[qemu.git] / block / nfs.c

/*
 * QEMU Block driver for native access to files on NFS shares
 *
 * Copyright (c) 2014 Peter Lieven <[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 "config-host.h"

#include <poll.h>
#include "qemu-common.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "block/block_int.h"
#include "trace.h"
#include "qemu/iov.h"
#include "qemu/uri.h"
#include "sysemu/sysemu.h"
#include <nfsc/libnfs.h>

typedef struct NFSClient {
    struct nfs_context *context;
    struct nfsfh *fh;
    int events;
    bool has_zero_init;
} NFSClient;

typedef struct NFSRPC {
    int ret;
    int complete;
    QEMUIOVector *iov;
    struct stat *st;
    Coroutine *co;
    QEMUBH *bh;
} NFSRPC;

static void nfs_process_read(void *arg);
static void nfs_process_write(void *arg);

static void nfs_set_events(NFSClient *client)
{
    int ev = nfs_which_events(client->context);
    if (ev != client->events) {
        qemu_aio_set_fd_handler(nfs_get_fd(client->context),
                      (ev & POLLIN) ? nfs_process_read : NULL,
                      (ev & POLLOUT) ? nfs_process_write : NULL,
                      client);

    }
    client->events = ev;
}

static void nfs_process_read(void *arg)
{
    NFSClient *client = arg;
    nfs_service(client->context, POLLIN);
    nfs_set_events(client);
}

static void nfs_process_write(void *arg)
{
    NFSClient *client = arg;
    nfs_service(client->context, POLLOUT);
    nfs_set_events(client);
}

static void nfs_co_init_task(NFSClient *client, NFSRPC *task)
{
    *task = (NFSRPC) {
        .co         = qemu_coroutine_self(),
    };
}

static void nfs_co_generic_bh_cb(void *opaque)
{
    NFSRPC *task = opaque;
    qemu_bh_delete(task->bh);
    qemu_coroutine_enter(task->co, NULL);
}

static void
nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
                  void *private_data)
{
    NFSRPC *task = private_data;
    task->complete = 1;
    task->ret = ret;
    if (task->ret > 0 && task->iov) {
        if (task->ret <= task->iov->size) {
            qemu_iovec_from_buf(task->iov, 0, data, task->ret);
        } else {
            task->ret = -EIO;
        }
    }
    if (task->ret == 0 && task->st) {
        memcpy(task->st, data, sizeof(struct stat));
    }
    if (task->co) {
        task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task);
        qemu_bh_schedule(task->bh);
    }
}

static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
                                     int64_t sector_num, int nb_sectors,
                                     QEMUIOVector *iov)
{
    NFSClient *client = bs->opaque;
    NFSRPC task;

    nfs_co_init_task(client, &task);
    task.iov = iov;

    if (nfs_pread_async(client->context, client->fh,
                        sector_num * BDRV_SECTOR_SIZE,
                        nb_sectors * BDRV_SECTOR_SIZE,
                        nfs_co_generic_cb, &task) != 0) {
        return -ENOMEM;
    }

    while (!task.complete) {
        nfs_set_events(client);
        qemu_coroutine_yield();
    }

    if (task.ret < 0) {
        return task.ret;
    }

    /* zero pad short reads */
    if (task.ret < iov->size) {
        qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
    }

    return 0;
}

static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
                                        int64_t sector_num, int nb_sectors,
                                        QEMUIOVector *iov)
{
    NFSClient *client = bs->opaque;
    NFSRPC task;
    char *buf = NULL;

    nfs_co_init_task(client, &task);

    buf = g_malloc(nb_sectors * BDRV_SECTOR_SIZE);
    qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);

    if (nfs_pwrite_async(client->context, client->fh,
                         sector_num * BDRV_SECTOR_SIZE,
                         nb_sectors * BDRV_SECTOR_SIZE,
                         buf, nfs_co_generic_cb, &task) != 0) {
        g_free(buf);
        return -ENOMEM;
    }

    while (!task.complete) {
        nfs_set_events(client);
        qemu_coroutine_yield();
    }

    g_free(buf);

    if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
        return task.ret < 0 ? task.ret : -EIO;
    }

    return 0;
}

static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
{
    NFSClient *client = bs->opaque;
    NFSRPC task;

    nfs_co_init_task(client, &task);

    if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
                        &task) != 0) {
        return -ENOMEM;
    }

    while (!task.complete) {
        nfs_set_events(client);
        qemu_coroutine_yield();
    }

    return task.ret;
}

/* TODO Convert to fine grained options */
static QemuOptsList runtime_opts = {
    .name = "nfs",
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
    .desc = {
        {
            .name = "filename",
            .type = QEMU_OPT_STRING,
            .help = "URL to the NFS file",
        },
        { /* end of list */ }
    },
};

static void nfs_client_close(NFSClient *client)
{
    if (client->context) {
        if (client->fh) {
            nfs_close(client->context, client->fh);
        }
        qemu_aio_set_fd_handler(nfs_get_fd(client->context), NULL, NULL, NULL);
        nfs_destroy_context(client->context);
    }
    memset(client, 0, sizeof(NFSClient));
}

static void nfs_file_close(BlockDriverState *bs)
{
    NFSClient *client = bs->opaque;
    nfs_client_close(client);
}

static int64_t nfs_client_open(NFSClient *client, const char *filename,
                               int flags, Error **errp)
{
    int ret = -EINVAL, i;
    struct stat st;
    URI *uri;
    QueryParams *qp = NULL;
    char *file = NULL, *strp = NULL;

    uri = uri_parse(filename);
    if (!uri) {
        error_setg(errp, "Invalid URL specified");
        goto fail;
    }
    strp = strrchr(uri->path, '/');
    if (strp == NULL) {
        error_setg(errp, "Invalid URL specified");
        goto fail;
    }
    file = g_strdup(strp);
    *strp = 0;

    client->context = nfs_init_context();
    if (client->context == NULL) {
        error_setg(errp, "Failed to init NFS context");
        goto fail;
    }

    qp = query_params_parse(uri->query);
    for (i = 0; i < qp->n; i++) {
        if (!qp->p[i].value) {
            error_setg(errp, "Value for NFS parameter expected: %s",
                       qp->p[i].name);
            goto fail;
        }
        if (!strncmp(qp->p[i].name, "uid", 3)) {
            nfs_set_uid(client->context, atoi(qp->p[i].value));
        } else if (!strncmp(qp->p[i].name, "gid", 3)) {
            nfs_set_gid(client->context, atoi(qp->p[i].value));
        } else if (!strncmp(qp->p[i].name, "tcp-syncnt", 10)) {
            nfs_set_tcp_syncnt(client->context, atoi(qp->p[i].value));
        } else {
            error_setg(errp, "Unknown NFS parameter name: %s",
                       qp->p[i].name);
            goto fail;
        }
    }

    ret = nfs_mount(client->context, uri->server, uri->path);
    if (ret < 0) {
        error_setg(errp, "Failed to mount nfs share: %s",
                   nfs_get_error(client->context));
        goto fail;
    }

    if (flags & O_CREAT) {
        ret = nfs_creat(client->context, file, 0600, &client->fh);
        if (ret < 0) {
            error_setg(errp, "Failed to create file: %s",
                       nfs_get_error(client->context));
            goto fail;
        }
    } else {
        ret = nfs_open(client->context, file, flags, &client->fh);
        if (ret < 0) {
            error_setg(errp, "Failed to open file : %s",
                       nfs_get_error(client->context));
            goto fail;
        }
    }

    ret = nfs_fstat(client->context, client->fh, &st);
    if (ret < 0) {
        error_setg(errp, "Failed to fstat file: %s",
                   nfs_get_error(client->context));
        goto fail;
    }

    ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
    client->has_zero_init = S_ISREG(st.st_mode);
    goto out;
fail:
    nfs_client_close(client);
out:
    if (qp) {
        query_params_free(qp);
    }
    uri_free(uri);
    g_free(file);
    return ret;
}

static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
                         Error **errp) {
    NFSClient *client = bs->opaque;
    int64_t ret;
    QemuOpts *opts;
    Error *local_err = NULL;

    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
    qemu_opts_absorb_qdict(opts, options, &local_err);
    if (error_is_set(&local_err)) {
        error_propagate(errp, local_err);
        return -EINVAL;
    }
    ret = nfs_client_open(client, qemu_opt_get(opts, "filename"),
                          (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
                          errp);
    if (ret < 0) {
        return ret;
    }
    bs->total_sectors = ret;
    return 0;
}

static int nfs_file_create(const char *url, QEMUOptionParameter *options,
                           Error **errp)
{
    int ret = 0;
    int64_t total_size = 0;
    NFSClient *client = g_malloc0(sizeof(NFSClient));

    /* Read out options */
    while (options && options->name) {
        if (!strcmp(options->name, "size")) {
            total_size = options->value.n;
        }
        options++;
    }

    ret = nfs_client_open(client, url, O_CREAT, errp);
    if (ret < 0) {
        goto out;
    }
    ret = nfs_ftruncate(client->context, client->fh, total_size);
    nfs_client_close(client);
out:
    g_free(client);
    return ret;
}

static int nfs_has_zero_init(BlockDriverState *bs)
{
    NFSClient *client = bs->opaque;
    return client->has_zero_init;
}

static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
{
    NFSClient *client = bs->opaque;
    NFSRPC task = {0};
    struct stat st;

    task.st = &st;
    if (nfs_fstat_async(client->context, client->fh, nfs_co_generic_cb,
                        &task) != 0) {
        return -ENOMEM;
    }

    while (!task.complete) {
        nfs_set_events(client);
        qemu_aio_wait();
    }

    return (task.ret < 0 ? task.ret : st.st_blocks * st.st_blksize);
}

static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
{
    NFSClient *client = bs->opaque;
    return nfs_ftruncate(client->context, client->fh, offset);
}

static BlockDriver bdrv_nfs = {
    .format_name     = "nfs",
    .protocol_name   = "nfs",

    .instance_size   = sizeof(NFSClient),
    .bdrv_needs_filename = true,
    .bdrv_has_zero_init = nfs_has_zero_init,
    .bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
    .bdrv_truncate = nfs_file_truncate,

    .bdrv_file_open  = nfs_file_open,
    .bdrv_close      = nfs_file_close,
    .bdrv_create     = nfs_file_create,

    .bdrv_co_readv         = nfs_co_readv,
    .bdrv_co_writev        = nfs_co_writev,
    .bdrv_co_flush_to_disk = nfs_co_flush,
};

