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 --- block/nbd.c | 123 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 74 insertions(+), 49 deletions(-) diff --git a/block/nbd.c b/block/nbd.c index 7bb881fef4..e37b0f6ab0 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" @@ -43,6 +44,8 @@ #include "block/nbd.h" #include "block/block_int.h" +#include "qemu/yank.h" + #define EN_OPTSTR ":exportname=" #define MAX_NBD_REQUESTS 16 @@ -84,6 +87,8 @@ typedef struct BDRVNBDState { NBDReply reply; BlockDriverState *bs; + char *yank_name; + /* Connection parameters */ uint32_t reconnect_delay; SocketAddress *saddr; @@ -93,10 +98,10 @@ typedef struct BDRVNBDState { char *x_dirty_bitmap; } BDRVNBDState; -static QIOChannelSocket *nbd_establish_connection(SocketAddress *saddr, - Error **errp); -static int nbd_client_handshake(BlockDriverState *bs, QIOChannelSocket *sioc, - Error **errp); +static int nbd_establish_connection(BlockDriverState *bs, SocketAddress *saddr, + Error **errp); +static int nbd_client_handshake(BlockDriverState *bs, Error **errp); +static void nbd_yank(void *opaque); static void nbd_clear_bdrvstate(BDRVNBDState *s) { @@ -109,17 +114,19 @@ static void nbd_clear_bdrvstate(BDRVNBDState *s) s->tlscredsid = NULL; g_free(s->x_dirty_bitmap); s->x_dirty_bitmap = NULL; + g_free(s->yank_name); + s->yank_name = NULL; } static void nbd_channel_error(BDRVNBDState *s, int ret) { if (ret == -EIO) { - if (s->state == NBD_CLIENT_CONNECTED) { + if (atomic_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 (atomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); } s->state = NBD_CLIENT_QUIT; @@ -170,7 +177,7 @@ 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 (atomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { qio_channel_attach_aio_context(QIO_CHANNEL(s->ioc), new_context); } @@ -237,20 +244,20 @@ 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 = atomic_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 atomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; } static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) { int ret; Error *local_err = NULL; - QIOChannelSocket *sioc; if (!nbd_client_connecting(s)) { return; @@ -283,21 +290,21 @@ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) /* Finalize previous connection if any */ if (s->ioc) { nbd_client_detach_aio_context(s->bs); + yank_unregister_function(s->yank_name, nbd_yank, s->bs); object_unref(OBJECT(s->sioc)); s->sioc = NULL; object_unref(OBJECT(s->ioc)); s->ioc = NULL; } - sioc = nbd_establish_connection(s->saddr, &local_err); - if (!sioc) { + if (nbd_establish_connection(s->bs, s->saddr, &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; @@ -334,7 +341,7 @@ static coroutine_fn void nbd_co_reconnect_loop(BDRVNBDState *s) nbd_reconnect_attempt(s); while (nbd_client_connecting(s)) { - if (s->state == NBD_CLIENT_CONNECTING_WAIT && + if (atomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT && qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - start_time_ns > delay_ns) { s->state = NBD_CLIENT_CONNECTING_NOWAIT; @@ -371,7 +378,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque) int ret = 0; Error *local_err = NULL; - while (s->state != NBD_CLIENT_QUIT) { + while (atomic_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 @@ -386,7 +393,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque) nbd_co_reconnect_loop(s); } - if (s->state != NBD_CLIENT_CONNECTED) { + if (atomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { continue; } @@ -441,6 +448,7 @@ static coroutine_fn void nbd_connection_entry(void *opaque) s->connection_co = NULL; if (s->ioc) { nbd_client_detach_aio_context(s->bs); + yank_unregister_function(s->yank_name, nbd_yank, s->bs); object_unref(OBJECT(s->sioc)); s->sioc = NULL; object_unref(OBJECT(s->ioc)); @@ -465,7 +473,7 @@ 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 (atomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { rc = -EIO; goto err; } @@ -492,7 +500,7 @@ 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 (rc >= 0 && atomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED) { if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, NULL) < 0) { rc = -EIO; @@ -807,7 +815,7 @@ 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 (atomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { error_setg(errp, "Connection closed"); return -EIO; } @@ -966,7 +974,7 @@ 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 (atomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { error_setg(&local_err, "Connection closed"); nbd_iter_channel_error(iter, -EIO, &local_err); goto break_loop; @@ -991,7 +999,8 @@ 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) || + atomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTED) { goto break_loop; } @@ -1423,6 +1432,15 @@ static int nbd_client_reopen_prepare(BDRVReopenState *state, return 0; } +static void nbd_yank(void *opaque) +{ + BlockDriverState *bs = opaque; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + atomic_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; @@ -1435,52 +1453,53 @@ 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"); + yank_register_function(s->yank_name, nbd_yank, bs); - 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; + yank_unregister_function(s->yank_name, nbd_yank, bs); + object_unref(OBJECT(s->sioc)); + s->sioc = NULL; + return -1; } - qio_channel_set_delay(QIO_CHANNEL(sioc), false); + 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(s->yank_name, nbd_yank, bs); + object_unref(OBJECT(s->sioc)); s->sioc = NULL; return ret; } @@ -1508,7 +1527,7 @@ 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)); } @@ -1524,9 +1543,10 @@ 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(s->yank_name, nbd_yank, bs); + object_unref(OBJECT(s->sioc)); s->sioc = NULL; return ret; @@ -1918,7 +1938,6 @@ 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) { @@ -1928,18 +1947,23 @@ static int nbd_open(BlockDriverState *bs, QDict *options, int flags, s->bs = bs; qemu_co_mutex_init(&s->send_mutex); qemu_co_queue_init(&s->free_sema); + s->yank_name = g_strconcat("blockdev:", bs->node_name, NULL); + yank_register_instance(s->yank_name); /* * 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(s->yank_name); + g_free(s->yank_name); + s->yank_name = NULL; return -ECONNREFUSED; } - ret = nbd_client_handshake(bs, sioc, errp); + ret = nbd_client_handshake(bs, errp); if (ret < 0) { + yank_unregister_instance(s->yank_name); nbd_clear_bdrvstate(s); return ret; } @@ -1997,6 +2021,7 @@ static void nbd_close(BlockDriverState *bs) BDRVNBDState *s = bs->opaque; nbd_client_close(bs); + yank_unregister_instance(s->yank_name); nbd_clear_bdrvstate(s); } -- 2.20.1