diff options
| -rw-r--r-- | block/nbd.c | 76 |
1 files changed, 40 insertions, 36 deletions
diff --git a/block/nbd.c b/block/nbd.c index 3cba874b1c..a5c690cef7 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -35,7 +35,6 @@ #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" @@ -72,10 +71,11 @@ typedef struct BDRVNBDState { NBDExportInfo info; /* - * Protects free_sema, in_flight, requests[].coroutine, + * Protects state, free_sema, in_flight, requests[].coroutine, * reconnect_delay_timer. */ QemuMutex requests_lock; + NBDClientState state; CoQueue free_sema; int in_flight; NBDClientRequest requests[MAX_NBD_REQUESTS]; @@ -83,7 +83,6 @@ typedef struct BDRVNBDState { CoMutex send_mutex; CoMutex receive_mutex; - NBDClientState state; QEMUTimer *open_timer; @@ -132,11 +131,6 @@ static void nbd_clear_bdrvstate(BlockDriverState *bs) s->x_dirty_bitmap = NULL; } -static bool nbd_client_connected(BDRVNBDState *s) -{ - return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED; -} - static bool coroutine_fn nbd_recv_coroutine_wake_one(NBDClientRequest *req) { if (req->receiving) { @@ -159,14 +153,15 @@ static void coroutine_fn nbd_recv_coroutines_wake(BDRVNBDState *s, bool all) } } -static void coroutine_fn nbd_channel_error(BDRVNBDState *s, int ret) +/* Called with s->requests_lock held. */ +static void coroutine_fn nbd_channel_error_locked(BDRVNBDState *s, int ret) { - if (nbd_client_connected(s)) { + if (s->state == NBD_CLIENT_CONNECTED) { qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); } if (ret == -EIO) { - if (nbd_client_connected(s)) { + if (s->state == NBD_CLIENT_CONNECTED) { s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : NBD_CLIENT_CONNECTING_NOWAIT; } @@ -177,6 +172,12 @@ static void coroutine_fn nbd_channel_error(BDRVNBDState *s, int ret) nbd_recv_coroutines_wake(s, true); } +static void coroutine_fn nbd_channel_error(BDRVNBDState *s, int ret) +{ + QEMU_LOCK_GUARD(&s->requests_lock); + nbd_channel_error_locked(s, ret); +} + static void reconnect_delay_timer_del(BDRVNBDState *s) { if (s->reconnect_delay_timer) { @@ -189,20 +190,18 @@ static void reconnect_delay_timer_cb(void *opaque) { BDRVNBDState *s = opaque; - if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { + reconnect_delay_timer_del(s); + WITH_QEMU_LOCK_GUARD(&s->requests_lock) { + if (s->state != NBD_CLIENT_CONNECTING_WAIT) { + return; + } s->state = NBD_CLIENT_CONNECTING_NOWAIT; - nbd_co_establish_connection_cancel(s->conn); } - - reconnect_delay_timer_del(s); + nbd_co_establish_connection_cancel(s->conn); } static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) { - if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { - return; - } - assert(!s->reconnect_delay_timer); s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), QEMU_CLOCK_REALTIME, @@ -225,7 +224,9 @@ static void nbd_teardown_connection(BlockDriverState *bs) s->ioc = NULL; } - s->state = NBD_CLIENT_QUIT; + WITH_QEMU_LOCK_GUARD(&s->requests_lock) { + s->state = NBD_CLIENT_QUIT; + } } static void open_timer_del(BDRVNBDState *s) @@ -254,15 +255,15 @@ static void open_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) timer_mod(s->open_timer, expire_time_ns); } -static bool nbd_client_connecting_wait(BDRVNBDState *s) -{ - return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; -} - static bool nbd_client_will_reconnect(BDRVNBDState *s) { - return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; + /* + * Called only after a socket error, so this is not performance sensitive. + */ + QEMU_LOCK_GUARD(&s->requests_lock); + return s->state == NBD_CLIENT_CONNECTING_WAIT; } + /* * Update @bs with information learned during a completed negotiation process. * Return failure if the server's advertised options are incompatible with the @@ -347,22 +348,24 @@ int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); /* successfully connected */ - s->state = NBD_CLIENT_CONNECTED; + WITH_QEMU_LOCK_GUARD(&s->requests_lock) { + s->state = NBD_CLIENT_CONNECTED; + } return 0; } +/* Called with s->requests_lock held. */ static bool nbd_client_connecting(BDRVNBDState *s) { - NBDClientState state = qatomic_load_acquire(&s->state); - return state == NBD_CLIENT_CONNECTING_WAIT || - state == NBD_CLIENT_CONNECTING_NOWAIT; + return s->state == NBD_CLIENT_CONNECTING_WAIT || + s->state == NBD_CLIENT_CONNECTING_NOWAIT; } /* Called with s->requests_lock taken. */ static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) { - bool blocking = nbd_client_connecting_wait(s); + bool blocking = s->state == NBD_CLIENT_CONNECTING_WAIT; /* * Now we are sure that nobody is accessing the channel, and no one will @@ -477,17 +480,17 @@ static int coroutine_fn nbd_co_send_request(BlockDriverState *bs, qemu_mutex_lock(&s->requests_lock); while (s->in_flight == MAX_NBD_REQUESTS || - (!nbd_client_connected(s) && s->in_flight > 0)) { + (s->state != NBD_CLIENT_CONNECTED && s->in_flight > 0)) { qemu_co_queue_wait(&s->free_sema, &s->requests_lock); } s->in_flight++; - if (!nbd_client_connected(s)) { + if (s->state != NBD_CLIENT_CONNECTED) { if (nbd_client_connecting(s)) { nbd_reconnect_attempt(s); qemu_co_queue_restart_all(&s->free_sema); } - if (!nbd_client_connected(s)) { + if (s->state != NBD_CLIENT_CONNECTED) { rc = -EIO; goto err; } @@ -530,7 +533,7 @@ static int coroutine_fn nbd_co_send_request(BlockDriverState *bs, if (rc < 0) { qemu_mutex_lock(&s->requests_lock); err: - nbd_channel_error(s, rc); + nbd_channel_error_locked(s, rc); if (i != -1) { s->requests[i].coroutine = NULL; } @@ -1443,8 +1446,9 @@ static void nbd_yank(void *opaque) BlockDriverState *bs = opaque; BDRVNBDState *s = (BDRVNBDState *)bs->opaque; - qatomic_store_release(&s->state, NBD_CLIENT_QUIT); + QEMU_LOCK_GUARD(&s->requests_lock); qio_channel_shutdown(QIO_CHANNEL(s->ioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); + s->state = NBD_CLIENT_QUIT; } static void nbd_client_close(BlockDriverState *bs) |