On Thu, Oct 15, 2026 at 10:34:25PM +0800, [email protected] wrote:
> From: Jianyun Gao <[email protected]>
>
> When dax_range_compare_iter() returns a negative error code (e.g. -EIO),
> dax_dedupe_file_range_compare() incorrectly returns 'ret' which holds the
> positive return value from iomap_iter() indicating more iterations remain.
> This positive value leaks to the caller, where vfs_dedupe_file_range()
> interprets it as success (bytes_deduped = len), causing userspace to
> incorrectly believe deduplication completed.
>
> Return 'status' instead to propagate the actual error code.
Hi Jianyun,
I looked at merging this today but the Sashiko response stopped me.
I do see you addressed Sashiko in v1, ignored Sashiko in v2.
If this v3 Sashiko complaint is one you've already addressed, please
reply saying so. Thanks!
-- Alison
>
> Fixes: 0e79e3736d54 ("fsdax: dedupe: iter two files at the same time")
> Cc: [email protected]
> Signed-off-by: Jianyun Gao <[email protected]>
> Reviewed-by: Jan Kara <[email protected]>
> Reviewed-by: "Darrick J. Wong" <[email protected]>
> ---
> Changes in v3:
> - Fix the Fixes tag to point to the commit that actually introduced
> the bug (0e79e3736d54), not the one that renamed the variable
> - Add Reviewed-by from Darrick J. Wong
>
> Link:
> https://lore.kernel.org/lkml/[email protected]/ #
> v2
> fs/dax.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/dax.c b/fs/dax.c
> index 6ba50142eeb2..1f6a4fbb97bd 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -2261,7 +2261,7 @@ int dax_dedupe_file_range_compare(struct inode *src,
> loff_t srcoff,
> status = dax_range_compare_iter(&src_iter, &dst_iter,
> min(src_iter.len, dst_iter.len), same);
> if (status < 0)
> - return ret;
> + return status;
> src_iter.status = dst_iter.status = status;
> }
> return ret;
> --
> 2.34.1
>
>
