if (!elr)
3946         return NULL;
3947
3948     elr->lr_super = sb;
3949     elr->lr_first_not_zeroed = start;
3950     if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS)) {
3951         elr->lr_mode = EXT4_LI_MODE_ITABLE;
3952         elr->lr_next_group = start;
3953     } else {
3954         elr->lr_mode = EXT4_LI_MODE_PREFETCH_BBITMAP;
3955     }
3956
3957     /*
3958      * Randomize first schedule time of the request to
3959      * spread the inode table initialization requests
3960      * better.
3961      */
3962     elr->lr_next_sched = jiffies + (prandom_u32() %
3963                 (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3964     return elr;
3965 }
3966
3967 int ext4_register_li_request(struct super_block *sb,
3968                  ext4_group_t first_not_zeroed)
3969 {
3970     struct ext4_sb_info *sbi = EXT4_SB(sb);
3971     struct ext4_li_request *elr = NULL;
3972     ext4_group_t ngroups = sbi->s_groups_count;
3973     int ret = 0;
3974
3975     mutex_lock(&ext4_li_mtx);
3976     if (sbi->s_li_request != NULL) {
3977         /*
3978          * Reset timeout so it can be computed again, because
3979          * s_li_wait_mult might have changed.
3980          */
3981         sbi->s_li_request->lr_timeout = 0;
3982         goto out;
3983     }
3984
3985     if (test_opt(sb, NO_PREFETCH_BLOCK_BITMAPS) &&
3986         (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3987          !test_opt(sb, INIT_INODE_TABLE)))
3988         goto out;
3989
3990     elr = ext4_li_request_new(sb, first_not_zeroed);
3991     if (!elr) {
3992         ret = -ENOMEM;
3993         goto out;
3994     }
3995
3996     if (NULL == ext4_li_info) {
3997         ret = ext4_li_info_new();
3998         if (ret)
3999             goto out;
4000     }
4001
4002     mutex_lock(&ext4_li_info->li_list_mtx);
4003     list_add(&elr->lr_request, &ext4_li_info->li_request_list);
4004     mutex_unlock(&ext4_li_info->li_list_mtx);
4005
4006     sbi->s_li_request = elr;
4007     /*
4008      * set elr to NULL here since it has been inserted to
4009      * the request_list and the removal and free of it is
4010      * handled by ext4_clear_request_list from now on.
4011      */
4012     elr = NULL;
4013
4014     if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
4015         ret = ext4_run_lazyinit_thread();
4016         if (ret)
4017             goto out;
4018     }
4019 out:
4020     mutex_unlock(&ext4_li_mtx);
4021     if (ret)
4022         kfree(elr);
4023     return ret;
4024 }
4025
4026 /*
4027  * We do not need to lock anything since this is called on
4028  * module unload.
4029  */
4030 static void ext4_destroy_lazyinit_thread(void)
4031 {
4032     /*
4033      * If thread exited earlier
4034      * there's nothing to be done.
4035      */
4036     if (!ext4_li_info || !ext4_lazyinit_task)
4037         return;
4038
4039     kthread_stop(ext4_lazyinit_task);
4040 }
4041
4042 static int set_journal_csum_feature_set(struct super_block *sb)
4043 {
4044     int ret = 1;
4045     int compat, incompat;
4046     struct ext4_sb_info *sbi = EXT4_SB(sb);
4047
4048     if (ext4_has_metadata_csum(sb)) {
4049         /* journal checksum v3 */
4050         compat = 0;
4051         incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
4052     } else {
4053         /* journal checksum v1 */
4054         compat = JBD2_FEATURE_COMPAT_CHECKSUM;
4055         incompat = 0;
4056     }
4057
4058     jbd2_journal_clear_features(sbi->s_journal,
4059             JBD2_FEATURE_COMPAT_CHECKSUM, 0,
4060             JBD2_FEATURE_INCOMPAT_CSUM_V3 |
4061             JBD2_FEATURE_INCOMPAT_CSUM_V2);
4062     if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4063         ret = jbd2_journal_set_features(sbi->s_journal,
4064                 compat, 0,
4065                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
4066                 incompat);
4067     } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
4068         ret = jbd2_journal_set_features(sbi->s_journal,
4069                 compat, 0,
4070                 incompat);
4071         jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4072                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4073     } else {
4074         jbd2_journal_clear_features(sbi->s_journal, 0, 0,
4075                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
4076     }
4077
4078     return ret;
4079 }
4080
4081 /*
4082  * Note: calculating the overhead so we can be compatible with
4083  * historical BSD practice is quite difficult in the face of
4084  * clusters/bigalloc.  This is because multiple metadata blocks from
4085  * different block group can end up in the same allocation cluster.
4086  * Calculating the exact overhead in the face of clustered allocation
4087  * requires either O(all block bitmaps) in memory or O(number of block
4088  * groups**2) in time.  We will still calculate the superblock for
4089  * older file systems --- and if we come across with a bigalloc file
4090  * system with zero in s_overhead_clusters the estimate will be close to
4091  * correct especially for very large cluster sizes --- but for newer
4092  * file systems, it's better to calculate this figure once at mkfs
4093  * time, and store it in the superblock.  If the superblock value is
4094  * present (even for non-bigalloc file systems), we will use it.
4095  */
4096 static int count_overhead(struct super_block *sb, ext4_group_t grp,
4097               char *buf)
4098 {
4099     struct ext4_sb_info *sbi = EXT4_SB(sb);
4100     struct ext4_group_desc  *gdp;
4101     ext4_fsblk_t        first_block, last_block, b;
4102     ext4_group_t        i, ngroups = ext4_get_groups_count(sb);
4103     int         s, j, count = 0;
4104     int         has_super = ext4_bg_has_super(sb, grp);
4105
4106     if (!ext4_has_feature_bigalloc(sb))
4107         return (has_super + ext4_bg_num_gdb(sb, grp) +
4108             (has_super ? le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0) +
4109             sbi->s_itb_per_group + 2);
4110
4111     first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
4112         (grp * EXT4_BLOCKS_PER_GROUP(sb));
4113     last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
4114     for (i = 0; i < ngroups; i++) {
4115         gdp = ext4_get_group_desc(sb, i, NULL);
4116         b = ext4_block_bitmap(sb, gdp);
4117         if (b >= first_block && b <= last_block) {
4118             ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4119             count++;
4120         }
4121         b = ext4_inode_bitmap(sb, gdp);
4122         if (b >= first_block && b <= last_block) {
4123             ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
4124             count++;
4125         }
4126         b = ext4_inode_table(sb, gdp);
4127         if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
4128             for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
4129                 int c = EXT4_B2C(sbi, b - first_block);
4130                 ext4_set_bit(c, buf);
4131                 count++;
4132             }
4133         if (i != grp)
4134             continue;
4135         s = 0;
4136         if (ext4_bg_has_super(sb, grp)) {
4137             ext4_set_bit(s++, buf);
4138             count++;
4139         }
4140         j = ext4_bg_num_gdb(sb, grp);
4141         if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
4142             ext4_error(sb, "Invalid number of block group "
4143                    "descriptor blocks: %d", j);
4144             j = EXT4_BLOCKS_PER_GROUP(sb) - s;
4145         }
4146         count += j;
4147         for (; j > 0; j--)
4148             ext4_set_bit(EXT4_B2C(sbi, s++), buf);
4149     }
4150     if (!count)
4151         return 0;
4152     return EXT4_CLUSTERS_PER_GROUP(sb) -
4153         ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
4154 }
4155
4156 /*
4157  * Compute the overhead and stash it in sbi->s_overhead
4158  */
4159 int ext4_calculate_overhead(struct super_block *sb)
4160 {
4161     struct ext4_sb_info *sbi = EXT4_SB(sb);
4162     struct ext4_super_block *es = sbi->s_es;
4163     struct inode *j_inode;
4164     unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
4165     ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4166     ext4_fsblk_t overhead = 0;
4167     char *buf = (char *) get_zeroed_page(GFP_NOFS);
4168
4169     if (!buf)
4170         return -ENOMEM;
4171
4172     /*
4173      * Compute the overhead (FS structures).  This is constant
4174      * for a given filesystem unless the number of block groups
4175      * changes so we cache the previous value until it does.
4176      */
4177
4178     /*
4179      * All of the blocks before first_data_block are overhead
4180      */
4181     overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4182
4183     /*
4184      * Add the overhead found in each block group
4185      */
4186     for (i = 0; i < ngroups; i++) {
4187         int blks;
4188
4189         blks = count_overhead(sb, i, buf);
4190         overhead += blks;
4191         if (blks)
4192             memset(buf, 0, PAGE_SIZE);
4193         cond_resched();
4194     }
4195
4196     /*
4197      * Add the internal journal blocks whether the journal has been
4198      * loaded or not
4199      */
4200     if (sbi->s_journal && !sbi->s_journal_bdev)
4201         overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
4202     else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
4203         /* j_inum for internal journal is non-zero */
4204         j_inode = ext4_get_journal_inode(sb, j_inum);
4205         if (j_inode) {
4206             j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
4207             overhead += EXT4_NUM_B2C(sbi, j_blocks);
4208             iput(j_inode);
4209         } else {
4210             ext4_msg(sb, KERN_ERR, "can't get journal size");
4211         }
4212     }
4213     sbi->s_overhead = overhead;
4214     smp_wmb();
4215     free_page((unsigned long) buf);
4216     return 0;
4217 }
4218
4219 static void ext4_set_resv_clusters(struct super_block *sb)
4220 {
4221     ext4_fsblk_t resv_clusters;
4222     struct ext4_sb_info *sbi = EXT4_SB(sb);
4223
4224     /*
4225      * There's no need to reserve anything when we aren't using extents.
4226      * The space estimates are exact, there are no unwritten extents,
4227      * hole punching doesn't need new metadata... This is needed especially
4228      * to keep ext2/3 backward compatibility.
4229      */
4230     if (!ext4_has_feature_extents(sb))
4231         return;
4232     /*
4233      * By default we reserve 2% or 4096 clusters, whichever is smaller.
4234      * This should cover the situations where we can not afford to run
4235      * out of space like for example punch hole, or converting
4236      * unwritten extents in delalloc path. In most cases such
4237      * allocation would require 1, or 2 blocks, higher numbers are
4238      * very rare.
4239      */
4240     resv_clusters = (ext4_blocks_count(sbi->s_es) >>
4241              sbi->s_cluster_bits);
4242
4243     do_div(resv_clusters, 50);
4244     resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
4245
4246     atomic64_set(&sbi->s_resv_clusters, resv_clusters);
4247 }
4248
4249 static const char *ext4_quota_mode(struct super_block *sb)
4250 {
4251 #ifdef CONFIG_QUOTA
4252     if (!ext4_quota_capable(sb))
4253         return "none";
4254
4255     if (EXT4_SB(sb)->s_journal && ext4_is_quota_journalled(sb))
4256         return "journalled";
4257     else
4258         return "writeback";
4259 #else
4260     return "disabled";
4261 #endif
4262 }
4263
4264 static void ext4_setup_csum_trigger(struct super_block *sb,
4265                     enum ext4_journal_trigger_type type,
4266                     void (*trigger)(
4267                     struct jbd2_buffer_trigger_type *type,
4268                     struct buffer_head *bh,
4269                     void *mapped_data,
4270                     size_t size))
4271 {
4272     struct ext4_sb_info *sbi = EXT4_SB(sb);
4273
4274     sbi->s_journal_triggers[type].sb = sb;
4275     sbi->s_journal_triggers[type].tr_triggers.t_frozen = trigger;
4276 }
4277
4278 static void ext4_free_sbi(struct ext4_sb_info *sbi)
4279 {
4280     if (!sbi)
4281         return;
4282
4283     kfree(sbi->s_blockgroup_lock);
4284     fs_put_dax(sbi->s_daxdev, NULL);
4285     kfree(sbi);
4286 }
4287
4288 static struct ext4_sb_info *ext4_alloc_sbi(struct super_block *sb)
4289 {
4290     struct ext4_sb_info *sbi;
4291
4292     sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
4293     if (!sbi)
4294         return NULL;
4295
4296     sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,
4297                        NULL, NULL);
4298
4299     sbi->s_blockgroup_lock =
4300         kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
4301
4302     if (!sbi->s_blockgroup_lock)
4303         goto err_out;
4304
4305     sb->s_fs_info = sbi;
4306     sbi->s_sb = sb;
4307     return sbi;
4308 err_out:
4309     fs_put_dax(sbi->s_daxdev, NULL);
4310     kfree(sbi);
4311     return NULL;
4312 }
4313
4314 static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
4315 {
4316     struct buffer_head *bh, **group_desc;
4317     struct ext4_super_block *es = NULL;
4318     struct ext4_sb_info *sbi = EXT4_SB(sb);
4319     struct flex_groups **flex_groups;
4320     ext4_fsblk_t block;
4321     ext4_fsblk_t logical_sb_block;
4322     unsigned long offset = 0;
4323     unsigned long def_mount_opts;
4324     struct inode *root;
4325     int ret = -ENOMEM;
4326     int blocksize, clustersize;
4327     unsigned int db_count;
4328     unsigned int i;
4329     int needs_recovery, has_huge_files;
4330     __u64 blocks_count;
4331     int err = 0;
4332     ext4_group_t first_not_zeroed;
4333     struct ext4_fs_context *ctx = fc->fs_private;
4334     int silent = fc->sb_flags & SB_SILENT;
4335
4336     /* Set defaults for the variables that will be set during parsing */
4337     if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO))
4338         ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4339
4340     sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
4341     sbi->s_sectors_written_start =
4342         part_stat_read(sb->s_bdev, sectors[STAT_WRITE]);
4343
4344     /* -EINVAL is default */
4345     ret = -EINVAL;
4346     blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
4347     if (!blocksize) {
4348         ext4_msg(sb, KERN_ERR, "unable to set blocksize");
4349         goto out_fail;
4350     }
4351
4352     /*
4353      * The ext4 superblock will not be buffer aligned for other than 1kB
4354      * block sizes.  We need to calculate the offset from buffer start.
