From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, vsementsov@virtuozzo.com,
eblake@redhat.com, mreitz@redhat.com, kwolf@redhat.com,
rvkagan@yandex-team.ru, den@openvz.org
Subject: [PATCH v3 08/33] block/nbd: drop thr->state
Date: Fri, 16 Apr 2021 11:08:46 +0300 [thread overview]
Message-ID: <20210416080911.83197-9-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20210416080911.83197-1-vsementsov@virtuozzo.com>
We don't need all these states. The code refactored to use two boolean
variables looks simpler.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block/nbd.c | 125 ++++++++++++++--------------------------------------
1 file changed, 34 insertions(+), 91 deletions(-)
diff --git a/block/nbd.c b/block/nbd.c
index e1f39eda6c..2b26a033a4 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -66,24 +66,6 @@ typedef enum NBDClientState {
NBD_CLIENT_QUIT
} NBDClientState;
-typedef enum NBDConnectThreadState {
- /* No thread, no pending results */
- CONNECT_THREAD_NONE,
-
- /* Thread is running, no results for now */
- CONNECT_THREAD_RUNNING,
-
- /*
- * Thread is running, but requestor exited. Thread should close
- * the new socket and free the connect state on exit.
- */
- CONNECT_THREAD_RUNNING_DETACHED,
-
- /* Thread finished, results are stored in a state */
- CONNECT_THREAD_FAIL,
- CONNECT_THREAD_SUCCESS
-} NBDConnectThreadState;
-
typedef struct NBDConnectThread {
/* Initialization constants */
SocketAddress *saddr; /* address to connect to */
@@ -97,7 +79,8 @@ typedef struct NBDConnectThread {
QemuMutex mutex;
/* All further fields are protected by mutex */
- NBDConnectThreadState state; /* current state of the thread */
+ bool running; /* thread is running now */
+ bool detached; /* thread is detached and should cleanup the state */
Coroutine *wait_co; /* nbd_co_establish_connection() wait in yield() */
} NBDConnectThread;
@@ -147,17 +130,17 @@ static void nbd_clear_bdrvstate(BlockDriverState *bs)
{
BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
NBDConnectThread *thr = s->connect_thread;
- bool thr_running;
+ bool do_free;
qemu_mutex_lock(&thr->mutex);
- thr_running = thr->state == CONNECT_THREAD_RUNNING;
- if (thr_running) {
- thr->state = CONNECT_THREAD_RUNNING_DETACHED;
+ if (thr->running) {
+ thr->detached = true;
}
+ do_free = !thr->running && !thr->detached;
qemu_mutex_unlock(&thr->mutex);
/* the runaway thread will clean it up itself */
- if (!thr_running) {
+ if (do_free) {
nbd_free_connect_thread(thr);
}
@@ -373,7 +356,6 @@ static void nbd_init_connect_thread(BDRVNBDState *s)
*s->connect_thread = (NBDConnectThread) {
.saddr = QAPI_CLONE(SocketAddress, s->saddr),
- .state = CONNECT_THREAD_NONE,
};
qemu_mutex_init(&s->connect_thread->mutex);
@@ -408,20 +390,13 @@ static void *connect_thread_func(void *opaque)
qemu_mutex_lock(&thr->mutex);
- switch (thr->state) {
- case CONNECT_THREAD_RUNNING:
- thr->state = ret < 0 ? CONNECT_THREAD_FAIL : CONNECT_THREAD_SUCCESS;
- if (thr->wait_co) {
- aio_co_schedule(NULL, thr->wait_co);
- thr->wait_co = NULL;
- }
- break;
- case CONNECT_THREAD_RUNNING_DETACHED:
- do_free = true;
- break;
- default:
- abort();
+ assert(thr->running);
+ thr->running = false;
+ if (thr->wait_co) {
+ aio_co_schedule(NULL, thr->wait_co);
+ thr->wait_co = NULL;
}
+ do_free = thr->detached;
qemu_mutex_unlock(&thr->mutex);
@@ -435,36 +410,24 @@ static void *connect_thread_func(void *opaque)
