2 * QEMU Block driver for native access to files on NFS shares
4 * Copyright (c) 2014-2017 Peter Lieven <pl@kamp.de>
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
25 #include "qemu/osdep.h"
30 #include "qemu/config-file.h"
31 #include "qemu/error-report.h"
32 #include "qapi/error.h"
33 #include "block/block_int.h"
34 #include "block/qdict.h"
37 #include "qemu/main-loop.h"
38 #include "qemu/module.h"
39 #include "qemu/option.h"
41 #include "qemu/cutils.h"
42 #include "sysemu/replay.h"
43 #include "qapi/qapi-visit-block-core.h"
44 #include "qapi/qmp/qdict.h"
45 #include "qapi/qmp/qstring.h"
46 #include "qapi/qobject-input-visitor.h"
47 #include "qapi/qobject-output-visitor.h"
48 #include <nfsc/libnfs.h>
51 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
52 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
53 #define QEMU_NFS_MAX_DEBUG_LEVEL 2
55 typedef struct NFSClient {
56 struct nfs_context *context;
60 AioContext *aio_context;
66 int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug;
69 typedef struct NFSRPC {
79 static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
82 QueryParams *qp = NULL;
85 uri = uri_parse(filename);
87 error_setg(errp, "Invalid URI specified");
90 if (g_strcmp0(uri->scheme, "nfs") != 0) {
91 error_setg(errp, "URI scheme must be 'nfs'");
96 error_setg(errp, "missing hostname in URI");
101 error_setg(errp, "missing file path in URI");
105 qp = query_params_parse(uri->query);
107 error_setg(errp, "could not parse query parameters");
111 qdict_put_str(options, "server.host", uri->server);
112 qdict_put_str(options, "server.type", "inet");
113 qdict_put_str(options, "path", uri->path);
115 for (i = 0; i < qp->n; i++) {
116 unsigned long long val;
117 if (!qp->p[i].value) {
118 error_setg(errp, "Value for NFS parameter expected: %s",
122 if (parse_uint_full(qp->p[i].value, &val, 0)) {
123 error_setg(errp, "Illegal value for NFS parameter: %s",
127 if (!strcmp(qp->p[i].name, "uid")) {
128 qdict_put_str(options, "user", qp->p[i].value);
129 } else if (!strcmp(qp->p[i].name, "gid")) {
130 qdict_put_str(options, "group", qp->p[i].value);
131 } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
132 qdict_put_str(options, "tcp-syn-count", qp->p[i].value);
133 } else if (!strcmp(qp->p[i].name, "readahead")) {
134 qdict_put_str(options, "readahead-size", qp->p[i].value);
135 } else if (!strcmp(qp->p[i].name, "pagecache")) {
136 qdict_put_str(options, "page-cache-size", qp->p[i].value);
137 } else if (!strcmp(qp->p[i].name, "debug")) {
138 qdict_put_str(options, "debug", qp->p[i].value);
140 error_setg(errp, "Unknown NFS parameter name: %s",
148 query_params_free(qp);
154 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
156 const QDictEntry *qe;
158 for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
159 if (!strcmp(qe->key, "host") ||
160 !strcmp(qe->key, "path") ||
161 !strcmp(qe->key, "user") ||
162 !strcmp(qe->key, "group") ||
163 !strcmp(qe->key, "tcp-syn-count") ||
164 !strcmp(qe->key, "readahead-size") ||
165 !strcmp(qe->key, "page-cache-size") ||
166 !strcmp(qe->key, "debug") ||
167 strstart(qe->key, "server.", NULL))
169 error_setg(errp, "Option %s cannot be used with a filename",
178 static void nfs_parse_filename(const char *filename, QDict *options,
181 if (nfs_has_filename_options_conflict(options, errp)) {
185 nfs_parse_uri(filename, options, errp);
188 static void nfs_process_read(void *arg);
189 static void nfs_process_write(void *arg);
191 /* Called with QemuMutex held. */
192 static void nfs_set_events(NFSClient *client)
194 int ev = nfs_which_events(client->context);
195 if (ev != client->events) {