4355      */
4356     if (blocksize != EXT4_MIN_BLOCK_SIZE) {
4357         logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4358         offset = do_div(logical_sb_block, blocksize);
4359     } else {
4360         logical_sb_block = sbi->s_sb_block;
4361     }
4362
4363     bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4364     if (IS_ERR(bh)) {
4365         ext4_msg(sb, KERN_ERR, "unable to read superblock");
4366         ret = PTR_ERR(bh);
4367         goto out_fail;
4368     }
4369     /*
4370      * Note: s_es must be initialized as soon as possible because
4371      *       some ext4 macro-instructions depend on its value
4372      */
4373     es = (struct ext4_super_block *) (bh->b_data + offset);
4374     sbi->s_es = es;
4375     sb->s_magic = le16_to_cpu(es->s_magic);
4376     if (sb->s_magic != EXT4_SUPER_MAGIC)
4377         goto cantfind_ext4;
4378     sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
4379
4380     /* Warn if metadata_csum and gdt_csum are both set. */
4381     if (ext4_has_feature_metadata_csum(sb) &&
4382         ext4_has_feature_gdt_csum(sb))
4383         ext4_warning(sb, "metadata_csum and uninit_bg are "
4384                  "redundant flags; please run fsck.");
4385
4386     /* Check for a known checksum algorithm */
4387     if (!ext4_verify_csum_type(sb, es)) {
4388         ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4389              "unknown checksum algorithm.");
4390         silent = 1;
4391         goto cantfind_ext4;
4392     }
4393     ext4_setup_csum_trigger(sb, EXT4_JTR_ORPHAN_FILE,
4394                 ext4_orphan_file_block_trigger);
4395
4396     /* Load the checksum driver */
4397     sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
4398     if (IS_ERR(sbi->s_chksum_driver)) {
4399         ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
4400         ret = PTR_ERR(sbi->s_chksum_driver);
4401         sbi->s_chksum_driver = NULL;
4402         goto failed_mount;
4403     }
4404
4405     /* Check superblock checksum */
4406     if (!ext4_superblock_csum_verify(sb, es)) {
4407         ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
4408              "invalid superblock checksum.  Run e2fsck?");
4409         silent = 1;
4410         ret = -EFSBADCRC;
4411         goto cantfind_ext4;
4412     }
4413
4414     /* Precompute checksum seed for all metadata */
4415     if (ext4_has_feature_csum_seed(sb))
4416         sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
4417     else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
4418         sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
4419                            sizeof(es->s_uuid));
4420
4421     /* Set defaults before we parse the mount options */
4422     def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
4423     set_opt(sb, INIT_INODE_TABLE);
4424     if (def_mount_opts & EXT4_DEFM_DEBUG)
4425         set_opt(sb, DEBUG);
4426     if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
4427         set_opt(sb, GRPID);
4428     if (def_mount_opts & EXT4_DEFM_UID16)
4429         set_opt(sb, NO_UID32);
4430     /* xattr user namespace & acls are now defaulted on */
4431     set_opt(sb, XATTR_USER);
4432 #ifdef CONFIG_EXT4_FS_POSIX_ACL
4433     set_opt(sb, POSIX_ACL);
4434 #endif
4435     if (ext4_has_feature_fast_commit(sb))
4436         set_opt2(sb, JOURNAL_FAST_COMMIT);
4437     /* don't forget to enable journal_csum when metadata_csum is enabled. */
4438     if (ext4_has_metadata_csum(sb))
4439         set_opt(sb, JOURNAL_CHECKSUM);
4440
4441     if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
4442         set_opt(sb, JOURNAL_DATA);
4443     else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
4444         set_opt(sb, ORDERED_DATA);
4445     else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
4446         set_opt(sb, WRITEBACK_DATA);
4447
4448     if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
4449         set_opt(sb, ERRORS_PANIC);
4450     else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
4451         set_opt(sb, ERRORS_CONT);
4452     else
4453         set_opt(sb, ERRORS_RO);
4454     /* block_validity enabled by default; disable with noblock_validity */
4455     set_opt(sb, BLOCK_VALIDITY);
4456     if (def_mount_opts & EXT4_DEFM_DISCARD)
4457         set_opt(sb, DISCARD);
4458
4459     sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
4460     sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
4461     sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
4462     sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
4463     sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
4464
4465     if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
4466         set_opt(sb, BARRIER);
4467
4468     /*
4469      * enable delayed allocation by default
4470      * Use -o nodelalloc to turn it off
4471      */
4472     if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
4473         ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
4474         set_opt(sb, DELALLOC);
4475
4476     /*
4477      * set default s_li_wait_mult for lazyinit, for the case there is
4478      * no mount option specified.
4479      */
4480     sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
4481
4482     if (le32_to_cpu(es->s_log_block_size) >
4483         (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4484         ext4_msg(sb, KERN_ERR,
4485              "Invalid log block size: %u",
4486              le32_to_cpu(es->s_log_block_size));
4487         goto failed_mount;
4488     }
4489     if (le32_to_cpu(es->s_log_cluster_size) >
4490         (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4491         ext4_msg(sb, KERN_ERR,
4492              "Invalid log cluster size: %u",
4493              le32_to_cpu(es->s_log_cluster_size));
4494         goto failed_mount;
4495     }
4496
4497     blocksize = EXT4_MIN_BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
4498
4499     if (blocksize == PAGE_SIZE)
4500         set_opt(sb, DIOREAD_NOLOCK);
4501
4502     if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4503         sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4504         sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4505     } else {
4506         sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4507         sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4508         if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4509             ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4510                  sbi->s_first_ino);
4511             goto failed_mount;
4512         }
4513         if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4514             (!is_power_of_2(sbi->s_inode_size)) ||
4515             (sbi->s_inode_size > blocksize)) {
4516             ext4_msg(sb, KERN_ERR,
4517                    "unsupported inode size: %d",
4518                    sbi->s_inode_size);
4519             ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
4520             goto failed_mount;
4521         }
4522         /*
4523          * i_atime_extra is the last extra field available for
4524          * [acm]times in struct ext4_inode. Checking for that
4525          * field should suffice to ensure we have extra space
4526          * for all three.
4527          */
4528         if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4529             sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4530             sb->s_time_gran = 1;
4531             sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4532         } else {
4533             sb->s_time_gran = NSEC_PER_SEC;
4534             sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4535         }
4536         sb->s_time_min = EXT4_TIMESTAMP_MIN;
4537     }
4538     if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
4539         sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4540             EXT4_GOOD_OLD_INODE_SIZE;
4541         if (ext4_has_feature_extra_isize(sb)) {
4542             unsigned v, max = (sbi->s_inode_size -
4543                        EXT4_GOOD_OLD_INODE_SIZE);
4544
4545             v = le16_to_cpu(es->s_want_extra_isize);
4546             if (v > max) {
4547                 ext4_msg(sb, KERN_ERR,
4548                      "bad s_want_extra_isize: %d", v);
4549                 goto failed_mount;
4550             }
4551             if (sbi->s_want_extra_isize < v)
4552                 sbi->s_want_extra_isize = v;
4553
4554             v = le16_to_cpu(es->s_min_extra_isize);
4555             if (v > max) {
4556                 ext4_msg(sb, KERN_ERR,
4557                      "bad s_min_extra_isize: %d", v);
4558                 goto failed_mount;
4559             }
4560             if (sbi->s_want_extra_isize < v)
4561                 sbi->s_want_extra_isize = v;
4562         }
4563     }
4564
4565     err = parse_apply_sb_mount_options(sb, ctx);
4566     if (err < 0)
4567         goto failed_mount;
4568
4569     sbi->s_def_mount_opt = sbi->s_mount_opt;
4570
4571     err = ext4_check_opt_consistency(fc, sb);
4572     if (err < 0)
4573         goto failed_mount;
4574
4575     ext4_apply_options(fc, sb);
4576
4577 #if IS_ENABLED(CONFIG_UNICODE)
4578     if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
4579         const struct ext4_sb_encodings *encoding_info;
4580         struct unicode_map *encoding;
4581         __u16 encoding_flags = le16_to_cpu(es->s_encoding_flags);
4582
4583         encoding_info = ext4_sb_read_encoding(es);
4584         if (!encoding_info) {
4585             ext4_msg(sb, KERN_ERR,
4586                  "Encoding requested by superblock is unknown");
4587             goto failed_mount;
4588         }
4589
4590         encoding = utf8_load(encoding_info->version);
4591         if (IS_ERR(encoding)) {
4592             ext4_msg(sb, KERN_ERR,
4593                  "can't mount with superblock charset: %s-%u.%u.%u "
4594                  "not supported by the kernel. flags: 0x%x.",
4595                  encoding_info->name,
4596                  unicode_major(encoding_info->version),
4597                  unicode_minor(encoding_info->version),
4598                  unicode_rev(encoding_info->version),
4599                  encoding_flags);
4600             goto failed_mount;
4601         }
4602         ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
4603              "%s-%u.%u.%u with flags 0x%hx", encoding_info->name,
4604              unicode_major(encoding_info->version),
4605              unicode_minor(encoding_info->version),
4606              unicode_rev(encoding_info->version),
4607              encoding_flags);
4608
4609         sb->s_encoding = encoding;
4610         sb->s_encoding_flags = encoding_flags;
4611     }
4612 #endif
4613
4614     if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4615         printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
4616         /* can't mount with both data=journal and dioread_nolock. */
4617         clear_opt(sb, DIOREAD_NOLOCK);
4618         clear_opt2(sb, JOURNAL_FAST_COMMIT);
4619         if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4620             ext4_msg(sb, KERN_ERR, "can't mount with "
4621                  "both data=journal and delalloc");
4622             goto failed_mount;
4623         }
4624         if (test_opt(sb, DAX_ALWAYS)) {
4625             ext4_msg(sb, KERN_ERR, "can't mount with "
4626                  "both data=journal and dax");
4627             goto failed_mount;
4628         }
4629         if (ext4_has_feature_encrypt(sb)) {
4630             ext4_msg(sb, KERN_WARNING,
4631                  "encrypted files will use data=ordered "
4632                  "instead of data journaling mode");
4633         }
4634         if (test_opt(sb, DELALLOC))
4635             clear_opt(sb, DELALLOC);
4636     } else {
4637         sb->s_iflags |= SB_I_CGROUPWB;
4638     }
4639
4640     sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
4641         (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
4642
4643     if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
4644         (ext4_has_compat_features(sb) ||
4645          ext4_has_ro_compat_features(sb) ||
4646          ext4_has_incompat_features(sb)))
4647         ext4_msg(sb, KERN_WARNING,
4648                "feature flags set on rev 0 fs, "
4649                "running e2fsck is recommended");
4650
4651     if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4652         set_opt2(sb, HURD_COMPAT);
4653         if (ext4_has_feature_64bit(sb)) {
4654             ext4_msg(sb, KERN_ERR,
4655                  "The Hurd can't support 64-bit file systems");
4656             goto failed_mount;
4657         }
4658
4659         /*
4660          * ea_inode feature uses l_i_version field which is not
4661          * available in HURD_COMPAT mode.
4662          */
4663         if (ext4_has_feature_ea_inode(sb)) {
4664             ext4_msg(sb, KERN_ERR,
4665                  "ea_inode feature is not supported for Hurd");
4666             goto failed_mount;
4667         }
4668     }
4669
4670     if (IS_EXT2_SB(sb)) {
4671         if (ext2_feature_set_ok(sb))
4672             ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4673                  "using the ext4 subsystem");
4674         else {
4675             /*
4676              * If we're probing be silent, if this looks like
4677              * it's actually an ext[34] filesystem.
4678              */
4679             if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4680                 goto failed_mount;
4681             ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4682                  "to feature incompatibilities");
4683             goto failed_mount;
4684         }
4685     }
4686
4687     if (IS_EXT3_SB(sb)) {
4688         if (ext3_feature_set_ok(sb))
4689             ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4690                  "using the ext4 subsystem");
4691         else {
4692             /*
4693              * If we're probing be silent, if this looks like
4694              * it's actually an ext4 filesystem.
4695              */
4696             if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4697                 goto failed_mount;
4698             ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4699                  "to feature incompatibilities");
4700             goto failed_mount;
4701         }
4702     }
4703
4704     /*
4705      * Check feature flags regardless of the revision level, since we
4706      * previously didn't change the revision level when setting the flags,
4707      * so there is a chance incompat flags are set on a rev 0 filesystem.
4708      */
4709     if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4710         goto failed_mount;
4711
4712     if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4713         ext4_msg(sb, KERN_ERR,
4714              "Number of reserved GDT blocks insanely large: %d",
4715              le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4716         goto failed_mount;
4717     }
4718
4719     if (sbi->s_daxdev) {
4720         if (blocksize == PAGE_SIZE)
4721             set_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags);
4722         else
4723             ext4_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");
4724     }
4725
4726     if (sbi->s_mount_opt & EXT4_MOUNT_DAX_ALWAYS) {
4727         if (ext4_has_feature_inline_data(sb)) {
4728             ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4729                     " that may contain inline data");
4730             goto failed_mount;
4731         }
4732         if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags)) {
4733             ext4_msg(sb, KERN_ERR,
4734                 "DAX unsupported by block device.");
4735             goto failed_mount;
4736         }
4737     }
4738
4739     if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4740         ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4741              es->s_encryption_level);
4742         goto failed_mount;
4743     }
4744
4745     if (sb->s_blocksize != blocksize) {
4746         /*
4747          * bh must be released before kill_bdev(), otherwise
4748          * it won't be freed and its page also. kill_bdev()
4749          * is called by sb_set_blocksize().
