Re: [Qemu-devel] [PATCH v4 03/10] sheepdog: check return values of qemu_co_recv/send correctly

[Stefan Hajnoczi]

On Fri, Jul 26, 2013 at 03:10:45PM +0900, MORITA Kazutaka wrote:
 If qemu_co_recv/send doesn't return the specified length, it means
 that an error happened.
 
 Tested-and-reviewed-by: Liu Yuan namei.u...@gmail.com
 Signed-off-by: MORITA Kazutaka morita.kazut...@lab.ntt.co.jp
 ---
  block/sheepdog.c | 16 
  1 file changed, 8 insertions(+), 8 deletions(-)
 
 diff --git a/block/sheepdog.c b/block/sheepdog.c
 index 6a41ad9..c6e9b89 100644
 --- a/block/sheepdog.c
 +++ b/block/sheepdog.c
 @@ -489,13 +489,13 @@ static coroutine_fn int send_co_req(int sockfd, 
 SheepdogReq *hdr, void *data,
  int ret;
  
  ret = qemu_co_send(sockfd, hdr, sizeof(*hdr));
 -if (ret  sizeof(*hdr)) {
 +if (ret != sizeof(*hdr)) {
  error_report(failed to send a req, %s, strerror(errno));

Does this rely on qemu_co_send_recv() getting ret=-1 errno=EPIPE from
iov_send_recv()?  I want to check that I understand what happens when
the socket is closed by the other side.

Stefan

[Qemu-devel] [PATCH v4 03/10] sheepdog: check return values of qemu_co_recv/send correctly

[MORITA Kazutaka]

If qemu_co_recv/send doesn't return the specified length, it means
that an error happened.

Tested-and-reviewed-by: Liu Yuan namei.u...@gmail.com
Signed-off-by: MORITA Kazutaka morita.kazut...@lab.ntt.co.jp
---
 block/sheepdog.c | 16 
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/block/sheepdog.c b/block/sheepdog.c
index 6a41ad9..c6e9b89 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -489,13 +489,13 @@ static coroutine_fn int send_co_req(int sockfd, 
SheepdogReq *hdr, void *data,
 int ret;
 
 ret = qemu_co_send(sockfd, hdr, sizeof(*hdr));
-if (ret  sizeof(*hdr)) {
+if (ret != sizeof(*hdr)) {
 error_report(failed to send a req, %s, strerror(errno));
 return ret;
 }
 
 ret = qemu_co_send(sockfd, data, *wlen);
-if (ret  *wlen) {
+if (ret != *wlen) {
 error_report(failed to send a req, %s, strerror(errno));
 }
 
@@ -548,7 +548,7 @@ static coroutine_fn void do_co_req(void *opaque)
 qemu_aio_set_fd_handler(sockfd, restart_co_req, NULL, have_co_req, co);
 
 ret = qemu_co_recv(sockfd, hdr, sizeof(*hdr));
-if (ret  sizeof(*hdr)) {
+if (ret != sizeof(*hdr)) {
 error_report(failed to get a rsp, %s, strerror(errno));
 ret = -errno;
 goto out;
@@ -560,7 +560,7 @@ static coroutine_fn void do_co_req(void *opaque)
 
 if (*rlen) {
 ret = qemu_co_recv(sockfd, data, *rlen);
-if (ret  *rlen) {
+if (ret != *rlen) {
 error_report(failed to get the data, %s, strerror(errno));
 ret = -errno;
 goto out;
@@ -671,7 +671,7 @@ static void coroutine_fn aio_read_response(void *opaque)
 
 /* read a header */
 ret = qemu_co_recv(fd, rsp, sizeof(rsp));
-if (ret  0) {
+if (ret != sizeof(rsp)) {
 error_report(failed to get the header, %s, strerror(errno));
 goto out;
 }
@@ -722,7 +722,7 @@ static void coroutine_fn aio_read_response(void *opaque)
 case AIOCB_READ_UDATA:
 ret = qemu_co_recvv(fd, acb-qiov-iov, acb-qiov-niov,
 aio_req-iov_offset, rsp.data_length);
-if (ret  0) {
+if (ret != rsp.data_length) {
 error_report(failed to get the data, %s, strerror(errno));
 goto out;
 }
@@ -1075,7 +1075,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState 
*s, AIOReq *aio_req,
 
 /* send a header */
 ret = qemu_co_send(s-fd, hdr, sizeof(hdr));
-if (ret  0) {
+if (ret != sizeof(hdr)) {
 qemu_co_mutex_unlock(s-lock);
 error_report(failed to send a req, %s, strerror(errno));
 return -errno;
@@ -1083,7 +1083,7 @@ static int coroutine_fn add_aio_request(BDRVSheepdogState 
*s, AIOReq *aio_req,
 
 if (wlen) {
 ret = qemu_co_sendv(s-fd, iov, niov, aio_req-iov_offset, wlen);
-if (ret  0) {
+if (ret != wlen) {
 qemu_co_mutex_unlock(s-lock);
 error_report(failed to send a data, %s, strerror(errno));
 return -errno;
-- 
1.8.1.3.566.gaa39828