iov_iter_advance() needs to do some non-trivial work when it's given
0 as argument (skip all empty iovecs, mostly). We used to implement
it via iterate_and_advance(); we no longer do so and for all other
users of iterate_and_advance() zero length is a no-op.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
lib/iov_iter.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 906e9d49c487..ebb907c6393c 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -117,7 +117,7 @@
#define iterate_and_advance(i, n, v, I, B, K, X) { \
if (unlikely(i->count < n)) \
n = i->count; \
- if (i->count) { \
+ if (likely(n)) { \
size_t skip = i->iov_offset; \
if (likely(iter_is_iovec(i))) { \
const struct iovec *iov; \
--
2.11.0