static void nfs_block_init(void)
{
    bdrv_register(&bdrv_nfs);
}

block_init(nfs_block_init);
Commit	Line	Data
6542aa9c PL	1	/*
	2	* QEMU Block driver for native access to files on NFS shares
	3	*
	4	* Copyright (c) 2014 Peter Lieven <[email protected]>
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
	25	#include "config-host.h"
	26
	27	#include <poll.h>
	28	#include "qemu-common.h"
	29	#include "qemu/config-file.h"
	30	#include "qemu/error-report.h"
	31	#include "block/block_int.h"
	32	#include "trace.h"
	33	#include "qemu/iov.h"
	34	#include "qemu/uri.h"
	35	#include "sysemu/sysemu.h"
	36	#include <nfsc/libnfs.h>
	37
	38	typedef struct NFSClient {
	39	struct nfs_context *context;
	40	struct nfsfh *fh;
	41	int events;
	42	bool has_zero_init;
	43	} NFSClient;
	44
	45	typedef struct NFSRPC {
	46	int ret;
	47	int complete;
	48	QEMUIOVector *iov;
	49	struct stat *st;
	50	Coroutine *co;
	51	QEMUBH *bh;
	52	} NFSRPC;
	53
	54	static void nfs_process_read(void *arg);
	55	static void nfs_process_write(void *arg);
	56
	57	static void nfs_set_events(NFSClient *client)
	58	{
	59	int ev = nfs_which_events(client->context);
	60	if (ev != client->events) {
	61	qemu_aio_set_fd_handler(nfs_get_fd(client->context),
	62	(ev & POLLIN) ? nfs_process_read : NULL,
	63	(ev & POLLOUT) ? nfs_process_write : NULL,
	64	client);
65
66	}
67	client->events = ev;
68	}
69
70	static void nfs_process_read(void *arg)
71	{
72	NFSClient *client = arg;
73	nfs_service(client->context, POLLIN);
74	nfs_set_events(client);
75	}
76
77	static void nfs_process_write(void *arg)
78	{
79	NFSClient *client = arg;
80	nfs_service(client->context, POLLOUT);
81	nfs_set_events(client);
82	}
83
84	static void nfs_co_init_task(NFSClient client, NFSRPC task)
85	{
86	*task = (NFSRPC) {
87	.co = qemu_coroutine_self(),
88	};
89	}
90
91	static void nfs_co_generic_bh_cb(void *opaque)
92	{
93	NFSRPC *task = opaque;
94	qemu_bh_delete(task->bh);
95	qemu_coroutine_enter(task->co, NULL);
96	}
97
98	static void
99	nfs_co_generic_cb(int ret, struct nfs_context nfs, void data,
100	void *private_data)
101	{
102	NFSRPC *task = private_data;
103	task->complete = 1;
104	task->ret = ret;
105	if (task->ret > 0 && task->iov) {
106	if (task->ret <= task->iov->size) {
107	qemu_iovec_from_buf(task->iov, 0, data, task->ret);
108	} else {
109	task->ret = -EIO;
110	}
111	}
112	if (task->ret == 0 && task->st) {
113	memcpy(task->st, data, sizeof(struct stat));
114	}
115	if (task->co) {
116	task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task);
117	qemu_bh_schedule(task->bh);
118	}
119	}
120
121	static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
122	int64_t sector_num, int nb_sectors,
123	QEMUIOVector *iov)
124	{
125	NFSClient *client = bs->opaque;
126	NFSRPC task;
127
128	nfs_co_init_task(client, &task);
129	task.iov = iov;
130
131	if (nfs_pread_async(client->context, client->fh,
132	sector_num * BDRV_SECTOR_SIZE,
133	nb_sectors * BDRV_SECTOR_SIZE,
134	nfs_co_generic_cb, &task) != 0) {
135	return -ENOMEM;
136	}
137
138	while (!task.complete) {
139	nfs_set_events(client);
140	qemu_coroutine_yield();
141	}
142
143	if (task.ret < 0) {
144	return task.ret;
145	}
146
147	/* zero pad short reads */
148	if (task.ret < iov->size) {
149	qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
150	}
151
152	return 0;
153	}
154
155	static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
156	int64_t sector_num, int nb_sectors,
157	QEMUIOVector *iov)
158	{
159	NFSClient *client = bs->opaque;
160	NFSRPC task;
