fs/ubifs/super.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * This file is part of UBIFS.
0004  *
0005  * Copyright (C) 2006-2008 Nokia Corporation.
0006  *
0007  * Authors: Artem Bityutskiy (Битюцкий Артём)
0008  *          Adrian Hunter
0009  */
0010
0011 /*
0012  * This file implements UBIFS initialization and VFS superblock operations. Some
0013  * initialization stuff which is rather large and complex is placed at
0014  * corresponding subsystems, but most of it is here.
0015  */
0016
0017 #include <linux/init.h>
0018 #include <linux/slab.h>
0019 #include <linux/module.h>
0020 #include <linux/ctype.h>
0021 #include <linux/kthread.h>
0022 #include <linux/parser.h>
0023 #include <linux/seq_file.h>
0024 #include <linux/mount.h>
0025 #include <linux/math64.h>
0026 #include <linux/writeback.h>
0027 #include "ubifs.h"
0028
0029 static int ubifs_default_version_set(const char *val, const struct kernel_param *kp)
0030 {
0031     int n = 0, ret;
0032
0033     ret = kstrtoint(val, 10, &n);
0034     if (ret != 0 || n < 4 || n > UBIFS_FORMAT_VERSION)
0035         return -EINVAL;
0036     return param_set_int(val, kp);
0037 }
0038
0039 static const struct kernel_param_ops ubifs_default_version_ops = {
0040     .set = ubifs_default_version_set,
0041     .get = param_get_int,
0042 };
0043
0044 int ubifs_default_version = UBIFS_FORMAT_VERSION;
0045 module_param_cb(default_version, &ubifs_default_version_ops, &ubifs_default_version, 0600);
0046
0047 /*
0048  * Maximum amount of memory we may 'kmalloc()' without worrying that we are
0049  * allocating too much.
0050  */
0051 #define UBIFS_KMALLOC_OK (128*1024)
0052
0053 /* Slab cache for UBIFS inodes */
0054 static struct kmem_cache *ubifs_inode_slab;
0055
0056 /* UBIFS TNC shrinker description */
0057 static struct shrinker ubifs_shrinker_info = {
0058     .scan_objects = ubifs_shrink_scan,
0059     .count_objects = ubifs_shrink_count,
0060     .seeks = DEFAULT_SEEKS,
0061 };
0062
0063 /**
0064  * validate_inode - validate inode.
0065  * @c: UBIFS file-system description object
0066  * @inode: the inode to validate
0067  *
0068  * This is a helper function for 'ubifs_iget()' which validates various fields
0069  * of a newly built inode to make sure they contain sane values and prevent
0070  * possible vulnerabilities. Returns zero if the inode is all right and
0071  * a non-zero error code if not.
0072  */
0073 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
0074 {
0075     int err;
0076     const struct ubifs_inode *ui = ubifs_inode(inode);
0077
0078     if (inode->i_size > c->max_inode_sz) {
0079         ubifs_err(c, "inode is too large (%lld)",
0080               (long long)inode->i_size);
0081         return 1;
0082     }
0083
0084     if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
0085         ubifs_err(c, "unknown compression type %d", ui->compr_type);
0086         return 2;
0087     }
0088
0089     if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
0090         return 3;
0091
0092     if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
0093         return 4;
0094
0095     if (ui->xattr && !S_ISREG(inode->i_mode))
0096         return 5;
0097
0098     if (!ubifs_compr_present(c, ui->compr_type)) {
0099         ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
0100                inode->i_ino, ubifs_compr_name(c, ui->compr_type));
0101     }
0102
0103     err = dbg_check_dir(c, inode);
0104     return err;
0105 }
0106
0107 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
0108 {
0109     int err;
0110     union ubifs_key key;
0111     struct ubifs_ino_node *ino;
0112     struct ubifs_info *c = sb->s_fs_info;
0113     struct inode *inode;
0114     struct ubifs_inode *ui;
0115
0116     dbg_gen("inode %lu", inum);
0117
0118     inode = iget_locked(sb, inum);
0119     if (!inode)
0120         return ERR_PTR(-ENOMEM);
0121     if (!(inode->i_state & I_NEW))
0122         return inode;
0123     ui = ubifs_inode(inode);
0124
0125     ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
0126     if (!ino) {
0127         err = -ENOMEM;
0128         goto out;
0129     }
0130
0131     ino_key_init(c, &key, inode->i_ino);
0132
0133     err = ubifs_tnc_lookup(c, &key, ino);
0134     if (err)
0135         goto out_ino;
0136
0137     inode->i_flags |= S_NOCMTIME;
0138
0139     if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
0140         inode->i_flags |= S_NOATIME;
0141
0142     set_nlink(inode, le32_to_cpu(ino->nlink));
0143     i_uid_write(inode, le32_to_cpu(ino->uid));
0144     i_gid_write(inode, le32_to_cpu(ino->gid));
0145     inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
0146     inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
0147     inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
0148     inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
0149     inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
0150     inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
0151     inode->i_mode = le32_to_cpu(ino->mode);
0152     inode->i_size = le64_to_cpu(ino->size);
0153
0154     ui->data_len    = le32_to_cpu(ino->data_len);
0155     ui->flags       = le32_to_cpu(ino->flags);
0156     ui->compr_type  = le16_to_cpu(ino->compr_type);
0157     ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
0158     ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
0159     ui->xattr_size  = le32_to_cpu(ino->xattr_size);
0160     ui->xattr_names = le32_to_cpu(ino->xattr_names);
0161     ui->synced_i_size = ui->ui_size = inode->i_size;
0162
0163     ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
0164
0165     err = validate_inode(c, inode);
0166     if (err)
0167         goto out_invalid;
0168
0169     switch (inode->i_mode & S_IFMT) {
0170     case S_IFREG:
0171         inode->i_mapping->a_ops = &ubifs_file_address_operations;
0172         inode->i_op = &ubifs_file_inode_operations;
0173         inode->i_fop = &ubifs_file_operations;
0174         if (ui->xattr) {
0175             ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
0176             if (!ui->data) {
0177                 err = -ENOMEM;
0178                 goto out_ino;
0179             }
0180             memcpy(ui->data, ino->data, ui->data_len);
0181             ((char *)ui->data)[ui->data_len] = '\0';
0182         } else if (ui->data_len != 0) {
0183             err = 10;
0184             goto out_invalid;
0185         }
0186         break;
0187     case S_IFDIR:
0188         inode->i_op  = &ubifs_dir_inode_operations;
0189         inode->i_fop = &ubifs_dir_operations;
0190         if (ui->data_len != 0) {
0191             err = 11;
0192             goto out_invalid;
0193         }
0194         break;
0195     case S_IFLNK:
0196         inode->i_op = &ubifs_symlink_inode_operations;
0197         if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
0198             err = 12;
0199             goto out_invalid;
0200         }
0201         ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
0202         if (!ui->data) {
0203             err = -ENOMEM;
0204             goto out_ino;
0205         }
0206         memcpy(ui->data, ino->data, ui->data_len);
0207         ((char *)ui->data)[ui->data_len] = '\0';
0208         break;
0209     case S_IFBLK:
0210     case S_IFCHR:
0211     {
0212         dev_t rdev;
0213         union ubifs_dev_desc *dev;
0214
0215         ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
0216         if (!ui->data) {
0217             err = -ENOMEM;
0218             goto out_ino;
0219         }
0220
0221         dev = (union ubifs_dev_desc *)ino->data;
0222         if (ui->data_len == sizeof(dev->new))
0223             rdev = new_decode_dev(le32_to_cpu(dev->new));
0224         else if (ui->data_len == sizeof(dev->huge))
0225             rdev = huge_decode_dev(le64_to_cpu(dev->huge));
0226         else {
0227             err = 13;
0228             goto out_invalid;
0229         }
0230         memcpy(ui->data, ino->data, ui->data_len);
0231         inode->i_op = &ubifs_file_inode_operations;
0232         init_special_inode(inode, inode->i_mode, rdev);
0233         break;
0234     }
0235     case S_IFSOCK:
0236     case S_IFIFO:
0237         inode->i_op = &ubifs_file_inode_operations;
0238         init_special_inode(inode, inode->i_mode, 0);
0239         if (ui->data_len != 0) {
0240             err = 14;
0241             goto out_invalid;
0242         }
0243         break;
0244     default:
0245         err = 15;
0246         goto out_invalid;
0247     }
0248
0249     kfree(ino);
0250     ubifs_set_inode_flags(inode);
0251     unlock_new_inode(inode);
0252     return inode;
0253
0254 out_invalid:
0255     ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
0256     ubifs_dump_node(c, ino, UBIFS_MAX_INO_NODE_SZ);
0257     ubifs_dump_inode(c, inode);
0258     err = -EINVAL;
0259 out_ino:
0260     kfree(ino);
0261 out:
0262     ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
0263     iget_failed(inode);
0264     return ERR_PTR(err);
0265 }
0266
0267 static struct inode *ubifs_alloc_inode(struct super_block *sb)
0268 {
0269     struct ubifs_inode *ui;
0270
0271     ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);
0272     if (!ui)
0273         return NULL;
0274
0275     memset((void *)ui + sizeof(struct inode), 0,
0276            sizeof(struct ubifs_inode) - sizeof(struct inode));
0277     mutex_init(&ui->ui_mutex);
0278     init_rwsem(&ui->xattr_sem);
0279     spin_lock_init(&ui->ui_lock);
0280     return &ui->vfs_inode;
0281 };
0282
0283 static void ubifs_free_inode(struct inode *inode)
0284 {
0285     struct ubifs_inode *ui = ubifs_inode(inode);
0286
0287     kfree(ui->data);
0288     fscrypt_free_inode(inode);
0289
0290     kmem_cache_free(ubifs_inode_slab, ui);
0291 }
0292
0293 /*
0294  * Note, Linux write-back code calls this without 'i_mutex'.
