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block/nbd.c: Add yank feature

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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 <lukasstraub2@web.de>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <b73eb07db6d1fcd00667beb13ae6117260f002c3.1609167865.git.lukasstraub2@web.de>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Lukas Straub 2020-12-28 16:08:44 +01:00 committed by Markus Armbruster
parent 50186051f4
commit fee091cdff
1 changed files with 92 additions and 61 deletions
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153
block/nbd.c
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@ -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);
}