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Re: [PATCH 06/14] block/nbd: further segregation of connect-thread
From: |
Roman Kagan |
Subject: |
Re: [PATCH 06/14] block/nbd: further segregation of connect-thread |
Date: |
Thu, 8 Apr 2021 13:44:35 +0300 |
On Wed, Apr 07, 2021 at 01:46:29PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> Add personal state NBDConnectThread for connect-thread and
> nbd_connect_thread_start() function. Next step would be moving
> connect-thread to a separate file.
>
> Note that we stop publishing thr->sioc during
> qio_channel_socket_connect_sync(). Which probably means that we can't
> early-cancel qio_channel_socket_connect_sync() call in
> nbd_free_connect_thread(). Still, when thread is detached it doesn't
> make big sense, and we have no guarantee anyway.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
> block/nbd.c | 57 ++++++++++++++++++++++++++++++++++++-----------------
> 1 file changed, 39 insertions(+), 18 deletions(-)
>
> diff --git a/block/nbd.c b/block/nbd.c
> index e16c6d636a..23eb8adab1 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -85,8 +85,6 @@ typedef enum NBDConnectThreadState {
> } NBDConnectThreadState;
>
> typedef struct NBDConnectCB {
> - /* Initialization constants */
> - SocketAddress *saddr; /* address to connect to */
> /*
> * Bottom half to schedule on completion. Scheduled only if bh_ctx is not
> * NULL
> @@ -103,6 +101,15 @@ typedef struct NBDConnectCB {
> AioContext *bh_ctx; /* where to schedule bh (NULL means don't schedule)
> */
> } NBDConnectCB;
>
> +typedef void (*NBDConnectThreadCallback)(QIOChannelSocket *sioc, int ret,
> + void *opaque);
> +
> +typedef struct NBDConnectThread {
> + SocketAddress *saddr; /* address to connect to */
> + NBDConnectThreadCallback cb;
> + void *cb_opaque;
> +} NBDConnectThread;
> +
> typedef struct BDRVNBDState {
> QIOChannelSocket *sioc; /* The master data channel */
> QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
> @@ -367,7 +374,6 @@ static void nbd_init_connect_thread(BDRVNBDState *s)
> s->connect_thread = g_new(NBDConnectCB, 1);
>
> *s->connect_thread = (NBDConnectCB) {
> - .saddr = QAPI_CLONE(SocketAddress, s->saddr),
> .state = CONNECT_THREAD_NONE,
> .bh_func = connect_bh,
> .bh_opaque = s,
> @@ -378,20 +384,18 @@ static void nbd_init_connect_thread(BDRVNBDState *s)
>
> static void nbd_free_connect_thread(NBDConnectCB *thr)
> {
> - if (thr->sioc) {
> - qio_channel_close(QIO_CHANNEL(thr->sioc), NULL);
> - }
Doesn't this result in an open channel leak? (The original code here
seems to be missing an unref, too.)
> - qapi_free_SocketAddress(thr->saddr);
> g_free(thr);
> }
>
> -static void connect_thread_cb(int ret, void *opaque)
> +static void connect_thread_cb(QIOChannelSocket *sioc, int ret, void *opaque)
> {
> NBDConnectCB *thr = opaque;
> bool do_free = false;
>
> qemu_mutex_lock(&thr->mutex);
>
> + thr->sioc = sioc;
> +
> switch (thr->state) {
> case CONNECT_THREAD_RUNNING:
> thr->state = ret < 0 ? CONNECT_THREAD_FAIL : CONNECT_THREAD_SUCCESS;
> @@ -418,27 +422,45 @@ static void connect_thread_cb(int ret, void *opaque)
>
> static void *connect_thread_func(void *opaque)
> {
> - NBDConnectCB *thr = opaque;
> + NBDConnectThread *thr = opaque;
> int ret;
> + QIOChannelSocket *sioc = qio_channel_socket_new();
>
> - thr->sioc = qio_channel_socket_new();
> -
> - ret = qio_channel_socket_connect_sync(thr->sioc, thr->saddr, NULL);
> + ret = qio_channel_socket_connect_sync(sioc, thr->saddr, NULL);
> if (ret < 0) {
> - object_unref(OBJECT(thr->sioc));
> - thr->sioc = NULL;
> + object_unref(OBJECT(sioc));
> + sioc = NULL;
> }
>
> - connect_thread_cb(ret, thr);
> + thr->cb(sioc, ret, thr->cb_opaque);
> +
> + qapi_free_SocketAddress(thr->saddr);
> + g_free(thr);
>
> return NULL;
> }
>
> +static void nbd_connect_thread_start(const SocketAddress *saddr,
> + NBDConnectThreadCallback cb,
> + void *cb_opaque)
> +{
> + QemuThread thread;
> + NBDConnectThread *thr = g_new(NBDConnectThread, 1);
> +
> + *thr = (NBDConnectThread) {
> + .saddr = QAPI_CLONE(SocketAddress, saddr),
> + .cb = cb,
> + .cb_opaque = cb_opaque,
> + };
> +
> + qemu_thread_create(&thread, "nbd-connect",
> + connect_thread_func, thr, QEMU_THREAD_DETACHED);
> +}
> +
> static int coroutine_fn
> nbd_co_establish_connection(BlockDriverState *bs)
> {
> int ret;
> - QemuThread thread;
> BDRVNBDState *s = bs->opaque;
> NBDConnectCB *thr = s->connect_thread;
>
> @@ -448,8 +470,7 @@ nbd_co_establish_connection(BlockDriverState *bs)
> case CONNECT_THREAD_FAIL:
> case CONNECT_THREAD_NONE:
> thr->state = CONNECT_THREAD_RUNNING;
> - qemu_thread_create(&thread, "nbd-connect",
> - connect_thread_func, thr, QEMU_THREAD_DETACHED);
> + nbd_connect_thread_start(s->saddr, connect_thread_cb, thr);
> break;
> case CONNECT_THREAD_SUCCESS:
> /* Previous attempt finally succeeded in background */
> --
> 2.29.2
>
- [PATCH 00/14] nbd: move reconnect-thread to separate file, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 01/14] block/nbd: BDRVNBDState: drop unused connect_err, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 03/14] block/nbd: drop unused NBDConnectThread::err field, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 04/14] block/nbd: split connect_thread_cb() out of connect_thread_func(), Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 02/14] block/nbd: nbd_co_establish_connection(): drop unused errp, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 06/14] block/nbd: further segregation of connect-thread, Vladimir Sementsov-Ogievskiy, 2021/04/07
- Re: [PATCH 06/14] block/nbd: further segregation of connect-thread,
Roman Kagan <=
- [PATCH 05/14] block/nbd: rename NBDConnectThread to NBDConnectCB, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 08/14] block/nbd: move nbd connect-thread to nbd/client-connect.c, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 07/14] block/nbd: drop nbd_free_connect_thread(), Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 09/14] block/nbd: NBDConnectCB: drop bh_* fields, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 10/14] block/nbd: move wait_connect field under mutex protection, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 11/14] block/nbd: refactor connect_bh(), Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 12/14] block/nbd: refactor nbd_co_establish_connection, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 13/14] block/nbd: nbd_co_establish_connection_cancel(): rename wake to do_wake, Vladimir Sementsov-Ogievskiy, 2021/04/07
- [PATCH 14/14] block/nbd: drop thr->state, Vladimir Sementsov-Ogievskiy, 2021/04/07
- DROP THIS Re: [PATCH 00/14] nbd: move reconnect-thread to separate file, Vladimir Sementsov-Ogievskiy, 2021/04/08