Instead of marking dirty-state on mount, do it just before updating the metadata. Therefore, if no write operation is performed, the boot sector will not be updated. This eliminates unnecessary dirty mark / unmark and reduces the risk of boot sector corruption. Also, keep boot-sec bh in sb to suppress errors when updating dirty.
Signed-off-by: Tetsuhiro Kohada <[email protected]> --- fs/fat/dir.c | 2 + fs/fat/fat.h | 4 ++ fs/fat/fatent.c | 8 +++- fs/fat/file.c | 1 + fs/fat/inode.c | 100 +++++++++++++++++++++++-------------------- fs/fat/misc.c | 1 + fs/fat/namei_msdos.c | 1 + fs/fat/namei_vfat.c | 1 + 8 files changed, 70 insertions(+), 48 deletions(-) diff --git a/fs/fat/dir.c b/fs/fat/dir.c index c4a274285858..d0236908dfc5 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -1033,6 +1033,7 @@ int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo) struct buffer_head *bh; int err = 0, nr_slots; + fat_set_state(sb, true); /* * First stage: Remove the shortname. By this, the directory * entry is removed. @@ -1327,6 +1328,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots, } found: + fat_set_state(sb, true); err = 0; pos -= free_slots * sizeof(*de); nr_slots -= free_slots; diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 922a0c6ba46c..870369603746 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -76,6 +76,7 @@ struct msdos_sb_info { struct mutex fat_lock; struct mutex nfs_build_inode_lock; struct mutex s_lock; + struct mutex bootsec_lock; unsigned int prev_free; /* previously allocated cluster number */ unsigned int free_clusters; /* -1 if undefined */ unsigned int free_clus_valid; /* is free_clusters valid? */ @@ -101,6 +102,8 @@ struct msdos_sb_info { struct hlist_head dir_hashtable[FAT_HASH_SIZE]; unsigned int dirty; /* fs state before mount */ + u8 state; /* current fs state */ + struct buffer_head *boot_bh; struct rcu_head rcu; }; @@ -423,6 +426,7 @@ static inline unsigned long fat_dir_hash(int logstart) return hash_32(logstart, FAT_HASH_BITS); } extern int fat_add_cluster(struct inode *inode); +extern void fat_set_state(struct super_block *sb, bool dirty); /* fat/misc.c */ extern __printf(3, 4) __cold diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index f7e3304b7802..5c4cebfdf337 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -472,6 +472,7 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster) BUG_ON(nr_cluster > (MAX_BUF_PER_PAGE / 2)); /* fixed limit */ + fat_set_state(sb, true); lock_fat(sbi); if (sbi->free_clusters != -1 && sbi->free_clus_valid && sbi->free_clusters < nr_cluster) { @@ -559,6 +560,7 @@ int fat_free_clusters(struct inode *inode, int cluster) int i, err, nr_bhs; int first_cl = cluster, dirty_fsinfo = 0; + fat_set_state(sb, true); nr_bhs = 0; fatent_init(&fatent); lock_fat(sbi); @@ -741,9 +743,11 @@ int fat_count_free_clusters(struct super_block *sb) } while (fat_ent_next(sbi, &fatent)); cond_resched(); } - sbi->free_clusters = free; sbi->free_clus_valid = 1; - mark_fsinfo_dirty(sb); + if (sbi->free_clusters != free) { + sbi->free_clusters = free; + mark_fsinfo_dirty(sb); + } fatent_brelse(&fatent); out: unlock_fat(sbi); diff --git a/fs/fat/file.c b/fs/fat/file.c index f9ee27cf4d7c..04af56276cda 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -314,6 +314,7 @@ static int fat_free(struct inode *inode, int skip) if (MSDOS_I(inode)->i_start == 0) return 0; + fat_set_state(sb, true); fat_cache_inval_inode(inode); wait = IS_DIRSYNC(inode); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index bab9b202b496..cb7b50746b9b 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -662,52 +662,45 @@ static void fat_evict_inode(struct inode *inode) fat_detach(inode); } -static void fat_set_state(struct super_block *sb, - unsigned int set, unsigned int force) +void fat_set_state(struct super_block *sb, bool dirty) { - struct buffer_head *bh; struct fat_boot_sector *b; struct msdos_sb_info *sbi = MSDOS_SB(sb); + u8 newstate; /* do not change any thing if mounted read only */ - if (sb_rdonly(sb) && !force) + if (sb_rdonly(sb)) return; /* do not change state if fs was dirty */ - if (sbi->dirty) { - /* warn only on set (mount). */ - if (set) - fat_msg(sb, KERN_WARNING, "Volume was not properly " - "unmounted. Some data may be corrupt. " - "Please run fsck."); + if (sbi->dirty) return; - } - - bh = sb_bread(sb, 0); - if (bh == NULL) { - fat_msg(sb, KERN_ERR, "unable to read boot sector " - "to mark fs as dirty"); - return; - } - b = (struct fat_boot_sector *) bh->b_data; + if (dirty) + newstate = sbi->state | FAT_STATE_DIRTY; + else + newstate = sbi->state & ~FAT_STATE_DIRTY; - if (is_fat32(sbi)) { - if (set) - b->fat32.state |= FAT_STATE_DIRTY; - else - b->fat32.state &= ~FAT_STATE_DIRTY; - } else /* fat 16 and 12 */ { - if (set) - b->fat16.state |= FAT_STATE_DIRTY; - else - b->fat16.state &= ~FAT_STATE_DIRTY; - } + /* do nothing if state is same */ + if (newstate == sbi->state) + return; + mutex_lock(&sbi->bootsec_lock); + if (newstate == READ_ONCE(sbi->state)) + goto