Doing a forced check on an ext4 file system with inline_data and
large_dir results in lots of fsck messages. To reproduce:
truncate -s 100000000 ext4.img
misc/mke2fs -t ext4 -I 512 -O 'inline_data,large_dir' ext4.img
mkdir m
sudo mount ext4.img m
mkdir m/aa
sudo umount m
e2fsck/e2fsck -f -n ext4.img
The last command gives this output:
[root@localhost e2fsprogs-kernel]# e2fsck/e2fsck -f -n ext4-2.img
e2fsck 1.45.2 (27-May-2019)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
'..' in /aa (12) is <The NULL inode> (0), should be / (2).
Fix? no
Pass 4: Checking reference counts
Inode 2 ref count is 4, should be 3. Fix? no
Inode 12 ref count is 2, should be 1. Fix? no
Pass 5: Checking group summary information
ext4-2.img: ********** WARNING: Filesystem still has errors **********
ext4-2.img: 12/24384 files (0.0% non-contiguous), 17874/97656 blocks
Rootcause of this issue is large_dir optimization that is not
appropriate for inline_data.
Let's not optimize it if inline_data is set.
Reported-by: Rasmus Villemoes <[email protected]>
Signed-off-by: Artem Blagodarenko <[email protected]>
---
e2fsck/pass2.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/e2fsck/pass2.c b/e2fsck/pass2.c
index a7d9c47d..8b40e93d 100644
--- a/e2fsck/pass2.c
+++ b/e2fsck/pass2.c
@@ -980,7 +980,8 @@ static int check_dir_block(ext2_filsys fs,
* very large and then the files are deleted. For now, all that is
* needed is to avoid e2fsck filling in these holes as part of
* feature flag. */
- if (db->blk == 0 && ext2fs_has_feature_largedir(fs->super))
+ if (db->blk == 0 && ext2fs_has_feature_largedir(fs->super) &&
+ !ext2fs_has_feature_inline_data(fs->super))
return 0;
if (db->blk == 0 && !inline_data_size) {
--
2.14.3
On Fri, Jun 14, 2019 at 05:42:37PM +0300, Artem Blagodarenko wrote:
> Doing a forced check on an ext4 file system with inline_data and
> large_dir results in lots of fsck messages. To reproduce:
> ...
>
> Rootcause of this issue is large_dir optimization that is not
> appropriate for inline_data.
>
> Let's not optimize it if inline_data is set.
>
> Reported-by: Rasmus Villemoes <[email protected]>
> Signed-off-by: Artem Blagodarenko <[email protected]>
Thanks, applied, although I corrected the commit description. The
initial description now reads:
e2fsck: correctly handle inline directories when large_dir is enabled.
Historically, e2fsck has required that directories not contain holes.
(In fact, as of this writing, ext4 still requires this to be the
case.) Commit ae9efd05a98 ("e2fsck: 3 level hash tree directory
optimization") removed this requirement if the large_dir feature is
enabled; however, the way it was done caused it to incorrectly handle
inline directories.
To reproduce the problem fixed by this commit:
...
BTW, Removing the directory hole check in commit ae9efd05a98 for file
systems with the large_dir feature enabled was a wee bit optimistic,
since the kernel will still mark the file system as corrupted.
Fixing the kernel so that it doesn't complain about directories with
holes is going to be a bit more complicated than just removing the
check in __ext4_read_dirblock():
if (!bh) {
ext4_error_inode(inode, func, line, block,
"Directory hole found");
return ERR_PTR(-EFSCORRUPTED);
}
(That's because we have to fix all of the callers of
ext4_read_dirblock() to handle the case where it returns NULL if there
is no directory block at that specified location.)
I should have caught that when reviewing the e2fsprogs commit; my bad.
At this point, we should just fix the kernel so it can handle
directories with holes (both for large_dir and non-large_dir
directories).
- Ted