196 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
198 (ev & POLLIN) ? nfs_process_read : NULL,
199 (ev & POLLOUT) ? nfs_process_write : NULL,
206 static void nfs_process_read(void *arg)
208 NFSClient *client = arg;
210 qemu_mutex_lock(&client->mutex);
211 nfs_service(client->context, POLLIN);
212 nfs_set_events(client);
213 qemu_mutex_unlock(&client->mutex);
216 static void nfs_process_write(void *arg)
218 NFSClient *client = arg;
220 qemu_mutex_lock(&client->mutex);
221 nfs_service(client->context, POLLOUT);
222 nfs_set_events(client);
223 qemu_mutex_unlock(&client->mutex);
226 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
229 .co = qemu_coroutine_self(),
231 .client = bs->opaque,
235 static void nfs_co_generic_bh_cb(void *opaque)
237 NFSRPC *task = opaque;
240 aio_co_wake(task->co);
243 /* Called (via nfs_service) with QemuMutex held. */
245 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
248 NFSRPC *task = private_data;
251 if (task->ret > 0 && task->iov) {
252 if (task->ret <= task->iov->size) {
253 qemu_iovec_from_buf(task->iov, 0, data, task->ret);
259 error_report("NFS Error: %s", nfs_get_error(nfs));
261 replay_bh_schedule_oneshot_event(task->client->aio_context,
262 nfs_co_generic_bh_cb, task);
265 static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, int64_t offset,
266 int64_t bytes, QEMUIOVector *iov,
267 BdrvRequestFlags flags)
269 NFSClient *client = bs->opaque;
272 nfs_co_init_task(bs, &task);
275 WITH_QEMU_LOCK_GUARD(&client->mutex) {
276 if (nfs_pread_async(client->context, client->fh,
277 offset, bytes, nfs_co_generic_cb, &task) != 0) {
281 nfs_set_events(client);
283 while (!task.complete) {
284 qemu_coroutine_yield();
291 /* zero pad short reads */
292 if (task.ret < iov->size) {
293 qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
299 static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, int64_t offset,
300 int64_t bytes, QEMUIOVector *iov,
301 BdrvRequestFlags flags)
303 NFSClient *client = bs->opaque;
306 bool my_buffer = false;
308 nfs_co_init_task(bs, &task);
310 if (iov->niov != 1) {
311 buf = g_try_malloc(bytes);
312 if (bytes && buf == NULL) {
315 qemu_iovec_to_buf(iov, 0, buf, bytes);
318 buf = iov->iov[0].iov_base;
321 WITH_QEMU_LOCK_GUARD(&client->mutex) {
322 if (nfs_pwrite_async(client->context, client->fh,
324 nfs_co_generic_cb, &task) != 0) {
331 nfs_set_events(client);
333 while (!task.complete) {
334 qemu_coroutine_yield();
341 if (task.ret != bytes) {
342 return task.ret < 0 ? task.ret : -EIO;
348 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
350 NFSClient *client = bs->opaque;
353 nfs_co_init_task(bs, &task);
355 WITH_QEMU_LOCK_GUARD(&client->mutex) {
356 if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
361 nfs_set_events(client);
363 while (!task.complete) {
364 qemu_coroutine_yield();
370 static void nfs_detach_aio_context(BlockDriverState *bs)
372 NFSClient *client = bs->opaque;
374 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
375 false, NULL, NULL, NULL, NULL, NULL);
379 static void nfs_attach_aio_context(BlockDriverState *bs,
380 AioContext *new_context)
382 NFSClient *client = bs->opaque;
384 client->aio_context = new_context;
385 nfs_set_events(client);
388 static void nfs_client_close(NFSClient *client)
390 if (client->context) {
391 qemu_mutex_lock(&client->mutex);
392 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
393 false, NULL, NULL, NULL, NULL, NULL);
394 qemu_mutex_unlock(&client->mutex);
396 nfs_close(client->context, client->fh);
399 #ifdef LIBNFS_FEATURE_UMOUNT
400 nfs_umount(client->context);
402 nfs_destroy_context(client->context);
403 client->context = NULL;
