From fee091cdffe73c6d5094ec67b8245ede58aced5b Mon Sep 17 00:00:00 2001 From: Lukas Straub Date: Mon, 28 Dec 2020 16:08:44 +0100 Subject: block/nbd.c: Add yank feature Register a yank function which shuts down the socket and sets s->state = NBD_CLIENT_QUIT. This is the same behaviour as if an error occured. Signed-off-by: Lukas Straub Acked-by: Stefan Hajnoczi Reviewed-by: Eric Blake Message-Id: Signed-off-by: Markus Armbruster --- block/nbd.c | 153 ++++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 92 insertions(+), 61 deletions(-) (limited to 'block') diff --git a/block/nbd.c b/block/nbd.c index 242a258f3a..42e10c7c93 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -35,6 +35,7 @@ #include "qemu/option.h" #include "qemu/cutils.h" #include "qemu/main-loop.h" +#include "qemu/atomic.h" #include "qapi/qapi-visit-sockets.h" #include "qapi/qmp/qstring.h" @@ -44,6 +45,8 @@ #include "block/nbd.h" #include "block/block_int.h" +#include "qemu/yank.h" + #define EN_OPTSTR ":exportname=" #define MAX_NBD_REQUESTS 16 @@ -141,14 +144,13 @@ typedef struct BDRVNBDState { NBDConnectThread *connect_thread; } BDRVNBDState; -static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, - Error **errp); -static QIOChannelSocket *nbd_co_establish_connection(BlockDriverState *bs, - Error **errp); +static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr, + Error **errp); +static int nbd_co_establish_connection(BlockDriverState *bs, Error **errp); static void nbd_co_establish_connection_cancel(BlockDriverState *bs, bool detach); -static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc, - Error **errp); +static int nbd_client_handshake(BlockDriverState *bs, Error **errp); +static void nbd_yank(void *opaque); static void nbd_clear_bdrvstate(BDRVNBDState *s) { @@ -166,12 +168,12 @@ static void nbd_clear_bdrvstate(BDRVNBDState *s) static void nbd_channel_error(BDRVNBDState *s, int ret) { if (ret == -EIO) { - if (s->state == NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : NBD_CLIENT_CONNECTING_NOWAIT; } } else { - if (s->state == NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); } s->state = NBD_CLIENT_QUIT; @@ -203,7 +205,7 @@ static void reconnect_delay_timer_cb(void *opaque) { BDRVNBDState *s = opaque; - if (s->state == NBD_CLIENT_CONNECTING_WAIT) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { s->state = NBD_CLIENT_CONNECTING_NOWAIT; while (qemu_co_enter_next(&s->free_sema, NULL)) { /* Resume all queued requests */ @@ -215,7 +217,7 @@ static void reconnect_delay_timer_cb(void *opaque) static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) { - if (s->state != NBD_CLIENT_CONNECTING_WAIT) { + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { return; } @@ -260,7 +262,7 @@ static void nbd_client_attach_aio_context(BlockDriverState *bs, * s->connection_co is either yielded from nbd_receive_reply or from * nbd_co_reconnect_loop() */ - if (s->state == NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { qio_channel_attach_aio_context(QIO_CHANNEL(s->ioc), new_context); } @@ -286,7 +288,7 @@ static void coroutine_fn nbd_client_co_drain_begin(BlockDriverState *bs) reconnect_delay_timer_del(s); - if (s->state == NBD_CLIENT_CONNECTING_WAIT) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { s->state = NBD_CLIENT_CONNECTING_NOWAIT; qemu_co_queue_restart_all(&s->free_sema); } @@ -337,13 +339,14 @@ static void nbd_teardown_connection(BlockDriverState *bs) static bool nbd_client_connecting(BDRVNBDState *s) { - return s->state == NBD_CLIENT_CONNECTING_WAIT || - s->state == NBD_CLIENT_CONNECTING_NOWAIT; + NBDClientState state = qatomic_load_acquire(&s->state); + return state == NBD_CLIENT_CONNECTING_WAIT || + state == NBD_CLIENT_CONNECTING_NOWAIT; } static bool nbd_client_connecting_wait(BDRVNBDState *s) { - return s->state == NBD_CLIENT_CONNECTING_WAIT; + return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; } static void connect_bh(void *opaque) @@ -423,12 +426,12 @@ static void *connect_thread_func(void *opaque) return NULL; } -static QIOChannelSocket *coroutine_fn +static int coroutine_fn nbd_co_establish_connection(BlockDriverState *bs, Error **errp) { + int ret; QemuThread thread; BDRVNBDState *s = bs->opaque; - QIOChannelSocket *res; NBDConnectThread *thr = s->connect_thread; qemu_mutex_lock(&thr->mutex); @@ -445,10 +448,12 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp) case CONNECT_THREAD_SUCCESS: /* Previous attempt finally succeeded in background */ thr->state = CONNECT_THREAD_NONE; - res = thr->sioc; + 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 res; + return 0; case CONNECT_THREAD_RUNNING: /* Already running, will wait */ break; @@ -480,8 +485,13 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp) thr->state = CONNECT_THREAD_NONE; error_propagate(errp, thr->err); thr->err = NULL; - res = thr->sioc; + s->sioc = thr->sioc; thr->sioc = NULL; + if (s->sioc) { + 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: @@ -490,7 +500,7 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp) * failed. Still connect thread is executing in background, and its * result may be used for next connection attempt. */ - res = NULL; + ret = -1; error_setg(errp, "Connection attempt cancelled by other operation"); break; @@ -507,7 +517,7 @@ nbd_co_establish_connection(BlockDriverState *bs, Error **errp) qemu_mutex_unlock(&thr->mutex); - return res; + return ret; } /* @@ -560,7 +570,6 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) { int ret; Error *local_err = NULL; - QIOChannelSocket *sioc; if (!nbd_client_connecting(s)) { return; @@ -593,21 +602,22 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) /* Finalize previous connection if any */ if (s->ioc) { qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), + nbd_yank, s->bs); object_unref(OBJECT(s->sioc)); s->sioc = NULL; object_unref(OBJECT(s->ioc)); s->ioc = NULL; } - sioc = nbd_co_establish_connection(s->bs, &local_err); - if (!sioc) { + if (nbd_co_establish_connection(s->bs, &local_err) < 0) { ret = -ECONNREFUSED; goto out; } bdrv_dec_in_flight(s->bs); - ret = nbd_client_handshake(s->bs, sioc, &local_err); + ret = nbd_client_handshake(s->bs, &local_err); if (s->drained) { s->wait_drained_end = true; @@ -639,7 +649,7 @@ static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s) uint64_t timeout = 1 * NANOSECONDS_PER_SECOND; uint64_t max_timeout = 16 * NANOSECONDS_PER_SECOND; - if (s->state == NBD_CLIENT_CONNECTING_WAIT) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { reconnect_delay_timer_init(s, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + s->reconnect_delay * NANOSECONDS_PER_SECOND); } @@ -682,7 +692,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque) int ret = 0; Error *local_err = NULL; - while (s->state != NBD_CLIENT_QUIT) { + while (qatomic_load_acquire(&s->state) != NBD_CLIENT_QUIT) { /* * The NBD client can only really be considered idle when it has * yielded from qio_channel_readv_all_eof(), waiting for data. This is @@ -697,7 +707,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque) nbd_co_reconnect_loop(s); } - if (s->state != NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { continue; } @@ -752,6 +762,8 @@ static coroutine_fn void nbd_connection_entry(void *opaque) s->connection_co = NULL; if (s->ioc) { qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), + nbd_yank, s->bs); object_unref(OBJECT(s->sioc)); s->sioc = NULL; object_unref(OBJECT(s->ioc)); @@ -776,7 +788,7 @@ static int nbd_co_send_request(BlockDriverState *bs, qemu_co_queue_wait(&s->free_sema, &s->send_mutex); } - if (s->state != NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { rc = -EIO; goto err; } @@ -803,7 +815,8 @@ static int nbd_co_send_request(BlockDriverState *bs, if (qiov) { qio_channel_set_cork(s->ioc, true); rc = nbd_send_request(s->ioc, request); - if (rc >= 0 && s->state == NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED && + rc >= 0) { if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, NULL) < 0) { rc = -EIO; @@ -1128,7 +1141,7 @@ static coroutine_fn int nbd_co_do_receive_one_chunk( s->requests[i].receiving = true; qemu_coroutine_yield(); s->requests[i].receiving = false; - if (s->state != NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { error_setg(errp, "Connection closed"); return -EIO; } @@ -1287,7 +1300,7 @@ static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, NBDReply local_reply; NBDStructuredReplyChunk *chunk; Error *local_err = NULL; - if (s->state != NBD_CLIENT_CONNECTED) { + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { error_setg(&local_err, "Connection closed"); nbd_iter_channel_error(iter, -EIO, &local_err); goto break_loop; @@ -1312,7 +1325,8 @@ static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, } /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ - if (nbd_reply_is_simple(reply) || s->state != NBD_CLIENT_CONNECTED) { + if (nbd_reply_is_simple(reply) || + qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { goto break_loop; } @@ -1744,6 +1758,15 @@ static int nbd_client_reopen_prepare(BDRVReopenState *state, return 0; } +static void nbd_yank(void *opaque) +{ + BlockDriverState *bs = opaque; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + qatomic_store_release(&s->state, NBD_CLIENT_QUIT); + qio_channel_shutdown(QIO_CHANNEL(s->sioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); +} + static void nbd_client_close(BlockDriverState *bs) { BDRVNBDState *s = (BDRVNBDState *)bs->opaque; @@ -1756,52 +1779,53 @@ static void nbd_client_close(BlockDriverState *bs) nbd_teardown_connection(bs); } -static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, - Error **errp) +static int nbd_establish_connection(BlockDriverState *bs, + SocketAddress *saddr, + Error **errp) { ERRP_GUARD(); - QIOChannelSocket *sioc; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; - sioc = qio_channel_socket_new(); - qio_channel_set_name(QIO_CHANNEL(sioc), "nbd-client"); + s->sioc = qio_channel_socket_new(); + qio_channel_set_name(QIO_CHANNEL(s->sioc), "nbd-client"); - qio_channel_socket_connect_sync(sioc, saddr, errp); + qio_channel_socket_connect_sync(s->sioc, saddr, errp); if (*errp) { - object_unref(OBJECT(sioc)); - return NULL; + object_unref(OBJECT(s->sioc)); + s->sioc = NULL; + return -1; } - qio_channel_set_delay(QIO_CHANNEL(sioc), false); + yank_register_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), nbd_yank, bs); + qio_channel_set_delay(QIO_CHANNEL(s->sioc), false); - return sioc; + return 0; } -/* nbd_client_handshake takes ownership on sioc. On failure it is unref'ed. */ -static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc, - Error **errp) +/* nbd_client_handshake takes ownership on s->sioc. On failure it's unref'ed. */ +static int nbd_client_handshake(BlockDriverState *bs, Error **errp) { BDRVNBDState *s = (BDRVNBDState *)bs->opaque; AioContext *aio_context = bdrv_get_aio_context(bs); int ret; trace_nbd_client_handshake(s->export); - - s->sioc = sioc; - - qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL); - qio_channel_attach_aio_context(QIO_CHANNEL(sioc), aio_context); + qio_channel_set_blocking(QIO_CHANNEL(s->sioc), false, NULL); + qio_channel_attach_aio_context(QIO_CHANNEL(s->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(s->x_dirty_bitmap); s->info.name = g_strdup(s->export ?: ""); - ret = nbd_receive_negotiate(aio_context, QIO_CHANNEL(sioc), s->tlscreds, + ret = nbd_receive_negotiate(aio_context, QIO_CHANNEL(s->sioc), s->tlscreds, s->hostname, &s->ioc, &s->info, errp); g_free(s->info.x_dirty_bitmap); g_free(s->info.name); if (ret < 0) { - object_unref(OBJECT(sioc)); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), + nbd_yank, bs); + object_unref(OBJECT(s->sioc)); s->sioc = NULL; return ret; } @@ -1834,7 +1858,7 @@ static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc, } if (!s->ioc) { - s->ioc = QIO_CHANNEL(sioc); + s->ioc = QIO_CHANNEL(s->sioc); object_ref(OBJECT(s->ioc)); } @@ -1850,9 +1874,11 @@ static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc, { NBDRequest request = { .type = NBD_CMD_DISC }; - nbd_send_request(s->ioc ?: QIO_CHANNEL(sioc), &request); + nbd_send_request(s->ioc ?: QIO_CHANNEL(s->sioc), &request); - object_unref(OBJECT(sioc)); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(bs->node_name), + nbd_yank, bs); + object_unref(OBJECT(s->sioc)); s->sioc = NULL; return ret; @@ -2244,7 +2270,6 @@ 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) { @@ -2255,17 +2280,22 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, qemu_co_mutex_init(&s->send_mutex); qemu_co_queue_init(&s->free_sema); + if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { + return -EEXIST; + } + /* * establish TCP connection, return error if it fails * TODO: Configurable retry-until-timeout behaviour. */ - sioc = nbd_establish_connection(s->saddr, errp); - if (!sioc) { + if (nbd_establish_connection(bs, s->saddr, errp) < 0) { + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); return -ECONNREFUSED; } - ret = nbd_client_handshake(bs, sioc, errp); + ret = nbd_client_handshake(bs, errp); if (ret < 0) { + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); nbd_clear_bdrvstate(s); return ret; } @@ -2325,6 +2355,7 @@ static void nbd_close(BlockDriverState *bs) BDRVNBDState *s = bs->opaque; nbd_client_close(bs); + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); nbd_clear_bdrvstate(s); } -- cgit v1.2.3