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0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
0004  */
0005 
0006 #include <linux/fs_context.h>
0007 #include <linux/fs_parser.h>
0008 #include <linux/module.h>
0009 #include <linux/init.h>
0010 #include <linux/time.h>
0011 #include <linux/mount.h>
0012 #include <linux/cred.h>
0013 #include <linux/statfs.h>
0014 #include <linux/seq_file.h>
0015 #include <linux/blkdev.h>
0016 #include <linux/fs_struct.h>
0017 #include <linux/iversion.h>
0018 #include <linux/nls.h>
0019 #include <linux/buffer_head.h>
0020 #include <linux/magic.h>
0021 
0022 #include "exfat_raw.h"
0023 #include "exfat_fs.h"
0024 
0025 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
0026 static struct kmem_cache *exfat_inode_cachep;
0027 
0028 static void exfat_free_iocharset(struct exfat_sb_info *sbi)
0029 {
0030     if (sbi->options.iocharset != exfat_default_iocharset)
0031         kfree(sbi->options.iocharset);
0032 }
0033 
0034 static void exfat_delayed_free(struct rcu_head *p)
0035 {
0036     struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
0037 
0038     unload_nls(sbi->nls_io);
0039     exfat_free_iocharset(sbi);
0040     exfat_free_upcase_table(sbi);
0041     kfree(sbi);
0042 }
0043 
0044 static void exfat_put_super(struct super_block *sb)
0045 {
0046     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0047 
0048     mutex_lock(&sbi->s_lock);
0049     exfat_free_bitmap(sbi);
0050     brelse(sbi->boot_bh);
0051     mutex_unlock(&sbi->s_lock);
0052 
0053     call_rcu(&sbi->rcu, exfat_delayed_free);
0054 }
0055 
0056 static int exfat_sync_fs(struct super_block *sb, int wait)
0057 {
0058     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0059     int err = 0;
0060 
0061     if (!wait)
0062         return 0;
0063 
0064     /* If there are some dirty buffers in the bdev inode */
0065     mutex_lock(&sbi->s_lock);
0066     sync_blockdev(sb->s_bdev);
0067     if (exfat_clear_volume_dirty(sb))
0068         err = -EIO;
0069     mutex_unlock(&sbi->s_lock);
0070     return err;
0071 }
0072 
0073 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
0074 {
0075     struct super_block *sb = dentry->d_sb;
0076     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0077     unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
0078 
0079     if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
0080         mutex_lock(&sbi->s_lock);
0081         if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
0082             mutex_unlock(&sbi->s_lock);
0083             return -EIO;
0084         }
0085         mutex_unlock(&sbi->s_lock);
0086     }
0087 
0088     buf->f_type = sb->s_magic;
0089     buf->f_bsize = sbi->cluster_size;
0090     buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
0091     buf->f_bfree = buf->f_blocks - sbi->used_clusters;
0092     buf->f_bavail = buf->f_bfree;
0093     buf->f_fsid = u64_to_fsid(id);
0094     /* Unicode utf16 255 characters */
0095     buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
0096     return 0;
0097 }
0098 
0099 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
0100 {
0101     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0102     struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
0103 
0104     /* retain persistent-flags */
0105     new_flags |= sbi->vol_flags_persistent;
0106 
0107     /* flags are not changed */
0108     if (sbi->vol_flags == new_flags)
0109         return 0;
0110 
0111     sbi->vol_flags = new_flags;
0112 
0113     /* skip updating volume dirty flag,
0114      * if this volume has been mounted with read-only
0115      */
0116     if (sb_rdonly(sb))
0117         return 0;
0118 
0119     p_boot->vol_flags = cpu_to_le16(new_flags);
0120 
0121     set_buffer_uptodate(sbi->boot_bh);
0122     mark_buffer_dirty(sbi->boot_bh);
0123 
0124     __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