0295  */
0296 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
0297 {
0298     int err = 0;
0299     struct ubifs_info *c = inode->i_sb->s_fs_info;
0300     struct ubifs_inode *ui = ubifs_inode(inode);
0301
0302     ubifs_assert(c, !ui->xattr);
0303     if (is_bad_inode(inode))
0304         return 0;
0305
0306     mutex_lock(&ui->ui_mutex);
0307     /*
0308      * Due to races between write-back forced by budgeting
0309      * (see 'sync_some_inodes()') and background write-back, the inode may
0310      * have already been synchronized, do not do this again. This might
0311      * also happen if it was synchronized in an VFS operation, e.g.
0312      * 'ubifs_link()'.
0313      */
0314     if (!ui->dirty) {
0315         mutex_unlock(&ui->ui_mutex);
0316         return 0;
0317     }
0318
0319     /*
0320      * As an optimization, do not write orphan inodes to the media just
0321      * because this is not needed.
0322      */
0323     dbg_gen("inode %lu, mode %#x, nlink %u",
0324         inode->i_ino, (int)inode->i_mode, inode->i_nlink);
0325     if (inode->i_nlink) {
0326         err = ubifs_jnl_write_inode(c, inode);
0327         if (err)
0328             ubifs_err(c, "can't write inode %lu, error %d",
0329                   inode->i_ino, err);
0330         else
0331             err = dbg_check_inode_size(c, inode, ui->ui_size);
0332     }
0333
0334     ui->dirty = 0;
0335     mutex_unlock(&ui->ui_mutex);
0336     ubifs_release_dirty_inode_budget(c, ui);
0337     return err;
0338 }
0339
0340 static int ubifs_drop_inode(struct inode *inode)
0341 {
0342     int drop = generic_drop_inode(inode);
0343
0344     if (!drop)
0345         drop = fscrypt_drop_inode(inode);
0346
0347     return drop;
0348 }
0349
0350 static void ubifs_evict_inode(struct inode *inode)
0351 {
0352     int err;
0353     struct ubifs_info *c = inode->i_sb->s_fs_info;
0354     struct ubifs_inode *ui = ubifs_inode(inode);
0355
0356     if (ui->xattr)
0357         /*
0358          * Extended attribute inode deletions are fully handled in
0359          * 'ubifs_removexattr()'. These inodes are special and have
0360          * limited usage, so there is nothing to do here.
0361          */
0362         goto out;
0363
0364     dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
0365     ubifs_assert(c, !atomic_read(&inode->i_count));
0366
0367     truncate_inode_pages_final(&inode->i_data);
0368
0369     if (inode->i_nlink)
0370         goto done;
0371
0372     if (is_bad_inode(inode))
0373         goto out;
0374
0375     ui->ui_size = inode->i_size = 0;
0376     err = ubifs_jnl_delete_inode(c, inode);
0377     if (err)
0378         /*
0379          * Worst case we have a lost orphan inode wasting space, so a
0380          * simple error message is OK here.
0381          */
0382         ubifs_err(c, "can't delete inode %lu, error %d",
0383               inode->i_ino, err);
0384
0385 out:
0386     if (ui->dirty)
0387         ubifs_release_dirty_inode_budget(c, ui);
0388     else {
0389         /* We've deleted something - clean the "no space" flags */
0390         c->bi.nospace = c->bi.nospace_rp = 0;
0391         smp_wmb();
0392     }
0393 done:
0394     clear_inode(inode);
0395     fscrypt_put_encryption_info(inode);
0396 }
0397
0398 static void ubifs_dirty_inode(struct inode *inode, int flags)
0399 {
0400     struct ubifs_info *c = inode->i_sb->s_fs_info;
0401     struct ubifs_inode *ui = ubifs_inode(inode);
0402
0403     ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
0404     if (!ui->dirty) {
0405         ui->dirty = 1;
0406         dbg_gen("inode %lu",  inode->i_ino);
0407     }
0408 }
0409
0410 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
0411 {
0412     struct ubifs_info *c = dentry->d_sb->s_fs_info;
0413     unsigned long long free;
0414     __le32 *uuid = (__le32 *)c->uuid;
0415
0416     free = ubifs_get_free_space(c);
0417     dbg_gen("free space %lld bytes (%lld blocks)",
0418         free, free >> UBIFS_BLOCK_SHIFT);
0419
0420     buf->f_type = UBIFS_SUPER_MAGIC;
0421     buf->f_bsize = UBIFS_BLOCK_SIZE;
0422     buf->f_blocks = c->block_cnt;
0423     buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
0424     if (free > c->report_rp_size)
0425         buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
0426     else
0427         buf->f_bavail = 0;
0428     buf->f_files = 0;
0429     buf->f_ffree = 0;
0430     buf->f_namelen = UBIFS_MAX_NLEN;
0431     buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
0432     buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
0433     ubifs_assert(c, buf->f_bfree <= c->block_cnt);
0434     return 0;
0435 }
0436
0437 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
0438 {
0439     struct ubifs_info *c = root->d_sb->s_fs_info;
0440
0441     if (c->mount_opts.unmount_mode == 2)
0442         seq_puts(s, ",fast_unmount");
0443     else if (c->mount_opts.unmount_mode == 1)
0444         seq_puts(s, ",norm_unmount");
0445
0446     if (c->mount_opts.bulk_read == 2)
0447         seq_puts(s, ",bulk_read");
0448     else if (c->mount_opts.bulk_read == 1)
0449         seq_puts(s, ",no_bulk_read");
0450
0451     if (c->mount_opts.chk_data_crc == 2)
0452         seq_puts(s, ",chk_data_crc");
0453     else if (c->mount_opts.chk_data_crc == 1)
0454         seq_puts(s, ",no_chk_data_crc");
0455
0456     if (c->mount_opts.override_compr) {
0457         seq_printf(s, ",compr=%s",
0458                ubifs_compr_name(c, c->mount_opts.compr_type));
0459     }
0460
0461     seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));
0462     seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
0463
0464     return 0;
0465 }
0466
0467 static int ubifs_sync_fs(struct super_block *sb, int wait)
0468 {
0469     int i, err;
0470     struct ubifs_info *c = sb->s_fs_info;
0471
0472     /*
0473      * Zero @wait is just an advisory thing to help the file system shove
0474      * lots of data into the queues, and there will be the second
0475      * '->sync_fs()' call, with non-zero @wait.
0476      */
0477     if (!wait)
0478         return 0;
0479
0480     /*
0481      * Synchronize write buffers, because 'ubifs_run_commit()' does not
0482      * do this if it waits for an already running commit.
0483      */
0484     for (i = 0; i < c->jhead_cnt; i++) {
0485         err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
0486         if (err)
0487             return err;
0488     }
0489
0490     /*
0491      * Strictly speaking, it is not necessary to commit the journal here,
0492      * synchronizing write-buffers would be enough. But committing makes
0493      * UBIFS free space predictions much more accurate, so we want to let
0494      * the user be able to get more accurate results of 'statfs()' after
0495      * they synchronize the file system.
0496      */
0497     err = ubifs_run_commit(c);
0498     if (err)
0499         return err;
0500
0501     return ubi_sync(c->vi.ubi_num);
0502 }
0503
0504 /**
0505  * init_constants_early - initialize UBIFS constants.
0506  * @c: UBIFS file-system description object
0507  *
0508  * This function initialize UBIFS constants which do not need the superblock to
0509  * be read. It also checks that the UBI volume satisfies basic UBIFS
0510  * requirements. Returns zero in case of success and a negative error code in
0511  * case of failure.
0512  */
0513 static int init_constants_early(struct ubifs_info *c)
0514 {
0515     if (c->vi.corrupted) {
0516         ubifs_warn(c, "UBI volume is corrupted - read-only mode");
0517         c->ro_media = 1;
0518     }
0519
0520     if (c->di.ro_mode) {
0521         ubifs_msg(c, "read-only UBI device");
0522         c->ro_media = 1;
0523     }
0524
0525     if (c->vi.vol_type == UBI_STATIC_VOLUME) {
0526         ubifs_msg(c, "static UBI volume - read-only mode");
0527         c->ro_media = 1;
0528     }
0529
0530     c->leb_cnt = c->vi.size;
0531     c->leb_size = c->vi.usable_leb_size;
0532     c->leb_start = c->di.leb_start;
0533     c->half_leb_size = c->leb_size / 2;
0534     c->min_io_size = c->di.min_io_size;
0535     c->min_io_shift = fls(c->min_io_size) - 1;
0536     c->max_write_size = c->di.max_write_size;
0537     c->max_write_shift = fls(c->max_write_size) - 1;
0538
0539     if (c->leb_size < UBIFS_MIN_LEB_SZ) {
0540         ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
0541                c->leb_size, UBIFS_MIN_LEB_SZ);
0542         return -EINVAL;
0543     }
0544
0545     if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
0546         ubifs_errc(c, "too few LEBs (%d), min. is %d",
0547                c->leb_cnt, UBIFS_MIN_LEB_CNT);
0548         return -EINVAL;
0549     }
0550
0551     if (!is_power_of_2(c->min_io_size)) {
0552         ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
0553         return -EINVAL;
0554     }
0555
0556     /*
0557      * Maximum write size has to be greater or equivalent to min. I/O
0558      * size, and be multiple of min. I/O size.
0559      */
0560     if (c->max_write_size < c->min_io_size ||
0561         c->max_write_size % c->min_io_size ||
0562         !is_power_of_2(c->max_write_size)) {
0563         ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
0564                c->max_write_size, c->min_io_size);
0565         return -EINVAL;
0566     }
0567
0568     /*
0569      * UBIFS aligns all node to 8-byte boundary, so to make function in
0570      * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
0571      * less than 8.
0572      */
0573     if (c->min_io_size < 8) {
0574         c->min_io_size = 8;
0575         c->min_io_shift = 3;
0576         if (c->max_write_size < c->min_io_size) {
0577             c->max_write_size = c->min_io_size;
0578             c->max_write_shift = c->min_io_shift;
0579         }
0580     }
0581
0582     c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
0583     c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
0584
0585     /*
0586      * Initialize node length ranges which are mostly needed for node
0587      * length validation.
0588      */
0589     c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
0590     c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
0591     c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
0592     c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
0593     c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
0594     c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
0595     c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
0596     c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
0597                 UBIFS_MAX_HMAC_LEN;
0598     c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
0599     c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
0600
0601     c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
0602     c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
0603     c->ranges[UBIFS_ORPH_NODE].min_len =
0604                 UBIFS_ORPH_NODE_SZ + sizeof(__le64);
0605     c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
0606     c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
0607     c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
0608     c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
0609     c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
0610     c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
0611     c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
0612     /*
0613      * Minimum indexing node size is amended later when superblock is
0614      * read and the key length is known.
