mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 03:59:52 +00:00
1ace7ceac5
All that CoQueue needs in order to become thread-safe is help from an external mutex. Add this to the API. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213181244.16297-6-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
430 lines
12 KiB
C
430 lines
12 KiB
C
/*
|
|
* QEMU Block driver for NBD
|
|
*
|
|
* Copyright (C) 2016 Red Hat, Inc.
|
|
* Copyright (C) 2008 Bull S.A.S.
|
|
* Author: Laurent Vivier <Laurent.Vivier@bull.net>
|
|
*
|
|
* Some parts:
|
|
* Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "nbd-client.h"
|
|
|
|
#define HANDLE_TO_INDEX(bs, handle) ((handle) ^ ((uint64_t)(intptr_t)bs))
|
|
#define INDEX_TO_HANDLE(bs, index) ((index) ^ ((uint64_t)(intptr_t)bs))
|
|
|
|
static void nbd_recv_coroutines_enter_all(BlockDriverState *bs)
|
|
{
|
|
NBDClientSession *s = nbd_get_client_session(bs);
|
|
int i;
|
|
|
|
for (i = 0; i < MAX_NBD_REQUESTS; i++) {
|
|
if (s->recv_coroutine[i]) {
|
|
qemu_coroutine_enter(s->recv_coroutine[i]);
|
|
}
|
|
}
|
|
BDRV_POLL_WHILE(bs, s->read_reply_co);
|
|
}
|
|
|
|
static void nbd_teardown_connection(BlockDriverState *bs)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
|
|
if (!client->ioc) { /* Already closed */
|
|
return;
|
|
}
|
|
|
|
/* finish any pending coroutines */
|
|
qio_channel_shutdown(client->ioc,
|
|
QIO_CHANNEL_SHUTDOWN_BOTH,
|
|
NULL);
|
|
nbd_recv_coroutines_enter_all(bs);
|
|
|
|
nbd_client_detach_aio_context(bs);
|
|
object_unref(OBJECT(client->sioc));
|
|
client->sioc = NULL;
|
|
object_unref(OBJECT(client->ioc));
|
|
client->ioc = NULL;
|
|
}
|
|
|
|
static coroutine_fn void nbd_read_reply_entry(void *opaque)
|
|
{
|
|
NBDClientSession *s = opaque;
|
|
uint64_t i;
|
|
int ret;
|
|
|
|
for (;;) {
|
|
assert(s->reply.handle == 0);
|
|
ret = nbd_receive_reply(s->ioc, &s->reply);
|
|
if (ret < 0) {
|
|
break;
|
|
}
|
|
|
|
/* There's no need for a mutex on the receive side, because the
|
|
* handler acts as a synchronization point and ensures that only
|
|
* one coroutine is called until the reply finishes.
|
|
*/
|
|
i = HANDLE_TO_INDEX(s, s->reply.handle);
|
|
if (i >= MAX_NBD_REQUESTS || !s->recv_coroutine[i]) {
|
|
break;
|
|
}
|
|
|
|
/* We're woken up by the recv_coroutine itself. Note that there
|
|
* is no race between yielding and reentering read_reply_co. This
|
|
* is because:
|
|
*
|
|
* - if recv_coroutine[i] runs on the same AioContext, it is only
|
|
* entered after we yield
|
|
*
|
|
* - if recv_coroutine[i] runs on a different AioContext, reentering
|
|
* read_reply_co happens through a bottom half, which can only
|
|
* run after we yield.