0125 
0126     return 0;
0127 }
0128 
0129 int exfat_set_volume_dirty(struct super_block *sb)
0130 {
0131     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0132 
0133     return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
0134 }
0135 
0136 int exfat_clear_volume_dirty(struct super_block *sb)
0137 {
0138     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0139 
0140     return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
0141 }
0142 
0143 static int exfat_show_options(struct seq_file *m, struct dentry *root)
0144 {
0145     struct super_block *sb = root->d_sb;
0146     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0147     struct exfat_mount_options *opts = &sbi->options;
0148 
0149     /* Show partition info */
0150     if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
0151         seq_printf(m, ",uid=%u",
0152                 from_kuid_munged(&init_user_ns, opts->fs_uid));
0153     if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
0154         seq_printf(m, ",gid=%u",
0155                 from_kgid_munged(&init_user_ns, opts->fs_gid));
0156     seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
0157     if (opts->allow_utime)
0158         seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
0159     if (opts->utf8)
0160         seq_puts(m, ",iocharset=utf8");
0161     else if (sbi->nls_io)
0162         seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
0163     if (opts->errors == EXFAT_ERRORS_CONT)
0164         seq_puts(m, ",errors=continue");
0165     else if (opts->errors == EXFAT_ERRORS_PANIC)
0166         seq_puts(m, ",errors=panic");
0167     else
0168         seq_puts(m, ",errors=remount-ro");
0169     if (opts->discard)
0170         seq_puts(m, ",discard");
0171     if (opts->keep_last_dots)
0172         seq_puts(m, ",keep_last_dots");
0173     if (opts->sys_tz)
0174         seq_puts(m, ",sys_tz");
0175     else if (opts->time_offset)
0176         seq_printf(m, ",time_offset=%d", opts->time_offset);
0177     return 0;
0178 }
0179 
0180 static struct inode *exfat_alloc_inode(struct super_block *sb)
0181 {
0182     struct exfat_inode_info *ei;
0183 
0184     ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
0185     if (!ei)
0186         return NULL;
0187 
0188     init_rwsem(&ei->truncate_lock);
0189     return &ei->vfs_inode;
0190 }
0191 
0192 static void exfat_free_inode(struct inode *inode)
0193 {
0194     kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
0195 }
0196 
0197 static const struct super_operations exfat_sops = {
0198     .alloc_inode    = exfat_alloc_inode,
0199     .free_inode = exfat_free_inode,
0200     .write_inode    = exfat_write_inode,
0201     .evict_inode    = exfat_evict_inode,
0202     .put_super  = exfat_put_super,
0203     .sync_fs    = exfat_sync_fs,
0204     .statfs     = exfat_statfs,
0205     .show_options   = exfat_show_options,
0206 };
0207 
0208 enum {
0209     Opt_uid,
0210     Opt_gid,
0211     Opt_umask,
0212     Opt_dmask,
0213     Opt_fmask,
0214     Opt_allow_utime,
0215     Opt_charset,
0216     Opt_errors,
0217     Opt_discard,
0218     Opt_keep_last_dots,
0219     Opt_sys_tz,
0220     Opt_time_offset,
0221 
0222     /* Deprecated options */
0223     Opt_utf8,
0224     Opt_debug,
0225     Opt_namecase,
0226     Opt_codepage,
0227 };
0228 
0229 static const struct constant_table exfat_param_enums[] = {
0230     { "continue",       EXFAT_ERRORS_CONT },
0231     { "panic",      EXFAT_ERRORS_PANIC },
0232     { "remount-ro",     EXFAT_ERRORS_RO },
0233     {}
0234 };
0235 
0236 static const struct fs_parameter_spec exfat_parameters[] = {
0237     fsparam_u32("uid",          Opt_uid),
0238     fsparam_u32("gid",          Opt_gid),
0239     fsparam_u32oct("umask",         Opt_umask),
0240     fsparam_u32oct("dmask",         Opt_dmask),
0241     fsparam_u32oct("fmask",         Opt_fmask),