0615      */
0616     c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
0617     /*
0618      * Maximum indexing node size is amended later when superblock is
0619      * read and the fanout is known.
0620      */
0621     c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
0622
0623     /*
0624      * Initialize dead and dark LEB space watermarks. See gc.c for comments
0625      * about these values.
0626      */
0627     c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
0628     c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
0629
0630     /*
0631      * Calculate how many bytes would be wasted at the end of LEB if it was
0632      * fully filled with data nodes of maximum size. This is used in
0633      * calculations when reporting free space.
0634      */
0635     c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
0636
0637     /* Buffer size for bulk-reads */
0638     c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
0639     if (c->max_bu_buf_len > c->leb_size)
0640         c->max_bu_buf_len = c->leb_size;
0641
0642     /* Log is ready, preserve one LEB for commits. */
0643     c->min_log_bytes = c->leb_size;
0644
0645     return 0;
0646 }
0647
0648 /**
0649  * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
0650  * @c: UBIFS file-system description object
0651  * @lnum: LEB the write-buffer was synchronized to
0652  * @free: how many free bytes left in this LEB
0653  * @pad: how many bytes were padded
0654  *
0655  * This is a callback function which is called by the I/O unit when the
0656  * write-buffer is synchronized. We need this to correctly maintain space
0657  * accounting in bud logical eraseblocks. This function returns zero in case of
0658  * success and a negative error code in case of failure.
0659  *
0660  * This function actually belongs to the journal, but we keep it here because
0661  * we want to keep it static.
0662  */
0663 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
0664 {
0665     return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
0666 }
0667
0668 /*
0669  * init_constants_sb - initialize UBIFS constants.
0670  * @c: UBIFS file-system description object
0671  *
0672  * This is a helper function which initializes various UBIFS constants after
0673  * the superblock has been read. It also checks various UBIFS parameters and
0674  * makes sure they are all right. Returns zero in case of success and a
0675  * negative error code in case of failure.
0676  */
0677 static int init_constants_sb(struct ubifs_info *c)
0678 {
0679     int tmp, err;
0680     long long tmp64;
0681
0682     c->main_bytes = (long long)c->main_lebs * c->leb_size;
0683     c->max_znode_sz = sizeof(struct ubifs_znode) +
0684                 c->fanout * sizeof(struct ubifs_zbranch);
0685
0686     tmp = ubifs_idx_node_sz(c, 1);
0687     c->ranges[UBIFS_IDX_NODE].min_len = tmp;
0688     c->min_idx_node_sz = ALIGN(tmp, 8);
0689
0690     tmp = ubifs_idx_node_sz(c, c->fanout);
0691     c->ranges[UBIFS_IDX_NODE].max_len = tmp;
0692     c->max_idx_node_sz = ALIGN(tmp, 8);
0693
0694     /* Make sure LEB size is large enough to fit full commit */
0695     tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
0696     tmp = ALIGN(tmp, c->min_io_size);
0697     if (tmp > c->leb_size) {
0698         ubifs_err(c, "too small LEB size %d, at least %d needed",
0699               c->leb_size, tmp);
0700         return -EINVAL;
0701     }
0702
0703     /*
0704      * Make sure that the log is large enough to fit reference nodes for
0705      * all buds plus one reserved LEB.
0706      */
0707     tmp64 = c->max_bud_bytes + c->leb_size - 1;
0708     c->max_bud_cnt = div_u64(tmp64, c->leb_size);
0709     tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
0710     tmp /= c->leb_size;
0711     tmp += 1;
0712     if (c->log_lebs < tmp) {
0713         ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
0714               c->log_lebs, tmp);
0715         return -EINVAL;
0716     }
0717
0718     /*
0719      * When budgeting we assume worst-case scenarios when the pages are not
0720      * be compressed and direntries are of the maximum size.
0721      *
0722      * Note, data, which may be stored in inodes is budgeted separately, so
0723      * it is not included into 'c->bi.inode_budget'.
0724      */
0725     c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
0726     c->bi.inode_budget = UBIFS_INO_NODE_SZ;
0727     c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
0728
0729     /*
0730      * When the amount of flash space used by buds becomes
0731      * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
0732      * The writers are unblocked when the commit is finished. To avoid
0733      * writers to be blocked UBIFS initiates background commit in advance,
0734      * when number of bud bytes becomes above the limit defined below.
0735      */
0736     c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
0737
0738     /*
0739      * Ensure minimum journal size. All the bytes in the journal heads are
0740      * considered to be used, when calculating the current journal usage.
0741      * Consequently, if the journal is too small, UBIFS will treat it as
0742      * always full.
0743      */
0744     tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
0745     if (c->bg_bud_bytes < tmp64)
0746         c->bg_bud_bytes = tmp64;
0747     if (c->max_bud_bytes < tmp64 + c->leb_size)
0748         c->max_bud_bytes = tmp64 + c->leb_size;
0749
0750     err = ubifs_calc_lpt_geom(c);
0751     if (err)
0752         return err;
0753
0754     /* Initialize effective LEB size used in budgeting calculations */
0755     c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
0756     return 0;
0757 }
0758
0759 /*
0760  * init_constants_master - initialize UBIFS constants.
0761  * @c: UBIFS file-system description object
0762  *
0763  * This is a helper function which initializes various UBIFS constants after
0764  * the master node has been read. It also checks various UBIFS parameters and
0765  * makes sure they are all right.
0766  */
0767 static void init_constants_master(struct ubifs_info *c)
0768 {
0769     long long tmp64;
0770
0771     c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
0772     c->report_rp_size = ubifs_reported_space(c, c->rp_size);
0773
0774     /*
0775      * Calculate total amount of FS blocks. This number is not used
0776      * internally because it does not make much sense for UBIFS, but it is
0777      * necessary to report something for the 'statfs()' call.
0778      *
0779      * Subtract the LEB reserved for GC, the LEB which is reserved for
0780      * deletions, minimum LEBs for the index, and assume only one journal
0781      * head is available.
0782      */
0783     tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
0784     tmp64 *= (long long)c->leb_size - c->leb_overhead;
0785     tmp64 = ubifs_reported_space(c, tmp64);
0786     c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
0787 }
0788
0789 /**
0790  * take_gc_lnum - reserve GC LEB.
0791  * @c: UBIFS file-system description object
0792  *
0793  * This function ensures that the LEB reserved for garbage collection is marked
0794  * as "taken" in lprops. We also have to set free space to LEB size and dirty
0795  * space to zero, because lprops may contain out-of-date information if the
0796  * file-system was un-mounted before it has been committed. This function
0797  * returns zero in case of success and a negative error code in case of
0798  * failure.
0799  */
0800 static int take_gc_lnum(struct ubifs_info *c)
0801 {
0802     int err;
0803
0804     if (c->gc_lnum == -1) {
0805         ubifs_err(c, "no LEB for GC");
0806         return -EINVAL;
0807     }
0808
0809     /* And we have to tell lprops that this LEB is taken */
0810     err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
0811                   LPROPS_TAKEN, 0, 0);
0812     return err;
0813 }
0814
0815 /**
0816  * alloc_wbufs - allocate write-buffers.
0817  * @c: UBIFS file-system description object
0818  *
0819  * This helper function allocates and initializes UBIFS write-buffers. Returns
0820  * zero in case of success and %-ENOMEM in case of failure.
0821  */
0822 static int alloc_wbufs(struct ubifs_info *c)
0823 {
0824     int i, err;
0825
0826     c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
0827                 GFP_KERNEL);
0828     if (!c->jheads)
0829         return -ENOMEM;
0830
0831     /* Initialize journal heads */
0832     for (i = 0; i < c->jhead_cnt; i++) {
0833         INIT_LIST_HEAD(&c->jheads[i].buds_list);
0834         err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
0835         if (err)
0836             return err;
0837
0838         c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
0839         c->jheads[i].wbuf.jhead = i;
0840         c->jheads[i].grouped = 1;
0841         c->jheads[i].log_hash = ubifs_hash_get_desc(c);
0842         if (IS_ERR(c->jheads[i].log_hash)) {
0843             err = PTR_ERR(c->jheads[i].log_hash);
0844             goto out;
0845         }
0846     }
0847
0848     /*
0849      * Garbage Collector head does not need to be synchronized by timer.
0850      * Also GC head nodes are not grouped.
0851      */
0852     c->jheads[GCHD].wbuf.no_timer = 1;
0853     c->jheads[GCHD].grouped = 0;
0854
0855     return 0;
0856
0857 out:
0858     while (i--)
0859         kfree(c->jheads[i].log_hash);
0860
0861     return err;
0862 }
0863
0864 /**
0865  * free_wbufs - free write-buffers.
0866  * @c: UBIFS file-system description object
0867  */
0868 static void free_wbufs(struct ubifs_info *c)
0869 {
0870     int i;
0871
0872     if (c->jheads) {
0873         for (i = 0; i < c->jhead_cnt; i++) {
0874             kfree(c->jheads[i].wbuf.buf);
0875             kfree(c->jheads[i].wbuf.inodes);
0876             kfree(c->jheads[i].log_hash);
0877         }
0878         kfree(c->jheads);
0879         c->jheads = NULL;
0880     }
0881 }
0882
0883 /**
0884  * free_orphans - free orphans.
0885  * @c: UBIFS file-system description object
0886  */
0887 static void free_orphans(struct ubifs_info *c)
0888 {
0889     struct ubifs_orphan *orph;
0890
0891     while (c->orph_dnext) {
0892         orph = c->orph_dnext;
0893         c->orph_dnext = orph->dnext;
0894         list_del(&orph->list);
0895         kfree(orph);
0896     }
0897
0898     while (!list_empty(&c->orph_list)) {
0899         orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
0900         list_del(&orph->list);
0901         kfree(orph);
0902         ubifs_err(c, "orphan list not empty at unmount");
0903     }
0904
0905     vfree(c->orph_buf);
0906     c->orph_buf = NULL;
0907 }
0908
0909 /**
0910  * free_buds - free per-bud objects.
