Re: [PATCH 1/2] btrfs: use proper inclusive end in extent_fiemap()

On Tue, 28 Jul 2026 at 08:46, Qu Wenruo <[email protected]> wrote:
> The @end parameter for all extent io tree helpers is inclusive, but
> the call site in extent_fiemap() is passing exclusive end.
>
> Fix it to follow the common pattern.
>
> Fixes: ac3c0d36a2a2 ("btrfs: make fiemap more efficient and accurate reporting extent sharedness")
> Signed-off-by: Qu Wenruo <[email protected]>
> ---
>  fs/btrfs/fiemap.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/fiemap.c b/fs/btrfs/fiemap.c
> index ba6a360074c0..2f2ae0b76799 100644
> --- a/fs/btrfs/fiemap.c
> +++ b/fs/btrfs/fiemap.c
> @@ -657,7 +657,7 @@ static int extent_fiemap(struct btrfs_inode *inode,
>
>  restart:
>         range_start = round_down(start, sectorsize);
> -       range_end = round_up(start + len, sectorsize);
> +       range_end = round_up(start + len, sectorsize) - 1;
>         prev_extent_end = range_start;
>
>         btrfs_lock_extent(&inode->io_tree, range_start, range_end, &cached_state);
> @@ -710,7 +710,7 @@ static int extent_fiemap(struct btrfs_inode *inode,
>
>                 /* We have in implicit hole (NO_HOLES feature enabled). */
>                 if (prev_extent_end < key.offset) {
> -                       const u64 hole_end = min(key.offset, range_end) - 1;
> +                       const u64 hole_end = min(key.offset - 1, range_end);
>
>                         ret = fiemap_process_hole(inode, fieinfo, &cache,
>                                                   &delalloc_cached_state,
> @@ -812,10 +812,10 @@ static int extent_fiemap(struct btrfs_inode *inode,
>         if (!stopped && prev_extent_end < range_end) {
>                 ret = fiemap_process_hole(inode, fieinfo, &cache,
>                                           &delalloc_cached_state, backref_ctx,
> -                                         0, 0, 0, prev_extent_end, range_end - 1);
> +                                         0, 0, 0, prev_extent_end, range_end);
>                 if (ret < 0)
>                         goto out_unlock;
> -               prev_extent_end = range_end;
> +               prev_extent_end = range_end + 1;
>         }
>
>         if (cache.cached && cache.offset + cache.len >= last_extent_end) {
> --
> 2.54.0

I don't really get why you left out these:

@@ -680,7 +680,7 @@ static int extent_fiemap(struct btrfs_inode *inode,
                goto check_eof_delalloc;
        }

-       while (prev_extent_end < range_end) {
+       while (prev_extent_end <= range_end) {
                struct extent_buffer *leaf = path->nodes[0];
                struct btrfs_file_extent_item *ei;
                struct btrfs_key key;
@@ -809,13 +809,13 @@ static int extent_fiemap(struct btrfs_inode *inode,
        }

 check_eof_delalloc:
-       if (!stopped && prev_extent_end < range_end) {
+       if (!stopped && prev_extent_end <= range_end) {
                ret = fiemap_process_hole(inode, fieinfo, &cache,
                                          &delalloc_cached_state, backref_ctx,

Am I missing something?

--nX