4750          */
4751         brelse(bh);
4752         /* Validate the filesystem blocksize */
4753         if (!sb_set_blocksize(sb, blocksize)) {
4754             ext4_msg(sb, KERN_ERR, "bad block size %d",
4755                     blocksize);
4756             bh = NULL;
4757             goto failed_mount;
4758         }
4759
4760         logical_sb_block = sbi->s_sb_block * EXT4_MIN_BLOCK_SIZE;
4761         offset = do_div(logical_sb_block, blocksize);
4762         bh = ext4_sb_bread_unmovable(sb, logical_sb_block);
4763         if (IS_ERR(bh)) {
4764             ext4_msg(sb, KERN_ERR,
4765                    "Can't read superblock on 2nd try");
4766             ret = PTR_ERR(bh);
4767             bh = NULL;
4768             goto failed_mount;
4769         }
4770         es = (struct ext4_super_block *)(bh->b_data + offset);
4771         sbi->s_es = es;
4772         if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4773             ext4_msg(sb, KERN_ERR,
4774                    "Magic mismatch, very weird!");
4775             goto failed_mount;
4776         }
4777     }
4778
4779     has_huge_files = ext4_has_feature_huge_file(sb);
4780     sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4781                               has_huge_files);
4782     sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4783
4784     sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4785     if (ext4_has_feature_64bit(sb)) {
4786         if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4787             sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4788             !is_power_of_2(sbi->s_desc_size)) {
4789             ext4_msg(sb, KERN_ERR,
4790                    "unsupported descriptor size %lu",
4791                    sbi->s_desc_size);
4792             goto failed_mount;
4793         }
4794     } else
4795         sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4796
4797     sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4798     sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4799
4800     sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4801     if (sbi->s_inodes_per_block == 0)
4802         goto cantfind_ext4;
4803     if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4804         sbi->s_inodes_per_group > blocksize * 8) {
4805         ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4806              sbi->s_inodes_per_group);
4807         goto failed_mount;
4808     }
4809     sbi->s_itb_per_group = sbi->s_inodes_per_group /
4810                     sbi->s_inodes_per_block;
4811     sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4812     sbi->s_sbh = bh;
4813     sbi->s_mount_state = le16_to_cpu(es->s_state) & ~EXT4_FC_REPLAY;
4814     sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4815     sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4816
4817     for (i = 0; i < 4; i++)
4818         sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4819     sbi->s_def_hash_version = es->s_def_hash_version;
4820     if (ext4_has_feature_dir_index(sb)) {
4821         i = le32_to_cpu(es->s_flags);
4822         if (i & EXT2_FLAGS_UNSIGNED_HASH)
4823             sbi->s_hash_unsigned = 3;
4824         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4825 #ifdef __CHAR_UNSIGNED__
4826             if (!sb_rdonly(sb))
4827                 es->s_flags |=
4828                     cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4829             sbi->s_hash_unsigned = 3;
4830 #else
4831             if (!sb_rdonly(sb))
4832                 es->s_flags |=
4833                     cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4834 #endif
4835         }
4836     }
4837
4838     /* Handle clustersize */
4839     clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4840     if (ext4_has_feature_bigalloc(sb)) {
4841         if (clustersize < blocksize) {
4842             ext4_msg(sb, KERN_ERR,
4843                  "cluster size (%d) smaller than "
4844                  "block size (%d)", clustersize, blocksize);
4845             goto failed_mount;
4846         }
4847         sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4848             le32_to_cpu(es->s_log_block_size);
4849         sbi->s_clusters_per_group =
4850             le32_to_cpu(es->s_clusters_per_group);
4851         if (sbi->s_clusters_per_group > blocksize * 8) {
4852             ext4_msg(sb, KERN_ERR,
4853                  "#clusters per group too big: %lu",
4854                  sbi->s_clusters_per_group);
4855             goto failed_mount;
4856         }
4857         if (sbi->s_blocks_per_group !=
4858             (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4859             ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4860                  "clusters per group (%lu) inconsistent",
4861                  sbi->s_blocks_per_group,
4862                  sbi->s_clusters_per_group);
4863             goto failed_mount;
4864         }
4865     } else {
4866         if (clustersize != blocksize) {
4867             ext4_msg(sb, KERN_ERR,
4868                  "fragment/cluster size (%d) != "
4869                  "block size (%d)", clustersize, blocksize);
4870             goto failed_mount;
4871         }
4872         if (sbi->s_blocks_per_group > blocksize * 8) {
4873             ext4_msg(sb, KERN_ERR,
4874                  "#blocks per group too big: %lu",
4875                  sbi->s_blocks_per_group);
4876             goto failed_mount;
4877         }
4878         sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4879         sbi->s_cluster_bits = 0;
4880     }
4881     sbi->s_cluster_ratio = clustersize / blocksize;
4882
4883     /* Do we have standard group size of clustersize * 8 blocks ? */
4884     if (sbi->s_blocks_per_group == clustersize << 3)
4885         set_opt2(sb, STD_GROUP_SIZE);
4886
4887     /*
4888      * Test whether we have more sectors than will fit in sector_t,
4889      * and whether the max offset is addressable by the page cache.
4890      */
4891     err = generic_check_addressable(sb->s_blocksize_bits,
4892                     ext4_blocks_count(es));
4893     if (err) {
4894         ext4_msg(sb, KERN_ERR, "filesystem"
4895              " too large to mount safely on this system");
4896         goto failed_mount;
4897     }
4898
4899     if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4900         goto cantfind_ext4;
4901
4902     /* check blocks count against device size */
4903     blocks_count = sb_bdev_nr_blocks(sb);
4904     if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4905         ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4906                "exceeds size of device (%llu blocks)",
4907                ext4_blocks_count(es), blocks_count);
4908         goto failed_mount;
4909     }
4910
4911     /*
4912      * It makes no sense for the first data block to be beyond the end
4913      * of the filesystem.
4914      */
4915     if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4916         ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4917              "block %u is beyond end of filesystem (%llu)",
4918              le32_to_cpu(es->s_first_data_block),
4919              ext4_blocks_count(es));
4920         goto failed_mount;
4921     }
4922     if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4923         (sbi->s_cluster_ratio == 1)) {
4924         ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4925              "block is 0 with a 1k block and cluster size");
4926         goto failed_mount;
4927     }
4928
4929     blocks_count = (ext4_blocks_count(es) -
4930             le32_to_cpu(es->s_first_data_block) +
4931             EXT4_BLOCKS_PER_GROUP(sb) - 1);
4932     do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4933     if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4934         ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
4935                "(block count %llu, first data block %u, "
4936                "blocks per group %lu)", blocks_count,
4937                ext4_blocks_count(es),
4938                le32_to_cpu(es->s_first_data_block),
4939                EXT4_BLOCKS_PER_GROUP(sb));
4940         goto failed_mount;
4941     }
4942     sbi->s_groups_count = blocks_count;
4943     sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4944             (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4945     if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4946         le32_to_cpu(es->s_inodes_count)) {
4947         ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4948              le32_to_cpu(es->s_inodes_count),
4949              ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4950         ret = -EINVAL;
4951         goto failed_mount;
4952     }
4953     db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4954            EXT4_DESC_PER_BLOCK(sb);
4955     if (ext4_has_feature_meta_bg(sb)) {
4956         if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4957             ext4_msg(sb, KERN_WARNING,
4958                  "first meta block group too large: %u "
4959                  "(group descriptor block count %u)",
4960                  le32_to_cpu(es->s_first_meta_bg), db_count);
4961             goto failed_mount;
4962         }
4963     }
4964     rcu_assign_pointer(sbi->s_group_desc,
4965                kvmalloc_array(db_count,
4966                       sizeof(struct buffer_head *),
4967                       GFP_KERNEL));
4968     if (sbi->s_group_desc == NULL) {
4969         ext4_msg(sb, KERN_ERR, "not enough memory");
4970         ret = -ENOMEM;
4971         goto failed_mount;
4972     }
4973
4974     bgl_lock_init(sbi->s_blockgroup_lock);
4975
4976     /* Pre-read the descriptors into the buffer cache */
4977     for (i = 0; i < db_count; i++) {
4978         block = descriptor_loc(sb, logical_sb_block, i);
4979         ext4_sb_breadahead_unmovable(sb, block);
4980     }
4981
4982     for (i = 0; i < db_count; i++) {
4983         struct buffer_head *bh;
4984
4985         block = descriptor_loc(sb, logical_sb_block, i);
4986         bh = ext4_sb_bread_unmovable(sb, block);
4987         if (IS_ERR(bh)) {
4988             ext4_msg(sb, KERN_ERR,
4989                    "can't read group descriptor %d", i);
4990             db_count = i;
4991             ret = PTR_ERR(bh);
4992             goto failed_mount2;
4993         }
4994         rcu_read_lock();
4995         rcu_dereference(sbi->s_group_desc)[i] = bh;
4996         rcu_read_unlock();
4997     }
4998     sbi->s_gdb_count = db_count;
4999     if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
5000         ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
5001         ret = -EFSCORRUPTED;
5002         goto failed_mount2;
5003     }
5004
5005     timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
5006     spin_lock_init(&sbi->s_error_lock);
5007     INIT_WORK(&sbi->s_error_work, flush_stashed_error_work);
5008
5009     /* Register extent status tree shrinker */
5010     if (ext4_es_register_shrinker(sbi))
5011         goto failed_mount3;
5012
5013     sbi->s_stripe = ext4_get_stripe_size(sbi);
5014     sbi->s_extent_max_zeroout_kb = 32;
5015
5016     /*
5017      * set up enough so that it can read an inode
5018      */
5019     sb->s_op = &ext4_sops;
5020     sb->s_export_op = &ext4_export_ops;
5021     sb->s_xattr = ext4_xattr_handlers;
5022 #ifdef CONFIG_FS_ENCRYPTION
5023     sb->s_cop = &ext4_cryptops;
5024 #endif
5025 #ifdef CONFIG_FS_VERITY
5026     sb->s_vop = &ext4_verityops;
5027 #endif
5028 #ifdef CONFIG_QUOTA
5029     sb->dq_op = &ext4_quota_operations;
5030     if (ext4_has_feature_quota(sb))
5031         sb->s_qcop = &dquot_quotactl_sysfile_ops;
5032     else
5033         sb->s_qcop = &ext4_qctl_operations;
5034     sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
5035 #endif
5036     memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
5037
5038     INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
5039     mutex_init(&sbi->s_orphan_lock);
5040
5041     /* Initialize fast commit stuff */
5042     atomic_set(&sbi->s_fc_subtid, 0);
5043     INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_MAIN]);
5044     INIT_LIST_HEAD(&sbi->s_fc_q[FC_Q_STAGING]);
5045     INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
5046     INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
5047     sbi->s_fc_bytes = 0;
5048     ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
5049     sbi->s_fc_ineligible_tid = 0;
5050     spin_lock_init(&sbi->s_fc_lock);
5051     memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
5052     sbi->s_fc_replay_state.fc_regions = NULL;
5053     sbi->s_fc_replay_state.fc_regions_size = 0;
5054     sbi->s_fc_replay_state.fc_regions_used = 0;
5055     sbi->s_fc_replay_state.fc_regions_valid = 0;
5056     sbi->s_fc_replay_state.fc_modified_inodes = NULL;
5057     sbi->s_fc_replay_state.fc_modified_inodes_size = 0;
5058     sbi->s_fc_replay_state.fc_modified_inodes_used = 0;
5059
5060     sb->s_root = NULL;
5061
5062     needs_recovery = (es->s_last_orphan != 0 ||
5063               ext4_has_feature_orphan_present(sb) ||
5064               ext4_has_feature_journal_needs_recovery(sb));
5065
5066     if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
5067         if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
5068             goto failed_mount3a;
5069
5070     /*
5071      * The first inode we look at is the journal inode.  Don't try
5072      * root first: it may be modified in the journal!