0242     fsparam_u32oct("allow_utime",       Opt_allow_utime),
0243     fsparam_string("iocharset",     Opt_charset),
0244     fsparam_enum("errors",          Opt_errors, exfat_param_enums),
0245     fsparam_flag("discard",         Opt_discard),
0246     fsparam_flag("keep_last_dots",      Opt_keep_last_dots),
0247     fsparam_flag("sys_tz",          Opt_sys_tz),
0248     fsparam_s32("time_offset",      Opt_time_offset),
0249     __fsparam(NULL, "utf8",         Opt_utf8, fs_param_deprecated,
0250           NULL),
0251     __fsparam(NULL, "debug",        Opt_debug, fs_param_deprecated,
0252           NULL),
0253     __fsparam(fs_param_is_u32, "namecase",  Opt_namecase,
0254           fs_param_deprecated, NULL),
0255     __fsparam(fs_param_is_u32, "codepage",  Opt_codepage,
0256           fs_param_deprecated, NULL),
0257     {}
0258 };
0259 
0260 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
0261 {
0262     struct exfat_sb_info *sbi = fc->s_fs_info;
0263     struct exfat_mount_options *opts = &sbi->options;
0264     struct fs_parse_result result;
0265     int opt;
0266 
0267     opt = fs_parse(fc, exfat_parameters, param, &result);
0268     if (opt < 0)
0269         return opt;
0270 
0271     switch (opt) {
0272     case Opt_uid:
0273         opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
0274         break;
0275     case Opt_gid:
0276         opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
0277         break;
0278     case Opt_umask:
0279         opts->fs_fmask = result.uint_32;
0280         opts->fs_dmask = result.uint_32;
0281         break;
0282     case Opt_dmask:
0283         opts->fs_dmask = result.uint_32;
0284         break;
0285     case Opt_fmask:
0286         opts->fs_fmask = result.uint_32;
0287         break;
0288     case Opt_allow_utime:
0289         opts->allow_utime = result.uint_32 & 0022;
0290         break;
0291     case Opt_charset:
0292         exfat_free_iocharset(sbi);
0293         opts->iocharset = param->string;
0294         param->string = NULL;
0295         break;
0296     case Opt_errors:
0297         opts->errors = result.uint_32;
0298         break;
0299     case Opt_discard:
0300         opts->discard = 1;
0301         break;
0302     case Opt_keep_last_dots:
0303         opts->keep_last_dots = 1;
0304         break;
0305     case Opt_sys_tz:
0306         opts->sys_tz = 1;
0307         break;
0308     case Opt_time_offset:
0309         /*
0310          * Make the limit 24 just in case someone invents something
0311          * unusual.
0312          */
0313         if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
0314             return -EINVAL;
0315         opts->time_offset = result.int_32;
0316         break;
0317     case Opt_utf8:
0318     case Opt_debug:
0319     case Opt_namecase:
0320     case Opt_codepage:
0321         break;
0322     default:
0323         return -EINVAL;
0324     }
0325 
0326     return 0;
0327 }
0328 
0329 static void exfat_hash_init(struct super_block *sb)
0330 {
0331     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0332     int i;
0333 
0334     spin_lock_init(&sbi->inode_hash_lock);
0335     for (i = 0; i < EXFAT_HASH_SIZE; i++)
0336         INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
0337 }
0338 
0339 static int exfat_read_root(struct inode *inode)
0340 {
0341     struct super_block *sb = inode->i_sb;
0342     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0343     struct exfat_inode_info *ei = EXFAT_I(inode);
0344     struct exfat_chain cdir;
0345     int num_subdirs, num_clu = 0;
0346 
0347     exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
0348     ei->entry = -1;
0349     ei->start_clu = sbi->root_dir;
0350     ei->flags = ALLOC_FAT_CHAIN;
0351     ei->type = TYPE_DIR;
0352     ei->version = 0;
0353     ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
