On Tue, Feb 27, 2024 at 09:00:50PM +0800, Baokun Li wrote:
> commit 2331fd4a49864e1571b4f50aa3aa1536ed6220d0 upstream.
>
> After updating bb_free in mb_free_blocks, it is possible to return without
> updating bb_fragments because the block being freed is found to have
> already been freed, which leads to inconsistency between bb_free and
> bb_fragments.
>
> Since the group may be unlocked in ext4_grp_locked_error(), this can lead
> to problems such as dividing by zero when calculating the average fragment
> length. Hence move the update of bb_free to after the block double-free
> check guarantees that the corresponding statistics are updated only after
> the core block bitmap is modified.
>
> Fixes: eabe0444df90 ("ext4: speed-up releasing blocks on commit")
> CC: <stable@xxxxxxxxxxxxxxx> # 3.10
> Suggested-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
> Reviewed-by: Jan Kara <jack@xxxxxxx>
> Link: https://lore.kernel.org/r/20240104142040.2835097-5-libaokun1@xxxxxxxxxx
> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
> ---
> fs/ext4/mballoc.c | 39 +++++++++++++++++++++------------------
> 1 file changed, 21 insertions(+), 18 deletions(-)
We also need this for 5.10.y and older, right?
Queued up now, thanks!
greg k-h
