Hi,
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> When using the logical to ino ioctl v2, if the flag to ignore offsets of
> file extent items (BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET) is given, the
> backref walking code ends up not returning references for all file offsets
> of an inode that point to the given logical bytenr. This happens since
> kernel 6.2, commit 6ce6ba534418 ("btrfs: use a single argument for extent
> offset in backref walking functions"), as it mistakenly skipped the search
> for file extent items in a leaf that point to the target extent if that
> flag is given. Instead it should only skip the filtering done by
> check_extent_in_eb() - that is, it should not avoid the calls to that
> function.
>
> So fix this by always calling check_extent_in_eb() and have this function
> do the filtering only if an extent offset is given and the flag to ignore
> offsets is not set.
> Fixes: 6ce6ba534418 ("btrfs: use a single argument for extent offset in backref walking functions")
> Reported-by: Vladimir Panteleev <git@xxxxxxxxxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/linux-btrfs/CAHhfkvwo=nmzrJSqZ2qMfF-rZB-ab6ahHnCD_sq9h4o8v+M7QQ@xxxxxxxxxxxxxx/
> Tested-by: Vladimir Panteleev <git@xxxxxxxxxxxxxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx # 6.2+
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
fstests(btrfs/299) will fail with this patch.
Best Regards
Wang Yugui (wangyugui@xxxxxxxxxxxx)
2023/05/04
> ---
> fs/btrfs/backref.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
> index e54f0884802a..8e61be3fe9a8 100644
> --- a/fs/btrfs/backref.c
> +++ b/fs/btrfs/backref.c
> @@ -45,7 +45,9 @@ static int check_extent_in_eb(struct btrfs_backref_walk_ctx *ctx,
> int root_count;
> bool cached;
>
> - if (!btrfs_file_extent_compression(eb, fi) &&
> + if (!ctx->ignore_extent_item_pos &&
> + ctx->extent_item_pos > 0 &&
> + !btrfs_file_extent_compression(eb, fi) &&
> !btrfs_file_extent_encryption(eb, fi) &&
> !btrfs_file_extent_other_encoding(eb, fi)) {
> u64 data_offset;
> @@ -552,13 +554,10 @@ static int add_all_parents(struct btrfs_backref_walk_ctx *ctx,
> count++;
> else
> goto next;
> - if (!ctx->ignore_extent_item_pos) {
> - ret = check_extent_in_eb(ctx, &key, eb, fi, &eie);
> - if (ret == BTRFS_ITERATE_EXTENT_INODES_STOP ||
> - ret < 0)
> - break;
> - }
> - if (ret > 0)
> + ret = check_extent_in_eb(ctx, &key, eb, fi, &eie);
> + if (ret == BTRFS_ITERATE_EXTENT_INODES_STOP || ret < 0)
> + break;
> + else if (ret > 0)
> goto next;
> ret = ulist_add_merge_ptr(parents, eb->start,
> eie, (void **)&old, GFP_NOFS);
> --
> 2.35.1
