Re: [PATCH] btrfs: initialize offset early

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2022/1/28 20:35, Muhammad Usama Anjum wrote:
> Jump to out label can happen before offset is initialized. offset is
> being used in code after out label. initialize offset early to cater
> this case.
>
> Fixes: 585f784357d8 ("btrfs: use scrub_simple_mirror() to handle RAID56 data stripe scrub")
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

Thanks for the fix.

Although the patch is only in misc-next, and due to another triggered
ASSERT(), the series will be reworked soon.

Thanks,
Qu

> ---
>   fs/btrfs/scrub.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 26bbe93c3aa3c..3ace9766527ba 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -3530,7 +3530,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>   	u64 logic_end;
>   	u64 physical_end;
>   	u64 increment;	/* The logical increment after finishing one stripe */
> -	u64 offset;	/* Offset inside the chunk */
> +	u64 offset = 0;	/* Offset inside the chunk */
>   	u64 stripe_logical;
>   	u64 stripe_end;
>
> @@ -3602,7 +3602,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
>   	ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
>
>   	physical = map->stripes[stripe_index].physical;
> -	offset = 0;
>   	nstripes = div64_u64(dev_extent_len, map->stripe_len);
>   	get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
>   	increment = map->stripe_len * nr_data_stripes(map);