0911  * @c: UBIFS file-system description object
0912  */
0913 static void free_buds(struct ubifs_info *c)
0914 {
0915     struct ubifs_bud *bud, *n;
0916
0917     rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
0918         kfree(bud);
0919 }
0920
0921 /**
0922  * check_volume_empty - check if the UBI volume is empty.
0923  * @c: UBIFS file-system description object
0924  *
0925  * This function checks if the UBIFS volume is empty by looking if its LEBs are
0926  * mapped or not. The result of checking is stored in the @c->empty variable.
0927  * Returns zero in case of success and a negative error code in case of
0928  * failure.
0929  */
0930 static int check_volume_empty(struct ubifs_info *c)
0931 {
0932     int lnum, err;
0933
0934     c->empty = 1;
0935     for (lnum = 0; lnum < c->leb_cnt; lnum++) {
0936         err = ubifs_is_mapped(c, lnum);
0937         if (unlikely(err < 0))
0938             return err;
0939         if (err == 1) {
0940             c->empty = 0;
0941             break;
0942         }
0943
0944         cond_resched();
0945     }
0946
0947     return 0;
0948 }
0949
0950 /*
0951  * UBIFS mount options.
0952  *
0953  * Opt_fast_unmount: do not run a journal commit before un-mounting
0954  * Opt_norm_unmount: run a journal commit before un-mounting
0955  * Opt_bulk_read: enable bulk-reads
0956  * Opt_no_bulk_read: disable bulk-reads
0957  * Opt_chk_data_crc: check CRCs when reading data nodes
0958  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
0959  * Opt_override_compr: override default compressor
0960  * Opt_assert: set ubifs_assert() action
0961  * Opt_auth_key: The key name used for authentication
0962  * Opt_auth_hash_name: The hash type used for authentication
0963  * Opt_err: just end of array marker
0964  */
0965 enum {
0966     Opt_fast_unmount,
0967     Opt_norm_unmount,
0968     Opt_bulk_read,
0969     Opt_no_bulk_read,
0970     Opt_chk_data_crc,
0971     Opt_no_chk_data_crc,
0972     Opt_override_compr,
0973     Opt_assert,
0974     Opt_auth_key,
0975     Opt_auth_hash_name,
0976     Opt_ignore,
0977     Opt_err,
0978 };
0979
0980 static const match_table_t tokens = {
0981     {Opt_fast_unmount, "fast_unmount"},
0982     {Opt_norm_unmount, "norm_unmount"},
0983     {Opt_bulk_read, "bulk_read"},
0984     {Opt_no_bulk_read, "no_bulk_read"},
0985     {Opt_chk_data_crc, "chk_data_crc"},
0986     {Opt_no_chk_data_crc, "no_chk_data_crc"},
0987     {Opt_override_compr, "compr=%s"},
0988     {Opt_auth_key, "auth_key=%s"},
0989     {Opt_auth_hash_name, "auth_hash_name=%s"},
0990     {Opt_ignore, "ubi=%s"},
0991     {Opt_ignore, "vol=%s"},
0992     {Opt_assert, "assert=%s"},
0993     {Opt_err, NULL},
0994 };
0995
0996 /**
0997  * parse_standard_option - parse a standard mount option.
0998  * @option: the option to parse
0999  *
1000  * Normally, standard mount options like "sync" are passed to file-systems as
1001  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
1002  * be present in the options string. This function tries to deal with this
1003  * situation and parse standard options. Returns 0 if the option was not
1004  * recognized, and the corresponding integer flag if it was.
1005  *
1006  * UBIFS is only interested in the "sync" option, so do not check for anything
1007  * else.
1008  */
1009 static int parse_standard_option(const char *option)
1010 {
1011
1012     pr_notice("UBIFS: parse %s\n", option);
1013     if (!strcmp(option, "sync"))
1014         return SB_SYNCHRONOUS;
1015     return 0;
1016 }
1017
1018 /**
1019  * ubifs_parse_options - parse mount parameters.
1020  * @c: UBIFS file-system description object
1021  * @options: parameters to parse
1022  * @is_remount: non-zero if this is FS re-mount
1023  *
1024  * This function parses UBIFS mount options and returns zero in case success
1025  * and a negative error code in case of failure.
1026  */
1027 static int ubifs_parse_options(struct ubifs_info *c, char *options,
1028                    int is_remount)
1029 {
1030     char *p;
1031     substring_t args[MAX_OPT_ARGS];
1032
1033     if (!options)
1034         return 0;
1035
1036     while ((p = strsep(&options, ","))) {
1037         int token;
1038
1039         if (!*p)
1040             continue;
1041
1042         token = match_token(p, tokens, args);
1043         switch (token) {
1044         /*
1045          * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1046          * We accept them in order to be backward-compatible. But this
1047          * should be removed at some point.
1048          */
1049         case Opt_fast_unmount:
1050             c->mount_opts.unmount_mode = 2;
1051             break;
1052         case Opt_norm_unmount:
1053             c->mount_opts.unmount_mode = 1;
1054             break;
1055         case Opt_bulk_read:
1056             c->mount_opts.bulk_read = 2;
1057             c->bulk_read = 1;
1058             break;
1059         case Opt_no_bulk_read:
1060             c->mount_opts.bulk_read = 1;
1061             c->bulk_read = 0;
1062             break;
1063         case Opt_chk_data_crc:
1064             c->mount_opts.chk_data_crc = 2;
1065             c->no_chk_data_crc = 0;
1066             break;
1067         case Opt_no_chk_data_crc:
1068             c->mount_opts.chk_data_crc = 1;
1069             c->no_chk_data_crc = 1;
1070             break;
1071         case Opt_override_compr:
1072         {
1073             char *name = match_strdup(&args[0]);
1074
1075             if (!name)
1076                 return -ENOMEM;
1077             if (!strcmp(name, "none"))
1078                 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1079             else if (!strcmp(name, "lzo"))
1080                 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1081             else if (!strcmp(name, "zlib"))
1082                 c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1083             else if (!strcmp(name, "zstd"))
1084                 c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;
1085             else {
1086                 ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1087                 kfree(name);
1088                 return -EINVAL;
1089             }
1090             kfree(name);
1091             c->mount_opts.override_compr = 1;
1092             c->default_compr = c->mount_opts.compr_type;
1093             break;
1094         }
1095         case Opt_assert:
1096         {
1097             char *act = match_strdup(&args[0]);
1098
1099             if (!act)
1100                 return -ENOMEM;
1101             if (!strcmp(act, "report"))
1102                 c->assert_action = ASSACT_REPORT;
1103             else if (!strcmp(act, "read-only"))
1104                 c->assert_action = ASSACT_RO;
1105             else if (!strcmp(act, "panic"))
1106                 c->assert_action = ASSACT_PANIC;
1107             else {
1108                 ubifs_err(c, "unknown assert action \"%s\"", act);
1109                 kfree(act);
1110                 return -EINVAL;
1111             }
1112             kfree(act);
1113             break;
1114         }
1115         case Opt_auth_key:
1116             if (!is_remount) {
1117                 c->auth_key_name = kstrdup(args[0].from,
1118                                 GFP_KERNEL);
1119                 if (!c->auth_key_name)
1120                     return -ENOMEM;
1121             }
1122             break;
1123         case Opt_auth_hash_name:
1124             if (!is_remount) {
1125                 c->auth_hash_name = kstrdup(args[0].from,
1126                                 GFP_KERNEL);
1127                 if (!c->auth_hash_name)
1128                     return -ENOMEM;
1129             }
1130             break;
1131         case Opt_ignore:
1132             break;
1133         default:
1134         {
1135             unsigned long flag;
1136             struct super_block *sb = c->vfs_sb;
1137
1138             flag = parse_standard_option(p);
1139             if (!flag) {
1140                 ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1141                       p);
1142                 return -EINVAL;
1143             }
1144             sb->s_flags |= flag;
1145             break;
1146         }
1147         }
1148     }
1149
1150     return 0;
1151 }
1152
1153 /*
1154  * ubifs_release_options - release mount parameters which have been dumped.
1155  * @c: UBIFS file-system description object
1156  */
1157 static void ubifs_release_options(struct ubifs_info *c)
1158 {
1159     kfree(c->auth_key_name);
1160     c->auth_key_name = NULL;
1161     kfree(c->auth_hash_name);
1162     c->auth_hash_name = NULL;
1163 }
1164
1165 /**
1166  * destroy_journal - destroy journal data structures.
1167  * @c: UBIFS file-system description object
1168  *
1169  * This function destroys journal data structures including those that may have
1170  * been created by recovery functions.
1171  */
1172 static void destroy_journal(struct ubifs_info *c)
1173 {
1174     while (!list_empty(&c->unclean_leb_list)) {
1175         struct ubifs_unclean_leb *ucleb;
1176
1177         ucleb = list_entry(c->unclean_leb_list.next,
1178                    struct ubifs_unclean_leb, list);
1179         list_del(&ucleb->list);
1180         kfree(ucleb);
1181     }
1182     while (!list_empty(&c->old_buds)) {
1183         struct ubifs_bud *bud;
1184
1185         bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1186         list_del(&bud->list);
1187         kfree(bud);
1188     }
1189     ubifs_destroy_idx_gc(c);
1190     ubifs_destroy_size_tree(c);
1191     ubifs_tnc_close(c);
1192     free_buds(c);
1193 }
1194
1195 /**
1196  * bu_init - initialize bulk-read information.
1197  * @c: UBIFS file-system description object
1198  */
1199 static void bu_init(struct ubifs_info *c)
1200 {
1201     ubifs_assert(c, c->bulk_read == 1);
1202
1203     if (c->bu.buf)
1204         return; /* Already initialized */
1205
1206 again:
1207     c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1208     if (!c->bu.buf) {
1209         if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1210             c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1211             goto again;
1212         }
1213
1214         /* Just disable bulk-read */
1215         ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1216                c->max_bu_buf_len);
1217         c->mount_opts.bulk_read = 1;
1218         c->bulk_read = 0;
1219         return;
1220     }
1221 }
1222
1223 /**
1224  * check_free_space - check if there is enough free space to mount.