|
|
*/
|
|
aio_co_wake(s->recv_coroutine[i]);
|
|
qemu_coroutine_yield();
|
|
}
|
|
s->read_reply_co = NULL;
|
|
}
|
|
|
|
static int nbd_co_send_request(BlockDriverState *bs,
|
|
NBDRequest *request,
|
|
QEMUIOVector *qiov)
|
|
{
|
|
NBDClientSession *s = nbd_get_client_session(bs);
|
|
int rc, ret, i;
|
|
|
|
qemu_co_mutex_lock(&s->send_mutex);
|
|
|
|
for (i = 0; i < MAX_NBD_REQUESTS; i++) {
|
|
if (s->recv_coroutine[i] == NULL) {
|
|
s->recv_coroutine[i] = qemu_coroutine_self();
|
|
break;
|
|
}
|
|
}
|
|
|
|
g_assert(qemu_in_coroutine());
|
|
assert(i < MAX_NBD_REQUESTS);
|
|
request->handle = INDEX_TO_HANDLE(s, i);
|
|
|
|
if (!s->ioc) {
|
|
qemu_co_mutex_unlock(&s->send_mutex);
|
|
return -EPIPE;
|
|
}
|
|
|
|
if (qiov) {
|
|
qio_channel_set_cork(s->ioc, true);
|
|
rc = nbd_send_request(s->ioc, request);
|
|
if (rc >= 0) {
|
|
ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len,
|
|
false);
|
|
if (ret != request->len) {
|
|
rc = -EIO;
|
|
}
|
|
}
|
|
qio_channel_set_cork(s->ioc, false);
|
|
} else {
|
|
rc = nbd_send_request(s->ioc, request);
|
|
}
|
|
qemu_co_mutex_unlock(&s->send_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static void nbd_co_receive_reply(NBDClientSession *s,
|
|
NBDRequest *request,
|
|
NBDReply *reply,
|
|
QEMUIOVector *qiov)
|
|
{
|
|
int ret;
|
|
|
|
/* Wait until we're woken up by nbd_read_reply_entry. */
|
|
qemu_coroutine_yield();
|
|
*reply = s->reply;
|
|
if (reply->handle != request->handle ||
|
|
!s->ioc) {
|
|
reply->error = EIO;
|
|
} else {
|
|
if (qiov && reply->error == 0) {
|
|
ret = nbd_wr_syncv(s->ioc, qiov->iov, qiov->niov, request->len,
|
|
true);
|
|
if (ret != request->len) {
|
|
reply->error = EIO;
|
|
}
|
|
}
|
|
|
|
/* Tell the read handler to read another header. */
|
|
s->reply.handle = 0;
|
|
}
|
|
}
|
|
|
|
static void nbd_coroutine_start(NBDClientSession *s,
|
|
NBDRequest *request)
|
|
{
|
|
/* Poor man semaphore. The free_sema is locked when no other request
|
|
* can be accepted, and unlocked after receiving one reply. */
|
|
if (s->in_flight == MAX_NBD_REQUESTS) {
|
|
qemu_co_queue_wait(&s->free_sema, NULL);
|
|
assert(s->in_flight < MAX_NBD_REQUESTS);
|
|
}
|
|
s->in_flight++;
|
|
|
|
/* s->recv_coroutine[i] is set as soon as we get the send_lock. */
|
|
}
|
|
|
|
static void nbd_coroutine_end(BlockDriverState *bs,
|
|
NBDRequest *request)
|
|
{
|
|
NBDClientSession *s = nbd_get_client_session(bs);
|
|
int i = HANDLE_TO_INDEX(s, request->handle);
|
|
|
|
s->recv_coroutine[i] = NULL;
|
|
s->in_flight--;
|
|
qemu_co_queue_next(&s->free_sema);
|
|
|
|
/* Kick the read_reply_co to get the next reply. */
|
|
if (s->read_reply_co) {
|
|
aio_co_wake(s->read_reply_co);
|
|
}
|
|
}
|
|
|
|
int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t bytes, QEMUIOVector *qiov, int flags)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = {
|
|
.type = NBD_CMD_READ,
|
|
.from = offset,
|
|
.len = bytes,
|
|
};
|
|
NBDReply reply;
|
|
ssize_t ret;
|
|
|
|
assert(bytes <= NBD_MAX_BUFFER_SIZE);
|
|
assert(!flags);
|
|
|
|
nbd_coroutine_start(client, &request);
|
|
ret = nbd_co_send_request(bs, &request, NULL);
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
} else {
|
|
nbd_co_receive_reply(client, &request, &reply, qiov);
|
|
}
|
|
nbd_coroutine_end(bs, &request);
|
|
return -reply.error;
|
|
}
|
|
|
|
int nbd_client_co_pwritev(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t bytes, QEMUIOVector *qiov, int flags)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = {
|
|
.type = NBD_CMD_WRITE,
|
|
.from = offset,
|
|
.len = bytes,
|
|
};
|
|
NBDReply reply;
|
|
ssize_t ret;
|
|
|
|
if (flags & BDRV_REQ_FUA) {
|
|
assert(client->nbdflags & NBD_FLAG_SEND_FUA);
|
|
request.flags |= NBD_CMD_FLAG_FUA;
|
|
}
|
|
|
|
assert(bytes <= NBD_MAX_BUFFER_SIZE);
|
|
|
|
nbd_coroutine_start(client, &request);
|
|
ret = nbd_co_send_request(bs, &request, qiov);
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
} else {
|
|
nbd_co_receive_reply(client, &request, &reply, NULL);
|
|
}
|
|
nbd_coroutine_end(bs, &request);
|
|
return -reply.error;
|
|
}
|
|
|
|
int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
|
|
int count, BdrvRequestFlags flags)
|
|
{
|
|
ssize_t ret;