405 g_free(client->path);
406 qemu_mutex_destroy(&client->mutex);
407 qapi_free_NFSServer(client->server);
408 client->server = NULL;
411 static void nfs_file_close(BlockDriverState *bs)
413 NFSClient *client = bs->opaque;
414 nfs_client_close(client);
417 static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts,
418 int flags, int open_flags, Error **errp)
420 int64_t ret = -EINVAL;
422 char *file = NULL, *strp = NULL;
424 qemu_mutex_init(&client->mutex);
426 client->path = g_strdup(opts->path);
428 strp = strrchr(client->path, '/');
430 error_setg(errp, "Invalid URL specified");
433 file = g_strdup(strp);
436 /* Steal the NFSServer object from opts; set the original pointer to NULL
437 * to avoid use after free and double free. */
438 client->server = opts->server;
441 client->context = nfs_init_context();
442 if (client->context == NULL) {
443 error_setg(errp, "Failed to init NFS context");
447 if (opts->has_user) {
448 client->uid = opts->user;
449 nfs_set_uid(client->context, client->uid);
452 if (opts->has_group) {
453 client->gid = opts->group;
454 nfs_set_gid(client->context, client->gid);
457 if (opts->has_tcp_syn_count) {
458 client->tcp_syncnt = opts->tcp_syn_count;
459 nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
462 #ifdef LIBNFS_FEATURE_READAHEAD
463 if (opts->has_readahead_size) {
464 if (open_flags & BDRV_O_NOCACHE) {
465 error_setg(errp, "Cannot enable NFS readahead "
466 "if cache.direct = on");
469 client->readahead = opts->readahead_size;
470 if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
471 warn_report("Truncating NFS readahead size to %d",
472 QEMU_NFS_MAX_READAHEAD_SIZE);
473 client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
475 nfs_set_readahead(client->context, client->readahead);
476 #ifdef LIBNFS_FEATURE_PAGECACHE
477 nfs_set_pagecache_ttl(client->context, 0);
479 client->cache_used = true;
483 #ifdef LIBNFS_FEATURE_PAGECACHE
484 if (opts->has_page_cache_size) {
485 if (open_flags & BDRV_O_NOCACHE) {
486 error_setg(errp, "Cannot enable NFS pagecache "
487 "if cache.direct = on");
490 client->pagecache = opts->page_cache_size;
491 if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
492 warn_report("Truncating NFS pagecache size to %d pages",
493 QEMU_NFS_MAX_PAGECACHE_SIZE);
494 client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
496 nfs_set_pagecache(client->context, client->pagecache);
497 nfs_set_pagecache_ttl(client->context, 0);
498 client->cache_used = true;
502 #ifdef LIBNFS_FEATURE_DEBUG
503 if (opts->has_debug) {
504 client->debug = opts->debug;
505 /* limit the maximum debug level to avoid potential flooding
506 * of our log files. */
507 if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
508 warn_report("Limiting NFS debug level to %d",
509 QEMU_NFS_MAX_DEBUG_LEVEL);
510 client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
512 nfs_set_debug(client->context, client->debug);
516 ret = nfs_mount(client->context, client->server->host, client->path);
518 error_setg(errp, "Failed to mount nfs share: %s",
519 nfs_get_error(client->context));
523 if (flags & O_CREAT) {
524 ret = nfs_creat(client->context, file, 0600, &client->fh);
526 error_setg(errp, "Failed to create file: %s",
527 nfs_get_error(client->context));
531 ret = nfs_open(client->context, file, flags, &client->fh);
533 error_setg(errp, "Failed to open file : %s",
534 nfs_get_error(client->context));
539 ret = nfs_fstat(client->context, client->fh, &st);
541 error_setg(errp, "Failed to fstat file: %s",
542 nfs_get_error(client->context));
546 ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
548 client->st_blocks = st.st_blocks;