5073      */
5074     if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
5075         err = ext4_load_journal(sb, es, ctx->journal_devnum);
5076         if (err)
5077             goto failed_mount3a;
5078     } else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
5079            ext4_has_feature_journal_needs_recovery(sb)) {
5080         ext4_msg(sb, KERN_ERR, "required journal recovery "
5081                "suppressed and not mounted read-only");
5082         goto failed_mount_wq;
5083     } else {
5084         /* Nojournal mode, all journal mount options are illegal */
5085         if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
5086             ext4_msg(sb, KERN_ERR, "can't mount with "
5087                  "journal_checksum, fs mounted w/o journal");
5088             goto failed_mount_wq;
5089         }
5090         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5091             ext4_msg(sb, KERN_ERR, "can't mount with "
5092                  "journal_async_commit, fs mounted w/o journal");
5093             goto failed_mount_wq;
5094         }
5095         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
5096             ext4_msg(sb, KERN_ERR, "can't mount with "
5097                  "commit=%lu, fs mounted w/o journal",
5098                  sbi->s_commit_interval / HZ);
5099             goto failed_mount_wq;
5100         }
5101         if (EXT4_MOUNT_DATA_FLAGS &
5102             (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
5103             ext4_msg(sb, KERN_ERR, "can't mount with "
5104                  "data=, fs mounted w/o journal");
5105             goto failed_mount_wq;
5106         }
5107         sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
5108         clear_opt(sb, JOURNAL_CHECKSUM);
5109         clear_opt(sb, DATA_FLAGS);
5110         clear_opt2(sb, JOURNAL_FAST_COMMIT);
5111         sbi->s_journal = NULL;
5112         needs_recovery = 0;
5113         goto no_journal;
5114     }
5115
5116     if (ext4_has_feature_64bit(sb) &&
5117         !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5118                        JBD2_FEATURE_INCOMPAT_64BIT)) {
5119         ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
5120         goto failed_mount_wq;
5121     }
5122
5123     if (!set_journal_csum_feature_set(sb)) {
5124         ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
5125              "feature set");
5126         goto failed_mount_wq;
5127     }
5128
5129     if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
5130         !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
5131                       JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
5132         ext4_msg(sb, KERN_ERR,
5133             "Failed to set fast commit journal feature");
5134         goto failed_mount_wq;
5135     }
5136
5137     /* We have now updated the journal if required, so we can
5138      * validate the data journaling mode. */
5139     switch (test_opt(sb, DATA_FLAGS)) {
5140     case 0:
5141         /* No mode set, assume a default based on the journal
5142          * capabilities: ORDERED_DATA if the journal can
5143          * cope, else JOURNAL_DATA
5144          */
5145         if (jbd2_journal_check_available_features
5146             (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5147             set_opt(sb, ORDERED_DATA);
5148             sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
5149         } else {
5150             set_opt(sb, JOURNAL_DATA);
5151             sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
5152         }
5153         break;
5154
5155     case EXT4_MOUNT_ORDERED_DATA:
5156     case EXT4_MOUNT_WRITEBACK_DATA:
5157         if (!jbd2_journal_check_available_features
5158             (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
5159             ext4_msg(sb, KERN_ERR, "Journal does not support "
5160                    "requested data journaling mode");
5161             goto failed_mount_wq;
5162         }
5163         break;
5164     default:
5165         break;
5166     }
5167
5168     if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
5169         test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5170         ext4_msg(sb, KERN_ERR, "can't mount with "
5171             "journal_async_commit in data=ordered mode");
5172         goto failed_mount_wq;
5173     }
5174
5175     set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
5176
5177     sbi->s_journal->j_submit_inode_data_buffers =
5178         ext4_journal_submit_inode_data_buffers;
5179     sbi->s_journal->j_finish_inode_data_buffers =
5180         ext4_journal_finish_inode_data_buffers;
5181
5182 no_journal:
5183     if (!test_opt(sb, NO_MBCACHE)) {
5184         sbi->s_ea_block_cache = ext4_xattr_create_cache();
5185         if (!sbi->s_ea_block_cache) {
5186             ext4_msg(sb, KERN_ERR,
5187                  "Failed to create ea_block_cache");
5188             goto failed_mount_wq;
5189         }
5190
5191         if (ext4_has_feature_ea_inode(sb)) {
5192             sbi->s_ea_inode_cache = ext4_xattr_create_cache();
5193             if (!sbi->s_ea_inode_cache) {
5194                 ext4_msg(sb, KERN_ERR,
5195                      "Failed to create ea_inode_cache");
5196                 goto failed_mount_wq;
5197             }
5198         }
5199     }
5200
5201     if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
5202         ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
5203         goto failed_mount_wq;
5204     }
5205
5206     /*
5207      * Get the # of file system overhead blocks from the
5208      * superblock if present.
5209      */
5210     sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
5211     /* ignore the precalculated value if it is ridiculous */
5212     if (sbi->s_overhead > ext4_blocks_count(es))
5213         sbi->s_overhead = 0;
5214     /*
5215      * If the bigalloc feature is not enabled recalculating the
5216      * overhead doesn't take long, so we might as well just redo
5217      * it to make sure we are using the correct value.
5218      */
5219     if (!ext4_has_feature_bigalloc(sb))
5220         sbi->s_overhead = 0;
5221     if (sbi->s_overhead == 0) {
5222         err = ext4_calculate_overhead(sb);
5223         if (err)
5224             goto failed_mount_wq;
5225     }
5226
5227     /*
5228      * The maximum number of concurrent works can be high and
5229      * concurrency isn't really necessary.  Limit it to 1.
5230      */
5231     EXT4_SB(sb)->rsv_conversion_wq =
5232         alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
5233     if (!EXT4_SB(sb)->rsv_conversion_wq) {
5234         printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
5235         ret = -ENOMEM;
5236         goto failed_mount4;
5237     }
5238
5239     /*
5240      * The jbd2_journal_load will have done any necessary log recovery,
5241      * so we can safely mount the rest of the filesystem now.
5242      */
5243
5244     root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
5245     if (IS_ERR(root)) {
5246         ext4_msg(sb, KERN_ERR, "get root inode failed");
5247         ret = PTR_ERR(root);
5248         root = NULL;
5249         goto failed_mount4;
5250     }
5251     if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
5252         ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
5253         iput(root);
5254         goto failed_mount4;
5255     }
5256
5257     sb->s_root = d_make_root(root);
5258     if (!sb->s_root) {
5259         ext4_msg(sb, KERN_ERR, "get root dentry failed");
5260         ret = -ENOMEM;
5261         goto failed_mount4;
5262     }
5263
5264     ret = ext4_setup_super(sb, es, sb_rdonly(sb));
5265     if (ret == -EROFS) {
5266         sb->s_flags |= SB_RDONLY;
5267         ret = 0;
5268     } else if (ret)
5269         goto failed_mount4a;
5270
5271     ext4_set_resv_clusters(sb);
5272
5273     if (test_opt(sb, BLOCK_VALIDITY)) {
5274         err = ext4_setup_system_zone(sb);
5275         if (err) {
5276             ext4_msg(sb, KERN_ERR, "failed to initialize system "
5277                  "zone (%d)", err);
5278             goto failed_mount4a;
5279         }
5280     }
5281     ext4_fc_replay_cleanup(sb);
5282
5283     ext4_ext_init(sb);
5284
5285     /*
5286      * Enable optimize_scan if number of groups is > threshold. This can be
5287      * turned off by passing "mb_optimize_scan=0". This can also be
5288      * turned on forcefully by passing "mb_optimize_scan=1".
5289      */
5290     if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) {
5291         if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
5292             set_opt2(sb, MB_OPTIMIZE_SCAN);
5293         else
5294             clear_opt2(sb, MB_OPTIMIZE_SCAN);
5295     }
5296
5297     err = ext4_mb_init(sb);
5298     if (err) {
5299         ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
5300              err);
5301         goto failed_mount5;
5302     }
5303
5304     /*
5305      * We can only set up the journal commit callback once
5306      * mballoc is initialized
5307      */
5308     if (sbi->s_journal)
5309         sbi->s_journal->j_commit_callback =
5310             ext4_journal_commit_callback;
5311
5312     block = ext4_count_free_clusters(sb);
5313     ext4_free_blocks_count_set(sbi->s_es,
5314                    EXT4_C2B(sbi, block));
5315     err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
5316                   GFP_KERNEL);
5317     if (!err) {
5318         unsigned long freei = ext4_count_free_inodes(sb);
5319         sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
5320         err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
5321                       GFP_KERNEL);
5322     }
5323     if (!err)
5324         err = percpu_counter_init(&sbi->s_dirs_counter,
5325                       ext4_count_dirs(sb), GFP_KERNEL);
5326     if (!err)
5327         err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
5328                       GFP_KERNEL);
5329     if (!err)
5330         err = percpu_counter_init(&sbi->s_sra_exceeded_retry_limit, 0,
5331                       GFP_KERNEL);
5332     if (!err)
5333         err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
5334
5335     if (err) {
5336         ext4_msg(sb, KERN_ERR, "insufficient memory");
5337         goto failed_mount6;
5338     }
5339
5340     if (ext4_has_feature_flex_bg(sb))
5341         if (!ext4_fill_flex_info(sb)) {
5342             ext4_msg(sb, KERN_ERR,
5343                    "unable to initialize "
5344                    "flex_bg meta info!");
5345             ret = -ENOMEM;
5346             goto failed_mount6;
5347         }
5348
5349     err = ext4_register_li_request(sb, first_not_zeroed);
5350     if (err)
5351         goto failed_mount6;
5352
5353     err = ext4_register_sysfs(sb);
5354     if (err)
5355         goto failed_mount7;
5356
5357     err = ext4_init_orphan_info(sb);
5358     if (err)
5359         goto failed_mount8;
5360 #ifdef CONFIG_QUOTA
5361     /* Enable quota usage during mount. */
5362     if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
5363         err = ext4_enable_quotas(sb);
5364         if (err)
5365             goto failed_mount9;
5366     }
5367 #endif  /* CONFIG_QUOTA */
5368
5369     /*
5370      * Save the original bdev mapping's wb_err value which could be
5371      * used to detect the metadata async write error.
5372      */
5373     spin_lock_init(&sbi->s_bdev_wb_lock);
5374     errseq_check_and_advance(&sb->s_bdev->bd_inode->i_mapping->wb_err,
5375                  &sbi->s_bdev_wb_err);
5376     sb->s_bdev->bd_super = sb;
5377     EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
5378     ext4_orphan_cleanup(sb, es);
5379     EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
5380     /*
5381      * Update the checksum after updating free space/inode counters and
5382      * ext4_orphan_cleanup. Otherwise the superblock can have an incorrect
5383      * checksum in the buffer cache until it is written out and
5384      * e2fsprogs programs trying to open a file system immediately
5385      * after it is mounted can fail.
5386      */
5387     ext4_superblock_csum_set(sb);
5388     if (needs_recovery) {
5389         ext4_msg(sb, KERN_INFO, "recovery complete");
5390         err = ext4_mark_recovery_complete(sb, es);
5391         if (err)
5392             goto failed_mount9;
5393     }
5394
5395     if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev))
5396         ext4_msg(sb, KERN_WARNING,
5397              "mounting with \"discard\" option, but the device does not support discard");
5398
5399     if (es->s_error_count)
5400         mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
5401
5402     /* Enable message ratelimiting. Default is 10 messages per 5 secs. */
5403     ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
5404     ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
5405     ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
5406     atomic_set(&sbi->s_warning_count, 0);
5407     atomic_set(&sbi->s_msg_count, 0);
5408
5409     return 0;
5410
5411 cantfind_ext4:
5412     if (!silent)
5413         ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
5414     goto failed_mount;
5415
5416 failed_mount9:
5417     ext4_release_orphan_info(sb);
5418 failed_mount8:
5419     ext4_unregister_sysfs(sb);
5420     kobject_put(&sbi->s_kobj);
5421 failed_mount7:
5422     ext4_unregister_li_request(sb);
5423 failed_mount6:
5424     ext4_mb_release(sb);
5425     rcu_read_lock();
5426     flex_groups = rcu_dereference(sbi->s_flex_groups);
5427     if (flex_groups) {
5428         for (i = 0; i < sbi->s_flex_groups_allocated; i++)
5429             kvfree(flex_groups[i]);
5430         kvfree(flex_groups);
5431     }
5432     rcu_read_unlock();
5433     percpu_counter_destroy(&sbi->s_freeclusters_counter);
5434     percpu_counter_destroy(&sbi->s_freeinodes_counter);
5435     percpu_counter_destroy(&sbi->s_dirs_counter);
5436     percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
5437     percpu_counter_destroy(&sbi->s_sra_exceeded_retry_limit);
5438     percpu_free_rwsem(&sbi->s_writepages_rwsem);
5439 failed_mount5:
5440     ext4_ext_release(sb);
5441     ext4_release_system_zone(sb);
5442 failed_mount4a:
5443     dput(sb->s_root);
5444     sb->s_root = NULL;
5445 failed_mount4:
5446     ext4_msg(sb, KERN_ERR, "mount failed");
5447     if (EXT4_SB(sb)->rsv_conversion_wq)
5448         destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
5449 failed_mount_wq:
5450     ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
5451     sbi->s_ea_inode_cache = NULL;
5452
5453     ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
5454     sbi->s_ea_block_cache = NULL;
5455
5456     if (sbi->s_journal) {
5457         /* flush s_error_work before journal destroy. */
5458         flush_work(&sbi->s_error_work);
5459         jbd2_journal_destroy(sbi->s_journal);
5460         sbi->s_journal = NULL;
5461     }
5462 failed_mount3a:
5463     ext4_es_unregister_shrinker(sbi);
5464 failed_mount3:
5465     /* flush s_error_work before sbi destroy */
5466     flush_work(&sbi->s_error_work);
5467     del_timer_sync(&sbi->s_err_report);
5468     ext4_stop_mmpd(sbi);
5469 failed_mount2:
5470     rcu_read_lock();
5471     group_desc = rcu_dereference(sbi->s_group_desc);
5472     for (i = 0; i < db_count; i++)
5473         brelse(group_desc[i]);
5474     kvfree(group_desc);
5475     rcu_read_unlock();
5476 failed_mount:
5477     if (sbi->s_chksum_driver)
5478         crypto_free_shash(sbi->s_chksum_driver);
5479
5480 #if IS_ENABLED(CONFIG_UNICODE)
5481     utf8_unload(sb->s_encoding);
5482 #endif
5483
5484 #ifdef CONFIG_QUOTA
5485     for (i = 0; i < EXT4_MAXQUOTAS; i++)
5486         kfree(get_qf_name(sb, sbi, i));
5487 #endif
5488     fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy);
5489     /* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */
5490     brelse(bh);
5491     ext4_blkdev_remove(sbi);
5492 out_fail:
5493     sb->s_fs_info = NULL;
5494     return err ? err : ret;
5495 }
5496
5497 static int ext4_fill_super(struct super_block *sb, struct fs_context *fc)
5498 {
5499     struct ext4_fs_context *ctx = fc->fs_private;
5500     struct ext4_sb_info *sbi;
5501     const char *descr;
5502     int ret;
5503
5504     sbi = ext4_alloc_sbi(sb);
5505     if (!sbi)
5506         return -ENOMEM;
5507
5508     fc->s_fs_info = sbi;
5509
5510     /* Cleanup superblock name */
5511     strreplace(sb->s_id, '/', '!');
5512
5513     sbi->s_sb_block = 1;    /* Default super block location */
5514     if (ctx->spec & EXT4_SPEC_s_sb_block)
5515         sbi->s_sb_block = ctx->s_sb_block;
5516
5517     ret = __ext4_fill_super(fc, sb);
5518     if (ret < 0)
5519         goto free_sbi;
5520
5521     if (sbi->s_journal) {
5522         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
5523             descr = " journalled data mode";
5524         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
5525             descr = " ordered data mode";
5526         else
5527             descr = " writeback data mode";
5528     } else
5529         descr = "out journal";
5530
5531     if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
5532         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
5533              "Quota mode: %s.", descr, ext4_quota_mode(sb));
5534
5535     /* Update the s_overhead_clusters if necessary */
5536     ext4_update_overhead(sb, false);
5537     return 0;
5538
5539 free_sbi:
5540     ext4_free_sbi(sbi);
5541     fc->s_fs_info = NULL;
5542     return ret;
5543 }
5544
5545 static int ext4_get_tree(struct fs_context *fc)
5546 {
5547     return get_tree_bdev(fc, ext4_fill_super);
5548 }
5549
5550 /*
5551  * Setup any per-fs journal parameters now.  We'll do this both on
5552  * initial mount, once the journal has been initialised but before we've
5553  * done any recovery; and again on any subsequent remount.
