aio: add AioPollFn and io_poll() interface
[qemu.git] / block / nfs.c
1 /*
2 * QEMU Block driver for native access to files on NFS shares
3 *
4 * Copyright (c) 2014-2016 Peter Lieven <pl@kamp.de>
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 "qemu/osdep.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 "qapi/error.h"
32 #include "block/block_int.h"
33 #include "trace.h"
34 #include "qemu/iov.h"
35 #include "qemu/uri.h"
36 #include "qemu/cutils.h"
37 #include "sysemu/sysemu.h"
38 #include "qapi/qmp/qdict.h"
39 #include "qapi/qmp/qint.h"
40 #include "qapi/qmp/qstring.h"
41 #include "qapi-visit.h"
42 #include "qapi/qobject-input-visitor.h"
43 #include "qapi/qobject-output-visitor.h"
44 #include <nfsc/libnfs.h>
45
46
47 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
48 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
49 #define QEMU_NFS_MAX_DEBUG_LEVEL 2
50
51 typedef struct NFSClient {
52 struct nfs_context *context;
53 struct nfsfh *fh;
54 int events;
55 bool has_zero_init;
56 AioContext *aio_context;
57 blkcnt_t st_blocks;
58 bool cache_used;
59 NFSServer *server;
60 char *path;
61 int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug;
62 } NFSClient;
63
64 typedef struct NFSRPC {
65 BlockDriverState *bs;
66 int ret;
67 int complete;
68 QEMUIOVector *iov;
69 struct stat *st;
70 Coroutine *co;
71 NFSClient *client;
72 } NFSRPC;
73
74 static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
75 {
76 URI *uri = NULL;
77 QueryParams *qp = NULL;
78 int ret = -EINVAL, i;
79
80 uri = uri_parse(filename);
81 if (!uri) {
82 error_setg(errp, "Invalid URI specified");
83 goto out;
84 }
85 if (strcmp(uri->scheme, "nfs") != 0) {
86 error_setg(errp, "URI scheme must be 'nfs'");
87 goto out;
88 }
89
90 if (!uri->server) {
91 error_setg(errp, "missing hostname in URI");
92 goto out;
93 }
94
95 if (!uri->path) {
96 error_setg(errp, "missing file path in URI");
97 goto out;
98 }
99
100 qp = query_params_parse(uri->query);
101 if (!qp) {
102 error_setg(errp, "could not parse query parameters");
103 goto out;
104 }
105
106 qdict_put(options, "server.host", qstring_from_str(uri->server));
107 qdict_put(options, "server.type", qstring_from_str("inet"));
108 qdict_put(options, "path", qstring_from_str(uri->path));
109
110 for (i = 0; i < qp->n; i++) {
111 if (!qp->p[i].value) {
112 error_setg(errp, "Value for NFS parameter expected: %s",
113 qp->p[i].name);
114 goto out;
115 }
116 if (parse_uint_full(qp->p[i].value, NULL, 0)) {
117 error_setg(errp, "Illegal value for NFS parameter: %s",
118 qp->p[i].name);
119 goto out;
120 }
121 if (!strcmp(qp->p[i].name, "uid")) {
122 qdict_put(options, "user",
123 qstring_from_str(qp->p[i].value));
124 } else if (!strcmp(qp->p[i].name, "gid")) {
125 qdict_put(options, "group",
126 qstring_from_str(qp->p[i].value));
127 } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
128 qdict_put(options, "tcp-syn-count",
129 qstring_from_str(qp->p[i].value));
130 } else if (!strcmp(qp->p[i].name, "readahead")) {
131 qdict_put(options, "readahead-size",
132 qstring_from_str(qp->p[i].value));
133 } else if (!strcmp(qp->p[i].name, "pagecache")) {
134 qdict_put(options, "page-cache-size",
135 qstring_from_str(qp->p[i].value));
136 } else if (!strcmp(qp->p[i].name, "debug")) {
137 qdict_put(options, "debug",
138 qstring_from_str(qp->p[i].value));
139 } else {
140 error_setg(errp, "Unknown NFS parameter name: %s",
141 qp->p[i].name);
142 goto out;
143 }
144 }
145 ret = 0;
146 out:
147 if (qp) {