550 client->has_zero_init = S_ISREG(st.st_mode);
555 nfs_client_close(client);
561 static BlockdevOptionsNfs *nfs_options_qdict_to_qapi(QDict *options,
564 BlockdevOptionsNfs *opts = NULL;
568 v = qobject_input_visitor_new_flat_confused(options, errp);
573 visit_type_BlockdevOptionsNfs(v, NULL, &opts, errp);
579 /* Remove the processed options from the QDict (the visitor processes
580 * _all_ options in the QDict) */
581 while ((e = qdict_first(options))) {
582 qdict_del(options, e->key);
588 static int64_t nfs_client_open_qdict(NFSClient *client, QDict *options,
589 int flags, int open_flags, Error **errp)
591 BlockdevOptionsNfs *opts;
594 opts = nfs_options_qdict_to_qapi(options, errp);
600 ret = nfs_client_open(client, opts, flags, open_flags, errp);
602 qapi_free_BlockdevOptionsNfs(opts);
606 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
608 NFSClient *client = bs->opaque;
611 client->aio_context = bdrv_get_aio_context(bs);
613 ret = nfs_client_open_qdict(client, options,
614 (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
615 bs->open_flags, errp);
620 bs->total_sectors = ret;
621 if (client->has_zero_init) {
622 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
627 static QemuOptsList nfs_create_opts = {
628 .name = "nfs-create-opts",
629 .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
632 .name = BLOCK_OPT_SIZE,
633 .type = QEMU_OPT_SIZE,
634 .help = "Virtual disk size"
636 { /* end of list */ }
640 static int nfs_file_co_create(BlockdevCreateOptions *options, Error **errp)
642 BlockdevCreateOptionsNfs *opts = &options->u.nfs;
643 NFSClient *client = g_new0(NFSClient, 1);
646 assert(options->driver == BLOCKDEV_DRIVER_NFS);
648 client->aio_context = qemu_get_aio_context();
650 ret = nfs_client_open(client, opts->location, O_CREAT, 0, errp);
654 ret = nfs_ftruncate(client->context, client->fh, opts->size);
655 nfs_client_close(client);
662 static int coroutine_fn nfs_file_co_create_opts(BlockDriver *drv,
667 BlockdevCreateOptions *create_options;
668 BlockdevCreateOptionsNfs *nfs_opts;
672 create_options = g_new0(BlockdevCreateOptions, 1);
673 create_options->driver = BLOCKDEV_DRIVER_NFS;
674 nfs_opts = &create_options->u.nfs;
676 /* Read out options */
677 nfs_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
680 options = qdict_new();
681 ret = nfs_parse_uri(url, options, errp);
686 nfs_opts->location = nfs_options_qdict_to_qapi(options, errp);
687 if (nfs_opts->location == NULL) {
692 ret = nfs_file_co_create(create_options, errp);
699 qobject_unref(options);
700 qapi_free_BlockdevCreateOptions(create_options);
704 static int nfs_has_zero_init(BlockDriverState *bs)
706 NFSClient *client = bs->opaque;
707 return client->has_zero_init;
711 /* Called (via nfs_service) with QemuMutex held. */
713 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
716 NFSRPC *task = private_data;
718 if (task->ret == 0) {
719 memcpy(task->st, data, sizeof(struct stat));
722 error_report("NFS Error: %s", nfs_get_error(nfs));
725 /* Set task->complete before reading bs->wakeup. */
726 qatomic_mb_set(&task->complete, 1);
727 bdrv_wakeup(task->bs);
730 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
732 NFSClient *client = bs->opaque;
736 if (bdrv_is_read_only(bs) &&
737 !(bs->open_flags & BDRV_O_NOCACHE)) {
738 return client->st_blocks * 512;
743 if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
748 nfs_set_events(client);
749 BDRV_POLL_WHILE(bs, !task.complete);
751 return (task.ret < 0 ? task.ret : st.st_blocks * 512);
755 static int coroutine_fn
756 nfs_file_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
757 PreallocMode prealloc, BdrvRequestFlags flags,
760 NFSClient *client = bs->opaque;
763 if (prealloc != PREALLOC_MODE_OFF) {
764 error_setg(errp, "Unsupported preallocation mode '%s'",
765 PreallocMode_str(prealloc));
769 ret = nfs_ftruncate(client->context, client->fh, offset);
771 error_setg_errno(errp, -ret, "Failed to truncate file");
778 /* Note that this will not re-establish a connection with the NFS server
779 * - it is effectively a NOP. */
780 static int nfs_reopen_prepare(BDRVReopenState *state,
781 BlockReopenQueue *queue, Error **errp)
783 NFSClient *client = state->bs->opaque;
787 if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
788 error_setg(errp, "Cannot open a read-only mount as read-write");
792 if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
793 error_setg(errp, "Cannot disable cache if libnfs readahead or"
794 " pagecache is enabled");
798 /* Update cache for read-only reopens */
799 if (!(state->flags & BDRV_O_RDWR)) {
800 ret = nfs_fstat(client->context, client->fh, &st);
802 error_setg(errp, "Failed to fstat file: %s",
803 nfs_get_error(client->context));
807 client->st_blocks = st.st_blocks;
814 static void nfs_refresh_filename(BlockDriverState *bs)
816 NFSClient *client = bs->opaque;
818 if (client->uid && !client->gid) {
819 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
820 "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
822 } else if (!client->uid && client->gid) {
823 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
824 "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
826 } else if (client->uid && client->gid) {
827 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
828 "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
829 client->server->host, client->path, client->uid, client->gid);
831 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
832 "nfs://%s%s", client->server->host, client->path);
836 static char *nfs_dirname(BlockDriverState *bs, Error **errp)
838 NFSClient *client = bs->opaque;
840 if (client->uid || client->gid) {
841 bdrv_refresh_filename(bs);
842 error_setg(errp, "Cannot generate a base directory for NFS node '%s'",
847 return g_strdup_printf("nfs://%s%s/", client->server->host, client->path);
850 #ifdef LIBNFS_FEATURE_PAGECACHE
851 static void coroutine_fn nfs_co_invalidate_cache(BlockDriverState *bs,
854 NFSClient *client = bs->opaque;
855 nfs_pagecache_invalidate(client->context, client->fh);
859 static const char *nfs_strong_runtime_opts[] = {
868 static BlockDriver bdrv_nfs = {
869 .format_name = "nfs",
870 .protocol_name = "nfs",
872 .instance_size = sizeof(NFSClient),
873 .bdrv_parse_filename = nfs_parse_filename,
874 .create_opts = &nfs_create_opts,
876 .bdrv_has_zero_init = nfs_has_zero_init,
877 /* libnfs does not provide the allocated filesize of a file on win32. */
879 .bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
881 .bdrv_co_truncate = nfs_file_co_truncate,
883 .bdrv_file_open = nfs_file_open,
884 .bdrv_close = nfs_file_close,
885 .bdrv_co_create = nfs_file_co_create,
886 .bdrv_co_create_opts = nfs_file_co_create_opts,
887 .bdrv_reopen_prepare = nfs_reopen_prepare,
889 .bdrv_co_preadv = nfs_co_preadv,
890 .bdrv_co_pwritev = nfs_co_pwritev,
891 .bdrv_co_flush_to_disk = nfs_co_flush,
893 .bdrv_detach_aio_context = nfs_detach_aio_context,
894 .bdrv_attach_aio_context = nfs_attach_aio_context,
895 .bdrv_refresh_filename = nfs_refresh_filename,
896 .bdrv_dirname = nfs_dirname,
898 .strong_runtime_opts = nfs_strong_runtime_opts,
900 #ifdef LIBNFS_FEATURE_PAGECACHE
901 .bdrv_co_invalidate_cache = nfs_co_invalidate_cache,
905 static void nfs_block_init(void)
907 bdrv_register(&bdrv_nfs);
910 block_init(nfs_block_init);