5554  */
5555 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
5556 {
5557     struct ext4_sb_info *sbi = EXT4_SB(sb);
5558
5559     journal->j_commit_interval = sbi->s_commit_interval;
5560     journal->j_min_batch_time = sbi->s_min_batch_time;
5561     journal->j_max_batch_time = sbi->s_max_batch_time;
5562     ext4_fc_init(sb, journal);
5563
5564     write_lock(&journal->j_state_lock);
5565     if (test_opt(sb, BARRIER))
5566         journal->j_flags |= JBD2_BARRIER;
5567     else
5568         journal->j_flags &= ~JBD2_BARRIER;
5569     if (test_opt(sb, DATA_ERR_ABORT))
5570         journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
5571     else
5572         journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
5573     write_unlock(&journal->j_state_lock);
5574 }
5575
5576 static struct inode *ext4_get_journal_inode(struct super_block *sb,
5577                          unsigned int journal_inum)
5578 {
5579     struct inode *journal_inode;
5580
5581     /*
5582      * Test for the existence of a valid inode on disk.  Bad things
5583      * happen if we iget() an unused inode, as the subsequent iput()
5584      * will try to delete it.
5585      */
5586     journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
5587     if (IS_ERR(journal_inode)) {
5588         ext4_msg(sb, KERN_ERR, "no journal found");
5589         return NULL;
5590     }
5591     if (!journal_inode->i_nlink) {
5592         make_bad_inode(journal_inode);
5593         iput(journal_inode);
5594         ext4_msg(sb, KERN_ERR, "journal inode is deleted");
5595         return NULL;
5596     }
5597
5598     ext4_debug("Journal inode found at %p: %lld bytes\n",
5599           journal_inode, journal_inode->i_size);
5600     if (!S_ISREG(journal_inode->i_mode)) {
5601         ext4_msg(sb, KERN_ERR, "invalid journal inode");
5602         iput(journal_inode);
5603         return NULL;
5604     }
5605     return journal_inode;
5606 }
5607
5608 static journal_t *ext4_get_journal(struct super_block *sb,
5609                    unsigned int journal_inum)
5610 {
5611     struct inode *journal_inode;
5612     journal_t *journal;
5613
5614     if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5615         return NULL;
5616
5617     journal_inode = ext4_get_journal_inode(sb, journal_inum);
5618     if (!journal_inode)
5619         return NULL;
5620
5621     journal = jbd2_journal_init_inode(journal_inode);
5622     if (!journal) {
5623         ext4_msg(sb, KERN_ERR, "Could not load journal inode");
5624         iput(journal_inode);
5625         return NULL;
5626     }
5627     journal->j_private = sb;
5628     ext4_init_journal_params(sb, journal);
5629     return journal;
5630 }
5631
5632 static journal_t *ext4_get_dev_journal(struct super_block *sb,
5633                        dev_t j_dev)
5634 {
5635     struct buffer_head *bh;
5636     journal_t *journal;
5637     ext4_fsblk_t start;
5638     ext4_fsblk_t len;
5639     int hblock, blocksize;
5640     ext4_fsblk_t sb_block;
5641     unsigned long offset;
5642     struct ext4_super_block *es;
5643     struct block_device *bdev;
5644
5645     if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5646         return NULL;
5647
5648     bdev = ext4_blkdev_get(j_dev, sb);
5649     if (bdev == NULL)
5650         return NULL;
5651
5652     blocksize = sb->s_blocksize;
5653     hblock = bdev_logical_block_size(bdev);
5654     if (blocksize < hblock) {
5655         ext4_msg(sb, KERN_ERR,
5656             "blocksize too small for journal device");
5657         goto out_bdev;
5658     }
5659
5660     sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
5661     offset = EXT4_MIN_BLOCK_SIZE % blocksize;
5662     set_blocksize(bdev, blocksize);
5663     if (!(bh = __bread(bdev, sb_block, blocksize))) {
5664         ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
5665                "external journal");
5666         goto out_bdev;
5667     }
5668
5669     es = (struct ext4_super_block *) (bh->b_data + offset);
5670     if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
5671         !(le32_to_cpu(es->s_feature_incompat) &
5672           EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
5673         ext4_msg(sb, KERN_ERR, "external journal has "
5674                     "bad superblock");
5675         brelse(bh);
5676         goto out_bdev;
5677     }
5678
5679     if ((le32_to_cpu(es->s_feature_ro_compat) &
5680          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
5681         es->s_checksum != ext4_superblock_csum(sb, es)) {
5682         ext4_msg(sb, KERN_ERR, "external journal has "
5683                        "corrupt superblock");
5684         brelse(bh);
5685         goto out_bdev;
5686     }
5687
5688     if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
5689         ext4_msg(sb, KERN_ERR, "journal UUID does not match");
5690         brelse(bh);
5691         goto out_bdev;
5692     }
5693
5694     len = ext4_blocks_count(es);
5695     start = sb_block + 1;
5696     brelse(bh); /* we're done with the superblock */
5697
5698     journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
5699                     start, len, blocksize);
5700     if (!journal) {
5701         ext4_msg(sb, KERN_ERR, "failed to create device journal");
5702         goto out_bdev;
5703     }
5704     journal->j_private = sb;
5705     if (ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO, true)) {
5706         ext4_msg(sb, KERN_ERR, "I/O error on journal device");
5707         goto out_journal;
5708     }
5709     if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
5710         ext4_msg(sb, KERN_ERR, "External journal has more than one "
5711                     "user (unsupported) - %d",
5712             be32_to_cpu(journal->j_superblock->s_nr_users));
5713         goto out_journal;
5714     }
5715     EXT4_SB(sb)->s_journal_bdev = bdev;
5716     ext4_init_journal_params(sb, journal);
5717     return journal;
5718
5719 out_journal:
5720     jbd2_journal_destroy(journal);
5721 out_bdev:
5722     ext4_blkdev_put(bdev);
5723     return NULL;
5724 }
5725
5726 static int ext4_load_journal(struct super_block *sb,
5727                  struct ext4_super_block *es,
5728                  unsigned long journal_devnum)
5729 {
5730     journal_t *journal;
5731     unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
5732     dev_t journal_dev;
5733     int err = 0;
5734     int really_read_only;
5735     int journal_dev_ro;
5736
5737     if (WARN_ON_ONCE(!ext4_has_feature_journal(sb)))
5738         return -EFSCORRUPTED;
5739
5740     if (journal_devnum &&
5741         journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5742         ext4_msg(sb, KERN_INFO, "external journal device major/minor "
5743             "numbers have changed");
5744         journal_dev = new_decode_dev(journal_devnum);
5745     } else
5746         journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
5747
5748     if (journal_inum && journal_dev) {
5749         ext4_msg(sb, KERN_ERR,
5750              "filesystem has both journal inode and journal device!");
5751         return -EINVAL;
5752     }
5753
5754     if (journal_inum) {
5755         journal = ext4_get_journal(sb, journal_inum);
5756         if (!journal)
5757             return -EINVAL;
5758     } else {
5759         journal = ext4_get_dev_journal(sb, journal_dev);
5760         if (!journal)
5761             return -EINVAL;
5762     }
5763
5764     journal_dev_ro = bdev_read_only(journal->j_dev);
5765     really_read_only = bdev_read_only(sb->s_bdev) | journal_dev_ro;
5766
5767     if (journal_dev_ro && !sb_rdonly(sb)) {
5768         ext4_msg(sb, KERN_ERR,
5769              "journal device read-only, try mounting with '-o ro'");
5770         err = -EROFS;
5771         goto err_out;
5772     }
5773
5774     /*
5775      * Are we loading a blank journal or performing recovery after a
5776      * crash?  For recovery, we need to check in advance whether we
5777      * can get read-write access to the device.
5778      */
5779     if (ext4_has_feature_journal_needs_recovery(sb)) {
5780         if (sb_rdonly(sb)) {
5781             ext4_msg(sb, KERN_INFO, "INFO: recovery "
5782                     "required on readonly filesystem");
5783             if (really_read_only) {
5784                 ext4_msg(sb, KERN_ERR, "write access "
5785                     "unavailable, cannot proceed "
5786                     "(try mounting with noload)");
5787                 err = -EROFS;
5788                 goto err_out;
5789             }
5790             ext4_msg(sb, KERN_INFO, "write access will "
5791                    "be enabled during recovery");
5792         }
5793     }
5794
5795     if (!(journal->j_flags & JBD2_BARRIER))
5796         ext4_msg(sb, KERN_INFO, "barriers disabled");
5797
5798     if (!ext4_has_feature_journal_needs_recovery(sb))
5799         err = jbd2_journal_wipe(journal, !really_read_only);
5800     if (!err) {
5801         char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5802         if (save)
5803             memcpy(save, ((char *) es) +
5804                    EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5805         err = jbd2_journal_load(journal);
5806         if (save)
5807             memcpy(((char *) es) + EXT4_S_ERR_START,
5808                    save, EXT4_S_ERR_LEN);
5809         kfree(save);
5810     }
5811
5812     if (err) {
5813         ext4_msg(sb, KERN_ERR, "error loading journal");
5814         goto err_out;
5815     }
5816
5817     EXT4_SB(sb)->s_journal = journal;
5818     err = ext4_clear_journal_err(sb, es);
5819     if (err) {
5820         EXT4_SB(sb)->s_journal = NULL;
5821         jbd2_journal_destroy(journal);
5822         return err;
5823     }
5824
5825     if (!really_read_only && journal_devnum &&
5826         journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5827         es->s_journal_dev = cpu_to_le32(journal_devnum);
5828
5829         /* Make sure we flush the recovery flag to disk. */
5830         ext4_commit_super(sb);
5831     }
5832
5833     return 0;
5834
5835 err_out:
5836     jbd2_journal_destroy(journal);
5837     return err;
5838 }
5839
5840 /* Copy state of EXT4_SB(sb) into buffer for on-disk superblock */
5841 static void ext4_update_super(struct super_block *sb)
5842 {
5843     struct ext4_sb_info *sbi = EXT4_SB(sb);
5844     struct ext4_super_block *es = sbi->s_es;
5845     struct buffer_head *sbh = sbi->s_sbh;
5846
5847     lock_buffer(sbh);
5848     /*
5849      * If the file system is mounted read-only, don't update the
5850      * superblock write time.  This avoids updating the superblock
5851      * write time when we are mounting the root file system
5852      * read/only but we need to replay the journal; at that point,
5853      * for people who are east of GMT and who make their clock
5854      * tick in localtime for Windows bug-for-bug compatibility,
5855      * the clock is set in the future, and this will cause e2fsck
5856      * to complain and force a full file system check.
5857      */
5858     if (!(sb->s_flags & SB_RDONLY))
5859         ext4_update_tstamp(es, s_wtime);
5860     es->s_kbytes_written =
5861         cpu_to_le64(sbi->s_kbytes_written +
5862             ((part_stat_read(sb->s_bdev, sectors[STAT_WRITE]) -
5863               sbi->s_sectors_written_start) >> 1));
5864     if (percpu_counter_initialized(&sbi->s_freeclusters_counter))
5865         ext4_free_blocks_count_set(es,
5866             EXT4_C2B(sbi, percpu_counter_sum_positive(
5867                 &sbi->s_freeclusters_counter)));
5868     if (percpu_counter_initialized(&sbi->s_freeinodes_counter))
5869         es->s_free_inodes_count =
5870             cpu_to_le32(percpu_counter_sum_positive(
5871                 &sbi->s_freeinodes_counter));
5872     /* Copy error information to the on-disk superblock */
5873     spin_lock(&sbi->s_error_lock);
5874     if (sbi->s_add_error_count > 0) {
5875         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5876         if (!es->s_first_error_time && !es->s_first_error_time_hi) {
5877             __ext4_update_tstamp(&es->s_first_error_time,
5878                          &es->s_first_error_time_hi,
5879                          sbi->s_first_error_time);
5880             strncpy(es->s_first_error_func, sbi->s_first_error_func,
5881                 sizeof(es->s_first_error_func));
5882             es->s_first_error_line =
5883                 cpu_to_le32(sbi->s_first_error_line);
5884             es->s_first_error_ino =
5885                 cpu_to_le32(sbi->s_first_error_ino);
5886             es->s_first_error_block =
5887                 cpu_to_le64(sbi->s_first_error_block);
5888             es->s_first_error_errcode =
5889                 ext4_errno_to_code(sbi->s_first_error_code);
5890         }
5891         __ext4_update_tstamp(&es->s_last_error_time,
5892                      &es->s_last_error_time_hi,
5893                      sbi->s_last_error_time);
5894         strncpy(es->s_last_error_func, sbi->s_last_error_func,
5895             sizeof(es->s_last_error_func));
5896         es->s_last_error_line = cpu_to_le32(sbi->s_last_error_line);
5897         es->s_last_error_ino = cpu_to_le32(sbi->s_last_error_ino);
5898         es->s_last_error_block = cpu_to_le64(sbi->s_last_error_block);
5899         es->s_last_error_errcode =
5900                 ext4_errno_to_code(sbi->s_last_error_code);
5901         /*
5902          * Start the daily error reporting function if it hasn't been
5903          * started already
5904          */
5905         if (!es->s_error_count)
5906             mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);
5907         le32_add_cpu(&es->s_error_count, sbi->s_add_error_count);
5908         sbi->s_add_error_count = 0;
5909     }
5910     spin_unlock(&sbi->s_error_lock);
5911
5912     ext4_superblock_csum_set(sb);
5913     unlock_buffer(sbh);
5914 }
5915
5916 static int ext4_commit_super(struct super_block *sb)
5917 {
5918     struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5919
5920     if (!sbh)
5921         return -EINVAL;
5922     if (block_device_ejected(sb))
5923         return -ENODEV;
5924
5925     ext4_update_super(sb);
5926
5927     lock_buffer(sbh);
5928     /* Buffer got discarded which means block device got invalidated */
5929     if (!buffer_mapped(sbh)) {
5930         unlock_buffer(sbh);
5931         return -EIO;
5932     }
5933
5934     if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5935         /*
5936          * Oh, dear.  A previous attempt to write the
5937          * superblock failed.  This could happen because the
5938          * USB device was yanked out.  Or it could happen to
5939          * be a transient write error and maybe the block will
5940          * be remapped.  Nothing we can do but to retry the
5941          * write and hope for the best.