1225  * @c: UBIFS file-system description object
1226  *
1227  * This function makes sure UBIFS has enough free space to be mounted in
1228  * read/write mode. UBIFS must always have some free space to allow deletions.
1229  */
1230 static int check_free_space(struct ubifs_info *c)
1231 {
1232     ubifs_assert(c, c->dark_wm > 0);
1233     if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1234         ubifs_err(c, "insufficient free space to mount in R/W mode");
1235         ubifs_dump_budg(c, &c->bi);
1236         ubifs_dump_lprops(c);
1237         return -ENOSPC;
1238     }
1239     return 0;
1240 }
1241
1242 /**
1243  * mount_ubifs - mount UBIFS file-system.
1244  * @c: UBIFS file-system description object
1245  *
1246  * This function mounts UBIFS file system. Returns zero in case of success and
1247  * a negative error code in case of failure.
1248  */
1249 static int mount_ubifs(struct ubifs_info *c)
1250 {
1251     int err;
1252     long long x, y;
1253     size_t sz;
1254
1255     c->ro_mount = !!sb_rdonly(c->vfs_sb);
1256     /* Suppress error messages while probing if SB_SILENT is set */
1257     c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1258
1259     err = init_constants_early(c);
1260     if (err)
1261         return err;
1262
1263     err = ubifs_debugging_init(c);
1264     if (err)
1265         return err;
1266
1267     err = ubifs_sysfs_register(c);
1268     if (err)
1269         goto out_debugging;
1270
1271     err = check_volume_empty(c);
1272     if (err)
1273         goto out_free;
1274
1275     if (c->empty && (c->ro_mount || c->ro_media)) {
1276         /*
1277          * This UBI volume is empty, and read-only, or the file system
1278          * is mounted read-only - we cannot format it.
1279          */
1280         ubifs_err(c, "can't format empty UBI volume: read-only %s",
1281               c->ro_media ? "UBI volume" : "mount");
1282         err = -EROFS;
1283         goto out_free;
1284     }
1285
1286     if (c->ro_media && !c->ro_mount) {
1287         ubifs_err(c, "cannot mount read-write - read-only media");
1288         err = -EROFS;
1289         goto out_free;
1290     }
1291
1292     /*
1293      * The requirement for the buffer is that it should fit indexing B-tree
1294      * height amount of integers. We assume the height if the TNC tree will
1295      * never exceed 64.
1296      */
1297     err = -ENOMEM;
1298     c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),
1299                      GFP_KERNEL);
1300     if (!c->bottom_up_buf)
1301         goto out_free;
1302
1303     c->sbuf = vmalloc(c->leb_size);
1304     if (!c->sbuf)
1305         goto out_free;
1306
1307     if (!c->ro_mount) {
1308         c->ileb_buf = vmalloc(c->leb_size);
1309         if (!c->ileb_buf)
1310             goto out_free;
1311     }
1312
1313     if (c->bulk_read == 1)
1314         bu_init(c);
1315
1316     if (!c->ro_mount) {
1317         c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1318                            UBIFS_CIPHER_BLOCK_SIZE,
1319                            GFP_KERNEL);
1320         if (!c->write_reserve_buf)
1321             goto out_free;
1322     }
1323
1324     c->mounting = 1;
1325
1326     if (c->auth_key_name) {
1327         if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {
1328             err = ubifs_init_authentication(c);
1329             if (err)
1330                 goto out_free;
1331         } else {
1332             ubifs_err(c, "auth_key_name, but UBIFS is built without"
1333                   " authentication support");
1334             err = -EINVAL;
1335             goto out_free;
1336         }
1337     }
1338
1339     err = ubifs_read_superblock(c);
1340     if (err)
1341         goto out_auth;
1342
1343     c->probing = 0;
1344
1345     /*
1346      * Make sure the compressor which is set as default in the superblock
1347      * or overridden by mount options is actually compiled in.
1348      */
1349     if (!ubifs_compr_present(c, c->default_compr)) {
1350         ubifs_err(c, "'compressor \"%s\" is not compiled in",
1351               ubifs_compr_name(c, c->default_compr));
1352         err = -ENOTSUPP;
1353         goto out_auth;
1354     }
1355
1356     err = init_constants_sb(c);
1357     if (err)
1358         goto out_auth;
1359
1360     sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;
1361     c->cbuf = kmalloc(sz, GFP_NOFS);
1362     if (!c->cbuf) {
1363         err = -ENOMEM;
1364         goto out_auth;
1365     }
1366
1367     err = alloc_wbufs(c);
1368     if (err)
1369         goto out_cbuf;
1370
1371     sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1372     if (!c->ro_mount) {
1373         /* Create background thread */
1374         c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1375         if (IS_ERR(c->bgt)) {
1376             err = PTR_ERR(c->bgt);
1377             c->bgt = NULL;
1378             ubifs_err(c, "cannot spawn \"%s\", error %d",
1379                   c->bgt_name, err);
1380             goto out_wbufs;
1381         }
1382     }
1383
1384     err = ubifs_read_master(c);
1385     if (err)
1386         goto out_master;
1387
1388     init_constants_master(c);
1389
1390     if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1391         ubifs_msg(c, "recovery needed");
1392         c->need_recovery = 1;
1393     }
1394
1395     if (c->need_recovery && !c->ro_mount) {
1396         err = ubifs_recover_inl_heads(c, c->sbuf);
1397         if (err)
1398             goto out_master;
1399     }
1400
1401     err = ubifs_lpt_init(c, 1, !c->ro_mount);
1402     if (err)
1403         goto out_master;
1404
1405     if (!c->ro_mount && c->space_fixup) {
1406         err = ubifs_fixup_free_space(c);
1407         if (err)
1408             goto out_lpt;
1409     }
1410
1411     if (!c->ro_mount && !c->need_recovery) {
1412         /*
1413          * Set the "dirty" flag so that if we reboot uncleanly we
1414          * will notice this immediately on the next mount.
1415          */
1416         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1417         err = ubifs_write_master(c);
1418         if (err)
1419             goto out_lpt;
1420     }
1421
1422     /*
1423      * Handle offline signed images: Now that the master node is
1424      * written and its validation no longer depends on the hash
1425      * in the superblock, we can update the offline signed
1426      * superblock with a HMAC version,
1427      */
1428     if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
1429         err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
1430         if (err)
1431             goto out_lpt;
1432         c->superblock_need_write = 1;
1433     }
1434
1435     if (!c->ro_mount && c->superblock_need_write) {
1436         err = ubifs_write_sb_node(c, c->sup_node);
1437         if (err)
1438             goto out_lpt;
1439         c->superblock_need_write = 0;
1440     }
1441
1442     err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1443     if (err)
1444         goto out_lpt;
1445
1446     err = ubifs_replay_journal(c);
1447     if (err)
1448         goto out_journal;
1449
1450     /* Calculate 'min_idx_lebs' after journal replay */
1451     c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1452
1453     err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1454     if (err)
1455         goto out_orphans;
1456
1457     if (!c->ro_mount) {
1458         int lnum;
1459
1460         err = check_free_space(c);
1461         if (err)
1462             goto out_orphans;
1463
1464         /* Check for enough log space */
1465         lnum = c->lhead_lnum + 1;
1466         if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1467             lnum = UBIFS_LOG_LNUM;
1468         if (lnum == c->ltail_lnum) {
1469             err = ubifs_consolidate_log(c);
1470             if (err)
1471                 goto out_orphans;
1472         }
1473
1474         if (c->need_recovery) {
1475             if (!ubifs_authenticated(c)) {
1476                 err = ubifs_recover_size(c, true);
1477                 if (err)
1478                     goto out_orphans;
1479             }
1480
1481             err = ubifs_rcvry_gc_commit(c);
1482             if (err)
1483                 goto out_orphans;
1484
1485             if (ubifs_authenticated(c)) {
1486                 err = ubifs_recover_size(c, false);
1487                 if (err)
1488                     goto out_orphans;
1489             }
1490         } else {
1491             err = take_gc_lnum(c);
1492             if (err)
1493                 goto out_orphans;
1494
1495             /*
1496              * GC LEB may contain garbage if there was an unclean
1497              * reboot, and it should be un-mapped.
1498              */
1499             err = ubifs_leb_unmap(c, c->gc_lnum);
1500             if (err)
1501                 goto out_orphans;
1502         }
1503
1504         err = dbg_check_lprops(c);
1505         if (err)
1506             goto out_orphans;
1507     } else if (c->need_recovery) {
1508         err = ubifs_recover_size(c, false);
1509         if (err)
1510             goto out_orphans;
1511     } else {
1512         /*
1513          * Even if we mount read-only, we have to set space in GC LEB
1514          * to proper value because this affects UBIFS free space
1515          * reporting. We do not want to have a situation when
1516          * re-mounting from R/O to R/W changes amount of free space.
1517          */
1518         err = take_gc_lnum(c);
1519         if (err)
1520             goto out_orphans;
1521     }
1522
1523     spin_lock(&ubifs_infos_lock);
1524     list_add_tail(&c->infos_list, &ubifs_infos);
1525     spin_unlock(&ubifs_infos_lock);
1526
1527     if (c->need_recovery) {
1528         if (c->ro_mount)
1529             ubifs_msg(c, "recovery deferred");
1530         else {
1531             c->need_recovery = 0;
1532             ubifs_msg(c, "recovery completed");
1533             /*
1534              * GC LEB has to be empty and taken at this point. But
1535              * the journal head LEBs may also be accounted as
1536              * "empty taken" if they are empty.
