[PATCH] fsdax: dedupe should compare the min of two iters' length

[Shiyang Ruan]

In an dedupe corporation iter loop, the length of iomap_iter decreases
because it implies the remaining length after each iteration.  The
compare function should use the min length of the current iters, not the
total length.

Fixes: 0e79e3736d54 ("fsdax: dedupe: iter two files at the same time")
Signed-off-by: Shiyang Ruan <ruansy.f...@fujitsu.com>
---
 fs/dax.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 3e457a16c7d1..9800b93ee14d 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -2022,8 +2022,8 @@ int dax_dedupe_file_range_compare(struct inode *src, 
loff_t srcoff,
 
        while ((ret = iomap_iter(&src_iter, ops)) > 0 &&
               (ret = iomap_iter(&dst_iter, ops)) > 0) {
-               compared = dax_range_compare_iter(&src_iter, &dst_iter, len,
-                                                 same);
+               compared = dax_range_compare_iter(&src_iter, &dst_iter,
+                               min(src_iter.len, dst_iter.len), same);
                if (compared < 0)
                        return ret;
                src_iter.processed = dst_iter.processed = compared;
-- 
2.39.2