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = {
|
|
.type = NBD_CMD_WRITE_ZEROES,
|
|
.from = offset,
|
|
.len = count,
|
|
};
|
|
NBDReply reply;
|
|
|
|
if (!(client->nbdflags & NBD_FLAG_SEND_WRITE_ZEROES)) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
if (flags & BDRV_REQ_FUA) {
|
|
assert(client->nbdflags & NBD_FLAG_SEND_FUA);
|
|
request.flags |= NBD_CMD_FLAG_FUA;
|
|
}
|
|
if (!(flags & BDRV_REQ_MAY_UNMAP)) {
|
|
request.flags |= NBD_CMD_FLAG_NO_HOLE;
|
|
}
|
|
|
|
nbd_coroutine_start(client, &request);
|
|
ret = nbd_co_send_request(bs, &request, NULL);
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
} else {
|
|
nbd_co_receive_reply(client, &request, &reply, NULL);
|
|
}
|
|
nbd_coroutine_end(bs, &request);
|
|
return -reply.error;
|
|
}
|
|
|
|
int nbd_client_co_flush(BlockDriverState *bs)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = { .type = NBD_CMD_FLUSH };
|
|
NBDReply reply;
|
|
ssize_t ret;
|
|
|
|
if (!(client->nbdflags & NBD_FLAG_SEND_FLUSH)) {
|
|
return 0;
|
|
}
|
|
|
|
request.from = 0;
|
|
request.len = 0;
|
|
|
|
nbd_coroutine_start(client, &request);
|
|
ret = nbd_co_send_request(bs, &request, NULL);
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
} else {
|
|
nbd_co_receive_reply(client, &request, &reply, NULL);
|
|
}
|
|
nbd_coroutine_end(bs, &request);
|
|
return -reply.error;
|
|
}
|
|
|
|
int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = {
|
|
.type = NBD_CMD_TRIM,
|
|
.from = offset,
|
|
.len = count,
|
|
};
|
|
NBDReply reply;
|
|
ssize_t ret;
|
|
|
|
if (!(client->nbdflags & NBD_FLAG_SEND_TRIM)) {
|
|
return 0;
|
|
}
|
|
|
|
nbd_coroutine_start(client, &request);
|
|
ret = nbd_co_send_request(bs, &request, NULL);
|
|
if (ret < 0) {
|
|
reply.error = -ret;
|
|
} else {
|
|
nbd_co_receive_reply(client, &request, &reply, NULL);
|
|
}
|
|
nbd_coroutine_end(bs, &request);
|
|
return -reply.error;
|
|
|
|
}
|
|
|
|
void nbd_client_detach_aio_context(BlockDriverState *bs)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
qio_channel_detach_aio_context(QIO_CHANNEL(client->sioc));
|
|
}
|
|
|
|
void nbd_client_attach_aio_context(BlockDriverState *bs,
|
|
AioContext *new_context)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
qio_channel_attach_aio_context(QIO_CHANNEL(client->sioc), new_context);
|
|
aio_co_schedule(new_context, client->read_reply_co);
|
|
}
|
|
|
|
void nbd_client_close(BlockDriverState *bs)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
NBDRequest request = { .type = NBD_CMD_DISC };
|
|
|
|
if (client->ioc == NULL) {
|
|
return;
|
|
}
|
|
|
|
nbd_send_request(client->ioc, &request);
|
|
|
|
nbd_teardown_connection(bs);
|
|
}
|
|
|
|
int nbd_client_init(BlockDriverState *bs,
|
|
QIOChannelSocket *sioc,
|
|
const char *export,
|
|
QCryptoTLSCreds *tlscreds,
|
|
const char *hostname,
|
|
Error **errp)
|
|
{
|
|
NBDClientSession *client = nbd_get_client_session(bs);
|
|
int ret;
|
|
|
|
/* NBD handshake */
|
|
logout("session init %s\n", export);
|
|
qio_channel_set_blocking(QIO_CHANNEL(sioc), true, NULL);
|
|
|
|
ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
|
|
&client->nbdflags,
|
|
tlscreds, hostname,
|
|
&client->ioc,
|
|
&client->size, errp);
|
|
if (ret < 0) {
|
|
logout("Failed to negotiate with the NBD server\n");
|
|
return ret;
|
|
}
|
|
if (client->nbdflags & NBD_FLAG_SEND_FUA) {
|
|
bs->supported_write_flags = BDRV_REQ_FUA;
|
|
bs->supported_zero_flags |= BDRV_REQ_FUA;
|
|
}
|
|
if (client->nbdflags & NBD_FLAG_SEND_WRITE_ZEROES) {
|
|
bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
|
|
qemu_co_mutex_init(&client->send_mutex);
|
|
qemu_co_queue_init(&client->free_sema);
|
|
client->sioc = sioc;
|
|
object_ref(OBJECT(client->sioc));
|
|
|
|
if (!client->ioc) {
|
|
client->ioc = QIO_CHANNEL(sioc);
|
|
object_ref(OBJECT(client->ioc));
|
|
}
|
|
|
|
/* Now that we're connected, set the socket to be non-blocking and
|
|
* kick the reply mechanism. */
|
|
qio_channel_set_blocking(QIO_CHANNEL(sioc), false, NULL);
|
|
client->read_reply_co = qemu_coroutine_create(nbd_read_reply_entry, client);
|
|
nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
|
|
|
|
logout("Established connection with NBD server\n");
|
|
return 0;
|
|
}
|