0354     ei->hint_stat.eidx = 0;
0355     ei->hint_stat.clu = sbi->root_dir;
0356     ei->hint_femp.eidx = EXFAT_HINT_NONE;
0357 
0358     exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
0359     if (exfat_count_num_clusters(sb, &cdir, &num_clu))
0360         return -EIO;
0361     i_size_write(inode, num_clu << sbi->cluster_size_bits);
0362 
0363     num_subdirs = exfat_count_dir_entries(sb, &cdir);
0364     if (num_subdirs < 0)
0365         return -EIO;
0366     set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
0367 
0368     inode->i_uid = sbi->options.fs_uid;
0369     inode->i_gid = sbi->options.fs_gid;
0370     inode_inc_iversion(inode);
0371     inode->i_generation = 0;
0372     inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
0373     inode->i_op = &exfat_dir_inode_operations;
0374     inode->i_fop = &exfat_dir_operations;
0375 
0376     inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >>
0377                 inode->i_blkbits;
0378     ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
0379     ei->i_size_aligned = i_size_read(inode);
0380     ei->i_size_ondisk = i_size_read(inode);
0381 
0382     exfat_save_attr(inode, ATTR_SUBDIR);
0383     inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
0384         current_time(inode);
0385     exfat_truncate_atime(&inode->i_atime);
0386     return 0;
0387 }
0388 
0389 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
0390 {
0391     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0392 
0393     if (!is_power_of_2(logical_sect)) {
0394         exfat_err(sb, "bogus logical sector size %u", logical_sect);
0395         return -EIO;
0396     }
0397 
0398     if (logical_sect < sb->s_blocksize) {
0399         exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
0400               logical_sect);
0401         return -EIO;
0402     }
0403 
0404     if (logical_sect > sb->s_blocksize) {
0405         brelse(sbi->boot_bh);
0406         sbi->boot_bh = NULL;
0407 
0408         if (!sb_set_blocksize(sb, logical_sect)) {
0409             exfat_err(sb, "unable to set blocksize %u",
0410                   logical_sect);
0411             return -EIO;
0412         }
0413         sbi->boot_bh = sb_bread(sb, 0);
0414         if (!sbi->boot_bh) {
0415             exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
0416                   sb->s_blocksize);
0417             return -EIO;
0418         }
0419     }
0420     return 0;
0421 }
0422 
0423 static int exfat_read_boot_sector(struct super_block *sb)
0424 {
0425     struct boot_sector *p_boot;
0426     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0427 
0428     /* set block size to read super block */
0429     sb_min_blocksize(sb, 512);
0430 
0431     /* read boot sector */
0432     sbi->boot_bh = sb_bread(sb, 0);
0433     if (!sbi->boot_bh) {
0434         exfat_err(sb, "unable to read boot sector");
0435         return -EIO;
0436     }
0437     p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
0438 
0439     /* check the validity of BOOT */
0440     if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
0441         exfat_err(sb, "invalid boot record signature");
0442         return -EINVAL;
0443     }
0444 
0445     if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
0446         exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
0447         return -EINVAL;
0448     }
0449 
0450     /*
0451      * must_be_zero field must be filled with zero to prevent mounting
0452      * from FAT volume.
0453      */
0454     if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
0455         return -EINVAL;
0456 
0457     if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
0458         exfat_err(sb, "bogus number of FAT structure");
0459         return -EINVAL;
0460     }
0461 
0462     /*
0463      * sect_size_bits could be at least 9 and at most 12.