1537              */
1538             ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1539         }
1540     } else
1541         ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1542
1543     err = dbg_check_filesystem(c);
1544     if (err)
1545         goto out_infos;
1546
1547     dbg_debugfs_init_fs(c);
1548
1549     c->mounting = 0;
1550
1551     ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1552           c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1553           c->ro_mount ? ", R/O mode" : "");
1554     x = (long long)c->main_lebs * c->leb_size;
1555     y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1556     ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1557           c->leb_size, c->leb_size >> 10, c->min_io_size,
1558           c->max_write_size);
1559     ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), max %d LEBs, journal size %lld bytes (%lld MiB, %d LEBs)",
1560           x, x >> 20, c->main_lebs, c->max_leb_cnt,
1561           y, y >> 20, c->log_lebs + c->max_bud_cnt);
1562     ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1563           c->report_rp_size, c->report_rp_size >> 10);
1564     ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1565           c->fmt_version, c->ro_compat_version,
1566           UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1567           c->big_lpt ? ", big LPT model" : ", small LPT model");
1568
1569     dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));
1570     dbg_gen("data journal heads:  %d",
1571         c->jhead_cnt - NONDATA_JHEADS_CNT);
1572     dbg_gen("log LEBs:            %d (%d - %d)",
1573         c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1574     dbg_gen("LPT area LEBs:       %d (%d - %d)",
1575         c->lpt_lebs, c->lpt_first, c->lpt_last);
1576     dbg_gen("orphan area LEBs:    %d (%d - %d)",
1577         c->orph_lebs, c->orph_first, c->orph_last);
1578     dbg_gen("main area LEBs:      %d (%d - %d)",
1579         c->main_lebs, c->main_first, c->leb_cnt - 1);
1580     dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1581     dbg_gen("total index bytes:   %llu (%llu KiB, %llu MiB)",
1582         c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1583         c->bi.old_idx_sz >> 20);
1584     dbg_gen("key hash type:       %d", c->key_hash_type);
1585     dbg_gen("tree fanout:         %d", c->fanout);
1586     dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1587     dbg_gen("max. znode size      %d", c->max_znode_sz);
1588     dbg_gen("max. index node size %d", c->max_idx_node_sz);
1589     dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1590         UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1591     dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1592         UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1593     dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1594         UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1595     dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1596         UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1597         UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1598     dbg_gen("dead watermark:      %d", c->dead_wm);
1599     dbg_gen("dark watermark:      %d", c->dark_wm);
1600     dbg_gen("LEB overhead:        %d", c->leb_overhead);
1601     x = (long long)c->main_lebs * c->dark_wm;
1602     dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1603         x, x >> 10, x >> 20);
1604     dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1605         c->max_bud_bytes, c->max_bud_bytes >> 10,
1606         c->max_bud_bytes >> 20);
1607     dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1608         c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1609         c->bg_bud_bytes >> 20);
1610     dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1611         c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1612     dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1613     dbg_gen("commit number:       %llu", c->cmt_no);
1614     dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));
1615     dbg_gen("max orphans:           %d", c->max_orphans);
1616
1617     return 0;
1618
1619 out_infos:
1620     spin_lock(&ubifs_infos_lock);
1621     list_del(&c->infos_list);
1622     spin_unlock(&ubifs_infos_lock);
1623 out_orphans:
1624     free_orphans(c);
1625 out_journal:
1626     destroy_journal(c);
1627 out_lpt:
1628     ubifs_lpt_free(c, 0);
1629 out_master:
1630     kfree(c->mst_node);
1631     kfree(c->rcvrd_mst_node);
1632     if (c->bgt)
1633         kthread_stop(c->bgt);
1634 out_wbufs:
1635     free_wbufs(c);
1636 out_cbuf:
1637     kfree(c->cbuf);
1638 out_auth:
1639     ubifs_exit_authentication(c);
1640 out_free:
1641     kfree(c->write_reserve_buf);
1642     kfree(c->bu.buf);
1643     vfree(c->ileb_buf);
1644     vfree(c->sbuf);
1645     kfree(c->bottom_up_buf);
1646     kfree(c->sup_node);
1647     ubifs_sysfs_unregister(c);
1648 out_debugging:
1649     ubifs_debugging_exit(c);
1650     return err;
1651 }
1652
1653 /**
1654  * ubifs_umount - un-mount UBIFS file-system.
1655  * @c: UBIFS file-system description object
1656  *
1657  * Note, this function is called to free allocated resourced when un-mounting,
1658  * as well as free resources when an error occurred while we were half way
1659  * through mounting (error path cleanup function). So it has to make sure the
1660  * resource was actually allocated before freeing it.
1661  */
1662 static void ubifs_umount(struct ubifs_info *c)
1663 {
1664     dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1665         c->vi.vol_id);
1666
1667     dbg_debugfs_exit_fs(c);
1668     spin_lock(&ubifs_infos_lock);
1669     list_del(&c->infos_list);
1670     spin_unlock(&ubifs_infos_lock);
1671
1672     if (c->bgt)
1673         kthread_stop(c->bgt);
1674
1675     destroy_journal(c);
1676     free_wbufs(c);
1677     free_orphans(c);
1678     ubifs_lpt_free(c, 0);
1679     ubifs_exit_authentication(c);
1680
1681     ubifs_release_options(c);
1682     kfree(c->cbuf);
1683     kfree(c->rcvrd_mst_node);
1684     kfree(c->mst_node);
1685     kfree(c->write_reserve_buf);
1686     kfree(c->bu.buf);
1687     vfree(c->ileb_buf);
1688     vfree(c->sbuf);
1689     kfree(c->bottom_up_buf);
1690     kfree(c->sup_node);
1691     ubifs_debugging_exit(c);
1692     ubifs_sysfs_unregister(c);
1693 }
1694
1695 /**
1696  * ubifs_remount_rw - re-mount in read-write mode.
1697  * @c: UBIFS file-system description object
1698  *
1699  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1700  * mode. This function allocates the needed resources and re-mounts UBIFS in
1701  * read-write mode.
1702  */
1703 static int ubifs_remount_rw(struct ubifs_info *c)
1704 {
1705     int err, lnum;
1706
1707     if (c->rw_incompat) {
1708         ubifs_err(c, "the file-system is not R/W-compatible");
1709         ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1710               c->fmt_version, c->ro_compat_version,
1711               UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1712         return -EROFS;
1713     }
1714
1715     mutex_lock(&c->umount_mutex);
1716     dbg_save_space_info(c);
1717     c->remounting_rw = 1;
1718     c->ro_mount = 0;
1719
1720     if (c->space_fixup) {
1721         err = ubifs_fixup_free_space(c);
1722         if (err)
1723             goto out;
1724     }
1725
1726     err = check_free_space(c);
1727     if (err)
1728         goto out;
1729
1730     if (c->need_recovery) {
1731         ubifs_msg(c, "completing deferred recovery");
1732         err = ubifs_write_rcvrd_mst_node(c);
1733         if (err)
1734             goto out;
1735         if (!ubifs_authenticated(c)) {
1736             err = ubifs_recover_size(c, true);
1737             if (err)
1738                 goto out;
1739         }
1740         err = ubifs_clean_lebs(c, c->sbuf);
1741         if (err)
1742             goto out;
1743         err = ubifs_recover_inl_heads(c, c->sbuf);
1744         if (err)
1745             goto out;
1746     } else {
1747         /* A readonly mount is not allowed to have orphans */
1748         ubifs_assert(c, c->tot_orphans == 0);
1749         err = ubifs_clear_orphans(c);
1750         if (err)
1751             goto out;
1752     }
1753
1754     if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1755         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1756         err = ubifs_write_master(c);
1757         if (err)
1758             goto out;
1759     }
1760
1761     if (c->superblock_need_write) {
1762         struct ubifs_sb_node *sup = c->sup_node;
1763
1764         err = ubifs_write_sb_node(c, sup);
1765         if (err)
1766             goto out;
1767
1768         c->superblock_need_write = 0;
1769     }
1770
1771     c->ileb_buf = vmalloc(c->leb_size);
1772     if (!c->ileb_buf) {
1773         err = -ENOMEM;
1774         goto out;
1775     }
1776
1777     c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1778                        UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1779     if (!c->write_reserve_buf) {
1780         err = -ENOMEM;
1781         goto out;
1782     }
1783
1784     err = ubifs_lpt_init(c, 0, 1);
1785     if (err)
1786         goto out;
1787
1788     /* Create background thread */
1789     c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1790     if (IS_ERR(c->bgt)) {
1791         err = PTR_ERR(c->bgt);
1792         c->bgt = NULL;
1793         ubifs_err(c, "cannot spawn \"%s\", error %d",
1794               c->bgt_name, err);
1795         goto out;
1796     }
1797
1798     c->orph_buf = vmalloc(c->leb_size);
1799     if (!c->orph_buf) {
1800         err = -ENOMEM;
1801         goto out;
1802     }
1803
1804     /* Check for enough log space */
1805     lnum = c->lhead_lnum + 1;
1806     if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1807         lnum = UBIFS_LOG_LNUM;
1808     if (lnum == c->ltail_lnum) {
1809         err = ubifs_consolidate_log(c);
1810         if (err)
1811             goto out;
1812     }
1813
1814     if (c->need_recovery) {
1815         err = ubifs_rcvry_gc_commit(c);
1816         if (err)
1817             goto out;
1818
1819         if (ubifs_authenticated(c)) {
1820             err = ubifs_recover_size(c, false);
1821             if (err)
1822                 goto out;
1823         }
1824     } else {
1825         err = ubifs_leb_unmap(c, c->gc_lnum);
1826     }
1827     if (err)
1828         goto out;
1829
1830     dbg_gen("re-mounted read-write");
1831     c->remounting_rw = 0;
1832
1833     if (c->need_recovery) {
1834         c->need_recovery = 0;
1835         ubifs_msg(c, "deferred recovery completed");
1836     } else {
1837         /*
1838          * Do not run the debugging space check if the were doing
1839          * recovery, because when we saved the information we had the
1840          * file-system in a state where the TNC and lprops has been
1841          * modified in memory, but all the I/O operations (including a
1842          * commit) were deferred. So the file-system was in
1843          * "non-committed" state. Now the file-system is in committed
1844          * state, and of course the amount of free space will change
1845          * because, for example, the old index size was imprecise.