148 query_params_free(qp);
149 }
150 if (uri) {
151 uri_free(uri);
152 }
153 return ret;
154 }
155
156 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
157 {
158 const QDictEntry *qe;
159
160 for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
161 if (!strcmp(qe->key, "host") ||
162 !strcmp(qe->key, "path") ||
163 !strcmp(qe->key, "user") ||
164 !strcmp(qe->key, "group") ||
165 !strcmp(qe->key, "tcp-syn-count") ||
166 !strcmp(qe->key, "readahead-size") ||
167 !strcmp(qe->key, "page-cache-size") ||
168 !strcmp(qe->key, "debug") ||
169 strstart(qe->key, "server.", NULL))
170 {
171 error_setg(errp, "Option %s cannot be used with a filename",
172 qe->key);
173 return true;
174 }
175 }
176
177 return false;
178 }
179
180 static void nfs_parse_filename(const char *filename, QDict *options,
181 Error **errp)
182 {
183 if (nfs_has_filename_options_conflict(options, errp)) {
184 return;
185 }
186
187 nfs_parse_uri(filename, options, errp);
188 }
189
190 static void nfs_process_read(void *arg);
191 static void nfs_process_write(void *arg);
192
193 static void nfs_set_events(NFSClient *client)
194 {
195 int ev = nfs_which_events(client->context);
196 if (ev != client->events) {
197 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
198 false,
199 (ev & POLLIN) ? nfs_process_read : NULL,
200 (ev & POLLOUT) ? nfs_process_write : NULL,
201 NULL, client);
202
203 }
204 client->events = ev;
205 }
206
207 static void nfs_process_read(void *arg)
208 {
209 NFSClient *client = arg;
210 nfs_service(client->context, POLLIN);
211 nfs_set_events(client);
212 }
213
214 static void nfs_process_write(void *arg)
215 {
216 NFSClient *client = arg;
217 nfs_service(client->context, POLLOUT);
218 nfs_set_events(client);
219 }
220
221 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
222 {
223 *task = (NFSRPC) {
224 .co = qemu_coroutine_self(),
225 .bs = bs,
226 .client = bs->opaque,
227 };
228 }
229
230 static void nfs_co_generic_bh_cb(void *opaque)
231 {
232 NFSRPC *task = opaque;
233 task->complete = 1;
234 qemu_coroutine_enter(task->co);
235 }
236
237 static void
238 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
239 void *private_data)
240 {
241 NFSRPC *task = private_data;
242 task->ret = ret;
243 assert(!task->st);
244 if (task->ret > 0 && task->iov) {
245 if (task->ret <= task->iov->size) {
246 qemu_iovec_from_buf(task->iov, 0, data, task->ret);
247 } else {
248 task->ret = -EIO;
249 }
250 }
251 if (task->ret < 0) {
252 error_report("NFS Error: %s", nfs_get_error(nfs));
253 }
254 aio_bh_schedule_oneshot(task->client->aio_context,
255 nfs_co_generic_bh_cb, task);
256 }
257
258 static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
259 int64_t sector_num, int nb_sectors,
260 QEMUIOVector *iov)
261 {
262 NFSClient *client = bs->opaque;
263 NFSRPC task;
264
265 nfs_co_init_task(bs, &task);
266 task.iov = iov;
267
268 if (nfs_pread_async(client->context, client->fh,
269 sector_num * BDRV_SECTOR_SIZE,
270 nb_sectors * BDRV_SECTOR_SIZE,
271 nfs_co_generic_cb, &task) != 0) {
272 return -ENOMEM;
273 }
274
275 nfs_set_events(client);
276 while (!task.complete) {
277 qemu_coroutine_yield();
278 }
279
280 if (task.ret < 0) {
281 return task.ret;
282 }
283
284 /* zero pad short reads */
285 if (task.ret < iov->size) {
286 qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
287 }
288
289 return 0;
290 }
291
292 static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
293 int64_t sector_num, int nb_sectors,
294 QEMUIOVector *iov)
295 {
296 NFSClient *client = bs->opaque;
297 NFSRPC task;
298 char *buf = NULL;
299
300 nfs_co_init_task(bs, &task);
301
302 buf = g_try_malloc(nb_sectors * BDRV_SECTOR_SIZE);
303 if (nb_sectors && buf == NULL) {
304 return -ENOMEM;
305 }
306
307 qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
308
309 if (nfs_pwrite_async(client->context, client->fh,
310 sector_num * BDRV_SECTOR_SIZE,
311 nb_sectors * BDRV_SECTOR_SIZE,
312 buf, nfs_co_generic_cb, &task) != 0) {
313 g_free(buf);
314 return -ENOMEM;
315 }
316
317 nfs_set_events(client);
318 while (!task.complete) {
319 qemu_coroutine_yield();
320 }
321
322 g_free(buf);
323
324 if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
325 return task.ret < 0 ? task.ret : -EIO;
326 }
327
328 return 0;
329 }
330
331 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
332 {
333 NFSClient *client = bs->opaque;
334 NFSRPC task;
335
336 nfs_co_init_task(bs, &task);
337
338 if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
339 &task) != 0) {
340 return -ENOMEM;
341 }
342
343 nfs_set_events(client);
344 while (!task.complete) {
345 qemu_coroutine_yield();
346 }
347
348 return task.ret;
349 }
350
351 static QemuOptsList runtime_opts = {
352 .name = "nfs",
353 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
354 .desc = {
355 {
356 .name = "path",
357 .type = QEMU_OPT_STRING,
358 .help = "Path of the image on the host",
359 },
360 {
361 .name = "uid",
362 .type = QEMU_OPT_NUMBER,
363 .help = "UID value to use when talking to the server",
364 },
365 {
366 .name = "gid",
367 .type = QEMU_OPT_NUMBER,
368 .help = "GID value to use when talking to the server",
369 },
370 {
371 .name = "tcp-syncnt",
372 .type = QEMU_OPT_NUMBER,
373 .help = "Number of SYNs to send during the session establish",
374 },
375 {
376 .name = "readahead",
377 .type = QEMU_OPT_NUMBER,
378 .help = "Set the readahead size in bytes",
379 },
380 {
381 .name = "pagecache",
382 .type = QEMU_OPT_NUMBER,
383 .help = "Set the pagecache size in bytes",
384 },
385 {
386 .name = "debug",
387 .type = QEMU_OPT_NUMBER,
388 .help = "Set the NFS debug level (max 2)",
389 },
390 { /* end of list */ }
391 },
392 };
393
394 static void nfs_detach_aio_context(BlockDriverState *bs)
395 {
396 NFSClient *client = bs->opaque;
397
398 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
399 false, NULL, NULL, NULL, NULL);
400 client->events = 0;
401 }
402
403 static void nfs_attach_aio_context(BlockDriverState *bs,
404 AioContext *new_context)
405 {
406 NFSClient *client = bs->opaque;
407
408 client->aio_context = new_context;
409 nfs_set_events(client);
410 }
411
412 static void nfs_client_close(NFSClient *client)
413 {
414 if (client->context) {
415 if (client->fh) {
416 nfs_close(client->context, client->fh);
417 }
418 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
419 false, NULL, NULL, NULL, NULL);
420 nfs_destroy_context(client->context);
421 }
422 memset(client, 0, sizeof(NFSClient));
423 }
424
425 static void nfs_file_close(BlockDriverState *bs)
426 {
427 NFSClient *client = bs->opaque;
428 nfs_client_close(client);
429 }
430
431 static NFSServer *nfs_config(QDict *options, Error **errp)
432 {
433 NFSServer *server = NULL;
434 QDict *addr = NULL;
435 QObject *crumpled_addr = NULL;
436 Visitor *iv = NULL;
437 Error *local_error = NULL;
438
439 qdict_extract_subqdict(options, &addr, "server.");
440 if (!qdict_size(addr)) {
441 error_setg(errp, "NFS server address missing");
442 goto out;
443 }
444