0464      */
0465     if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
0466         p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
0467         exfat_err(sb, "bogus sector size bits : %u",
0468                 p_boot->sect_size_bits);
0469         return -EINVAL;
0470     }
0471 
0472     /*
0473      * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
0474      */
0475     if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
0476         exfat_err(sb, "bogus sectors bits per cluster : %u",
0477                 p_boot->sect_per_clus_bits);
0478         return -EINVAL;
0479     }
0480 
0481     sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
0482     sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
0483     sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
0484         p_boot->sect_size_bits;
0485     sbi->cluster_size = 1 << sbi->cluster_size_bits;
0486     sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
0487     sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
0488     sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
0489     if (p_boot->num_fats == 2)
0490         sbi->FAT2_start_sector += sbi->num_FAT_sectors;
0491     sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
0492     sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
0493     /* because the cluster index starts with 2 */
0494     sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
0495         EXFAT_RESERVED_CLUSTERS;
0496 
0497     sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
0498     sbi->dentries_per_clu = 1 <<
0499         (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
0500 
0501     sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
0502     sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
0503     sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
0504     sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
0505 
0506     /* check consistencies */
0507     if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
0508         (u64)sbi->num_clusters * 4) {
0509         exfat_err(sb, "bogus fat length");
0510         return -EINVAL;
0511     }
0512 
0513     if (sbi->data_start_sector <
0514         (u64)sbi->FAT1_start_sector +
0515         (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
0516         exfat_err(sb, "bogus data start sector");
0517         return -EINVAL;
0518     }
0519 
0520     if (sbi->vol_flags & VOLUME_DIRTY)
0521         exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
0522     if (sbi->vol_flags & MEDIA_FAILURE)
0523         exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
0524 
0525     /* exFAT file size is limited by a disk volume size */
0526     sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
0527         sbi->cluster_size_bits;
0528 
0529     /* check logical sector size */
0530     if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
0531         return -EIO;
0532 
0533     return 0;
0534 }
0535 
0536 static int exfat_verify_boot_region(struct super_block *sb)
0537 {
0538     struct buffer_head *bh = NULL;
0539     u32 chksum = 0;
0540     __le32 *p_sig, *p_chksum;
0541     int sn, i;
0542 
0543     /* read boot sector sub-regions */
0544     for (sn = 0; sn < 11; sn++) {
0545         bh = sb_bread(sb, sn);
0546         if (!bh)
0547             return -EIO;
0548 
0549         if (sn != 0 && sn <= 8) {
0550             /* extended boot sector sub-regions */
0551             p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
0552             if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
0553                 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
0554                        sn, le32_to_cpu(*p_sig));
0555         }
0556 
0557         chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
0558             chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
0559         brelse(bh);
0560     }
0561 
0562     /* boot checksum sub-regions */
0563     bh = sb_bread(sb, sn);
0564     if (!bh)
0565         return -EIO;
0566 
0567     for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
0568         p_chksum = (__le32 *)&bh->b_data[i];
