From a8e2bb6a76c7c661c117327f70f06eb628554230 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 18 Jun 2019 14:43:21 +0300 Subject: [PATCH] block/nbd: use non-blocking io channel for nbd negotiation No reason to use blocking channel for negotiation and we'll benefit in further reconnect feature, as qio_channel reads and writes will do qemu_coroutine_yield while waiting for io completion. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Message-Id: <20190618114328.55249-3-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake --- block/nbd.c | 16 +++++++--------- include/block/nbd.h | 3 ++- nbd/client.c | 16 +++++++++++----- qemu-nbd.c | 2 +- 4 files changed, 21 insertions(+), 16 deletions(-) diff --git a/block/nbd.c b/block/nbd.c index c16d02528b..3a243d9de9 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -1175,6 +1175,7 @@ static int nbd_client_connect(BlockDriverState *bs, Error **errp) { BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + AioContext *aio_context = bdrv_get_aio_context(bs); int ret; /* @@ -1189,15 +1190,16 @@ static int nbd_client_connect(BlockDriverState *bs, /* NBD handshake */ trace_nbd_client_connect(export); - qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL); + qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL); + qio_channel_attach_aio_context(QIO_CHANNEL(sioc), aio_context); s->info.request_sizes = true; s->info.structured_reply = true; s->info.base_allocation = true; s->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap); s->info.name = g_strdup(export ?: ""); - ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname, - &s->ioc, &s->info, errp); + ret = nbd_receive_negotiate(aio_context, QIO_CHANNEL(sioc), tlscreds, + hostname, &s->ioc, &s->info, errp); g_free(s->info.x_dirty_bitmap); g_free(s->info.name); if (ret < 0) { @@ -1231,18 +1233,14 @@ static int nbd_client_connect(BlockDriverState *bs, object_ref(OBJECT(s->ioc)); } - qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL); - qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); - trace_nbd_client_connect_success(export); return 0; fail: /* - * We have connected, but must fail for other reasons. The - * connection is still blocking; send NBD_CMD_DISC as a courtesy - * to the server. + * We have connected, but must fail for other reasons. + * Send NBD_CMD_DISC as a courtesy to the server. */ { NBDRequest request = { .type = NBD_CMD_DISC }; diff --git a/include/block/nbd.h b/include/block/nbd.h index bb9f5bc021..7b36d672f0 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -304,7 +304,8 @@ struct NBDExportInfo { }; typedef struct NBDExportInfo NBDExportInfo; -int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, +int nbd_receive_negotiate(AioContext *aio_context, QIOChannel *ioc, + QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, NBDExportInfo *info, Error **errp); void nbd_free_export_list(NBDExportInfo *info, int count); diff --git a/nbd/client.c b/nbd/client.c index 4de30630c7..8f524c3e35 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -867,7 +867,8 @@ static int nbd_list_meta_contexts(QIOChannel *ioc, * 2: server is newstyle, but lacks structured replies * 3: server is newstyle and set up for structured replies */ -static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, +static int nbd_start_negotiate(AioContext *aio_context, QIOChannel *ioc, + QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, bool structured_reply, bool *zeroes, Error **errp) @@ -934,6 +935,10 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } ioc = *outioc; + if (aio_context) { + qio_channel_set_blocking(ioc, false, NULL); + qio_channel_attach_aio_context(ioc, aio_context); + } } else { error_setg(errp, "Server does not support STARTTLS"); return -EINVAL; @@ -998,7 +1003,8 @@ static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info, * Returns: negative errno: failure talking to server * 0: server is connected */ -int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, +int nbd_receive_negotiate(AioContext *aio_context, QIOChannel *ioc, + QCryptoTLSCreds *tlscreds, const char *hostname, QIOChannel **outioc, NBDExportInfo *info, Error **errp) { @@ -1009,7 +1015,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, assert(info->name); trace_nbd_receive_negotiate_name(info->name); - result = nbd_start_negotiate(ioc, tlscreds, hostname, outioc, + result = nbd_start_negotiate(aio_context, ioc, tlscreds, hostname, outioc, info->structured_reply, &zeroes, errp); info->structured_reply = false; @@ -1129,8 +1135,8 @@ int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, QIOChannel *sioc = NULL; *info = NULL; - result = nbd_start_negotiate(ioc, tlscreds, hostname, &sioc, true, NULL, - errp); + result = nbd_start_negotiate(NULL, ioc, tlscreds, hostname, &sioc, true, + NULL, errp); if (tlscreds && sioc) { ioc = sioc; } diff --git a/qemu-nbd.c b/qemu-nbd.c index a8cb39e510..049645491d 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -362,7 +362,7 @@ static void *nbd_client_thread(void *arg) goto out; } - ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), + ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), NULL, NULL, NULL, &info, &local_error); if (ret < 0) { if (local_error) {