Re: [PATCH v2 7/8] ext4: avoid allocating blocks from corrupted group in ext4_mb_find_by_goal()

From: Jan Kara
Date: Thu Jan 04 2024 - 05:47:57 EST


On Thu 21-12-23 23:05:57, Baokun Li wrote:
> Places the logic for checking if the group's block bitmap is corrupt under
> the protection of the group lock to avoid allocating blocks from the group
> with a corrupted block bitmap.
>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/ext4/mballoc.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 2bb29f0077bd..b862ca2750fd 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2340,12 +2340,10 @@ int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
> if (err)
> return err;
>
> - if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) {
> - ext4_mb_unload_buddy(e4b);
> - return 0;
> - }
> -
> ext4_lock_group(ac->ac_sb, group);
> + if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
> + goto out;
> +
> max = mb_find_extent(e4b, ac->ac_g_ex.fe_start,
> ac->ac_g_ex.fe_len, &ex);
> ex.fe_logical = 0xDEADFA11; /* debug value */
> @@ -2378,6 +2376,7 @@ int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
> ac->ac_b_ex = ex;
> ext4_mb_use_best_found(ac, e4b);
> }
> +out:
> ext4_unlock_group(ac->ac_sb, group);
> ext4_mb_unload_buddy(e4b);
>
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR