@@ -406,4 +406,15 @@ const char *nbd_info_lookup(uint16_t info);
const char *nbd_cmd_lookup(uint16_t info);
const char *nbd_err_lookup(int err);
+/* nbd/client-connection.c */
+typedef struct NBDClientConnection NBDClientConnection;
+
+NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr);
+void nbd_client_connection_unref(NBDClientConnection *conn);
+
+QIOChannelSocket *coroutine_fn
+nbd_co_establish_connection(NBDClientConnection *conn, Error **errp);
+
+void coroutine_fn nbd_co_establish_connection_cancel(NBDClientConnection *conn);
+
#endif
@@ -66,25 +66,6 @@ typedef enum NBDClientState {
NBD_CLIENT_QUIT
} NBDClientState;
-typedef struct NBDClientConnection {
- /* Initialization constants */
- SocketAddress *saddr; /* address to connect to */
-
- /*
- * Result of last attempt. Valid in FAIL and SUCCESS states.
- * If you want to steal error, don't forget to set pointer to NULL.
- */
- QIOChannelSocket *sioc;
- Error *err;
-
- int refcnt; /* atomic access */
-
- QemuMutex mutex;
- /* All further fields are protected by mutex */
- bool running; /* thread is running now */
- Coroutine *wait_co; /* nbd_co_establish_connection() wait in yield() */
-} NBDClientConnection;
-
typedef struct BDRVNBDState {
QIOChannelSocket *sioc; /* The master data channel */
QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
@@ -119,12 +100,8 @@ typedef struct BDRVNBDState {
NBDClientConnection *conn;
} BDRVNBDState;
-static void nbd_client_connection_unref(NBDClientConnection *conn);
static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr,
Error **errp);
-static coroutine_fn QIOChannelSocket *
-nbd_co_establish_connection(NBDClientConnection *conn, Error **errp);
-static void nbd_co_establish_connection_cancel(NBDClientConnection *conn);
static int nbd_client_handshake(BlockDriverState *bs, Error **errp);
static void nbd_yank(void *opaque);
@@ -336,150 +313,6 @@ static bool nbd_client_connecting_wait(BDRVNBDState *s)
return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT;
}
-static NBDClientConnection *
-nbd_client_connection_new(const SocketAddress *saddr)
-{
- NBDClientConnection *conn = g_new(NBDClientConnection, 1);
-
- *conn = (NBDClientConnection) {
- .saddr = QAPI_CLONE(SocketAddress, saddr),
- .refcnt = 1,
- };
-
- qemu_mutex_init(&conn->mutex);
-
- return conn;
-}
-
-static void nbd_client_connection_unref(NBDClientConnection *conn)
-{
- if (qatomic_dec_fetch(&conn->refcnt) == 0) {
- if (conn->sioc) {
- qio_channel_close(QIO_CHANNEL(conn->sioc), NULL);
- }
- error_free(conn->err);
- qapi_free_SocketAddress(conn->saddr);
- g_free(conn);
- }
-}
-
-static void *connect_thread_func(void *opaque)
-{
- NBDClientConnection *conn = opaque;
- int ret;
-
- conn->sioc = qio_channel_socket_new();
-
- error_free(conn->err);
- conn->err = NULL;
- ret = qio_channel_socket_connect_sync(conn->sioc, conn->saddr, &conn->err);
- if (ret < 0) {
- object_unref(OBJECT(conn->sioc));
- conn->sioc = NULL;
- }
-
- qemu_mutex_lock(&conn->mutex);
-
- assert(conn->running);
- conn->running = false;
- if (conn->wait_co) {
- aio_co_wake(conn->wait_co);
- conn->wait_co = NULL;
- }
-
- qemu_mutex_unlock(&conn->mutex);
-
- nbd_client_connection_unref(conn);
-
- return NULL;
-}
-
-/*
- * Get a new connection in context of @conn:
- * if thread is running, wait for completion
- * if thread is already succeeded in background, and user didn't get the
- * result, just return it now
- * otherwise if thread is not running, start a thread and wait for completion
- */
-static coroutine_fn QIOChannelSocket *
-nbd_co_establish_connection(NBDClientConnection *conn, Error **errp)
-{
- QIOChannelSocket *sioc = NULL;
- QemuThread thread;
-
- qemu_mutex_lock(&conn->mutex);
-
- /*
- * Don't call nbd_co_establish_connection() in several coroutines in
- * parallel. Only one call at once is supported.