445 crumpled_addr = qdict_crumple(addr, errp);
446 if (!crumpled_addr) {
447 goto out;
448 }
449
450 iv = qobject_input_visitor_new(crumpled_addr, true);
451 visit_type_NFSServer(iv, NULL, &server, &local_error);
452 if (local_error) {
453 error_propagate(errp, local_error);
454 goto out;
455 }
456
457 out:
458 QDECREF(addr);
459 qobject_decref(crumpled_addr);
460 visit_free(iv);
461 return server;
462 }
463
464
465 static int64_t nfs_client_open(NFSClient *client, QDict *options,
466 int flags, Error **errp, int open_flags)
467 {
468 int ret = -EINVAL;
469 QemuOpts *opts = NULL;
470 Error *local_err = NULL;
471 struct stat st;
472 char *file = NULL, *strp = NULL;
473
474 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
475 qemu_opts_absorb_qdict(opts, options, &local_err);
476 if (local_err) {
477 error_propagate(errp, local_err);
478 ret = -EINVAL;
479 goto fail;
480 }
481
482 client->path = g_strdup(qemu_opt_get(opts, "path"));
483 if (!client->path) {
484 ret = -EINVAL;
485 error_setg(errp, "No path was specified");
486 goto fail;
487 }
488
489 strp = strrchr(client->path, '/');
490 if (strp == NULL) {
491 error_setg(errp, "Invalid URL specified");
492 goto fail;
493 }
494 file = g_strdup(strp);
495 *strp = 0;
496
497 /* Pop the config into our state object, Exit if invalid */
498 client->server = nfs_config(options, errp);
499 if (!client->server) {
500 ret = -EINVAL;
501 goto fail;
502 }
503
504 client->context = nfs_init_context();
505 if (client->context == NULL) {
506 error_setg(errp, "Failed to init NFS context");
507 goto fail;
508 }
509
510 if (qemu_opt_get(opts, "uid")) {
511 client->uid = qemu_opt_get_number(opts, "uid", 0);
512 nfs_set_uid(client->context, client->uid);
513 }
514
515 if (qemu_opt_get(opts, "gid")) {
516 client->gid = qemu_opt_get_number(opts, "gid", 0);
517 nfs_set_gid(client->context, client->gid);
518 }
519
520 if (qemu_opt_get(opts, "tcp-syncnt")) {
521 client->tcp_syncnt = qemu_opt_get_number(opts, "tcp-syncnt", 0);
522 nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
523 }
524
525 #ifdef LIBNFS_FEATURE_READAHEAD
526 if (qemu_opt_get(opts, "readahead")) {
527 if (open_flags & BDRV_O_NOCACHE) {
528 error_setg(errp, "Cannot enable NFS readahead "
529 "if cache.direct = on");
530 goto fail;
531 }
532 client->readahead = qemu_opt_get_number(opts, "readahead", 0);
533 if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
534 error_report("NFS Warning: Truncating NFS readahead "
535 "size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
536 client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
537 }
538 nfs_set_readahead(client->context, client->readahead);
539 #ifdef LIBNFS_FEATURE_PAGECACHE
540 nfs_set_pagecache_ttl(client->context, 0);
541 #endif
542 client->cache_used = true;
543 }
544 #endif
545
546 #ifdef LIBNFS_FEATURE_PAGECACHE
547 if (qemu_opt_get(opts, "pagecache")) {
548 if (open_flags & BDRV_O_NOCACHE) {
549 error_setg(errp, "Cannot enable NFS pagecache "
550 "if cache.direct = on");
551 goto fail;
552 }
553 client->pagecache = qemu_opt_get_number(opts, "pagecache", 0);
554 if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
555 error_report("NFS Warning: Truncating NFS pagecache "
556 "size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
557 client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
558 }
559 nfs_set_pagecache(client->context, client->pagecache);
560 nfs_set_pagecache_ttl(client->context, 0);
561 client->cache_used = true;
562 }
563 #endif
564