5942          */
5943         ext4_msg(sb, KERN_ERR, "previous I/O error to "
5944                "superblock detected");
5945         clear_buffer_write_io_error(sbh);
5946         set_buffer_uptodate(sbh);
5947     }
5948     get_bh(sbh);
5949     /* Clear potential dirty bit if it was journalled update */
5950     clear_buffer_dirty(sbh);
5951     sbh->b_end_io = end_buffer_write_sync;
5952     submit_bh(REQ_OP_WRITE | REQ_SYNC |
5953           (test_opt(sb, BARRIER) ? REQ_FUA : 0), sbh);
5954     wait_on_buffer(sbh);
5955     if (buffer_write_io_error(sbh)) {
5956         ext4_msg(sb, KERN_ERR, "I/O error while writing "
5957                "superblock");
5958         clear_buffer_write_io_error(sbh);
5959         set_buffer_uptodate(sbh);
5960         return -EIO;
5961     }
5962     return 0;
5963 }
5964
5965 /*
5966  * Have we just finished recovery?  If so, and if we are mounting (or
5967  * remounting) the filesystem readonly, then we will end up with a
5968  * consistent fs on disk.  Record that fact.
5969  */
5970 static int ext4_mark_recovery_complete(struct super_block *sb,
5971                        struct ext4_super_block *es)
5972 {
5973     int err;
5974     journal_t *journal = EXT4_SB(sb)->s_journal;
5975
5976     if (!ext4_has_feature_journal(sb)) {
5977         if (journal != NULL) {
5978             ext4_error(sb, "Journal got removed while the fs was "
5979                    "mounted!");
5980             return -EFSCORRUPTED;
5981         }
5982         return 0;
5983     }
5984     jbd2_journal_lock_updates(journal);
5985     err = jbd2_journal_flush(journal, 0);
5986     if (err < 0)
5987         goto out;
5988
5989     if (sb_rdonly(sb) && (ext4_has_feature_journal_needs_recovery(sb) ||
5990         ext4_has_feature_orphan_present(sb))) {
5991         if (!ext4_orphan_file_empty(sb)) {
5992             ext4_error(sb, "Orphan file not empty on read-only fs.");
5993             err = -EFSCORRUPTED;
5994             goto out;
5995         }
5996         ext4_clear_feature_journal_needs_recovery(sb);
5997         ext4_clear_feature_orphan_present(sb);
5998         ext4_commit_super(sb);
5999     }
6000 out:
6001     jbd2_journal_unlock_updates(journal);
6002     return err;
6003 }
6004
6005 /*
6006  * If we are mounting (or read-write remounting) a filesystem whose journal
6007  * has recorded an error from a previous lifetime, move that error to the
6008  * main filesystem now.
6009  */
6010 static int ext4_clear_journal_err(struct super_block *sb,
6011                    struct ext4_super_block *es)
6012 {
6013     journal_t *journal;
6014     int j_errno;
6015     const char *errstr;
6016
6017     if (!ext4_has_feature_journal(sb)) {
6018         ext4_error(sb, "Journal got removed while the fs was mounted!");
6019         return -EFSCORRUPTED;
6020     }
6021
6022     journal = EXT4_SB(sb)->s_journal;
6023
6024     /*
6025      * Now check for any error status which may have been recorded in the
6026      * journal by a prior ext4_error() or ext4_abort()
6027      */
6028
6029     j_errno = jbd2_journal_errno(journal);
6030     if (j_errno) {
6031         char nbuf[16];
6032
6033         errstr = ext4_decode_error(sb, j_errno, nbuf);
6034         ext4_warning(sb, "Filesystem error recorded "
6035                  "from previous mount: %s", errstr);
6036         ext4_warning(sb, "Marking fs in need of filesystem check.");
6037
6038         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
6039         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
6040         ext4_commit_super(sb);
6041
6042         jbd2_journal_clear_err(journal);
6043         jbd2_journal_update_sb_errno(journal);
6044     }
6045     return 0;
6046 }
6047
6048 /*
6049  * Force the running and committing transactions to commit,
6050  * and wait on the commit.
6051  */
6052 int ext4_force_commit(struct super_block *sb)
6053 {
6054     journal_t *journal;
6055
6056     if (sb_rdonly(sb))
6057         return 0;
6058
6059     journal = EXT4_SB(sb)->s_journal;
6060     return ext4_journal_force_commit(journal);
6061 }
6062
6063 static int ext4_sync_fs(struct super_block *sb, int wait)
6064 {
6065     int ret = 0;
6066     tid_t target;
6067     bool needs_barrier = false;
6068     struct ext4_sb_info *sbi = EXT4_SB(sb);
6069
6070     if (unlikely(ext4_forced_shutdown(sbi)))
6071         return 0;
6072
6073     trace_ext4_sync_fs(sb, wait);
6074     flush_workqueue(sbi->rsv_conversion_wq);
6075     /*
6076      * Writeback quota in non-journalled quota case - journalled quota has
6077      * no dirty dquots
6078      */
6079     dquot_writeback_dquots(sb, -1);
6080     /*
6081      * Data writeback is possible w/o journal transaction, so barrier must
6082      * being sent at the end of the function. But we can skip it if
6083      * transaction_commit will do it for us.
6084      */
6085     if (sbi->s_journal) {
6086         target = jbd2_get_latest_transaction(sbi->s_journal);
6087         if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
6088             !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
6089             needs_barrier = true;
6090
6091         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
6092             if (wait)
6093                 ret = jbd2_log_wait_commit(sbi->s_journal,
6094                                target);
6095         }
6096     } else if (wait && test_opt(sb, BARRIER))
6097         needs_barrier = true;
6098     if (needs_barrier) {
6099         int err;
6100         err = blkdev_issue_flush(sb->s_bdev);
6101         if (!ret)
6102             ret = err;
6103     }
6104
6105     return ret;
6106 }
6107
6108 /*
6109  * LVM calls this function before a (read-only) snapshot is created.  This
6110  * gives us a chance to flush the journal completely and mark the fs clean.
6111  *
6112  * Note that only this function cannot bring a filesystem to be in a clean
6113  * state independently. It relies on upper layer to stop all data & metadata
6114  * modifications.
6115  */
6116 static int ext4_freeze(struct super_block *sb)
6117 {
6118     int error = 0;
6119     journal_t *journal;
6120
6121     if (sb_rdonly(sb))
6122         return 0;
6123
6124     journal = EXT4_SB(sb)->s_journal;
6125
6126     if (journal) {
6127         /* Now we set up the journal barrier. */
6128         jbd2_journal_lock_updates(journal);
6129
6130         /*
6131          * Don't clear the needs_recovery flag if we failed to
6132          * flush the journal.
6133          */
6134         error = jbd2_journal_flush(journal, 0);
6135         if (error < 0)
6136             goto out;
6137
6138         /* Journal blocked and flushed, clear needs_recovery flag. */
6139         ext4_clear_feature_journal_needs_recovery(sb);
6140         if (ext4_orphan_file_empty(sb))
6141             ext4_clear_feature_orphan_present(sb);
6142     }
6143
6144     error = ext4_commit_super(sb);
6145 out:
6146     if (journal)
6147         /* we rely on upper layer to stop further updates */
6148         jbd2_journal_unlock_updates(journal);
6149     return error;
6150 }
6151
6152 /*
6153  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
6154  * flag here, even though the filesystem is not technically dirty yet.
6155  */
6156 static int ext4_unfreeze(struct super_block *sb)
6157 {
6158     if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
6159         return 0;
6160
6161     if (EXT4_SB(sb)->s_journal) {
6162         /* Reset the needs_recovery flag before the fs is unlocked. */
6163         ext4_set_feature_journal_needs_recovery(sb);
6164         if (ext4_has_feature_orphan_file(sb))
6165             ext4_set_feature_orphan_present(sb);
6166     }
6167
6168     ext4_commit_super(sb);
6169     return 0;
6170 }
6171
6172 /*
6173  * Structure to save mount options for ext4_remount's benefit
6174  */
6175 struct ext4_mount_options {
6176     unsigned long s_mount_opt;
6177     unsigned long s_mount_opt2;
6178     kuid_t s_resuid;
6179     kgid_t s_resgid;
6180     unsigned long s_commit_interval;
6181     u32 s_min_batch_time, s_max_batch_time;
6182 #ifdef CONFIG_QUOTA
6183     int s_jquota_fmt;
6184     char *s_qf_names[EXT4_MAXQUOTAS];
6185 #endif
6186 };
6187
6188 static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
6189 {
6190     struct ext4_fs_context *ctx = fc->fs_private;
6191     struct ext4_super_block *es;
6192     struct ext4_sb_info *sbi = EXT4_SB(sb);
6193     unsigned long old_sb_flags;
6194     struct ext4_mount_options old_opts;
6195     ext4_group_t g;
6196     int err = 0;
6197 #ifdef CONFIG_QUOTA
6198     int enable_quota = 0;
6199     int i, j;
6200     char *to_free[EXT4_MAXQUOTAS];
6201 #endif
6202
6203
6204     /* Store the original options */
6205     old_sb_flags = sb->s_flags;
6206     old_opts.s_mount_opt = sbi->s_mount_opt;
6207     old_opts.s_mount_opt2 = sbi->s_mount_opt2;
6208     old_opts.s_resuid = sbi->s_resuid;
6209     old_opts.s_resgid = sbi->s_resgid;
6210     old_opts.s_commit_interval = sbi->s_commit_interval;
6211     old_opts.s_min_batch_time = sbi->s_min_batch_time;
6212     old_opts.s_max_batch_time = sbi->s_max_batch_time;
6213 #ifdef CONFIG_QUOTA
6214     old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
6215     for (i = 0; i < EXT4_MAXQUOTAS; i++)
6216         if (sbi->s_qf_names[i]) {
6217             char *qf_name = get_qf_name(sb, sbi, i);
6218
6219             old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
6220             if (!old_opts.s_qf_names[i]) {
6221                 for (j = 0; j < i; j++)
6222                     kfree(old_opts.s_qf_names[j]);
6223                 return -ENOMEM;
6224             }
6225         } else
6226             old_opts.s_qf_names[i] = NULL;
6227 #endif
6228     if (!(ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)) {
6229         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
6230             ctx->journal_ioprio =
6231                 sbi->s_journal->j_task->io_context->ioprio;
6232         else
6233             ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
6234
6235     }
6236
6237     ext4_apply_options(fc, sb);
6238
6239     if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
6240         test_opt(sb, JOURNAL_CHECKSUM)) {
6241         ext4_msg(sb, KERN_ERR, "changing journal_checksum "
6242              "during remount not supported; ignoring");
6243         sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
6244     }
6245
6246     if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
6247         if (test_opt2(sb, EXPLICIT_DELALLOC)) {
6248             ext4_msg(sb, KERN_ERR, "can't mount with "
6249                  "both data=journal and delalloc");
6250             err = -EINVAL;
6251             goto restore_opts;
6252         }
6253         if (test_opt(sb, DIOREAD_NOLOCK)) {
6254             ext4_msg(sb, KERN_ERR, "can't mount with "
6255                  "both data=journal and dioread_nolock");
6256             err = -EINVAL;
6257             goto restore_opts;
6258         }
6259     } else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
6260         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
6261             ext4_msg(sb, KERN_ERR, "can't mount with "
6262                 "journal_async_commit in data=ordered mode");
6263             err = -EINVAL;
6264             goto restore_opts;
6265         }
6266     }
6267
6268     if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
6269         ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
6270         err = -EINVAL;
6271         goto restore_opts;
6272     }
6273
6274     if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
6275         ext4_abort(sb, ESHUTDOWN, "Abort forced by user");
6276
6277     sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
6278         (test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
6279
6280     es = sbi->s_es;
6281
6282     if (sbi->s_journal) {
6283         ext4_init_journal_params(sb, sbi->s_journal);
6284         set_task_ioprio(sbi->s_journal->j_task, ctx->journal_ioprio);
6285     }
6286
6287     /* Flush outstanding errors before changing fs state */
6288     flush_work(&sbi->s_error_work);
6289
6290     if ((bool)(fc->sb_flags & SB_RDONLY) != sb_rdonly(sb)) {
6291         if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
6292             err = -EROFS;
6293             goto restore_opts;
6294         }
6295
6296         if (fc->sb_flags & SB_RDONLY) {
6297             err = sync_filesystem(sb);
6298             if (err < 0)
6299                 goto restore_opts;
6300             err = dquot_suspend(sb, -1);
6301             if (err < 0)
6302                 goto restore_opts;
6303
6304             /*
6305              * First of all, the unconditional stuff we have to do
6306              * to disable replay of the journal when we next remount
6307              */
6308             sb->s_flags |= SB_RDONLY;
6309
6310             /*
6311              * OK, test if we are remounting a valid rw partition
6312              * readonly, and if so set the rdonly flag and then
6313              * mark the partition as valid again.
