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[PATCH v2 1/5] block/nbd: split nbd_establish_connection out of nbd_clie
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH v2 1/5] block/nbd: split nbd_establish_connection out of nbd_client_connect |
Date: |
Mon, 27 Jul 2020 21:47:47 +0300 |
We are going to implement non-blocking version of
nbd_establish_connection, which for a while will be used only for
nbd_reconnect_attempt, not for nbd_open, so we need to call it
separately.
Refactor nbd_reconnect_attempt in a way which makes next commit
simpler.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block/nbd.c | 60 +++++++++++++++++++++++++++-------------------
block/trace-events | 4 ++--
2 files changed, 38 insertions(+), 26 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index 65a4f56924..2ec6623c18 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -93,7 +93,10 @@ typedef struct BDRVNBDState {
char *x_dirty_bitmap;
} BDRVNBDState;
-static int nbd_client_connect(BlockDriverState *bs, Error **errp);
+static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr,
+ Error **errp);
+static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc,
+ Error **errp);
static void nbd_clear_bdrvstate(BDRVNBDState *s)
{
@@ -241,7 +244,9 @@ static bool nbd_client_connecting_wait(BDRVNBDState *s)
static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s)
{
+ int ret;
Error *local_err = NULL;
+ QIOChannelSocket *sioc;
if (!nbd_client_connecting(s)) {
return;
@@ -280,19 +285,25 @@ static coroutine_fn void
nbd_reconnect_attempt(BDRVNBDState *s)
s->ioc = NULL;
}
- s->connect_status = nbd_client_connect(s->bs, &local_err);
+ sioc = nbd_establish_connection(s->saddr, &local_err);
+ if (!sioc) {
+ ret = -ECONNREFUSED;
+ goto out;
+ }
+
+ ret = nbd_client_handshake(s->bs, sioc, &local_err);
+
+out:
+ s->connect_status = ret;
error_free(s->connect_err);
s->connect_err = NULL;
error_propagate(&s->connect_err, local_err);
- if (s->connect_status < 0) {
- /* failed attempt */
- return;
+ if (ret >= 0) {
+ /* successfully connected */
+ s->state = NBD_CLIENT_CONNECTED;
+ qemu_co_queue_restart_all(&s->free_sema);
}
-
- /* successfully connected */
- s->state = NBD_CLIENT_CONNECTED;
- qemu_co_queue_restart_all(&s->free_sema);
}
static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s)
@@ -1425,24 +1436,15 @@ static QIOChannelSocket
*nbd_establish_connection(SocketAddress *saddr,
return sioc;
}
-static int nbd_client_connect(BlockDriverState *bs, Error **errp)
+/* nbd_client_handshake takes ownership on sioc. On failure it is unref'ed. */
+static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc,
+ Error **errp)
{
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
AioContext *aio_context = bdrv_get_aio_context(bs);
int ret;
- /*
- * establish TCP connection, return error if it fails
- * TODO: Configurable retry-until-timeout behaviour.
- */
- QIOChannelSocket *sioc = nbd_establish_connection(s->saddr, errp);
-
- if (!sioc) {
- return -ECONNREFUSED;
- }
-
- /* NBD handshake */
- trace_nbd_client_connect(s->export);
+ trace_nbd_client_handshake(s->export);
qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
qio_channel_attach_aio_context(QIO_CHANNEL(sioc), aio_context);
@@ -1489,7 +1491,7 @@ static int nbd_client_connect(BlockDriverState *bs, Error
**errp)
object_ref(OBJECT(s->ioc));
}
- trace_nbd_client_connect_success(s->export);
+ trace_nbd_client_handshake_success(s->export);
return 0;
@@ -1894,6 +1896,7 @@ static int nbd_open(BlockDriverState *bs, QDict *options,
int flags,
{
int ret;
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
+ QIOChannelSocket *sioc;
ret = nbd_process_options(bs, options, errp);
if (ret < 0) {
@@ -1904,7 +1907,16 @@ static int nbd_open(BlockDriverState *bs, QDict
*options, int flags,
qemu_co_mutex_init(&s->send_mutex);
qemu_co_queue_init(&s->free_sema);
- ret = nbd_client_connect(bs, errp);
+ /*
+ * establish TCP connection, return error if it fails
+ * TODO: Configurable retry-until-timeout behaviour.
+ */
+ sioc = nbd_establish_connection(s->saddr, errp);
+ if (!sioc) {
+ return -ECONNREFUSED;
+ }
+
+ ret = nbd_client_handshake(bs, sioc, errp);
if (ret < 0) {
nbd_clear_bdrvstate(s);
return ret;
diff --git a/block/trace-events b/block/trace-events
index d3533ca896..9158335061 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -168,8 +168,8 @@ nbd_parse_blockstatus_compliance(const char *err) "ignoring
extra data from non-
nbd_structured_read_compliance(const char *type) "server sent non-compliant
unaligned read %s chunk"
nbd_read_reply_entry_fail(int ret, const char *err) "ret = %d, err: %s"
nbd_co_request_fail(uint64_t from, uint32_t len, uint64_t handle, uint16_t
flags, uint16_t type, const char *name, int ret, const char *err) "Request
failed { .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64 ", .flags
= 0x%" PRIx16 ", .type = %" PRIu16 " (%s) } ret = %d, err: %s"
-nbd_client_connect(const char *export_name) "export '%s'"
-nbd_client_connect_success(const char *export_name) "export '%s'"
+nbd_client_handshake(const char *export_name) "export '%s'"
+nbd_client_handshake_success(const char *export_name) "export '%s'"
# ssh.c
ssh_restart_coroutine(void *co) "co=%p"
--
2.21.0
- [PATCH v2 for-5.1? 0/5] Fix nbd reconnect dead-locks, Vladimir Sementsov-Ogievskiy, 2020/07/27
- [PATCH v2 1/5] block/nbd: split nbd_establish_connection out of nbd_client_connect,
Vladimir Sementsov-Ogievskiy <=
- [PATCH v2 2/5] block/nbd: allow drain during reconnect attempt, Vladimir Sementsov-Ogievskiy, 2020/07/27
- [PATCH v2 3/5] block/nbd: on shutdown terminate connection attempt, Vladimir Sementsov-Ogievskiy, 2020/07/27
- [PATCH v2 4/5] block/nbd: nbd_co_reconnect_loop(): don't sleep if drained, Vladimir Sementsov-Ogievskiy, 2020/07/27
- [PATCH v2 5/5] block/nbd: use non-blocking connect: fix vm hang on connect(), Vladimir Sementsov-Ogievskiy, 2020/07/27
- Re: [PATCH v2 for-5.1? 0/5] Fix nbd reconnect dead-locks, Eric Blake, 2020/07/27