1846          */
1847         err = dbg_check_space_info(c);
1848     }
1849
1850     mutex_unlock(&c->umount_mutex);
1851     return err;
1852
1853 out:
1854     c->ro_mount = 1;
1855     vfree(c->orph_buf);
1856     c->orph_buf = NULL;
1857     if (c->bgt) {
1858         kthread_stop(c->bgt);
1859         c->bgt = NULL;
1860     }
1861     kfree(c->write_reserve_buf);
1862     c->write_reserve_buf = NULL;
1863     vfree(c->ileb_buf);
1864     c->ileb_buf = NULL;
1865     ubifs_lpt_free(c, 1);
1866     c->remounting_rw = 0;
1867     mutex_unlock(&c->umount_mutex);
1868     return err;
1869 }
1870
1871 /**
1872  * ubifs_remount_ro - re-mount in read-only mode.
1873  * @c: UBIFS file-system description object
1874  *
1875  * We assume VFS has stopped writing. Possibly the background thread could be
1876  * running a commit, however kthread_stop will wait in that case.
1877  */
1878 static void ubifs_remount_ro(struct ubifs_info *c)
1879 {
1880     int i, err;
1881
1882     ubifs_assert(c, !c->need_recovery);
1883     ubifs_assert(c, !c->ro_mount);
1884
1885     mutex_lock(&c->umount_mutex);
1886     if (c->bgt) {
1887         kthread_stop(c->bgt);
1888         c->bgt = NULL;
1889     }
1890
1891     dbg_save_space_info(c);
1892
1893     for (i = 0; i < c->jhead_cnt; i++) {
1894         err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1895         if (err)
1896             ubifs_ro_mode(c, err);
1897     }
1898
1899     c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1900     c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1901     c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1902     err = ubifs_write_master(c);
1903     if (err)
1904         ubifs_ro_mode(c, err);
1905
1906     vfree(c->orph_buf);
1907     c->orph_buf = NULL;
1908     kfree(c->write_reserve_buf);
1909     c->write_reserve_buf = NULL;
1910     vfree(c->ileb_buf);
1911     c->ileb_buf = NULL;
1912     ubifs_lpt_free(c, 1);
1913     c->ro_mount = 1;
1914     err = dbg_check_space_info(c);
1915     if (err)
1916         ubifs_ro_mode(c, err);
1917     mutex_unlock(&c->umount_mutex);
1918 }
1919
1920 static void ubifs_put_super(struct super_block *sb)
1921 {
1922     int i;
1923     struct ubifs_info *c = sb->s_fs_info;
1924
1925     ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1926
1927     /*
1928      * The following asserts are only valid if there has not been a failure
1929      * of the media. For example, there will be dirty inodes if we failed
1930      * to write them back because of I/O errors.
1931      */
1932     if (!c->ro_error) {
1933         ubifs_assert(c, c->bi.idx_growth == 0);
1934         ubifs_assert(c, c->bi.dd_growth == 0);
1935         ubifs_assert(c, c->bi.data_growth == 0);
1936     }
1937
1938     /*
1939      * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1940      * and file system un-mount. Namely, it prevents the shrinker from
1941      * picking this superblock for shrinking - it will be just skipped if
1942      * the mutex is locked.
1943      */
1944     mutex_lock(&c->umount_mutex);
1945     if (!c->ro_mount) {
1946         /*
1947          * First of all kill the background thread to make sure it does
1948          * not interfere with un-mounting and freeing resources.
1949          */
1950         if (c->bgt) {
1951             kthread_stop(c->bgt);
1952             c->bgt = NULL;
1953         }
1954
1955         /*
1956          * On fatal errors c->ro_error is set to 1, in which case we do
1957          * not write the master node.
1958          */
1959         if (!c->ro_error) {
1960             int err;
1961
1962             /* Synchronize write-buffers */
1963             for (i = 0; i < c->jhead_cnt; i++) {
1964                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1965                 if (err)
1966                     ubifs_ro_mode(c, err);
1967             }
1968
1969             /*
1970              * We are being cleanly unmounted which means the
1971              * orphans were killed - indicate this in the master
1972              * node. Also save the reserved GC LEB number.
1973              */
1974             c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1975             c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1976             c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1977             err = ubifs_write_master(c);
1978             if (err)
1979                 /*
1980                  * Recovery will attempt to fix the master area
1981                  * next mount, so we just print a message and
1982                  * continue to unmount normally.
1983                  */
1984                 ubifs_err(c, "failed to write master node, error %d",
1985                       err);
1986         } else {
1987             for (i = 0; i < c->jhead_cnt; i++)
1988                 /* Make sure write-buffer timers are canceled */
1989                 hrtimer_cancel(&c->jheads[i].wbuf.timer);
1990         }
1991     }
1992
1993     ubifs_umount(c);
1994     ubi_close_volume(c->ubi);
1995     mutex_unlock(&c->umount_mutex);
1996 }
1997
1998 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1999 {
2000     int err;
2001     struct ubifs_info *c = sb->s_fs_info;
2002
2003     sync_filesystem(sb);
2004     dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
2005
2006     err = ubifs_parse_options(c, data, 1);
2007     if (err) {
2008         ubifs_err(c, "invalid or unknown remount parameter");
2009         return err;
2010     }
2011
2012     if (c->ro_mount && !(*flags & SB_RDONLY)) {
2013         if (c->ro_error) {
2014             ubifs_msg(c, "cannot re-mount R/W due to prior errors");
2015             return -EROFS;
2016         }
2017         if (c->ro_media) {
2018             ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
2019             return -EROFS;
2020         }
2021         err = ubifs_remount_rw(c);
2022         if (err)
2023             return err;
2024     } else if (!c->ro_mount && (*flags & SB_RDONLY)) {
2025         if (c->ro_error) {
2026             ubifs_msg(c, "cannot re-mount R/O due to prior errors");
2027             return -EROFS;
2028         }
2029         ubifs_remount_ro(c);
2030     }
2031
2032     if (c->bulk_read == 1)
2033         bu_init(c);
2034     else {
2035         dbg_gen("disable bulk-read");
2036         mutex_lock(&c->bu_mutex);
2037         kfree(c->bu.buf);
2038         c->bu.buf = NULL;
2039         mutex_unlock(&c->bu_mutex);
2040     }
2041
2042     if (!c->need_recovery)
2043         ubifs_assert(c, c->lst.taken_empty_lebs > 0);
2044
2045     return 0;
2046 }
2047
2048 const struct super_operations ubifs_super_operations = {
2049     .alloc_inode   = ubifs_alloc_inode,
2050     .free_inode    = ubifs_free_inode,
2051     .put_super     = ubifs_put_super,
2052     .write_inode   = ubifs_write_inode,
2053     .drop_inode    = ubifs_drop_inode,
2054     .evict_inode   = ubifs_evict_inode,
2055     .statfs        = ubifs_statfs,
2056     .dirty_inode   = ubifs_dirty_inode,
2057     .remount_fs    = ubifs_remount_fs,
2058     .show_options  = ubifs_show_options,
2059     .sync_fs       = ubifs_sync_fs,
2060 };
2061
2062 /**
2063  * open_ubi - parse UBI device name string and open the UBI device.
2064  * @name: UBI volume name
2065  * @mode: UBI volume open mode
2066  *
2067  * The primary method of mounting UBIFS is by specifying the UBI volume
2068  * character device node path. However, UBIFS may also be mounted without any
2069  * character device node using one of the following methods:
2070  *
2071  * o ubiX_Y    - mount UBI device number X, volume Y;
2072  * o ubiY      - mount UBI device number 0, volume Y;
2073  * o ubiX:NAME - mount UBI device X, volume with name NAME;
2074  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2075  *
2076  * Alternative '!' separator may be used instead of ':' (because some shells
2077  * like busybox may interpret ':' as an NFS host name separator). This function
2078  * returns UBI volume description object in case of success and a negative
2079  * error code in case of failure.
2080  */
2081 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2082 {
2083     struct ubi_volume_desc *ubi;
2084     int dev, vol;
2085     char *endptr;
2086
2087     if (!name || !*name)
2088         return ERR_PTR(-EINVAL);
2089
2090     /* First, try to open using the device node path method */
2091     ubi = ubi_open_volume_path(name, mode);
2092     if (!IS_ERR(ubi))
2093         return ubi;
2094
2095     /* Try the "nodev" method */
2096     if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2097         return ERR_PTR(-EINVAL);
2098
2099     /* ubi:NAME method */
2100     if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2101         return ubi_open_volume_nm(0, name + 4, mode);
2102
2103     if (!isdigit(name[3]))
2104         return ERR_PTR(-EINVAL);
2105
2106     dev = simple_strtoul(name + 3, &endptr, 0);
2107
2108     /* ubiY method */
2109     if (*endptr == '\0')
2110         return ubi_open_volume(0, dev, mode);
2111
2112     /* ubiX_Y method */
2113     if (*endptr == '_' && isdigit(endptr[1])) {
2114         vol = simple_strtoul(endptr + 1, &endptr, 0);
2115         if (*endptr != '\0')
2116             return ERR_PTR(-EINVAL);
2117         return ubi_open_volume(dev, vol, mode);
2118     }
2119
2120     /* ubiX:NAME method */
2121     if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2122         return ubi_open_volume_nm(dev, ++endptr, mode);
2123
2124     return ERR_PTR(-EINVAL);
2125 }
2126
2127 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2128 {
2129     struct ubifs_info *c;
2130
2131     c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2132     if (c) {
2133         spin_lock_init(&c->cnt_lock);
2134         spin_lock_init(&c->cs_lock);
2135         spin_lock_init(&c->buds_lock);
2136         spin_lock_init(&c->space_lock);
2137         spin_lock_init(&c->orphan_lock);
2138         init_rwsem(&c->commit_sem);
2139         mutex_init(&c->lp_mutex);
2140         mutex_init(&c->tnc_mutex);
2141         mutex_init(&c->log_mutex);
2142         mutex_init(&c->umount_mutex);
2143         mutex_init(&c->bu_mutex);
2144         mutex_init(&c->write_reserve_mutex);
2145         init_waitqueue_head(&c->cmt_wq);
2146         c->buds = RB_ROOT;
2147         c->old_idx = RB_ROOT;
2148         c->size_tree = RB_ROOT;
2149         c->orph_tree = RB_ROOT;
2150         INIT_LIST_HEAD(&c->infos_list);
2151         INIT_LIST_HEAD(&c->idx_gc);
2152         INIT_LIST_HEAD(&c->replay_list);
2153         INIT_LIST_HEAD(&c->replay_buds);
2154         INIT_LIST_HEAD(&c->uncat_list);
2155         INIT_LIST_HEAD(&c->empty_list);
2156         INIT_LIST_HEAD(&c->freeable_list);
2157         INIT_LIST_HEAD(&c->frdi_idx_list);
2158         INIT_LIST_HEAD(&c->unclean_leb_list);
2159         INIT_LIST_HEAD(&c->old_buds);
2160         INIT_LIST_HEAD(&c->orph_list);
2161         INIT_LIST_HEAD(&c->orph_new);
2162         c->no_chk_data_crc = 1;
2163         c->assert_action = ASSACT_RO;
2164
2165         c->highest_inum = UBIFS_FIRST_INO;
2166         c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2167
2168         ubi_get_volume_info(ubi, &c->vi);
2169         ubi_get_device_info(c->vi.ubi_num, &c->di);
2170     }
2171     return c;
2172 }
2173
2174 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2175 {
2176     struct ubifs_info *c = sb->s_fs_info;
2177     struct inode *root;
2178     int err;
2179
2180     c->vfs_sb = sb;
2181     /* Re-open the UBI device in read-write mode */
2182     c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2183     if (IS_ERR(c->ubi)) {
2184         err = PTR_ERR(c->ubi);
2185         goto out;
2186     }
2187
2188     err = ubifs_parse_options(c, data, 0);
2189     if (err)
2190         goto out_close;
2191
2192     /*
2193      * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2194      * UBIFS, I/O is not deferred, it is done immediately in read_folio,
2195      * which means the user would have to wait not just for their own I/O
2196      * but the read-ahead I/O as well i.e. completely pointless.