static int coroutine_fn
nbd_co_establish_connection(BlockDriverState *bs, Error **errp)
{
- int ret;
QemuThread thread;
BDRVNBDState *s = bs->opaque;
NBDConnectThread *thr = s->connect_thread;
+ assert(!s->sioc);
+
qemu_mutex_lock(&thr->mutex);
- switch (thr->state) {
- case CONNECT_THREAD_FAIL:
- case CONNECT_THREAD_NONE:
+ if (!thr->running) {
+ if (thr->sioc) {
+ /* Previous attempt finally succeeded in background */
+ goto out;
+ }
+ thr->running = true;
error_free(thr->err);
thr->err = NULL;
- thr->state = CONNECT_THREAD_RUNNING;
qemu_thread_create(&thread, "nbd-connect",
connect_thread_func, thr, QEMU_THREAD_DETACHED);
- break;
- case CONNECT_THREAD_SUCCESS:
- /* Previous attempt finally succeeded in background */
- thr->state = CONNECT_THREAD_NONE;
- s->sioc = thr->sioc;
- thr->sioc = NULL;
- yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name),
- nbd_yank, bs);
- qemu_mutex_unlock(&thr->mutex);
- return 0;
- case CONNECT_THREAD_RUNNING:
- /* Already running, will wait */
- break;
- default:
- abort();
}
thr->wait_co = qemu_coroutine_self();
@@ -479,10 +442,15 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp)
qemu_mutex_lock(&thr->mutex);
- switch (thr->state) {
- case CONNECT_THREAD_SUCCESS:
- case CONNECT_THREAD_FAIL:
- thr->state = CONNECT_THREAD_NONE;
+out:
+ if (thr->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, thr->err);
thr->err = NULL;
s->sioc = thr->sioc;
@@ -491,33 +459,11 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp)
yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name),
nbd_yank, bs);
}
- ret = (s->sioc ? 0 : -1);
- break;
- case CONNECT_THREAD_RUNNING:
- case CONNECT_THREAD_RUNNING_DETACHED:
- /*
- * 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.
- */
- ret = -1;
- error_setg(errp, "Connection attempt cancelled by other operation");
- break;
-
- case CONNECT_THREAD_NONE:
- /*
- * Impossible. We've seen this thread running. So it should be
- * running or at least give some results.
- */
- abort();
-
- default:
- abort();
}
qemu_mutex_unlock(&thr->mutex);
- return ret;
+ return s->sioc ? 0 : -1;
}
/*
@@ -532,12 +478,9 @@ static void nbd_co_establish_connection_cancel(BlockDriverState *bs)
qemu_mutex_lock(&thr->mutex);
- if (thr->state == CONNECT_THREAD_RUNNING) {
- /* We can cancel only in running state, when bh is not yet scheduled */
- if (thr->wait_co) {
- aio_co_schedule(NULL, thr->wait_co);
- thr->wait_co = NULL;
- }
+ if (thr->wait_co) {
+ aio_co_schedule(NULL, thr->wait_co);
+ thr->wait_co = NULL;
}
qemu_mutex_unlock(&thr->mutex);
--
2.29.2
next prev parent reply other threads:[~2021-04-16 8:16 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 8:08 [PATCH v3 00/33] block/nbd: rework client connection Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 01/33] block/nbd: fix channel object leak Vladimir Sementsov-Ogievskiy
2021-05-24 21:31 ` Eric Blake
2021-05-25 4:47 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 02/33] block/nbd: fix how state is cleared on nbd_open() failure paths Vladimir Sementsov-Ogievskiy
2021-04-21 14:00 ` Roman Kagan
2021-04-21 22:27 ` Vladimir Sementsov-Ogievskiy
2021-04-22 8:49 ` Roman Kagan
2021-06-01 21:39 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 03/33] block/nbd: ensure ->connection_thread is always valid Vladimir Sementsov-Ogievskiy
2021-06-01 21:41 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 04/33] block/nbd: nbd_client_handshake(): fix leak of s->ioc Vladimir Sementsov-Ogievskiy
2021-04-22 8:59 ` Roman Kagan
2021-04-16 8:08 ` [PATCH v3 05/33] block/nbd: BDRVNBDState: drop unused connect_err and connect_status Vladimir Sementsov-Ogievskiy
2021-06-01 21:43 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 06/33] util/async: aio_co_schedule(): support reschedule in same ctx Vladimir Sementsov-Ogievskiy
2021-04-23 10:09 ` Roman Kagan
2021-04-26 8:52 ` Vladimir Sementsov-Ogievskiy
2021-05-12 6:56 ` Paolo Bonzini
2021-05-12 7:15 ` Vladimir Sementsov-Ogievskiy
2021-05-13 21:04 ` Paolo Bonzini
2021-05-14 17:27 ` Roman Kagan
2021-05-14 21:19 ` Paolo Bonzini
2021-06-08 18:45 ` Vladimir Sementsov-Ogievskiy
2021-06-09 9:35 ` Paolo Bonzini
2021-06-09 10:24 ` Vladimir Sementsov-Ogievskiy
2021-06-09 12:17 ` Paolo Bonzini
2021-04-16 8:08 ` [PATCH v3 07/33] block/nbd: simplify waking of nbd_co_establish_connection() Vladimir Sementsov-Ogievskiy
2021-04-27 21:44 ` Roman Kagan
2021-06-02 19:05 ` Eric Blake
2021-04-16 8:08 ` Vladimir Sementsov-Ogievskiy [this message]
2021-04-27 22:23 ` [PATCH v3 08/33] block/nbd: drop thr->state Roman Kagan
2021-04-28 8:01 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 09/33] block/nbd: bs-independent interface for nbd_co_establish_connection() Vladimir Sementsov-Ogievskiy
2021-06-02 19:14 ` Eric Blake
2021-06-08 10:12 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 10/33] block/nbd: make nbd_co_establish_connection_cancel() bs-independent Vladimir Sementsov-Ogievskiy
2021-06-02 21:18 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 11/33] block/nbd: rename NBDConnectThread to NBDClientConnection Vladimir Sementsov-Ogievskiy
2021-04-27 22:28 ` Roman Kagan
2021-06-02 21:21 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 12/33] block/nbd: introduce nbd_client_connection_new() Vladimir Sementsov-Ogievskiy
2021-06-02 21:22 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 13/33] block/nbd: introduce nbd_client_connection_release() Vladimir Sementsov-Ogievskiy
2021-04-27 22:35 ` Roman Kagan
2021-04-28 8:06 ` Vladimir Sementsov-Ogievskiy
2021-06-02 21:27 ` Eric Blake
2021-06-03 11:59 ` Vladimir Sementsov-Ogievskiy
2021-06-08 10:00 ` Vladimir Sementsov-Ogievskiy
2021-06-08 14:18 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 14/33] nbd: move connection code from block/nbd to nbd/client-connection Vladimir Sementsov-Ogievskiy
2021-04-27 22:45 ` Roman Kagan
2021-04-28 8:14 ` Vladimir Sementsov-Ogievskiy
2021-06-09 15:49 ` Vladimir Sementsov-Ogievskiy
2021-06-03 15:55 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 15/33] nbd/client-connection: use QEMU_LOCK_GUARD Vladimir Sementsov-Ogievskiy
2021-04-28 6:08 ` Roman Kagan
2021-04-28 8:17 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 16/33] nbd/client-connection: add possibility of negotiation Vladimir Sementsov-Ogievskiy
2021-05-11 10:45 ` Roman Kagan
2021-05-12 6:42 ` Vladimir Sementsov-Ogievskiy
2021-06-08 19:23 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 17/33] nbd/client-connection: implement connection retry Vladimir Sementsov-Ogievskiy
2021-05-11 20:54 ` Roman Kagan
2021-06-08 10:24 ` Vladimir Sementsov-Ogievskiy
2021-06-03 16:17 ` Eric Blake
2021-06-03 17:49 ` Vladimir Sementsov-Ogievskiy
2021-06-08 10:38 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:08 ` [PATCH v3 18/33] nbd/client-connection: shutdown connection on release Vladimir Sementsov-Ogievskiy
2021-05-11 21:08 ` Roman Kagan
2021-05-12 6:39 ` Vladimir Sementsov-Ogievskiy
2021-06-03 16:20 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 19/33] block/nbd: split nbd_handle_updated_info out of nbd_client_handshake() Vladimir Sementsov-Ogievskiy
2021-05-12 8:40 ` Roman Kagan
2021-06-03 16:29 ` Eric Blake
2021-06-09 17:23 ` Vladimir Sementsov-Ogievskiy
2021-06-09 18:28 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 20/33] block/nbd: use negotiation of NBDClientConnection Vladimir Sementsov-Ogievskiy
2021-06-03 18:05 ` Eric Blake
2021-04-16 8:08 ` [PATCH v3 21/33] qemu-socket: pass monitor link to socket_get_fd directly Vladimir Sementsov-Ogievskiy
2021-04-19 9:34 ` Daniel P. Berrangé
2021-04-19 10:09 ` Vladimir Sementsov-Ogievskiy
2021-05-12 9:40 ` Roman Kagan
2021-05-12 9:59 ` Daniel P. Berrangé
2021-05-13 11:02 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 22/33] block/nbd: pass monitor directly to connection thread Vladimir Sementsov-Ogievskiy
2021-06-03 18:16 ` Eric Blake
2021-06-03 18:31 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 23/33] block/nbd: nbd_teardown_connection() don't touch s->sioc Vladimir Sementsov-Ogievskiy
2021-06-03 19:04 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 24/33] block/nbd: drop BDRVNBDState::sioc Vladimir Sementsov-Ogievskiy
2021-06-03 19:12 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 25/33] nbd/client-connection: return only one io channel Vladimir Sementsov-Ogievskiy
2021-06-03 19:58 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 26/33] block-coroutine-wrapper: allow non bdrv_ prefix Vladimir Sementsov-Ogievskiy
2021-06-03 20:00 ` Eric Blake
2021-06-03 20:53 ` Eric Blake
2021-06-04 5:29 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 27/33] block/nbd: split nbd_co_do_establish_connection out of nbd_reconnect_attempt Vladimir Sementsov-Ogievskiy
2021-06-03 20:04 ` Eric Blake
2021-06-04 5:30 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 28/33] nbd/client-connection: do qio_channel_set_delay(false) Vladimir Sementsov-Ogievskiy
2021-06-03 20:48 ` Eric Blake
2021-06-04 5:32 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 29/33] nbd/client-connection: add option for non-blocking connection attempt Vladimir Sementsov-Ogievskiy
2021-06-03 20:51 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 30/33] block/nbd: reuse nbd_co_do_establish_connection() in nbd_open() Vladimir Sementsov-Ogievskiy
2021-06-03 20:57 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 31/33] block/nbd: add nbd_clinent_connected() helper Vladimir Sementsov-Ogievskiy
2021-05-12 7:06 ` Paolo Bonzini
2021-05-12 7:19 ` Vladimir Sementsov-Ogievskiy
2021-06-03 21:08 ` Eric Blake
2021-04-16 8:09 ` [PATCH v3 32/33] block/nbd: safer transition to receiving request Vladimir Sementsov-Ogievskiy
2021-06-03 21:11 ` Eric Blake
2021-06-04 5:36 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:09 ` [PATCH v3 33/33] block/nbd: drop connection_co Vladimir Sementsov-Ogievskiy
2021-04-16 8:14 ` Vladimir Sementsov-Ogievskiy
2021-04-16 8:21 ` Vladimir Sementsov-Ogievskiy
2021-06-03 21:27 ` Eric Blake
2021-06-04 5:39 ` Vladimir Sementsov-Ogievskiy
2021-05-12 6:54 ` [PATCH v3 00/33] block/nbd: rework client connection Paolo Bonzini
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