unlock; - mark_buffer_dirty(bh); - sync_dirty_buffer(bh); - brelse(bh); + b = (struct fat_boot_sector *) sbi->boot_bh->b_data; + if (is_fat32(sbi)) + b->fat32.state = newstate; + else /* fat 16 and 12 */ + b->fat16.state = newstate; + + mark_buffer_dirty(sbi->boot_bh); + sync_dirty_buffer(sbi->boot_bh); + sbi->state = newstate; +unlock: + mutex_unlock(&sbi->bootsec_lock); } +EXPORT_SYMBOL_GPL(fat_set_state); static void fat_reset_iocharset(struct fat_mount_options *opts) { @@ -731,7 +724,8 @@ static void fat_put_super(struct super_block *sb) { struct msdos_sb_info *sbi = MSDOS_SB(sb); - fat_set_state(sb, 0, 0); + fat_set_state(sb, false); + brelse(sbi->boot_bh); iput(sbi->fsinfo_inode); iput(sbi->fat_inode); @@ -799,6 +793,15 @@ static void __exit fat_destroy_inodecache(void) kmem_cache_destroy(fat_inode_cachep); } +static void fat_warn_volume_dirty(struct super_block *sb) +{ + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + if (sbi->dirty) + fat_msg(sb, KERN_WARNING, + "Volume was not properly unmounted. Some data may be corrupt. Please run fsck."); +} + static int fat_remount(struct super_block *sb, int *flags, char *data) { bool new_rdonly; @@ -811,9 +814,9 @@ static int fat_remount(struct super_block *sb, int *flags, char *data) new_rdonly = *flags & SB_RDONLY; if (new_rdonly != sb_rdonly(sb)) { if (new_rdonly) - fat_set_state(sb, 0, 0); + fat_set_state(sb, false); else - fat_set_state(sb, 1, 1); + fat_warn_volume_dirty(sb); } return 0; } @@ -856,6 +859,7 @@ static int __fat_write_inode(struct inode *inode, int wait) if (inode->i_ino == MSDOS_ROOT_INO) return 0; + fat_set_state(sb, true); retry: i_pos = fat_i_pos_read(sbi, inode); if (!i_pos) @@ -1604,7 +1608,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, { struct inode *root_inode = NULL, *fat_inode = NULL; struct inode *fsinfo_inode = NULL; - struct buffer_head *bh; + struct buffer_head *bh = NULL; struct fat_bios_param_block bpb; struct msdos_sb_info *sbi; u16 logical_sector_size; @@ -1657,7 +1661,6 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, if (error == -EINVAL && sbi->options.dos1xfloppy) error = fat_read_static_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent, &bpb); - brelse(bh); if (error == -EINVAL) goto out_invalid; @@ -1675,8 +1678,8 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, } if (logical_sector_size > sb->s_blocksize) { - struct buffer_head *bh_resize; - + brelse(bh); + bh = NULL; if (!sb_set_blocksize(sb, logical_sector_size)) { fat_msg(sb, KERN_ERR, "unable to set blocksize %u", logical_sector_size); @@ -1684,15 +1687,15 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, } /* Verify that the larger boot sector is fully readable */ - bh_resize = sb_bread(sb, 0); - if (bh_resize == NULL) { + bh = sb_bread(sb, 0); + if (bh == NULL) { fat_msg(sb, KERN_ERR, "unable to read boot sector" " (logical sector size = %lu)", sb->s_blocksize); goto out_fail; } - brelse(bh_resize); } + sbi->boot_bh = bh; mutex_init(&sbi->s_lock); sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; @@ -1783,9 +1786,11 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */ if (is_fat32(sbi)) - sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY; + sbi->state = bpb.fat32_state; else /* fat 16 or 12 */ - sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY; + sbi->state = bpb.fat16_state; + sbi->dirty = sbi->state & FAT_STATE_DIRTY; + mutex_init(&sbi->bootsec_lock); /* check that FAT table does not overflow */ fat_clusters = calc_fat_clusters(sb); @@ -1881,7 +1886,9 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, "the device does not support discard"); } - fat_set_state(sb, 1, 0); + if (!sb_rdonly(sb)) + fat_warn_volume_dirty(sb); + return 0; out_invalid: @@ -1897,6 +1904,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, unload_nls(sbi->nls_io); unload_nls(sbi->nls_disk); fat_reset_iocharset(&sbi->options); + brelse(bh); sb->s_fs_info = NULL; kfree(sbi); return error; diff --git a/fs/fat/misc.c b/fs/fat/misc.c index f1b2a1fc2a6a..e9d8dd5f03d6 100644 --- a/fs/fat/misc.c +++ b/fs/fat/misc.c @@ -83,6 +83,7 @@ int fat_clusters_flush(struct super_block *sb) le32_to_cpu(fsinfo->signature2), sbi->fsinfo_sector); } else { + fat_set_state(sb, true); if (sbi->free_clusters != -1) fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters); if (sbi->prev_free != -1) diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c index 9d062886fbc1..929b9773298c 100644 --- a/fs/fat/namei_msdos.c +++ b/fs/fat/namei_msdos.c @@ -508,6 +508,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name, } inode_inc_iversion(new_dir); + fat_set_state(new_dir->i_sb, true); fat_detach(old_inode); fat_attach(old_inode, new_i_pos); if (is_hid) diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index 0cdd0fb9f742..b466abba3744 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -943,6 +943,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, } inode_inc_iversion(new_dir); + fat_set_state(sb, true); fat_detach(old_inode); fat_attach(old_inode, new_i_pos); if (IS_DIRSYNC(new_dir)) { -- 2.30.2
