The iomap_iter() on a range of one file may loop more than once. In
this case, the inner dst_iter can update its iomap but the outer
src_iter can't. This may cause the wrong remapping in filesystem. Let
them called at the same time.
Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
---
fs/dax.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f1eb59bee0b5..354be56750c2 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1964,15 +1964,15 @@ int dax_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
.len = len,
.flags = IOMAP_DAX,
};
- int ret;
+ int ret, compared = 0;
- while ((ret = iomap_iter(&src_iter, ops)) > 0) {
- while ((ret = iomap_iter(&dst_iter, ops)) > 0) {
- dst_iter.processed = dax_range_compare_iter(&src_iter,
- &dst_iter, len, same);
- }
- if (ret <= 0)
- src_iter.processed = ret;
+ 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);
+ if (compared < 0)
+ return ret;
+ src_iter.processed = dst_iter.processed = compared;
}
return ret;
}
--
2.38.1