- */
- assert(!conn->wait_co);
-
- if (!conn->running) {
- if (conn->sioc) {
- /* Previous attempt finally succeeded in background */
- sioc = g_steal_pointer(&conn->sioc);
- qemu_mutex_unlock(&conn->mutex);
-
- return sioc;
- }
-
- conn->running = true;
- error_free(conn->err);
- conn->err = NULL;
- qatomic_inc(&conn->refcnt); /* for thread */
- qemu_thread_create(&thread, "nbd-connect",
- connect_thread_func, conn, QEMU_THREAD_DETACHED);
- }
-
- conn->wait_co = qemu_coroutine_self();
-
- qemu_mutex_unlock(&conn->mutex);
-
- /*
- * We are going to wait for connect-thread finish, but
- * nbd_co_establish_connection_cancel() can interrupt.
- */
- qemu_coroutine_yield();
-
- qemu_mutex_lock(&conn->mutex);
-
- if (conn->running) {
- /*
- * Obviously, drained section wants to start. Report the attempt as
- * failed. Still connect thread is executing in background, and its
- * result may be used for next connection attempt.
- */
- error_setg(errp, "Connection attempt cancelled by other operation");
- } else {
- error_propagate(errp, conn->err);
- conn->err = NULL;
- sioc = g_steal_pointer(&conn->sioc);
- }
-
- qemu_mutex_unlock(&conn->mutex);
-
- return sioc;
-}
-
-/*
- * nbd_co_establish_connection_cancel
- * Cancel nbd_co_establish_connection() asynchronously. Note, that it doesn't
- * stop the thread itself neither close the socket. It just safely wakes
- * nbd_co_establish_connection() sleeping in the yield().
- */
-static void nbd_co_establish_connection_cancel(NBDClientConnection *conn)
-{
- qemu_mutex_lock(&conn->mutex);
-
- if (conn->wait_co) {
- aio_co_wake(conn->wait_co);
- conn->wait_co = NULL;
- }
-
- qemu_mutex_unlock(&conn->mutex);
-}
-
static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
{
int ret;
new file mode 100644
@@ -0,0 +1,192 @@
+/*
+ * QEMU Block driver for NBD
+ *
+ * Copyright (c) 2021 Virtuozzo International GmbH.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+
+#include "block/nbd.h"
+
+#include "qapi/qapi-visit-sockets.h"
+#include "qapi/clone-visitor.h"
+
+struct NBDClientConnection {
+ /* Initialization constants */
+ SocketAddress *saddr; /* address to connect to */
+
+ /*
+ * Result of last attempt. Valid in FAIL and SUCCESS states.
+ * If you want to steal error, don't forget to set pointer to NULL.
+ */
+ QIOChannelSocket *sioc;
+ Error *err;
+
+ int refcnt; /* atomic access */
+
+ QemuMutex mutex;
+ /* All further fields are protected by mutex */
+ bool running; /* thread is running now */
+ Coroutine *wait_co; /* nbd_co_establish_connection() wait in yield() */
+};
+
+NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr)
+{
+ NBDClientConnection *conn = g_new(NBDClientConnection, 1);
+
+ *conn = (NBDClientConnection) {
+ .saddr = QAPI_CLONE(SocketAddress, saddr),
+ .refcnt = 1,
+ };
+
+ qemu_mutex_init(&conn->mutex);
+
+ return conn;
+}
+
+void nbd_client_connection_unref(NBDClientConnection *conn)
+{
+ if (qatomic_dec_fetch(&conn->refcnt) == 0) {
+ if (conn->sioc) {
+ qio_channel_close(QIO_CHANNEL(conn->sioc), NULL);
+ }
+ error_free(conn->err);
+ qapi_free_SocketAddress(conn->saddr);
+ g_free(conn);
+ }
+}
+
+static void *connect_thread_func(void *opaque)
+{
+ NBDClientConnection *conn = opaque;
+ int ret;
+
+ conn->sioc = qio_channel_socket_new();
+
+ error_free(conn->err);
+ conn->err = NULL;
+ ret = qio_channel_socket_connect_sync(conn->sioc, conn->saddr, &conn->err);
+ if (ret < 0) {
+ object_unref(OBJECT(conn->sioc));
+ conn->sioc = NULL;
+ }
+
+ qemu_mutex_lock(&conn->mutex);
+
+ assert(conn->running);
+ conn->running = false;
+ if (conn->wait_co) {
+ aio_co_wake(conn->wait_co);
+ conn->wait_co = NULL;
+ }
+
+ qemu_mutex_unlock(&conn->mutex);
+
+ nbd_client_connection_unref(conn);
+
+ return NULL;
+}
+
+/*
+ * Get a new connection in context of @conn:
+ * if thread is running, wait for completion
+ * if thread is already succeeded in background, and user didn't get the
+ * result, just return it now
+ * otherwise if thread is not running, start a thread and wait for completion
+ */
+QIOChannelSocket *coroutine_fn
+nbd_co_establish_connection(NBDClientConnection *conn, Error **errp)
+{
+ QIOChannelSocket *sioc = NULL;
+ QemuThread thread;
+
+ qemu_mutex_lock(&conn->mutex);
+
+ /*
+ * Don't call nbd_co_establish_connection() in several coroutines in
+ * parallel. Only one call at once is supported.