161	char *buf = NULL;
162
163	nfs_co_init_task(client, &task);
164
165	buf = g_malloc(nb_sectors * BDRV_SECTOR_SIZE);
166	qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
167
168	if (nfs_pwrite_async(client->context, client->fh,
169	sector_num * BDRV_SECTOR_SIZE,
170	nb_sectors * BDRV_SECTOR_SIZE,
171	buf, nfs_co_generic_cb, &task) != 0) {
172	g_free(buf);
173	return -ENOMEM;
174	}
175
176	while (!task.complete) {
177	nfs_set_events(client);
178	qemu_coroutine_yield();
179	}
180
181	g_free(buf);
182
183	if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
184	return task.ret < 0 ? task.ret : -EIO;
185	}
186
187	return 0;
188	}
189
190	static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
191	{
192	NFSClient *client = bs->opaque;
193	NFSRPC task;
194
195	nfs_co_init_task(client, &task);
196
197	if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
198	&task) != 0) {
199	return -ENOMEM;
200	}
201
202	while (!task.complete) {
203	nfs_set_events(client);
204	qemu_coroutine_yield();
205	}
206
207	return task.ret;
208	}
209
210	/* TODO Convert to fine grained options */
211	static QemuOptsList runtime_opts = {
212	.name = "nfs",
213	.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
214	.desc = {
215	{
216	.name = "filename",
217	.type = QEMU_OPT_STRING,
218	.help = "URL to the NFS file",
219	},
220	{ /* end of list */ }
221	},
222	};
223
224	static void nfs_client_close(NFSClient *client)
225	{
226	if (client->context) {
227	if (client->fh) {
228	nfs_close(client->context, client->fh);
229	}
230	qemu_aio_set_fd_handler(nfs_get_fd(client->context), NULL, NULL, NULL);
231	nfs_destroy_context(client->context);
232	}
233	memset(client, 0, sizeof(NFSClient));
234	}
235
236	static void nfs_file_close(BlockDriverState *bs)
237	{
238	NFSClient *client = bs->opaque;
239	nfs_client_close(client);
240	}
241
242	static int64_t nfs_client_open(NFSClient client, const char filename,
243	int flags, Error **errp)
244	{
245	int ret = -EINVAL, i;
246	struct stat st;
247	URI *uri;
248	QueryParams *qp = NULL;
249	char file = NULL, strp = NULL;
250
251	uri = uri_parse(filename);
252	if (!uri) {
253	error_setg(errp, "Invalid URL specified");
254	goto fail;
255	}
256	strp = strrchr(uri->path, '/');
257	if (strp == NULL) {
258	error_setg(errp, "Invalid URL specified");
259	goto fail;
260	}
261	file = g_strdup(strp);
262	*strp = 0;
263
264	client->context = nfs_init_context();
265	if (client->context == NULL) {
266	error_setg(errp, "Failed to init NFS context");
267	goto fail;
268	}
269
270	qp = query_params_parse(uri->query);
271	for (i = 0; i < qp->n; i++) {
272	if (!qp->p[i].value) {
273	error_setg(errp, "Value for NFS parameter expected: %s",
274	qp->p[i].name);
275	goto fail;
276	}
277	if (!strncmp(qp->p[i].name, "uid", 3)) {
278	nfs_set_uid(client->context, atoi(qp->p[i].value));
279	} else if (!strncmp(qp->p[i].name, "gid", 3)) {
280	nfs_set_gid(client->context, atoi(qp->p[i].value));
281	} else if (!strncmp(qp->p[i].name, "tcp-syncnt", 10)) {
282	nfs_set_tcp_syncnt(client->context, atoi(qp->p[i].value));
283	} else {
284	error_setg(errp, "Unknown NFS parameter name: %s",
285	qp->p[i].name);
286	goto fail;
287	}
288	}
289
290	ret = nfs_mount(client->context, uri->server, uri->path);
291	if (ret < 0) {
292	error_setg(errp, "Failed to mount nfs share: %s",
293	nfs_get_error(client->context));
294	goto fail;
295	}
296
297	if (flags & O_CREAT) {
298	ret = nfs_creat(client->context, file, 0600, &client->fh);
299	if (ret < 0) {
