| Message ID | 1547339800-50257-1-git-send-email-adilger@dilger.ca |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | ext4: don't update s_rev_level if not required | expand |
Hi Andreas, On Sun, Jan 13, 2019 at 1:36 AM Andreas Dilger <adilger@dilger.ca> wrote: > 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@dilger.ca> Thanks for your patch! > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1670,6 +1670,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) > } \ > static inline void ext4_set_feature_##name(struct super_block *sb) \ > { \ > + ext4_update_dynamic_rev(sb); \ This doesn't compile, as ext4_update_dynamic_rev() is used before its declaration: In file included from fs/ext4/bitmap.c:12:0: fs/ext4/ext4.h: In function ‘ext4_set_feature_dir_prealloc’: fs/ext4/ext4.h:1673:2: error: implicit declaration of function ‘ext4_update_dynamic_rev’ [-Werror=implicit-function-declaration] ext4_update_dynamic_rev(sb); \ ^ fs/ext4/ext4.h:1719:1: note: in expansion of macro ‘EXT4_FEATURE_COMPAT_FUNCS’ EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc, DIR_PREALLOC) ^~~~~~~~~~~~~~~~~~~~~~~~~ fs/ext4/ext4.h: At top level: fs/ext4/ext4.h:2678:13: warning: conflicting types for ‘ext4_update_dynamic_rev’ extern void ext4_update_dynamic_rev(struct super_block *sb); ^~~~~~~~~~~~~~~~~~~~~~~ fs/ext4/ext4.h:1673:2: note: previous implicit declaration of ‘ext4_update_dynamic_rev’ was here ext4_update_dynamic_rev(sb); \ ^ fs/ext4/ext4.h:1719:1: note: in expansion of macro ‘EXT4_FEATURE_COMPAT_FUNCS’ EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc, DIR_PREALLOC) ^~~~~~~~~~~~~~~~~~~~~~~~~ Moving the declaration up fixes that. Hence with that fixed: Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Sat, Jan 12, 2019 at 05:36:40PM -0700, Andreas Dilger wrote: > 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@dilger.ca> Thanks, applied. I had to move the declaration of ext4_update_dynamic_rev() earlier as Geert suggested. - Ted
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 185a05d..a1357f3 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1670,6 +1670,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) } \ 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); \ } \ @@ -1687,6 +1688,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) } \ 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); \ } \ @@ -1704,6 +1706,7 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei) } \ 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); \ } \ diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 34d7e07..f21f2ac 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5351,7 +5351,6 @@ static int ext4_do_update_inode(handle_t *handle, 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); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index fb12d3c..6e4cac6 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2249,7 +2249,6 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es, 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);
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@dilger.ca> --- fs/ext4/ext4.h | 3 +++ fs/ext4/inode.c | 1 - fs/ext4/super.c | 1 - 3 files changed, 3 insertions(+), 2 deletions(-)