From: Yu Kuai
mainline inclusion
from mainline-next-20211018
commit 6157a8f489909db00151a4e361903b9099b03b75
category: bugfix
issue: #I4NRS5
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
Signed-off-by: Yu Changchun
---------------------------
Check if sock_xmit() return 0 is useless because it'll never return
0, comment it and remove such checkings.
Signed-off-by: Yu Kuai
Reviewed-by: Ming Lei
Reviewed-by: Josef Bacik
Link: https://lore.kernel.org/r/20210916093350.1410403-6-yukuai3@huawei.com
Signed-off-by: Jens Axboe
Reviewed-by: Jason Yan
Signed-off-by: Chen Jun
Signed-off-by: Zheng Zengkai
Signed-off-by: Yu Changchun
---
drivers/block/nbd.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 11a936151b93..8bfade1c4ee6 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -479,7 +479,8 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
}
/*
- * Send or receive packet.
+ * Send or receive packet. Return a positive value on success and
+ * negtive value on failue, and never return 0.
*/
static int sock_xmit(struct nbd_device *nbd, int index, int send,
struct iov_iter *iter, int msg_flags, int *sent)
@@ -605,7 +606,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
result = sock_xmit(nbd, index, 1, &from,
(type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent);
trace_nbd_header_sent(req, handle);
- if (result <= 0) {
+ if (result < 0) {
if (was_interrupted(result)) {
/* If we havne't sent anything we can just return BUSY,
* however if we have sent something we need to make
@@ -649,7 +650,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
skip = 0;
}
result = sock_xmit(nbd, index, 1, &from, flags, &sent);
- if (result <= 0) {
+ if (result < 0) {
if (was_interrupted(result)) {
/* We've already sent the header, we
* have no choice but to set pending and
@@ -701,7 +702,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
reply.magic = 0;
iov_iter_kvec(&to, READ, &iov, 1, sizeof(reply));
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
- if (result <= 0) {
+ if (result < 0) {
if (!nbd_disconnected(config))
dev_err(disk_to_dev(nbd->disk),
"Receive control failed (result %d)\n", result);
@@ -772,7 +773,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
rq_for_each_segment(bvec, req, iter) {
iov_iter_bvec(&to, READ, &bvec, 1, bvec.bv_len);
result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL);
- if (result <= 0) {
+ if (result < 0) {
dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n",
result);
/*
@@ -1218,7 +1219,7 @@ static void send_disconnects(struct nbd_device *nbd)
iov_iter_kvec(&from, WRITE, &iov, 1, sizeof(request));
mutex_lock(&nsock->tx_lock);
ret = sock_xmit(nbd, i, 1, &from, 0, NULL);
- if (ret <= 0)
+ if (ret < 0)
dev_err(disk_to_dev(nbd->disk),
"Send disconnect failed %d\n", ret);
mutex_unlock(&nsock->tx_lock);
--
2.25.1
