On 2024/1/26 16:57, Baokun Li wrote:
> Now ac_groups_linear_remaining is of type __u16 and s_mb_max_linear_groups
> is of type unsigned int, so an overflow occurs when setting a value above
> 65535 through the mb_max_linear_groups sysfs interface. Therefore, the
> type of ac_groups_linear_remaining is set to __u32 to avoid overflow.
>
> Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning")
> CC: stable@xxxxxxxxxx
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Looks good to me.
Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
> ---
> fs/ext4/mballoc.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
> index d7aeb5da7d86..498af2abc5d8 100644
> --- a/fs/ext4/mballoc.h
> +++ b/fs/ext4/mballoc.h
> @@ -194,8 +194,8 @@ struct ext4_allocation_context {
>
> __u32 ac_groups_considered;
> __u32 ac_flags; /* allocation hints */
> + __u32 ac_groups_linear_remaining;
> __u16 ac_groups_scanned;
> - __u16 ac_groups_linear_remaining;
> __u16 ac_found;
> __u16 ac_cX_found[EXT4_MB_NUM_CRS];
> __u16 ac_tail;
>