300	error_setg(errp, "Failed to create file: %s",
301	nfs_get_error(client->context));
302	goto fail;
303	}
304	} else {
305	ret = nfs_open(client->context, file, flags, &client->fh);
306	if (ret < 0) {
307	error_setg(errp, "Failed to open file : %s",
308	nfs_get_error(client->context));
309	goto fail;
310	}
311	}
312
313	ret = nfs_fstat(client->context, client->fh, &st);
314	if (ret < 0) {
315	error_setg(errp, "Failed to fstat file: %s",
316	nfs_get_error(client->context));
317	goto fail;
318	}
319
320	ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
321	client->has_zero_init = S_ISREG(st.st_mode);
322	goto out;
323	fail:
324	nfs_client_close(client);
325	out:
326	if (qp) {
327	query_params_free(qp);
328	}
329	uri_free(uri);
330	g_free(file);
331	return ret;
332	}
333
334	static int nfs_file_open(BlockDriverState bs, QDict options, int flags,
335	Error **errp) {
336	NFSClient *client = bs->opaque;
337	int64_t ret;
338	QemuOpts *opts;
339	Error *local_err = NULL;
340
341	opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
342	qemu_opts_absorb_qdict(opts, options, &local_err);
343	if (error_is_set(&local_err)) {
344	error_propagate(errp, local_err);
345	return -EINVAL;
346	}
347	ret = nfs_client_open(client, qemu_opt_get(opts, "filename"),
348	(flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
349	errp);
350	if (ret < 0) {
351	return ret;
352	}
353	bs->total_sectors = ret;
354	return 0;
355	}
356
357	static int nfs_file_create(const char url, QEMUOptionParameter options,
358	Error **errp)
359	{
360	int ret = 0;
361	int64_t total_size = 0;
362	NFSClient *client = g_malloc0(sizeof(NFSClient));
363
364	/* Read out options */
365	while (options && options->name) {
366	if (!strcmp(options->name, "size")) {
367	total_size = options->value.n;
368	}
369	options++;
370	}
371
372	ret = nfs_client_open(client, url, O_CREAT, errp);
373	if (ret < 0) {
374	goto out;
375	}
376	ret = nfs_ftruncate(client->context, client->fh, total_size);
377	nfs_client_close(client);
378	out:
379	g_free(client);
380	return ret;
381	}
382
383	static int nfs_has_zero_init(BlockDriverState *bs)
384	{
385	NFSClient *client = bs->opaque;
386	return client->has_zero_init;
387	}
388
389	static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
390	{
391	NFSClient *client = bs->opaque;
392	NFSRPC task = {0};
393	struct stat st;
394
395	task.st = &st;
396	if (nfs_fstat_async(client->context, client->fh, nfs_co_generic_cb,
397	&task) != 0) {
398	return -ENOMEM;
399	}
400
401	while (!task.complete) {
402	nfs_set_events(client);
403	qemu_aio_wait();
404	}
405
406	return (task.ret < 0 ? task.ret : st.st_blocks * st.st_blksize);
407	}
408
409	static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
410	{
411	NFSClient *client = bs->opaque;
412	return nfs_ftruncate(client->context, client->fh, offset);
413	}
414
415	static BlockDriver bdrv_nfs = {
416	.format_name = "nfs",
417	.protocol_name = "nfs",
418
419	.instance_size = sizeof(NFSClient),
420	.bdrv_needs_filename = true,
421	.bdrv_has_zero_init = nfs_has_zero_init,
422	.bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
423	.bdrv_truncate = nfs_file_truncate,
424
425	.bdrv_file_open = nfs_file_open,
426	.bdrv_close = nfs_file_close,
427	.bdrv_create = nfs_file_create,
428
429	.bdrv_co_readv = nfs_co_readv,
430	.bdrv_co_writev = nfs_co_writev,
431	.bdrv_co_flush_to_disk = nfs_co_flush,
432	};
433
434	static void nfs_block_init(void)
435	{
436	bdrv_register(&bdrv_nfs);
437	}
438
439	block_init(nfs_block_init);