bvec_set_page has the following signature:
static inline void bvec_set_page(struct bio_vec *bv, struct page *page,
unsigned int len, unsigned int offset)
However, the usage in DRBD swaps the len and offset parameters. This
leads to a bvec with length=0 instead of the intended length=4096, which
causes sock_sendmsg to return -EIO.
This leaves DRBD unable to transmit any pages and thus completely
broken.
Swapping the parameters fixes the regression.
Fixes: eeac7405c735 ("drbd: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage()")
Reported-by: Serguei Ivantsov <manowar@xxxxxxxxxxxx>
Link: https://lore.kernel.org/regressions/CAKH+VT3YLmAn0Y8=q37UTDShqxDLsqPcQ4hBMzY7HPn7zNx+RQ@xxxxxxxxxxxxxx/
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@xxxxxxxxxx>
---
drivers/block/drbd/drbd_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 79ab532aabaf..6bc86106c7b2 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1557,7 +1557,7 @@ static int _drbd_send_page(struct drbd_peer_device *peer_device, struct page *pa
do {
int sent;
- bvec_set_page(&bvec, page, offset, len);
+ bvec_set_page(&bvec, page, len, offset);
iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, len);
sent = sock_sendmsg(socket, &msg);
--
2.41.0
