Because nbd_client_close removes the I/O handlers for the client
socket, there is no way that any suspended coroutines are restarted.
This will be a problem with the QEMU embedded NBD server, because
we will have a QMP command to forcibly close all connections with
the clients.
Instead, we can exploit the reference counting of NBDClients; shutdown
the client socket, which will make it readable and writeable. The
coroutines then will fail and exit cleanly. The last refcount finally
triggers the closure of the client.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
nbd.c | 18 +++++++++++-------
nbd.h | 3 +++
2 file modificati, 14 inserzioni(+), 7 rimozioni(-)
diff --git a/nbd.c b/nbd.c
index c1edbeb..cb4e8fe 100644
--- a/nbd.c
+++ b/nbd.c
@@ -657,18 +657,22 @@ static void nbd_client_get(NBDClient *client)
static void nbd_client_put(NBDClient *client)
{
if (--client->refcount == 0) {
+ qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
+ close(client->sock);
+ client->sock = -1;
+ if (client->close) {
+ client->close(client);
+ }
g_free(client);
}
}
-static void nbd_client_close(NBDClient *client)
+void nbd_client_close(NBDClient *client)
{
- qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
- close(client->sock);
- client->sock = -1;
- if (client->close) {
- client->close(client);
- }
+ /* Force requests to finish. They will drop their own references,
+ * then we'll close the socket and free the NBDClient.
+ */
+ shutdown(client->sock, 2);
nbd_client_put(client);
}
diff --git a/nbd.h b/nbd.h
index 40d58d3..6305d68 100644
--- a/nbd.h
+++ b/nbd.h
@@ -81,7 +81,10 @@ typedef struct NBDClient NBDClient;
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
off_t size, uint32_t nbdflags);
void nbd_export_close(NBDExport *exp);
+
NBDClient *nbd_client_new(NBDExport *exp, int csock,
void (*close)(NBDClient *));
+void nbd_client_close(NBDClient *client);
+
#endif
--
1.7.11.2
