From: Andreas Dilger <adilger@xxxxxxxxx> commit c9e716eb9b3455a83ed7c5f5a81256a3da779a95 upstream. Don't update the superblock s_rev_level during mount if it isn't actually necessary, only if superblock features are being set by the kernel. This was originally added for ext3 since it always set the INCOMPAT_RECOVER and HAS_JOURNAL features during mount, but this is not needed since no journal mode was added to ext4. That will allow Geert to mount his 20-year-old ext2 rev 0.0 m68k filesystem, as a testament of the backward compatibility of ext4. Fixes: 0390131ba84f ("ext4: Allow ext4 to run without a journal") Signed-off-by: Andreas Dilger <adilger@xxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/ext4.h | 6 +++++- fs/ext4/inode.c | 1 - fs/ext4/super.c | 1 - 3 files changed, 5 insertions(+), 3 deletions(-) --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1665,6 +1665,8 @@ static inline void ext4_clear_state_flag #define EXT4_FEATURE_INCOMPAT_INLINE_DATA 0x8000 /* data in inode */ #define EXT4_FEATURE_INCOMPAT_ENCRYPT 0x10000 +extern void ext4_update_dynamic_rev(struct super_block *sb); + #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \ static inline bool ext4_has_feature_##name(struct super_block *sb) \ { \ @@ -1673,6 +1675,7 @@ static inline bool ext4_has_feature_##na } \ static inline void ext4_set_feature_##name(struct super_block *sb) \ { \ + ext4_update_dynamic_rev(sb); \ EXT4_SB(sb)->s_es->s_feature_compat |= \ cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \ } \ @@ -1690,6 +1693,7 @@ static inline bool ext4_has_feature_##na } \ static inline void ext4_set_feature_##name(struct super_block *sb) \ { \ + ext4_update_dynamic_rev(sb); \ EXT4_SB(sb)->s_es->s_feature_ro_compat |= \ cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \ } \ @@ -1707,6 +1711,7 @@ static inline bool ext4_has_feature_##na } \ static inline void ext4_set_feature_##name(struct super_block *sb) \ { \ + ext4_update_dynamic_rev(sb); \ EXT4_SB(sb)->s_es->s_feature_incompat |= \ cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \ } \ @@ -2675,7 +2680,6 @@ do { \ #endif -extern void ext4_update_dynamic_rev(struct super_block *sb); extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb, __u32 compat); extern int ext4_update_rocompat_feature(handle_t *handle, --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5355,7 +5355,6 @@ static int ext4_do_update_inode(handle_t err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); if (err) goto out_brelse; - ext4_update_dynamic_rev(sb); ext4_set_feature_large_file(sb); ext4_handle_sync(handle); err = ext4_handle_dirty_super(handle, sb); --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2259,7 +2259,6 @@ static int ext4_setup_super(struct super es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT); le16_add_cpu(&es->s_mnt_count, 1); ext4_update_tstamp(es, s_mtime); - ext4_update_dynamic_rev(sb); if (sbi->s_journal) ext4_set_feature_journal_needs_recovery(sb);