[qemu.git] / block / nbd-client.c

/*
 * QEMU Block driver for  NBD
 *
 * Copyright (C) 2008 Bull S.A.S.
 *     Author: Laurent Vivier <[email protected]>
 *
 * Some parts:
 *    Copyright (C) 2007 Anthony Liguori <[email protected]>
 *
 * 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 "nbd-client.h"
#include "qemu/sockets.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(NbdClientSession *s)
{
    int i;

    for (i = 0; i < MAX_NBD_REQUESTS; i++) {
        if (s->recv_coroutine[i]) {
            qemu_coroutine_enter(s->recv_coroutine[i], NULL);
        }
    }
}

static void nbd_teardown_connection(BlockDriverState *bs)
{
    NbdClientSession *client = nbd_get_client_session(bs);

    /* finish any pending coroutines */
    shutdown(client->sock, 2);
    nbd_recv_coroutines_enter_all(client);

    nbd_client_detach_aio_context(bs);
    closesocket(client->sock);
    client->sock = -1;
}

static void nbd_reply_ready(void *opaque)
{
    BlockDriverState *bs = opaque;
    NbdClientSession *s = nbd_get_client_session(bs);
    uint64_t i;
    int ret;

    if (s->reply.handle == 0) {
        /* No reply already in flight.  Fetch a header.  It is possible
         * that another thread has done the same thing in parallel, so
         * the socket is not readable anymore.
         */
        ret = nbd_receive_reply(s->sock, &s->reply);
        if (ret == -EAGAIN) {
            return;
        }
        if (ret < 0) {
            s->reply.handle = 0;
            goto fail;
        }
    }

    /* 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) {
        goto fail;
    }

    if (s->recv_coroutine[i]) {
        qemu_coroutine_enter(s->recv_coroutine[i], NULL);
        return;
    }

fail:
    nbd_teardown_connection(bs);
}

static void nbd_restart_write(void *opaque)
{
    BlockDriverState *bs = opaque;

    qemu_coroutine_enter(nbd_get_client_session(bs)->send_coroutine, NULL);
}

static int nbd_co_send_request(BlockDriverState *bs,
                               struct nbd_request *request,
                               QEMUIOVector *qiov, int offset)
{
    NbdClientSession *s = nbd_get_client_session(bs);
    AioContext *aio_context;
    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;
        }
    }

    assert(i < MAX_NBD_REQUESTS);
    request->handle = INDEX_TO_HANDLE(s, i);
    s->send_coroutine = qemu_coroutine_self();
    aio_context = bdrv_get_aio_context(bs);

    aio_set_fd_handler(aio_context, s->sock,
                       nbd_reply_ready, nbd_restart_write, bs);
    if (qiov) {
        if (!s->is_unix) {
            socket_set_cork(s->sock, 1);
        }
        rc = nbd_send_request(s->sock, request);
        if (rc >= 0) {
            ret = qemu_co_sendv(s->sock, qiov->iov, qiov->niov,
                                offset, request->len);
            if (ret != request->len) {
                rc = -EIO;
            }
        }
        if (!s->is_unix) {
            socket_set_cork(s->sock, 0);
        }
    } else {
        rc = nbd_send_request(s->sock, request);
    }
    aio_set_fd_handler(aio_context, s->sock, nbd_reply_ready, NULL, bs);
    s->send_coroutine = NULL;
    qemu_co_mutex_unlock(&s->send_mutex);
    return rc;
}

static void nbd_co_receive_reply(NbdClientSession *s,
    struct nbd_request *request, struct nbd_reply *reply,
    QEMUIOVector *qiov, int offset)
{
    int ret;

    /* Wait until we're woken up by the read handler.  TODO: perhaps
     * peek at the next reply and avoid yielding if it's ours?  */
    qemu_coroutine_yield();
    *reply = s->reply;
    if (reply->handle != request->handle) {
        reply->error = EIO;
    } else {
        if (qiov && reply->error == 0) {
            ret = qemu_co_recvv(s->sock, qiov->iov, qiov->niov,
                                offset, request->len);
            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,
   struct nbd_request *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 - 1) {
        qemu_co_mutex_lock(&s->free_sema);
        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(NbdClientSession *s,
    struct nbd_request *request)
{
    int i = HANDLE_TO_INDEX(s, request->handle);
    s->recv_coroutine[i] = NULL;
    if (s->in_flight-- == MAX_NBD_REQUESTS) {
        qemu_co_mutex_unlock(&s->free_sema);
    }
}

static int nbd_co_readv_1(BlockDriverState *bs, int64_t sector_num,
                          int nb_sectors, QEMUIOVector *qiov,
                          int offset)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    struct nbd_request request = { .type = NBD_CMD_READ };
    struct nbd_reply reply;
    ssize_t ret;

    request.from = sector_num * 512;
    request.len = nb_sectors * 512;

    nbd_coroutine_start(client, &request);
    ret = nbd_co_send_request(bs, &request, NULL, 0);
    if (ret < 0) {
        reply.error = -ret;
    } else {
        nbd_co_receive_reply(client, &request, &reply, qiov, offset);
    }
    nbd_coroutine_end(client, &request);
    return -reply.error;

}

static int nbd_co_writev_1(BlockDriverState *bs, int64_t sector_num,
                           int nb_sectors, QEMUIOVector *qiov,
                           int offset)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    struct nbd_request request = { .type = NBD_CMD_WRITE };
    struct nbd_reply reply;
    ssize_t ret;

    if (!bdrv_enable_write_cache(bs) &&
        (client->nbdflags & NBD_FLAG_SEND_FUA)) {
        request.type |= NBD_CMD_FLAG_FUA;
    }

    request.from = sector_num * 512;
    request.len = nb_sectors * 512;

    nbd_coroutine_start(client, &request);
    ret = nbd_co_send_request(bs, &request, qiov, offset);
    if (ret < 0) {
        reply.error = -ret;
    } else {
        nbd_co_receive_reply(client, &request, &reply, NULL, 0);
    }
    nbd_coroutine_end(client, &request);
    return -reply.error;
}

/* qemu-nbd has a limit of slightly less than 1M per request.  Try to
 * remain aligned to 4K. */
#define NBD_MAX_SECTORS 2040

int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num,
                        int nb_sectors, QEMUIOVector *qiov)
{
    int offset = 0;
    int ret;
    while (nb_sectors > NBD_MAX_SECTORS) {
        ret = nbd_co_readv_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset);
        if (ret < 0) {
            return ret;
        }
        offset += NBD_MAX_SECTORS * 512;
        sector_num += NBD_MAX_SECTORS;
        nb_sectors -= NBD_MAX_SECTORS;
    }
    return nbd_co_readv_1(bs, sector_num, nb_sectors, qiov, offset);
}

int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num,
                         int nb_sectors, QEMUIOVector *qiov)
{
    int offset = 0;
    int ret;
    while (nb_sectors > NBD_MAX_SECTORS) {
        ret = nbd_co_writev_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset);
        if (ret < 0) {
            return ret;
        }
        offset += NBD_MAX_SECTORS * 512;
        sector_num += NBD_MAX_SECTORS;
        nb_sectors -= NBD_MAX_SECTORS;
    }
    return nbd_co_writev_1(bs, sector_num, nb_sectors, qiov, offset);
}

int nbd_client_co_flush(BlockDriverState *bs)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    struct nbd_request request = { .type = NBD_CMD_FLUSH };
    struct nbd_reply reply;
    ssize_t ret;

    if (!(client->nbdflags & NBD_FLAG_SEND_FLUSH)) {
        return 0;
    }

    if (client->nbdflags & NBD_FLAG_SEND_FUA) {
        request.type |= NBD_CMD_FLAG_FUA;
    }

    request.from = 0;
    request.len = 0;

    nbd_coroutine_start(client, &request);
    ret = nbd_co_send_request(bs, &request, NULL, 0);
    if (ret < 0) {
        reply.error = -ret;
    } else {
        nbd_co_receive_reply(client, &request, &reply, NULL, 0);
    }
    nbd_coroutine_end(client, &request);
    return -reply.error;
}

int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num,
                          int nb_sectors)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    struct nbd_request request = { .type = NBD_CMD_TRIM };
    struct nbd_reply reply;
    ssize_t ret;

    if (!(client->nbdflags & NBD_FLAG_SEND_TRIM)) {
        return 0;
    }
    request.from = sector_num * 512;
    request.len = nb_sectors * 512;

    nbd_coroutine_start(client, &request);
    ret = nbd_co_send_request(bs, &request, NULL, 0);
    if (ret < 0) {
        reply.error = -ret;
    } else {
        nbd_co_receive_reply(client, &request, &reply, NULL, 0);
    }
    nbd_coroutine_end(client, &request);
    return -reply.error;

}

void nbd_client_detach_aio_context(BlockDriverState *bs)
{
    aio_set_fd_handler(bdrv_get_aio_context(bs),
                       nbd_get_client_session(bs)->sock, NULL, NULL, NULL);
}

void nbd_client_attach_aio_context(BlockDriverState *bs,
                                   AioContext *new_context)
{
    aio_set_fd_handler(new_context, nbd_get_client_session(bs)->sock,
                       nbd_reply_ready, NULL, bs);
}

void nbd_client_close(BlockDriverState *bs)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    struct nbd_request request = {
        .type = NBD_CMD_DISC,
        .from = 0,
        .len = 0
    };

    if (client->sock == -1) {
        return;
    }

    nbd_send_request(client->sock, &request);

    nbd_teardown_connection(bs);
}

int nbd_client_init(BlockDriverState *bs, int sock, const char *export,
                    Error **errp)
{
    NbdClientSession *client = nbd_get_client_session(bs);
    int ret;

    /* NBD handshake */
    logout("session init %s\n", export);
    qemu_set_block(sock);
    ret = nbd_receive_negotiate(sock, export,
                                &client->nbdflags, &client->size, errp);
    if (ret < 0) {
        logout("Failed to negotiate with the NBD server\n");
        closesocket(sock);
        return ret;
    }

    qemu_co_mutex_init(&client->send_mutex);
    qemu_co_mutex_init(&client->free_sema);
    client->sock = sock;

    /* Now that we're connected, set the socket to be non-blocking and
     * kick the reply mechanism.  */
    qemu_set_nonblock(sock);
    nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));

    logout("Established connection with NBD server\n");
    return 0;
}
Commit	Line	Data
2302c1ca MAL	1	/*
	2	* QEMU Block driver for NBD
	3	*
	4	* Copyright (C) 2008 Bull S.A.S.
	5	* Author: Laurent Vivier <[email protected]>
	6	*
	7	* Some parts:
	8	* Copyright (C) 2007 Anthony Liguori <[email protected]>
	9	*
	10	* Permission is hereby granted, free of charge, to any person obtaining a copy
	11	* of this software and associated documentation files (the "Software"), to deal
	12	* in the Software without restriction, including without limitation the rights
	13	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	14	* copies of the Software, and to permit persons to whom the Software is
	15	* furnished to do so, subject to the following conditions:
	16	*
	17	* The above copyright notice and this permission notice shall be included in
	18	* all copies or substantial portions of the Software.
	19	*
	20	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	21	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	23	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	24	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	25	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	26	* THE SOFTWARE.
	27	*/
	28
	29	#include "nbd-client.h"
	30	#include "qemu/sockets.h"
	31
	32	#define HANDLE_TO_INDEX(bs, handle) ((handle) ^ ((uint64_t)(intptr_t)bs))
	33	#define INDEX_TO_HANDLE(bs, index) ((index) ^ ((uint64_t)(intptr_t)bs))
	34
69152c09 MAL	35	static void nbd_recv_coroutines_enter_all(NbdClientSession *s)
	36	{
	37	int i;
	38
	39	for (i = 0; i < MAX_NBD_REQUESTS; i++) {
	40	if (s->recv_coroutine[i]) {
	41	qemu_coroutine_enter(s->recv_coroutine[i], NULL);
	42	}
	43	}
	44	}
	45
f53a829b	46	static void nbd_teardown_connection(BlockDriverState *bs)
4a41a2d6	47	{
f53a829b HR	48	NbdClientSession *client = nbd_get_client_session(bs);
f53a829b HR	49
4a41a2d6 SH	50	/* finish any pending coroutines */
	51	shutdown(client->sock, 2);
	52	nbd_recv_coroutines_enter_all(client);
	53
f53a829b	54	nbd_client_detach_aio_context(bs);
4a41a2d6 SH	55	closesocket(client->sock);
	56	client->sock = -1;
	57	}
	58
2302c1ca MAL	59	static void nbd_reply_ready(void *opaque)
2302c1ca MAL	60	{
f53a829b HR	61	BlockDriverState *bs = opaque;
f53a829b HR	62	NbdClientSession *s = nbd_get_client_session(bs);
2302c1ca MAL	63	uint64_t i;
	64	int ret;
	65
	66	if (s->reply.handle == 0) {
	67	/* No reply already in flight. Fetch a header. It is possible
	68	* that another thread has done the same thing in parallel, so
	69	* the socket is not readable anymore.
	70	*/
	71	ret = nbd_receive_reply(s->sock, &s->reply);
	72	if (ret == -EAGAIN) {
	73	return;
	74	}
	75	if (ret < 0) {
	76	s->reply.handle = 0;
	77	goto fail;
	78	}
	79	}
	80
	81	/* There's no need for a mutex on the receive side, because the
	82	* handler acts as a synchronization point and ensures that only
	83	* one coroutine is called until the reply finishes. */
	84	i = HANDLE_TO_INDEX(s, s->reply.handle);
	85	if (i >= MAX_NBD_REQUESTS) {
	86	goto fail;
	87	}
	88
	89	if (s->recv_coroutine[i]) {
	90	qemu_coroutine_enter(s->recv_coroutine[i], NULL);
	91	return;
	92	}
	93
	94	fail:
f53a829b	95	nbd_teardown_connection(bs);
2302c1ca MAL	96	}
	97
	98	static void nbd_restart_write(void *opaque)
	99	{
f53a829b	100	BlockDriverState *bs = opaque;
2302c1ca	101
f53a829b	102	qemu_coroutine_enter(nbd_get_client_session(bs)->send_coroutine, NULL);
2302c1ca MAL	103	}
2302c1ca MAL	104
f53a829b HR	105	static int nbd_co_send_request(BlockDriverState *bs,
	106	struct nbd_request *request,
	107	QEMUIOVector *qiov, int offset)
2302c1ca	108	{
f53a829b	109	NbdClientSession *s = nbd_get_client_session(bs);
69447cd8	110	AioContext *aio_context;
141cabe6	111	int rc, ret, i;
2302c1ca MAL	112
2302c1ca MAL	113	qemu_co_mutex_lock(&s->send_mutex);
141cabe6 BW	114
	115	for (i = 0; i < MAX_NBD_REQUESTS; i++) {
	116	if (s->recv_coroutine[i] == NULL) {
	117	s->recv_coroutine[i] = qemu_coroutine_self();
	118	break;
	119	}
	120	}
	121
	122	assert(i < MAX_NBD_REQUESTS);
	123	request->handle = INDEX_TO_HANDLE(s, i);
2302c1ca	124	s->send_coroutine = qemu_coroutine_self();
f53a829b	125	aio_context = bdrv_get_aio_context(bs);
141cabe6	126
69447cd8	127	aio_set_fd_handler(aio_context, s->sock,
f53a829b	128	nbd_reply_ready, nbd_restart_write, bs);
2302c1ca MAL	129	if (qiov) {
	130	if (!s->is_unix) {
	131	socket_set_cork(s->sock, 1);
	132	}
	133	rc = nbd_send_request(s->sock, request);
	134	if (rc >= 0) {
	135	ret = qemu_co_sendv(s->sock, qiov->iov, qiov->niov,
	136	offset, request->len);
	137	if (ret != request->len) {
	138	rc = -EIO;
	139	}
	140	}
	141	if (!s->is_unix) {
	142	socket_set_cork(s->sock, 0);
	143	}
	144	} else {
	145	rc = nbd_send_request(s->sock, request);
	146	}
f53a829b	147	aio_set_fd_handler(aio_context, s->sock, nbd_reply_ready, NULL, bs);
2302c1ca MAL	148	s->send_coroutine = NULL;
	149	qemu_co_mutex_unlock(&s->send_mutex);
	150	return rc;
	151	}
	152
	153	static void nbd_co_receive_reply(NbdClientSession *s,
	154	struct nbd_request request, struct nbd_reply reply,
	155	QEMUIOVector *qiov, int offset)
	156	{
	157	int ret;
	158
	159	/* Wait until we're woken up by the read handler. TODO: perhaps
	160	* peek at the next reply and avoid yielding if it's ours? */
	161	qemu_coroutine_yield();
	162	*reply = s->reply;
	163	if (reply->handle != request->handle) {
	164	reply->error = EIO;
	165	} else {
	166	if (qiov && reply->error == 0) {
	167	ret = qemu_co_recvv(s->sock, qiov->iov, qiov->niov,
	168	offset, request->len);
	169	if (ret != request->len) {
	170	reply->error = EIO;
	171	}
	172	}
	173
	174	/* Tell the read handler to read another header. */
	175	s->reply.handle = 0;
	176	}
	177	}
	178
	179	static void nbd_coroutine_start(NbdClientSession *s,
	180	struct nbd_request *request)
	181	{
2302c1ca MAL	182	/* Poor man semaphore. The free_sema is locked when no other request
	183	* can be accepted, and unlocked after receiving one reply. */
	184	if (s->in_flight >= MAX_NBD_REQUESTS - 1) {
	185	qemu_co_mutex_lock(&s->free_sema);
	186	assert(s->in_flight < MAX_NBD_REQUESTS);
	187	}
	188	s->in_flight++;
	189
141cabe6	190	/* s->recv_coroutine[i] is set as soon as we get the send_lock. */
2302c1ca MAL	191	}
	192
	193	static void nbd_coroutine_end(NbdClientSession *s,
	194	struct nbd_request *request)
	195	{
	196	int i = HANDLE_TO_INDEX(s, request->handle);
	197	s->recv_coroutine[i] = NULL;
	198	if (s->in_flight-- == MAX_NBD_REQUESTS) {
	199	qemu_co_mutex_unlock(&s->free_sema);
	200	}
	201	}
	202
f53a829b	203	static int nbd_co_readv_1(BlockDriverState *bs, int64_t sector_num,
2302c1ca MAL	204	int nb_sectors, QEMUIOVector *qiov,
	205	int offset)
	206	{
f53a829b	207	NbdClientSession *client = nbd_get_client_session(bs);
b1b27b64	208	struct nbd_request request = { .type = NBD_CMD_READ };
2302c1ca MAL	209	struct nbd_reply reply;
	210	ssize_t ret;
	211
2302c1ca MAL	212	request.from = sector_num * 512;
	213	request.len = nb_sectors * 512;
	214
	215	nbd_coroutine_start(client, &request);
f53a829b	216	ret = nbd_co_send_request(bs, &request, NULL, 0);
2302c1ca MAL	217	if (ret < 0) {
	218	reply.error = -ret;
	219	} else {
	220	nbd_co_receive_reply(client, &request, &reply, qiov, offset);
	221	}
	222	nbd_coroutine_end(client, &request);
	223	return -reply.error;
	224
	225	}
	226
f53a829b	227	static int nbd_co_writev_1(BlockDriverState *bs, int64_t sector_num,
2302c1ca MAL	228	int nb_sectors, QEMUIOVector *qiov,
	229	int offset)
	230	{
f53a829b	231	NbdClientSession *client = nbd_get_client_session(bs);
b1b27b64	232	struct nbd_request request = { .type = NBD_CMD_WRITE };
2302c1ca MAL	233	struct nbd_reply reply;
	234	ssize_t ret;
	235
f53a829b	236	if (!bdrv_enable_write_cache(bs) &&
2302c1ca MAL	237	(client->nbdflags & NBD_FLAG_SEND_FUA)) {
	238	request.type \|= NBD_CMD_FLAG_FUA;
	239	}
	240
	241	request.from = sector_num * 512;
	242	request.len = nb_sectors * 512;
	243
	244	nbd_coroutine_start(client, &request);
f53a829b	245	ret = nbd_co_send_request(bs, &request, qiov, offset);
2302c1ca MAL	246	if (ret < 0) {
	247	reply.error = -ret;
	248	} else {
	249	nbd_co_receive_reply(client, &request, &reply, NULL, 0);
	250	}
	251	nbd_coroutine_end(client, &request);
	252	return -reply.error;
	253	}
	254
	255	/* qemu-nbd has a limit of slightly less than 1M per request. Try to
	256	* remain aligned to 4K. */
	257	#define NBD_MAX_SECTORS 2040
	258
f53a829b HR	259	int nbd_client_co_readv(BlockDriverState *bs, int64_t sector_num,
f53a829b HR	260	int nb_sectors, QEMUIOVector *qiov)
2302c1ca MAL	261	{
	262	int offset = 0;
	263	int ret;
	264	while (nb_sectors > NBD_MAX_SECTORS) {
f53a829b	265	ret = nbd_co_readv_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset);
2302c1ca MAL	266	if (ret < 0) {
	267	return ret;
	268	}
	269	offset += NBD_MAX_SECTORS * 512;
	270	sector_num += NBD_MAX_SECTORS;
	271	nb_sectors -= NBD_MAX_SECTORS;
	272	}
f53a829b	273	return nbd_co_readv_1(bs, sector_num, nb_sectors, qiov, offset);
2302c1ca MAL	274	}
2302c1ca MAL	275
f53a829b HR	276	int nbd_client_co_writev(BlockDriverState *bs, int64_t sector_num,
f53a829b HR	277	int nb_sectors, QEMUIOVector *qiov)
2302c1ca MAL	278	{
	279	int offset = 0;
	280	int ret;
	281	while (nb_sectors > NBD_MAX_SECTORS) {
f53a829b	282	ret = nbd_co_writev_1(bs, sector_num, NBD_MAX_SECTORS, qiov, offset);
2302c1ca MAL	283	if (ret < 0) {
	284	return ret;
	285	}
	286	offset += NBD_MAX_SECTORS * 512;
	287	sector_num += NBD_MAX_SECTORS;
	288	nb_sectors -= NBD_MAX_SECTORS;
	289	}
f53a829b	290	return nbd_co_writev_1(bs, sector_num, nb_sectors, qiov, offset);
2302c1ca MAL	291	}
2302c1ca MAL	292
f53a829b	293	int nbd_client_co_flush(BlockDriverState *bs)
2302c1ca	294	{
f53a829b	295	NbdClientSession *client = nbd_get_client_session(bs);
b1b27b64	296	struct nbd_request request = { .type = NBD_CMD_FLUSH };
2302c1ca MAL	297	struct nbd_reply reply;
	298	ssize_t ret;
	299
	300	if (!(client->nbdflags & NBD_FLAG_SEND_FLUSH)) {
	301	return 0;
	302	}
	303
2302c1ca MAL	304	if (client->nbdflags & NBD_FLAG_SEND_FUA) {
	305	request.type \|= NBD_CMD_FLAG_FUA;
	306	}
	307
	308	request.from = 0;
	309	request.len = 0;
	310
	311	nbd_coroutine_start(client, &request);
f53a829b	312	ret = nbd_co_send_request(bs, &request, NULL, 0);
2302c1ca MAL	313	if (ret < 0) {
	314	reply.error = -ret;
	315	} else {
	316	nbd_co_receive_reply(client, &request, &reply, NULL, 0);
	317	}
	318	nbd_coroutine_end(client, &request);
	319	return -reply.error;
	320	}
	321
f53a829b HR	322	int nbd_client_co_discard(BlockDriverState *bs, int64_t sector_num,
f53a829b HR	323	int nb_sectors)
2302c1ca	324	{
f53a829b	325	NbdClientSession *client = nbd_get_client_session(bs);
b1b27b64	326	struct nbd_request request = { .type = NBD_CMD_TRIM };
2302c1ca MAL	327	struct nbd_reply reply;
	328	ssize_t ret;
	329
	330	if (!(client->nbdflags & NBD_FLAG_SEND_TRIM)) {
	331	return 0;
	332	}
2302c1ca MAL	333	request.from = sector_num * 512;
	334	request.len = nb_sectors * 512;
	335
	336	nbd_coroutine_start(client, &request);
f53a829b	337	ret = nbd_co_send_request(bs, &request, NULL, 0);
2302c1ca MAL	338	if (ret < 0) {
	339	reply.error = -ret;
	340	} else {
	341	nbd_co_receive_reply(client, &request, &reply, NULL, 0);
	342	}
	343	nbd_coroutine_end(client, &request);
	344	return -reply.error;
	345
	346	}
	347
f53a829b	348	void nbd_client_detach_aio_context(BlockDriverState *bs)
69447cd8	349	{
f53a829b HR	350	aio_set_fd_handler(bdrv_get_aio_context(bs),
f53a829b HR	351	nbd_get_client_session(bs)->sock, NULL, NULL, NULL);
69447cd8 SH	352	}
69447cd8 SH	353
f53a829b HR	354	void nbd_client_attach_aio_context(BlockDriverState *bs,
f53a829b HR	355	AioContext *new_context)
69447cd8	356	{
f53a829b HR	357	aio_set_fd_handler(new_context, nbd_get_client_session(bs)->sock,
f53a829b HR	358	nbd_reply_ready, NULL, bs);
69447cd8 SH	359	}
69447cd8 SH	360
f53a829b	361	void nbd_client_close(BlockDriverState *bs)
2302c1ca	362	{
f53a829b	363	NbdClientSession *client = nbd_get_client_session(bs);
b1b27b64 MAL	364	struct nbd_request request = {
	365	.type = NBD_CMD_DISC,
	366	.from = 0,
	367	.len = 0
	368	};
2302c1ca	369
4a41a2d6 SH	370	if (client->sock == -1) {
	371	return;
	372	}
	373
	374	nbd_send_request(client->sock, &request);
5ad283eb	375
f53a829b	376	nbd_teardown_connection(bs);
2302c1ca MAL	377	}
2302c1ca MAL	378
f53a829b HR	379	int nbd_client_init(BlockDriverState bs, int sock, const char export,
f53a829b HR	380	Error **errp)
2302c1ca	381	{
f53a829b	382	NbdClientSession *client = nbd_get_client_session(bs);
2302c1ca MAL	383	int ret;
	384
	385	/* NBD handshake */
e2bc625f	386	logout("session init %s\n", export);
e53a18e4	387	qemu_set_block(sock);
e2bc625f	388	ret = nbd_receive_negotiate(sock, export,
3f472659	389	&client->nbdflags, &client->size, errp);
2302c1ca MAL	390	if (ret < 0) {
	391	logout("Failed to negotiate with the NBD server\n");
	392	closesocket(sock);
	393	return ret;
	394	}
	395
	396	qemu_co_mutex_init(&client->send_mutex);
	397	qemu_co_mutex_init(&client->free_sema);
2302c1ca MAL	398	client->sock = sock;
	399
	400	/* Now that we're connected, set the socket to be non-blocking and
	401	* kick the reply mechanism. */
	402	qemu_set_nonblock(sock);
f53a829b	403	nbd_client_attach_aio_context(bs, bdrv_get_aio_context(bs));
2302c1ca MAL	404
	405	logout("Established connection with NBD server\n");
	406	return 0;
	407	}