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authorStefan Hajnoczi <stefanha@redhat.com>2014-02-26 15:30:18 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-03-14 16:28:28 +0100
commit4a41a2d68a684241aca96dba066e0699941b730d (patch)
treec3c9a72476b39a3ee58029436fd24bc318d44093 /block/nbd-client.c
parent62e466e84592900756f080802782d0615c6a3b5c (diff)
nbd: close socket if connection breaks
nbd_receive_reply() is called by the event loop whenever data is available or the socket has been closed by the remote side. This patch closes the socket when an error occurs to prevent the nbd_receive_reply() handler from being called indefinitely after the connection has failed. Note that we were already correctly returning EIO for pending requests but leaving the nbd_receive_reply() handler registered resulted in high CPU consumption and a flood of error messages. Reuse nbd_teardown_connection() to close the socket. Reported-by: Zhifeng Cai <bluewindow@h3c.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/nbd-client.c')
-rw-r--r--block/nbd-client.c33
1 files changed, 18 insertions, 15 deletions
diff --git a/block/nbd-client.c b/block/nbd-client.c
index 0922b78292..7d698cb619 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -43,6 +43,17 @@ static void nbd_recv_coroutines_enter_all(NbdClientSession *s)
}
}
+static void nbd_teardown_connection(NbdClientSession *client)
+{
+ /* finish any pending coroutines */
+ shutdown(client->sock, 2);
+ nbd_recv_coroutines_enter_all(client);
+
+ qemu_aio_set_fd_handler(client->sock, NULL, NULL, NULL);
+ closesocket(client->sock);
+ client->sock = -1;
+}
+
static void nbd_reply_ready(void *opaque)
{
NbdClientSession *s = opaque;
@@ -78,7 +89,7 @@ static void nbd_reply_ready(void *opaque)
}
fail:
- nbd_recv_coroutines_enter_all(s);
+ nbd_teardown_connection(s);
}
static void nbd_restart_write(void *opaque)
@@ -324,7 +335,7 @@ int nbd_client_session_co_discard(NbdClientSession *client, int64_t sector_num,
}
-static void nbd_teardown_connection(NbdClientSession *client)
+void nbd_client_session_close(NbdClientSession *client)
{
struct nbd_request request = {
.type = NBD_CMD_DISC,
@@ -332,22 +343,14 @@ static void nbd_teardown_connection(NbdClientSession *client)
.len = 0
};
- nbd_send_request(client->sock, &request);
-
- /* finish any pending coroutines */
- shutdown(client->sock, 2);
- nbd_recv_coroutines_enter_all(client);
-
- qemu_aio_set_fd_handler(client->sock, NULL, NULL, NULL);
- closesocket(client->sock);
- client->sock = -1;
-}
-
-void nbd_client_session_close(NbdClientSession *client)
-{
if (!client->bs) {
return;
}
+ if (client->sock == -1) {
+ return;
+ }
+
+ nbd_send_request(client->sock, &request);
nbd_teardown_connection(client);
client->bs = NULL;