Re: [PATCH] btrfs: scrub: don't mark inline extents as errors on RST

[Johannes Thumshirn <Johannes.Thumshirn@wdc.com>]

On 20.08.24 16:35, Johannes Thumshirn wrote:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> 
> When scrubbing a RAID stripe-tree backed btrfs system, we're doing
> extent based block mappings. These block mappings go through the RAID
> stripe-tree to do logical to physical translation.
> 
> In case we're hitting an inline extent, there is no backing by the
> RAID stripe-tree for it and the block mapping returns an error. So the
> bit in the extent bitmap is marked as error.
> 
> Fix this by not marking mapping failures for inline extents as error.
> 
> Cc: Qu Wenru <wqu@suse.com>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Scratch that one, that apparently only works in my test environment.






> ---
>   fs/btrfs/scrub.c | 41 +++++++++++++++++++++++++++++++++++++++--
>   1 file changed, 39 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index b3afa6365823..8240b205699c 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -67,6 +67,7 @@ struct scrub_ctx;
>   /* Represent one sector and its needed info to verify the content. */
>   struct scrub_sector_verification {
>   	bool is_metadata;
> +	bool is_inline;
>   
>   	union {
>   		/*
> @@ -1479,6 +1480,34 @@ static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
>   	return ret;
>   }
>   
> +static bool extent_is_inline(struct btrfs_fs_info *fs_info,
> +			     u64 extent_start, u64 extent_len)
> +{
> +	struct btrfs_file_extent_item *ei;
> +	struct extent_buffer *leaf;
> +	struct btrfs_path *path;
> +	struct btrfs_root *extent_root = btrfs_extent_root(fs_info, extent_start);
> +	int ret;
> +	bool is_inline = false;
> +
> +	path = btrfs_alloc_path();
> +	if (!path)
> +		return false;
> +
> +	ret = btrfs_lookup_file_extent(NULL, extent_root, path, extent_start, extent_len, 0);
> +	if (ret < 0)
> +		goto out;
> +
> +	leaf = path->nodes[0];
> +	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item);
> +	if (btrfs_file_extent_type(leaf, ei) == BTRFS_FILE_EXTENT_INLINE)
> +		is_inline = true;
> +
> + out:
> +	btrfs_free_path(path);
> +	return is_inline;
> +}
> +
>   static void fill_one_extent_info(struct btrfs_fs_info *fs_info,
>   				 struct scrub_stripe *stripe,
>   				 u64 extent_start, u64 extent_len,
> @@ -1497,6 +1526,9 @@ static void fill_one_extent_info(struct btrfs_fs_info *fs_info,
>   		if (extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
>   			sector->is_metadata = true;
>   			sector->generation = extent_gen;
> +		} else {
> +			sector->is_inline = extent_is_inline(
> +				fs_info, extent_start, extent_len);
>   		}
>   	}
>   }
> @@ -1704,8 +1736,13 @@ static void scrub_submit_extent_sector_read(struct scrub_ctx *sctx,
>   					      &stripe_len, &bioc, &io_stripe, &mirror);
>   			btrfs_put_bioc(bioc);
>   			if (err < 0) {
> -				set_bit(i, &stripe->io_error_bitmap);
> -				set_bit(i, &stripe->error_bitmap);
> +				struct scrub_sector_verification *sector =
> +					&stripe->sectors[i];
> +
> +				if (!sector->is_inline) {
> +					set_bit(i, &stripe->io_error_bitmap);
> +					set_bit(i, &stripe->error_bitmap);
> +				}
>   				continue;
>   			}
>