6314              */
6315             if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
6316                 (sbi->s_mount_state & EXT4_VALID_FS))
6317                 es->s_state = cpu_to_le16(sbi->s_mount_state);
6318
6319             if (sbi->s_journal) {
6320                 /*
6321                  * We let remount-ro finish even if marking fs
6322                  * as clean failed...
6323                  */
6324                 ext4_mark_recovery_complete(sb, es);
6325             }
6326         } else {
6327             /* Make sure we can mount this feature set readwrite */
6328             if (ext4_has_feature_readonly(sb) ||
6329                 !ext4_feature_set_ok(sb, 0)) {
6330                 err = -EROFS;
6331                 goto restore_opts;
6332             }
6333             /*
6334              * Make sure the group descriptor checksums
6335              * are sane.  If they aren't, refuse to remount r/w.
6336              */
6337             for (g = 0; g < sbi->s_groups_count; g++) {
6338                 struct ext4_group_desc *gdp =
6339                     ext4_get_group_desc(sb, g, NULL);
6340
6341                 if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
6342                     ext4_msg(sb, KERN_ERR,
6343            "ext4_remount: Checksum for group %u failed (%u!=%u)",
6344         g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
6345                            le16_to_cpu(gdp->bg_checksum));
6346                     err = -EFSBADCRC;
6347                     goto restore_opts;
6348                 }
6349             }
6350
6351             /*
6352              * If we have an unprocessed orphan list hanging
6353              * around from a previously readonly bdev mount,
6354              * require a full umount/remount for now.
6355              */
6356             if (es->s_last_orphan || !ext4_orphan_file_empty(sb)) {
6357                 ext4_msg(sb, KERN_WARNING, "Couldn't "
6358                        "remount RDWR because of unprocessed "
6359                        "orphan inode list.  Please "
6360                        "umount/remount instead");
6361                 err = -EINVAL;
6362                 goto restore_opts;
6363             }
6364
6365             /*
6366              * Mounting a RDONLY partition read-write, so reread
6367              * and store the current valid flag.  (It may have
6368              * been changed by e2fsck since we originally mounted
6369              * the partition.)
6370              */
6371             if (sbi->s_journal) {
6372                 err = ext4_clear_journal_err(sb, es);
6373                 if (err)
6374                     goto restore_opts;
6375             }
6376             sbi->s_mount_state = (le16_to_cpu(es->s_state) &
6377                           ~EXT4_FC_REPLAY);
6378
6379             err = ext4_setup_super(sb, es, 0);
6380             if (err)
6381                 goto restore_opts;
6382
6383             sb->s_flags &= ~SB_RDONLY;
6384             if (ext4_has_feature_mmp(sb))
6385                 if (ext4_multi_mount_protect(sb,
6386                         le64_to_cpu(es->s_mmp_block))) {
6387                     err = -EROFS;
6388                     goto restore_opts;
6389                 }
6390 #ifdef CONFIG_QUOTA
6391             enable_quota = 1;
6392 #endif
6393         }
6394     }
6395
6396     /*
6397      * Reinitialize lazy itable initialization thread based on
6398      * current settings
6399      */
6400     if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
6401         ext4_unregister_li_request(sb);
6402     else {
6403         ext4_group_t first_not_zeroed;
6404         first_not_zeroed = ext4_has_uninit_itable(sb);
6405         ext4_register_li_request(sb, first_not_zeroed);
6406     }
6407
6408     /*
6409      * Handle creation of system zone data early because it can fail.
6410      * Releasing of existing data is done when we are sure remount will
6411      * succeed.
6412      */
6413     if (test_opt(sb, BLOCK_VALIDITY) && !sbi->s_system_blks) {
6414         err = ext4_setup_system_zone(sb);
6415         if (err)
6416             goto restore_opts;
6417     }
6418
6419     if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
6420         err = ext4_commit_super(sb);
6421         if (err)
6422             goto restore_opts;
6423     }
6424
6425 #ifdef CONFIG_QUOTA
6426     /* Release old quota file names */
6427     for (i = 0; i < EXT4_MAXQUOTAS; i++)
6428         kfree(old_opts.s_qf_names[i]);
6429     if (enable_quota) {
6430         if (sb_any_quota_suspended(sb))
6431             dquot_resume(sb, -1);
6432         else if (ext4_has_feature_quota(sb)) {
6433             err = ext4_enable_quotas(sb);
6434             if (err)
6435                 goto restore_opts;
6436         }
6437     }
6438 #endif
6439     if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6440         ext4_release_system_zone(sb);
6441
6442     if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6443         ext4_stop_mmpd(sbi);
6444
6445     return 0;
6446
6447 restore_opts:
6448     sb->s_flags = old_sb_flags;
6449     sbi->s_mount_opt = old_opts.s_mount_opt;
6450     sbi->s_mount_opt2 = old_opts.s_mount_opt2;
6451     sbi->s_resuid = old_opts.s_resuid;
6452     sbi->s_resgid = old_opts.s_resgid;
6453     sbi->s_commit_interval = old_opts.s_commit_interval;
6454     sbi->s_min_batch_time = old_opts.s_min_batch_time;
6455     sbi->s_max_batch_time = old_opts.s_max_batch_time;
6456     if (!test_opt(sb, BLOCK_VALIDITY) && sbi->s_system_blks)
6457         ext4_release_system_zone(sb);
6458 #ifdef CONFIG_QUOTA
6459     sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
6460     for (i = 0; i < EXT4_MAXQUOTAS; i++) {
6461         to_free[i] = get_qf_name(sb, sbi, i);
6462         rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
6463     }
6464     synchronize_rcu();
6465     for (i = 0; i < EXT4_MAXQUOTAS; i++)
6466         kfree(to_free[i]);
6467 #endif
6468     if (!ext4_has_feature_mmp(sb) || sb_rdonly(sb))
6469         ext4_stop_mmpd(sbi);
6470     return err;
6471 }
6472
6473 static int ext4_reconfigure(struct fs_context *fc)
6474 {
6475     struct super_block *sb = fc->root->d_sb;
6476     int ret;
6477
6478     fc->s_fs_info = EXT4_SB(sb);
6479
6480     ret = ext4_check_opt_consistency(fc, sb);
6481     if (ret < 0)
6482         return ret;
6483
6484     ret = __ext4_remount(fc, sb);
6485     if (ret < 0)
6486         return ret;
6487
6488     ext4_msg(sb, KERN_INFO, "re-mounted. Quota mode: %s.",
6489          ext4_quota_mode(sb));
6490
6491     return 0;
6492 }
6493
6494 #ifdef CONFIG_QUOTA
6495 static int ext4_statfs_project(struct super_block *sb,
6496                    kprojid_t projid, struct kstatfs *buf)
6497 {
6498     struct kqid qid;
6499     struct dquot *dquot;
6500     u64 limit;
6501     u64 curblock;
6502
6503     qid = make_kqid_projid(projid);
6504     dquot = dqget(sb, qid);
6505     if (IS_ERR(dquot))
6506         return PTR_ERR(dquot);
6507     spin_lock(&dquot->dq_dqb_lock);
6508
6509     limit = min_not_zero(dquot->dq_dqb.dqb_bsoftlimit,
6510                  dquot->dq_dqb.dqb_bhardlimit);
6511     limit >>= sb->s_blocksize_bits;
6512
6513     if (limit && buf->f_blocks > limit) {
6514         curblock = (dquot->dq_dqb.dqb_curspace +
6515                 dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
6516         buf->f_blocks = limit;
6517         buf->f_bfree = buf->f_bavail =
6518             (buf->f_blocks > curblock) ?
6519              (buf->f_blocks - curblock) : 0;
6520     }
6521
6522     limit = min_not_zero(dquot->dq_dqb.dqb_isoftlimit,
6523                  dquot->dq_dqb.dqb_ihardlimit);
6524     if (limit && buf->f_files > limit) {
6525         buf->f_files = limit;
6526         buf->f_ffree =
6527             (buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
6528              (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
6529     }
6530
6531     spin_unlock(&dquot->dq_dqb_lock);
6532     dqput(dquot);
6533     return 0;
6534 }
6535 #endif
6536
6537 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
6538 {
6539     struct super_block *sb = dentry->d_sb;
6540     struct ext4_sb_info *sbi = EXT4_SB(sb);
6541     struct ext4_super_block *es = sbi->s_es;
6542     ext4_fsblk_t overhead = 0, resv_blocks;
6543     s64 bfree;
6544     resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
6545
6546     if (!test_opt(sb, MINIX_DF))
6547         overhead = sbi->s_overhead;
6548
6549     buf->f_type = EXT4_SUPER_MAGIC;
6550     buf->f_bsize = sb->s_blocksize;
6551     buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
6552     bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
6553         percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
6554     /* prevent underflow in case that few free space is available */
6555     buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
6556     buf->f_bavail = buf->f_bfree -
6557             (ext4_r_blocks_count(es) + resv_blocks);
6558     if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
6559         buf->f_bavail = 0;
6560     buf->f_files = le32_to_cpu(es->s_inodes_count);
6561     buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
6562     buf->f_namelen = EXT4_NAME_LEN;
6563     buf->f_fsid = uuid_to_fsid(es->s_uuid);
6564
6565 #ifdef CONFIG_QUOTA
6566     if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
6567         sb_has_quota_limits_enabled(sb, PRJQUOTA))
6568         ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
6569 #endif
6570     return 0;
6571 }
6572
6573
6574 #ifdef CONFIG_QUOTA
6575
6576 /*
6577  * Helper functions so that transaction is started before we acquire dqio_sem
6578  * to keep correct lock ordering of transaction > dqio_sem
6579  */
6580 static inline struct inode *dquot_to_inode(struct dquot *dquot)
6581 {
6582     return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
6583 }
6584
6585 static int ext4_write_dquot(struct dquot *dquot)
6586 {
6587     int ret, err;
6588     handle_t *handle;
6589     struct inode *inode;
6590
6591     inode = dquot_to_inode(dquot);
6592     handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
6593                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
6594     if (IS_ERR(handle))
6595         return PTR_ERR(handle);
6596     ret = dquot_commit(dquot);
6597     err = ext4_journal_stop(handle);
6598     if (!ret)
6599         ret = err;
6600     return ret;
6601 }
6602
6603 static int ext4_acquire_dquot(struct dquot *dquot)
6604 {
6605     int ret, err;
6606     handle_t *handle;
6607
6608     handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6609                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
6610     if (IS_ERR(handle))
6611         return PTR_ERR(handle);
6612     ret = dquot_acquire(dquot);
6613     err = ext4_journal_stop(handle);
6614     if (!ret)
6615         ret = err;
6616     return ret;
6617 }
6618
6619 static int ext4_release_dquot(struct dquot *dquot)
6620 {
6621     int ret, err;
6622     handle_t *handle;
6623
6624     handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
6625                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
6626     if (IS_ERR(handle)) {
6627         /* Release dquot anyway to avoid endless cycle in dqput() */
6628         dquot_release(dquot);
6629         return PTR_ERR(handle);
6630     }
6631     ret = dquot_release(dquot);
6632     err = ext4_journal_stop(handle);
6633     if (!ret)
6634         ret = err;
6635     return ret;
6636 }
6637
6638 static int ext4_mark_dquot_dirty(struct dquot *dquot)
6639 {
6640     struct super_block *sb = dquot->dq_sb;
6641
6642     if (ext4_is_quota_journalled(sb)) {
6643         dquot_mark_dquot_dirty(dquot);
6644         return ext4_write_dquot(dquot);
6645     } else {
6646         return dquot_mark_dquot_dirty(dquot);
6647     }
6648 }
6649
6650 static int ext4_write_info(struct super_block *sb, int type)
6651 {
6652     int ret, err;
6653     handle_t *handle;
6654
6655     /* Data block + inode block */
6656     handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
6657     if (IS_ERR(handle))
6658         return PTR_ERR(handle);
6659     ret = dquot_commit_info(sb, type);
6660     err = ext4_journal_stop(handle);
6661     if (!ret)
6662         ret = err;
6663     return ret;
6664 }
6665
6666 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
6667 {
6668     struct ext4_inode_info *ei = EXT4_I(inode);
6669
6670     /* The first argument of lockdep_set_subclass has to be
6671      * *exactly* the same as the argument to init_rwsem() --- in
6672      * this case, in init_once() --- or lockdep gets unhappy
6673      * because the name of the lock is set using the
6674      * stringification of the argument to init_rwsem().
6675      */
6676     (void) ei;  /* shut up clang warning if !CONFIG_LOCKDEP */
6677     lockdep_set_subclass(&ei->i_data_sem, subclass);
6678 }
6679
6680 /*
6681  * Standard function to be called on quota_on
6682  */
6683 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
6684              const struct path *path)
6685 {
6686     int err;
6687
6688     if (!test_opt(sb, QUOTA))
6689         return -EINVAL;
6690
6691     /* Quotafile not on the same filesystem? */
6692     if (path->dentry->d_sb != sb)
6693         return -EXDEV;
6694
6695     /* Quota already enabled for this file? */
6696     if (IS_NOQUOTA(d_inode(path->dentry)))
6697         return -EBUSY;
6698
6699     /* Journaling quota? */
6700     if (EXT4_SB(sb)->s_qf_names[type]) {
6701         /* Quotafile not in fs root? */
6702         if (path->dentry->d_parent != sb->s_root)
6703             ext4_msg(sb, KERN_WARNING,
6704                 "Quota file not on filesystem root. "
6705                 "Journaled quota will not work");
6706         sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
6707     } else {
6708         /*
6709          * Clear the flag just in case mount options changed since
6710          * last time.
