diff mbox series

vhost: fix deadlock when vhost unregister.

Message ID 20190111134931.28402-1-findtheonlyway@gmail.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers show
Series vhost: fix deadlock when vhost unregister. | expand

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation success Compilation OK
ci/mellanox-Performance-Testing success Performance Testing PASS
ci/intel-Performance-Testing success Performance Testing PASS

Commit Message

孙文杰 Jan. 11, 2019, 1:49 p.m. UTC
When rte_vhost_driver_unregister  delete the connection fd,
    fdset_try_del will always try and donot release the
    vhostuser.mutex if the fd is busy, but the fdset_event_dispatch
    will set the  fd to busy and call vhost_user_msg_handler to get
    vhostuser.mutex, which will  cause deadlock. Unlock the
    vhost_user.mutexif fdset_try_del fail and relock it when retry.

    Signed-off-by: findtheonlway <findtheonlyway@gmail.com>
    Signed-off-by: sunwenjie <sunwenjie@didichuxing.com>
---
 lib/librte_vhost/socket.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Xiaolong Ye Jan. 15, 2019, 2:48 a.m. UTC | #1
Hi,

On 01/11, sunwenjie wrote:
>    When rte_vhost_driver_unregister  delete the connection fd,
>    fdset_try_del will always try and donot release the
>    vhostuser.mutex if the fd is busy, but the fdset_event_dispatch
>    will set the  fd to busy and call vhost_user_msg_handler to get
>    vhostuser.mutex, which will  cause deadlock. Unlock the
>    vhost_user.mutexif fdset_try_del fail and relock it when retry.
>
>    Signed-off-by: findtheonlway <findtheonlyway@gmail.com>
>    Signed-off-by: sunwenjie <sunwenjie@didichuxing.com>

The commit log and Signed-off-by tage should not be indented, and you should
get you commit log checked by `./devtools/check-git-log.sh -1`, and fix all the
errors it shows.

Btw, I think this is your v2 patch, and you should add the v2 tag in the
subject.

Thanks,
Xiaolong

>---
> lib/librte_vhost/socket.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
>index 9cf34ad17..7959c5ece 100644
>--- a/lib/librte_vhost/socket.c
>+++ b/lib/librte_vhost/socket.c
>@@ -961,13 +961,13 @@ rte_vhost_driver_unregister(const char *path)
> 	int count;
> 	struct vhost_user_connection *conn, *next;
> 
>+again:
> 	pthread_mutex_lock(&vhost_user.mutex);
> 
> 	for (i = 0; i < vhost_user.vsocket_cnt; i++) {
> 		struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
> 
> 		if (!strcmp(vsocket->path, path)) {
>-again:
> 			pthread_mutex_lock(&vsocket->conn_mutex);
> 			for (conn = TAILQ_FIRST(&vsocket->conn_list);
> 			     conn != NULL;
>@@ -981,6 +981,7 @@ rte_vhost_driver_unregister(const char *path)
> 				 */
> 				if (fdset_try_del(&vhost_user.fdset,
> 						  conn->connfd) == -1) {
>+					pthread_mutex_unlock(&vhost_user.mutex);
> 					pthread_mutex_unlock(
> 							&vsocket->conn_mutex);
> 					goto again;
>-- 
>2.20.1
>
diff mbox series

Patch

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 9cf34ad17..7959c5ece 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -961,13 +961,13 @@  rte_vhost_driver_unregister(const char *path)
 	int count;
 	struct vhost_user_connection *conn, *next;
 
+again:
 	pthread_mutex_lock(&vhost_user.mutex);
 
 	for (i = 0; i < vhost_user.vsocket_cnt; i++) {
 		struct vhost_user_socket *vsocket = vhost_user.vsockets[i];
 
 		if (!strcmp(vsocket->path, path)) {
-again:
 			pthread_mutex_lock(&vsocket->conn_mutex);
 			for (conn = TAILQ_FIRST(&vsocket->conn_list);
 			     conn != NULL;
@@ -981,6 +981,7 @@  rte_vhost_driver_unregister(const char *path)
 				 */
 				if (fdset_try_del(&vhost_user.fdset,
 						  conn->connfd) == -1) {
+					pthread_mutex_unlock(&vhost_user.mutex);
 					pthread_mutex_unlock(
 							&vsocket->conn_mutex);
 					goto again;