Re: [PATCH 04/21] ext4: get correct ext4_group_info in ext4_mb_prefetch_fini

From: IBM
Date: Fri Feb 17 2023 - 01:46:39 EST


Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx> writes:

> We always get ext4_group_desc with group + 1 and ext4_group_info with
> group to check if we need do initialize ext4_group_info for the group.
> Just get ext4_group_desc with group for ext4_group_info initialization
> check.
>
> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
> ---
> fs/ext4/mballoc.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 352ac9139fee..f24f80ecf318 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2570,13 +2570,13 @@ void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
> unsigned int nr)
> {
> while (nr-- > 0) {
> - struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group,
> - NULL);
> - struct ext4_group_info *grp = ext4_get_group_info(sb, group);
> + struct ext4_group_desc *gdp;
> + struct ext4_group_info *grp;

We can even declare these variables at the begining of the function like
in [1]. Also I would advise to rearrange any "fixes" patches at the
begining of the patch series and "cleanup" patches at the end.
e.g. this looks like a fix to me.

That way it is sometimes easier for people to cherry-pick any fixes if
required in their older kernel trees. ;)

[1]: https://lore.kernel.org/all/85bbcb3774e38de65b737ef0000241ddbdda73aa.1674822311.git.ojaswin@xxxxxxxxxxxxx/

-ritesh

>
> if (!group)
> group = ext4_get_groups_count(sb);
> group--;
> + gdp = ext4_get_group_desc(sb, group, NULL);
> grp = ext4_get_group_info(sb, group);
>
> if (EXT4_MB_GRP_NEED_INIT(grp) &&
> --
> 2.30.0