6711          */
6712         sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
6713     }
6714
6715     /*
6716      * When we journal data on quota file, we have to flush journal to see
6717      * all updates to the file when we bypass pagecache...
6718      */
6719     if (EXT4_SB(sb)->s_journal &&
6720         ext4_should_journal_data(d_inode(path->dentry))) {
6721         /*
6722          * We don't need to lock updates but journal_flush() could
6723          * otherwise be livelocked...
6724          */
6725         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
6726         err = jbd2_journal_flush(EXT4_SB(sb)->s_journal, 0);
6727         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
6728         if (err)
6729             return err;
6730     }
6731
6732     lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
6733     err = dquot_quota_on(sb, type, format_id, path);
6734     if (!err) {
6735         struct inode *inode = d_inode(path->dentry);
6736         handle_t *handle;
6737
6738         /*
6739          * Set inode flags to prevent userspace from messing with quota
6740          * files. If this fails, we return success anyway since quotas
6741          * are already enabled and this is not a hard failure.
6742          */
6743         inode_lock(inode);
6744         handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6745         if (IS_ERR(handle))
6746             goto unlock_inode;
6747         EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
6748         inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
6749                 S_NOATIME | S_IMMUTABLE);
6750         err = ext4_mark_inode_dirty(handle, inode);
6751         ext4_journal_stop(handle);
6752     unlock_inode:
6753         inode_unlock(inode);
6754         if (err)
6755             dquot_quota_off(sb, type);
6756     }
6757     if (err)
6758         lockdep_set_quota_inode(path->dentry->d_inode,
6759                          I_DATA_SEM_NORMAL);
6760     return err;
6761 }
6762
6763 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
6764                  unsigned int flags)
6765 {
6766     int err;
6767     struct inode *qf_inode;
6768     unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6769         le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6770         le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6771         le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6772     };
6773
6774     BUG_ON(!ext4_has_feature_quota(sb));
6775
6776     if (!qf_inums[type])
6777         return -EPERM;
6778
6779     qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
6780     if (IS_ERR(qf_inode)) {
6781         ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
6782         return PTR_ERR(qf_inode);
6783     }
6784
6785     /* Don't account quota for quota files to avoid recursion */
6786     qf_inode->i_flags |= S_NOQUOTA;
6787     lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
6788     err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
6789     if (err)
6790         lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
6791     iput(qf_inode);
6792
6793     return err;
6794 }
6795
6796 /* Enable usage tracking for all quota types. */
6797 int ext4_enable_quotas(struct super_block *sb)
6798 {
6799     int type, err = 0;
6800     unsigned long qf_inums[EXT4_MAXQUOTAS] = {
6801         le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
6802         le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
6803         le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
6804     };
6805     bool quota_mopt[EXT4_MAXQUOTAS] = {
6806         test_opt(sb, USRQUOTA),
6807         test_opt(sb, GRPQUOTA),
6808         test_opt(sb, PRJQUOTA),
6809     };
6810
6811     sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
6812     for (type = 0; type < EXT4_MAXQUOTAS; type++) {
6813         if (qf_inums[type]) {
6814             err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
6815                 DQUOT_USAGE_ENABLED |
6816                 (quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
6817             if (err) {
6818                 ext4_warning(sb,
6819                     "Failed to enable quota tracking "
6820                     "(type=%d, err=%d). Please run "
6821                     "e2fsck to fix.", type, err);
6822                 for (type--; type >= 0; type--) {
6823                     struct inode *inode;
6824
6825                     inode = sb_dqopt(sb)->files[type];
6826                     if (inode)
6827                         inode = igrab(inode);
6828                     dquot_quota_off(sb, type);
6829                     if (inode) {
6830                         lockdep_set_quota_inode(inode,
6831                             I_DATA_SEM_NORMAL);
6832                         iput(inode);
6833                     }
6834                 }
6835
6836                 return err;
6837             }
6838         }
6839     }
6840     return 0;
6841 }
6842
6843 static int ext4_quota_off(struct super_block *sb, int type)
6844 {
6845     struct inode *inode = sb_dqopt(sb)->files[type];
6846     handle_t *handle;
6847     int err;
6848
6849     /* Force all delayed allocation blocks to be allocated.
6850      * Caller already holds s_umount sem */
6851     if (test_opt(sb, DELALLOC))
6852         sync_filesystem(sb);
6853
6854     if (!inode || !igrab(inode))
6855         goto out;
6856
6857     err = dquot_quota_off(sb, type);
6858     if (err || ext4_has_feature_quota(sb))
6859         goto out_put;
6860
6861     inode_lock(inode);
6862     /*
6863      * Update modification times of quota files when userspace can
6864      * start looking at them. If we fail, we return success anyway since
6865      * this is not a hard failure and quotas are already disabled.
6866      */
6867     handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
6868     if (IS_ERR(handle)) {
6869         err = PTR_ERR(handle);
6870         goto out_unlock;
6871     }
6872     EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
6873     inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
6874     inode->i_mtime = inode->i_ctime = current_time(inode);
6875     err = ext4_mark_inode_dirty(handle, inode);
6876     ext4_journal_stop(handle);
6877 out_unlock:
6878     inode_unlock(inode);
6879 out_put:
6880     lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
6881     iput(inode);
6882     return err;
6883 out:
6884     return dquot_quota_off(sb, type);
6885 }
6886
6887 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6888  * acquiring the locks... As quota files are never truncated and quota code
6889  * itself serializes the operations (and no one else should touch the files)
6890  * we don't have to be afraid of races */
6891 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6892                    size_t len, loff_t off)
6893 {
6894     struct inode *inode = sb_dqopt(sb)->files[type];
6895     ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6896     int offset = off & (sb->s_blocksize - 1);
6897     int tocopy;
6898     size_t toread;
6899     struct buffer_head *bh;
6900     loff_t i_size = i_size_read(inode);
6901
6902     if (off > i_size)
6903         return 0;
6904     if (off+len > i_size)
6905         len = i_size-off;
6906     toread = len;
6907     while (toread > 0) {
6908         tocopy = sb->s_blocksize - offset < toread ?
6909                 sb->s_blocksize - offset : toread;
6910         bh = ext4_bread(NULL, inode, blk, 0);
6911         if (IS_ERR(bh))
6912             return PTR_ERR(bh);
6913         if (!bh)    /* A hole? */
6914             memset(data, 0, tocopy);
6915         else
6916             memcpy(data, bh->b_data+offset, tocopy);
6917         brelse(bh);
6918         offset = 0;
6919         toread -= tocopy;
6920         data += tocopy;
6921         blk++;
6922     }
6923     return len;
6924 }
6925
6926 /* Write to quotafile (we know the transaction is already started and has
6927  * enough credits) */
6928 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6929                 const char *data, size_t len, loff_t off)
6930 {
6931     struct inode *inode = sb_dqopt(sb)->files[type];
6932     ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6933     int err = 0, err2 = 0, offset = off & (sb->s_blocksize - 1);
6934     int retries = 0;
6935     struct buffer_head *bh;
6936     handle_t *handle = journal_current_handle();
6937
6938     if (!handle) {
6939         ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6940             " cancelled because transaction is not started",
6941             (unsigned long long)off, (unsigned long long)len);
6942         return -EIO;
6943     }
6944     /*
6945      * Since we account only one data block in transaction credits,
6946      * then it is impossible to cross a block boundary.
6947      */
6948     if (sb->s_blocksize - offset < len) {
6949         ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6950             " cancelled because not block aligned",
6951             (unsigned long long)off, (unsigned long long)len);
6952         return -EIO;
6953     }
6954
6955     do {
6956         bh = ext4_bread(handle, inode, blk,
6957                 EXT4_GET_BLOCKS_CREATE |
6958                 EXT4_GET_BLOCKS_METADATA_NOFAIL);
6959     } while (PTR_ERR(bh) == -ENOSPC &&
6960          ext4_should_retry_alloc(inode->i_sb, &retries));
6961     if (IS_ERR(bh))
6962         return PTR_ERR(bh);
6963     if (!bh)
6964         goto out;
6965     BUFFER_TRACE(bh, "get write access");
6966     err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE);
6967     if (err) {
6968         brelse(bh);
6969         return err;
6970     }
6971     lock_buffer(bh);
6972     memcpy(bh->b_data+offset, data, len);
6973     flush_dcache_page(bh->b_page);
6974     unlock_buffer(bh);
6975     err = ext4_handle_dirty_metadata(handle, NULL, bh);
6976     brelse(bh);
6977 out:
6978     if (inode->i_size < off + len) {
6979         i_size_write(inode, off + len);
6980         EXT4_I(inode)->i_disksize = inode->i_size;
6981         err2 = ext4_mark_inode_dirty(handle, inode);
6982         if (unlikely(err2 && !err))
6983             err = err2;
6984     }
6985     return err ? err : len;
6986 }
6987 #endif
6988
6989 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6990 static inline void register_as_ext2(void)
6991 {
6992     int err = register_filesystem(&ext2_fs_type);
6993     if (err)
6994         printk(KERN_WARNING
6995                "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6996 }
6997
6998 static inline void unregister_as_ext2(void)
6999 {
7000     unregister_filesystem(&ext2_fs_type);
7001 }
7002
7003 static inline int ext2_feature_set_ok(struct super_block *sb)
7004 {
7005     if (ext4_has_unknown_ext2_incompat_features(sb))
7006         return 0;
7007     if (sb_rdonly(sb))
7008         return 1;
7009     if (ext4_has_unknown_ext2_ro_compat_features(sb))
7010         return 0;
7011     return 1;
7012 }
7013 #else
7014 static inline void register_as_ext2(void) { }
7015 static inline void unregister_as_ext2(void) { }
7016 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
7017 #endif
7018
7019 static inline void register_as_ext3(void)
7020 {
7021     int err = register_filesystem(&ext3_fs_type);
7022     if (err)
7023         printk(KERN_WARNING
7024                "EXT4-fs: Unable to register as ext3 (%d)\n", err);
7025 }
7026
7027 static inline void unregister_as_ext3(void)
7028 {
7029     unregister_filesystem(&ext3_fs_type);
7030 }
7031
7032 static inline int ext3_feature_set_ok(struct super_block *sb)
7033 {
7034     if (ext4_has_unknown_ext3_incompat_features(sb))
7035         return 0;
7036     if (!ext4_has_feature_journal(sb))
7037         return 0;
7038     if (sb_rdonly(sb))
7039         return 1;
7040     if (ext4_has_unknown_ext3_ro_compat_features(sb))
7041         return 0;
7042     return 1;
7043 }
7044
7045 static struct file_system_type ext4_fs_type = {
7046     .owner          = THIS_MODULE,
7047     .name           = "ext4",
7048     .init_fs_context    = ext4_init_fs_context,
7049     .parameters     = ext4_param_specs,
7050     .kill_sb        = kill_block_super,
7051     .fs_flags       = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
7052 };
7053 MODULE_ALIAS_FS("ext4");
7054
7055 /* Shared across all ext4 file systems */
7056 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
7057
7058 static int __init ext4_init_fs(void)
7059 {
7060     int i, err;
7061
7062     ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
7063     ext4_li_info = NULL;
7064
7065     /* Build-time check for flags consistency */
7066     ext4_check_flag_values();
7067
7068     for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
7069         init_waitqueue_head(&ext4__ioend_wq[i]);
7070
7071     err = ext4_init_es();
7072     if (err)
7073         return err;
7074
7075     err = ext4_init_pending();
7076     if (err)
7077         goto out7;
7078
7079     err = ext4_init_post_read_processing();
7080     if (err)
7081         goto out6;
7082
7083     err = ext4_init_pageio();
7084     if (err)
7085         goto out5;
7086
7087     err = ext4_init_system_zone();
7088     if (err)
7089         goto out4;
7090
7091     err = ext4_init_sysfs();
7092     if (err)
7093         goto out3;
7094
7095     err = ext4_init_mballoc();
7096     if (err)
7097         goto out2;
7098     err = init_inodecache();
7099     if (err)
7100         goto out1;
7101
7102     err = ext4_fc_init_dentry_cache();
7103     if (err)
7104         goto out05;
7105
7106     register_as_ext3();
7107     register_as_ext2();
7108     err = register_filesystem(&ext4_fs_type);
7109     if (err)
7110         goto out;
7111
7112     return 0;
7113 out:
7114     unregister_as_ext2();
7115     unregister_as_ext3();
7116     ext4_fc_destroy_dentry_cache();
7117 out05:
7118     destroy_inodecache();
7119 out1:
7120     ext4_exit_mballoc();
7121 out2:
7122     ext4_exit_sysfs();
7123 out3:
7124     ext4_exit_system_zone();
7125 out4:
7126     ext4_exit_pageio();
7127 out5:
7128     ext4_exit_post_read_processing();
7129 out6:
7130     ext4_exit_pending();
7131 out7:
7132     ext4_exit_es();
7133
7134     return err;
7135 }
7136
7137 static void __exit ext4_exit_fs(void)
7138 {
7139     ext4_destroy_lazyinit_thread();
7140     unregister_as_ext2();
7141     unregister_as_ext3();
7142     unregister_filesystem(&ext4_fs_type);
7143     ext4_fc_destroy_dentry_cache();
7144     destroy_inodecache();
7145     ext4_exit_mballoc();
7146     ext4_exit_sysfs();
7147     ext4_exit_system_zone();
7148     ext4_exit_pageio();
7149     ext4_exit_post_read_processing();
7150     ext4_exit_es();
7151     ext4_exit_pending();
7152 }
7153
7154 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
7155 MODULE_DESCRIPTION("Fourth Extended Filesystem");
7156 MODULE_LICENSE("GPL");
7157 MODULE_SOFTDEP("pre: crc32c");
7158 module_init(ext4_init_fs)
7159 module_exit(ext4_exit_fs)