2197      *
2198      * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2199      * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2200      * writeback happening.
2201      */
2202     err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2203                    c->vi.vol_id);
2204     if (err)
2205         goto out_close;
2206     sb->s_bdi->ra_pages = 0;
2207     sb->s_bdi->io_pages = 0;
2208
2209     sb->s_fs_info = c;
2210     sb->s_magic = UBIFS_SUPER_MAGIC;
2211     sb->s_blocksize = UBIFS_BLOCK_SIZE;
2212     sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2213     sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2214     if (c->max_inode_sz > MAX_LFS_FILESIZE)
2215         sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2216     sb->s_op = &ubifs_super_operations;
2217     sb->s_xattr = ubifs_xattr_handlers;
2218     fscrypt_set_ops(sb, &ubifs_crypt_operations);
2219
2220     mutex_lock(&c->umount_mutex);
2221     err = mount_ubifs(c);
2222     if (err) {
2223         ubifs_assert(c, err < 0);
2224         goto out_unlock;
2225     }
2226
2227     /* Read the root inode */
2228     root = ubifs_iget(sb, UBIFS_ROOT_INO);
2229     if (IS_ERR(root)) {
2230         err = PTR_ERR(root);
2231         goto out_umount;
2232     }
2233
2234     sb->s_root = d_make_root(root);
2235     if (!sb->s_root) {
2236         err = -ENOMEM;
2237         goto out_umount;
2238     }
2239
2240     import_uuid(&sb->s_uuid, c->uuid);
2241
2242     mutex_unlock(&c->umount_mutex);
2243     return 0;
2244
2245 out_umount:
2246     ubifs_umount(c);
2247 out_unlock:
2248     mutex_unlock(&c->umount_mutex);
2249 out_close:
2250     ubifs_release_options(c);
2251     ubi_close_volume(c->ubi);
2252 out:
2253     return err;
2254 }
2255
2256 static int sb_test(struct super_block *sb, void *data)
2257 {
2258     struct ubifs_info *c1 = data;
2259     struct ubifs_info *c = sb->s_fs_info;
2260
2261     return c->vi.cdev == c1->vi.cdev;
2262 }
2263
2264 static int sb_set(struct super_block *sb, void *data)
2265 {
2266     sb->s_fs_info = data;
2267     return set_anon_super(sb, NULL);
2268 }
2269
2270 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2271             const char *name, void *data)
2272 {
2273     struct ubi_volume_desc *ubi;
2274     struct ubifs_info *c;
2275     struct super_block *sb;
2276     int err;
2277
2278     dbg_gen("name %s, flags %#x", name, flags);
2279
2280     /*
2281      * Get UBI device number and volume ID. Mount it read-only so far
2282      * because this might be a new mount point, and UBI allows only one
2283      * read-write user at a time.
2284      */
2285     ubi = open_ubi(name, UBI_READONLY);
2286     if (IS_ERR(ubi)) {
2287         if (!(flags & SB_SILENT))
2288             pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2289                    current->pid, name, (int)PTR_ERR(ubi));
2290         return ERR_CAST(ubi);
2291     }
2292
2293     c = alloc_ubifs_info(ubi);
2294     if (!c) {
2295         err = -ENOMEM;
2296         goto out_close;
2297     }
2298
2299     dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2300
2301     sb = sget(fs_type, sb_test, sb_set, flags, c);
2302     if (IS_ERR(sb)) {
2303         err = PTR_ERR(sb);
2304         kfree(c);
2305         goto out_close;
2306     }
2307
2308     if (sb->s_root) {
2309         struct ubifs_info *c1 = sb->s_fs_info;
2310         kfree(c);
2311         /* A new mount point for already mounted UBIFS */
2312         dbg_gen("this ubi volume is already mounted");
2313         if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2314             err = -EBUSY;
2315             goto out_deact;
2316         }
2317     } else {
2318         err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2319         if (err)
2320             goto out_deact;
2321         /* We do not support atime */
2322         sb->s_flags |= SB_ACTIVE;
2323         if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
2324             ubifs_msg(c, "full atime support is enabled.");
2325         else
2326             sb->s_flags |= SB_NOATIME;
2327     }
2328
2329     /* 'fill_super()' opens ubi again so we must close it here */
2330     ubi_close_volume(ubi);
2331
2332     return dget(sb->s_root);
2333
2334 out_deact:
2335     deactivate_locked_super(sb);
2336 out_close:
2337     ubi_close_volume(ubi);
2338     return ERR_PTR(err);
2339 }
2340
2341 static void kill_ubifs_super(struct super_block *s)
2342 {
2343     struct ubifs_info *c = s->s_fs_info;
2344     kill_anon_super(s);
2345     kfree(c);
2346 }
2347
2348 static struct file_system_type ubifs_fs_type = {
2349     .name    = "ubifs",
2350     .owner   = THIS_MODULE,
2351     .mount   = ubifs_mount,
2352     .kill_sb = kill_ubifs_super,
2353 };
2354 MODULE_ALIAS_FS("ubifs");
2355
2356 /*
2357  * Inode slab cache constructor.
2358  */
2359 static void inode_slab_ctor(void *obj)
2360 {
2361     struct ubifs_inode *ui = obj;
2362     inode_init_once(&ui->vfs_inode);
2363 }
2364
2365 static int __init ubifs_init(void)
2366 {
2367     int err;
2368
2369     BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2370
2371     /* Make sure node sizes are 8-byte aligned */
2372     BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2373     BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2374     BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2375     BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2376     BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2377     BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2378     BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2379     BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2380     BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2381     BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2382     BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2383
2384     BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2385     BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2386     BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2387     BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2388     BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2389     BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2390
2391     /* Check min. node size */
2392     BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2393     BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2394     BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2395     BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2396
2397     BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2398     BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2399     BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2400     BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2401
2402     /* Defined node sizes */
2403     BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2404     BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2405     BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2406     BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2407
2408     /*
2409      * We use 2 bit wide bit-fields to store compression type, which should
2410      * be amended if more compressors are added. The bit-fields are:
2411      * @compr_type in 'struct ubifs_inode', @default_compr in
2412      * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2413      */
2414     BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2415
2416     /*
2417      * We require that PAGE_SIZE is greater-than-or-equal-to
2418      * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2419      */
2420     if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2421         pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2422                current->pid, (unsigned int)PAGE_SIZE);
2423         return -EINVAL;
2424     }
2425
2426     ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2427                 sizeof(struct ubifs_inode), 0,
2428                 SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2429                 SLAB_ACCOUNT, &inode_slab_ctor);
2430     if (!ubifs_inode_slab)
2431         return -ENOMEM;
2432
2433     err = register_shrinker(&ubifs_shrinker_info, "ubifs-slab");
2434     if (err)
2435         goto out_slab;
2436
2437     err = ubifs_compressors_init();
2438     if (err)
2439         goto out_shrinker;
2440
2441     dbg_debugfs_init();
2442
2443     err = ubifs_sysfs_init();
2444     if (err)
2445         goto out_dbg;
2446
2447     err = register_filesystem(&ubifs_fs_type);
2448     if (err) {
2449         pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2450                current->pid, err);
2451         goto out_sysfs;
2452     }
2453     return 0;
2454
2455 out_sysfs:
2456     ubifs_sysfs_exit();
2457 out_dbg:
2458     dbg_debugfs_exit();
2459     ubifs_compressors_exit();
2460 out_shrinker:
2461     unregister_shrinker(&ubifs_shrinker_info);
2462 out_slab:
2463     kmem_cache_destroy(ubifs_inode_slab);
2464     return err;
2465 }
2466 /* late_initcall to let compressors initialize first */
2467 late_initcall(ubifs_init);
2468
2469 static void __exit ubifs_exit(void)
2470 {
2471     WARN_ON(!list_empty(&ubifs_infos));
2472     WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
2473
2474     dbg_debugfs_exit();
2475     ubifs_sysfs_exit();
2476     ubifs_compressors_exit();
2477     unregister_shrinker(&ubifs_shrinker_info);
2478
2479     /*
2480      * Make sure all delayed rcu free inodes are flushed before we
2481      * destroy cache.
2482      */
2483     rcu_barrier();
2484     kmem_cache_destroy(ubifs_inode_slab);
2485     unregister_filesystem(&ubifs_fs_type);
2486 }
2487 module_exit(ubifs_exit);
2488
2489 MODULE_LICENSE("GPL");
2490 MODULE_VERSION(__stringify(UBIFS_VERSION));
2491 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2492 MODULE_DESCRIPTION("UBIFS - UBI File System");