+ */
+ assert(!conn->wait_co);
+
+ if (!conn->running) {
+ if (conn->sioc) {
+ /* Previous attempt finally succeeded in background */
+ sioc = g_steal_pointer(&conn->sioc);
+ qemu_mutex_unlock(&conn->mutex);
+
+ return sioc;
+ }
+
+ conn->running = true;
+ error_free(conn->err);
+ conn->err = NULL;
+ qatomic_inc(&conn->refcnt); /* for thread */
+ qemu_thread_create(&thread, "nbd-connect",
+ connect_thread_func, conn, QEMU_THREAD_DETACHED);
+ }
+
+ conn->wait_co = qemu_coroutine_self();
+
+ qemu_mutex_unlock(&conn->mutex);
+
+ /*
+ * We are going to wait for connect-thread finish, but
+ * nbd_co_establish_connection_cancel() can interrupt.
+ */
+ qemu_coroutine_yield();
+
+ qemu_mutex_lock(&conn->mutex);
+
+ if (conn->running) {
+ /*
+ * Obviously, drained section wants to start. Report the attempt as
+ * failed. Still connect thread is executing in background, and its
+ * result may be used for next connection attempt.
+ */
+ error_setg(errp, "Connection attempt cancelled by other operation");
+ } else {
+ error_propagate(errp, conn->err);
+ conn->err = NULL;
+ sioc = g_steal_pointer(&conn->sioc);
+ }
+
+ qemu_mutex_unlock(&conn->mutex);
+
+ return sioc;
+}
+
+/*
+ * nbd_co_establish_connection_cancel
+ * Cancel nbd_co_establish_connection() asynchronously. Note, that it doesn't
+ * stop the thread itself neither close the socket. It just safely wakes
+ * nbd_co_establish_connection() sleeping in the yield().
+ */
+void coroutine_fn nbd_co_establish_connection_cancel(NBDClientConnection *conn)
+{
+ qemu_mutex_lock(&conn->mutex);
+
+ if (conn->wait_co) {
+ aio_co_wake(conn->wait_co);
+ conn->wait_co = NULL;
+ }
+
+ qemu_mutex_unlock(&conn->mutex);
+}
@@ -1,5 +1,6 @@
block_ss.add(files(
'client.c',
+ 'client-connection.c',
'common.c',
))
blockdev_ss.add(files(
We now have bs-independent connection API, which consists of four functions: nbd_client_connection_new() nbd_client_connection_unref() nbd_co_establish_connection() nbd_co_establish_connection_cancel() Move them to a separate file together with NBDClientConnection structure which becomes private to the new API. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> --- Hmm. I keep only Virtuozzo's copyright in a new file, as actually I've developed nbd-reconnection code. Still probably safer to save all copyrights. Let me now if you think so and I'll add them. include/block/nbd.h | 11 +++ block/nbd.c | 167 ---------------------------------- nbd/client-connection.c | 192 ++++++++++++++++++++++++++++++++++++++++ nbd/meson.build | 1 + 4 files changed, 204 insertions(+), 167 deletions(-) create mode 100644 nbd/client-connection.c