0569         if (le32_to_cpu(*p_chksum) != chksum) {
0570             exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
0571                   le32_to_cpu(*p_chksum), chksum);
0572             brelse(bh);
0573             return -EINVAL;
0574         }
0575     }
0576     brelse(bh);
0577     return 0;
0578 }
0579 
0580 /* mount the file system volume */
0581 static int __exfat_fill_super(struct super_block *sb)
0582 {
0583     int ret;
0584     struct exfat_sb_info *sbi = EXFAT_SB(sb);
0585 
0586     ret = exfat_read_boot_sector(sb);
0587     if (ret) {
0588         exfat_err(sb, "failed to read boot sector");
0589         goto free_bh;
0590     }
0591 
0592     ret = exfat_verify_boot_region(sb);
0593     if (ret) {
0594         exfat_err(sb, "invalid boot region");
0595         goto free_bh;
0596     }
0597 
0598     ret = exfat_create_upcase_table(sb);
0599     if (ret) {
0600         exfat_err(sb, "failed to load upcase table");
0601         goto free_bh;
0602     }
0603 
0604     ret = exfat_load_bitmap(sb);
0605     if (ret) {
0606         exfat_err(sb, "failed to load alloc-bitmap");
0607         goto free_upcase_table;
0608     }
0609 
0610     ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
0611     if (ret) {
0612         exfat_err(sb, "failed to scan clusters");
0613         goto free_alloc_bitmap;
0614     }
0615 
0616     return 0;
0617 
0618 free_alloc_bitmap:
0619     exfat_free_bitmap(sbi);
0620 free_upcase_table:
0621     exfat_free_upcase_table(sbi);
0622 free_bh:
0623     brelse(sbi->boot_bh);
0624     return ret;
0625 }
0626 
0627 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
0628 {
0629     struct exfat_sb_info *sbi = sb->s_fs_info;
0630     struct exfat_mount_options *opts = &sbi->options;
0631     struct inode *root_inode;
0632     int err;
0633 
0634     if (opts->allow_utime == (unsigned short)-1)
0635         opts->allow_utime = ~opts->fs_dmask & 0022;
0636 
0637     if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
0638         exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
0639         opts->discard = 0;
0640     }
0641 
0642     sb->s_flags |= SB_NODIRATIME;
0643     sb->s_magic = EXFAT_SUPER_MAGIC;
0644     sb->s_op = &exfat_sops;
0645 
0646     sb->s_time_gran = 10 * NSEC_PER_MSEC;
0647     sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
0648     sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
0649 
0650     err = __exfat_fill_super(sb);
0651     if (err) {
0652         exfat_err(sb, "failed to recognize exfat type");
0653         goto check_nls_io;
0654     }
0655 
0656     /* set up enough so that it can read an inode */
0657     exfat_hash_init(sb);
0658 
0659     if (!strcmp(sbi->options.iocharset, "utf8"))
0660         opts->utf8 = 1;
0661     else {
0662         sbi->nls_io = load_nls(sbi->options.iocharset);
0663         if (!sbi->nls_io) {
0664             exfat_err(sb, "IO charset %s not found",
0665                   sbi->options.iocharset);
0666             err = -EINVAL;
0667             goto free_table;
0668         }
0669     }
0670 
0671     if (sbi->options.utf8)
0672         sb->s_d_op = &exfat_utf8_dentry_ops;
0673     else
0674         sb->s_d_op = &exfat_dentry_ops;
0675 
0676     root_inode = new_inode(sb);
0677     if (!root_inode) {
0678         exfat_err(sb, "failed to allocate root inode");
0679         err = -ENOMEM;
0680         goto free_table;
0681     }
0682 
0683     root_inode->i_ino = EXFAT_ROOT_INO;
0684     inode_set_iversion(root_inode, 1);
0685     err = exfat_read_root(root_inode);
0686     if (err) {
0687         exfat_err(sb, "failed to initialize root inode");
0688         goto put_inode;
0689     }
0690 
0691     exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
0692     insert_inode_hash(root_inode);
0693 
0694     sb->s_root = d_make_root(root_inode);
0695     if (!sb->s_root) {
0696         exfat_err(sb, "failed to get the root dentry");
0697         err = -ENOMEM;
0698         goto free_table;
0699     }
0700 
0701     return 0;
0702 
0703 put_inode:
0704     iput(root_inode);
0705     sb->s_root = NULL;
0706 
0707 free_table:
