On Wed 19 Jun 2024 12:30:38 AM +02, Ben Hutchings wrote;
> On Tue, 2024-06-18 at 15:43 +0100, Luis Henriques (SUSE) wrote:
>> When fast-commit needs to track ranges, it has to handle inodes that have
>> inlined data in a different way because ext4_fc_write_inode_data(), in the
>> actual commit path, will attempt to map the required blocks for the range.
>> However, inodes that have inlined data will have it's data stored in
>> inode->i_block and, eventually, in the extended attribute space.
>>
>> Unfortunately, because fast commit doesn't currently support extended
>> attributes, the solution is to mark this commit as ineligible.
>>
>> Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1039883
>> Signed-off-by: Luis Henriques (SUSE) <luis.henriq...@linux.dev>
>
> Reported-by: Hervé Werner <dud...@hotmail.com>
> Tested-by: Ben Hutchings <b...@debian.org>
>
Thanks a lot, Ben.
> I think this should also have:
>
> Fixes: 9725958bb75c ("ext4: fast commit may miss tracking unwritten range
> during ftruncate")
>
> unless you think the problem is even older than that.
If my understanding is correct (hopefully someone will confirm that!), I
think the problem goes further back. That commit just makes it more
likely to be visible, but handling of inlined data is incorrect since the
fast_commit merge. So, I guess that's better to simply add:
Cc: sta...@vger.kernel.org
Cheers,
--
Luís
>
> Ben.
>
>> ---
>> fs/ext4/fast_commit.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
>> index 87c009e0c59a..d3a67bc06d10 100644
>> --- a/fs/ext4/fast_commit.c
>> +++ b/fs/ext4/fast_commit.c
>> @@ -649,6 +649,12 @@ void ext4_fc_track_range(handle_t *handle, struct inode
>> *inode, ext4_lblk_t star
>> if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
>> return;
>>
>> + if (ext4_has_inline_data(inode)) {
>> + ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR,
>> + handle);
>> + return;
>> + }
>> +
>> args.start = start;
>> args.end = end;
>>
>
> --
> Ben Hutchings
> For every complex problem
> there is a solution that is simple, neat, and wrong.
>
