On 2024/2/27 21:06, Greg KH wrote:
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
5.4.y and older will regenerate the buddy on error, so this is not needed. -- With Best Regards, Baokun Li .