0708     exfat_free_upcase_table(sbi);
0709     exfat_free_bitmap(sbi);
0710     brelse(sbi->boot_bh);
0711 
0712 check_nls_io:
0713     unload_nls(sbi->nls_io);
0714     exfat_free_iocharset(sbi);
0715     sb->s_fs_info = NULL;
0716     kfree(sbi);
0717     return err;
0718 }
0719 
0720 static int exfat_get_tree(struct fs_context *fc)
0721 {
0722     return get_tree_bdev(fc, exfat_fill_super);
0723 }
0724 
0725 static void exfat_free(struct fs_context *fc)
0726 {
0727     struct exfat_sb_info *sbi = fc->s_fs_info;
0728 
0729     if (sbi) {
0730         exfat_free_iocharset(sbi);
0731         kfree(sbi);
0732     }
0733 }
0734 
0735 static int exfat_reconfigure(struct fs_context *fc)
0736 {
0737     fc->sb_flags |= SB_NODIRATIME;
0738 
0739     /* volume flag will be updated in exfat_sync_fs */
0740     sync_filesystem(fc->root->d_sb);
0741     return 0;
0742 }
0743 
0744 static const struct fs_context_operations exfat_context_ops = {
0745     .parse_param    = exfat_parse_param,
0746     .get_tree   = exfat_get_tree,
0747     .free       = exfat_free,
0748     .reconfigure    = exfat_reconfigure,
0749 };
0750 
0751 static int exfat_init_fs_context(struct fs_context *fc)
0752 {
0753     struct exfat_sb_info *sbi;
0754 
0755     sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
0756     if (!sbi)
0757         return -ENOMEM;
0758 
0759     mutex_init(&sbi->s_lock);
0760     mutex_init(&sbi->bitmap_lock);
0761     ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
0762             DEFAULT_RATELIMIT_BURST);
0763 
0764     sbi->options.fs_uid = current_uid();
0765     sbi->options.fs_gid = current_gid();
0766     sbi->options.fs_fmask = current->fs->umask;
0767     sbi->options.fs_dmask = current->fs->umask;
0768     sbi->options.allow_utime = -1;
0769     sbi->options.iocharset = exfat_default_iocharset;
0770     sbi->options.errors = EXFAT_ERRORS_RO;
0771 
0772     fc->s_fs_info = sbi;
0773     fc->ops = &exfat_context_ops;
0774     return 0;
0775 }
0776 
0777 static struct file_system_type exfat_fs_type = {
0778     .owner          = THIS_MODULE,
0779     .name           = "exfat",
0780     .init_fs_context    = exfat_init_fs_context,
0781     .parameters     = exfat_parameters,
0782     .kill_sb        = kill_block_super,
0783     .fs_flags       = FS_REQUIRES_DEV,
0784 };
0785 
0786 static void exfat_inode_init_once(void *foo)
0787 {
0788     struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
0789 
0790     spin_lock_init(&ei->cache_lru_lock);
0791     ei->nr_caches = 0;
0792     ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
0793     INIT_LIST_HEAD(&ei->cache_lru);
0794     INIT_HLIST_NODE(&ei->i_hash_fat);
0795     inode_init_once(&ei->vfs_inode);
0796 }
0797 
0798 static int __init init_exfat_fs(void)
0799 {
0800     int err;
0801 
0802     err = exfat_cache_init();
0803     if (err)
0804         return err;
0805 
0806     exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
0807             sizeof(struct exfat_inode_info),
0808             0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
0809             exfat_inode_init_once);
0810     if (!exfat_inode_cachep) {
0811         err = -ENOMEM;
0812         goto shutdown_cache;
0813     }
0814 
0815     err = register_filesystem(&exfat_fs_type);
0816     if (err)
0817         goto destroy_cache;
0818 
0819     return 0;
0820 
0821 destroy_cache:
0822     kmem_cache_destroy(exfat_inode_cachep);
0823 shutdown_cache:
0824     exfat_cache_shutdown();
0825     return err;
0826 }
0827 
0828 static void __exit exit_exfat_fs(void)
0829 {
0830     /*
0831      * Make sure all delayed rcu free inodes are flushed before we
0832      * destroy cache.
0833      */
0834     rcu_barrier();
0835     kmem_cache_destroy(exfat_inode_cachep);
0836     unregister_filesystem(&exfat_fs_type);
0837     exfat_cache_shutdown();
0838 }
0839 
0840 module_init(init_exfat_fs);
0841 module_exit(exit_exfat_fs);
0842 
0843 MODULE_ALIAS_FS("exfat");
0844 MODULE_LICENSE("GPL");
0845 MODULE_DESCRIPTION("exFAT filesystem support");
0846 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
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