565 #ifdef LIBNFS_FEATURE_DEBUG
566 if (qemu_opt_get(opts, "debug")) {
567 client->debug = qemu_opt_get_number(opts, "debug", 0);
568 /* limit the maximum debug level to avoid potential flooding
569 * of our log files. */
570 if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
571 error_report("NFS Warning: Limiting NFS debug level "
572 "to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
573 client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
574 }
575 nfs_set_debug(client->context, client->debug);
576 }
577 #endif
578
579 ret = nfs_mount(client->context, client->server->host, client->path);
580 if (ret < 0) {
581 error_setg(errp, "Failed to mount nfs share: %s",
582 nfs_get_error(client->context));
583 goto fail;
584 }
585
586 if (flags & O_CREAT) {
587 ret = nfs_creat(client->context, file, 0600, &client->fh);
588 if (ret < 0) {
589 error_setg(errp, "Failed to create file: %s",
590 nfs_get_error(client->context));
591 goto fail;
592 }
593 } else {
594 ret = nfs_open(client->context, file, flags, &client->fh);
595 if (ret < 0) {
596 error_setg(errp, "Failed to open file : %s",
597 nfs_get_error(client->context));
598 goto fail;
599 }
600 }
601
602 ret = nfs_fstat(client->context, client->fh, &st);
603 if (ret < 0) {
604 error_setg(errp, "Failed to fstat file: %s",
605 nfs_get_error(client->context));
606 goto fail;
607 }
608
609 ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
610 client->st_blocks = st.st_blocks;
611 client->has_zero_init = S_ISREG(st.st_mode);
612 *strp = '/';
613 goto out;
614
615 fail:
616 nfs_client_close(client);
617 out:
618 qemu_opts_del(opts);
619 g_free(file);
620 return ret;
621 }
622
623 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
624 Error **errp) {
625 NFSClient *client = bs->opaque;
626 int64_t ret;
627
628 client->aio_context = bdrv_get_aio_context(bs);
629
630 ret = nfs_client_open(client, options,
631 (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
632 errp, bs->open_flags);
633 if (ret < 0) {
634 return ret;
635 }
636 bs->total_sectors = ret;
637 ret = 0;
638 return ret;
639 }
640
641 static QemuOptsList nfs_create_opts = {
642 .name = "nfs-create-opts",
643 .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
644 .desc = {
645 {
646 .name = BLOCK_OPT_SIZE,
647 .type = QEMU_OPT_SIZE,
648 .help = "Virtual disk size"
649 },
650 { /* end of list */ }
651 }
652 };
653
654 static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
655 {
656 int ret = 0;
657 int64_t total_size = 0;
658 NFSClient *client = g_new0(NFSClient, 1);
659 QDict *options = NULL;
660
661 client->aio_context = qemu_get_aio_context();
662
663 /* Read out options */
664 total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
665 BDRV_SECTOR_SIZE);
666
667 options = qdict_new();
668 ret = nfs_parse_uri(url, options, errp);
669 if (ret < 0) {
670 goto out;
671 }
672
673 ret = nfs_client_open(client, options, O_CREAT, errp, 0);
674 if (ret < 0) {
675 goto out;
676 }
677 ret = nfs_ftruncate(client->context, client->fh, total_size);
678 nfs_client_close(client);
679 out:
680 QDECREF(options);
681 g_free(client);
682 return ret;
683 }
684
685 static int nfs_has_zero_init(BlockDriverState *bs)
686 {
687 NFSClient *client = bs->opaque;
688 return client->has_zero_init;
689 }
690
691 static void
692 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
693 void *private_data)
694 {
695 NFSRPC *task = private_data;
696 task->ret = ret;
697 if (task->ret == 0) {
698 memcpy(task->st, data, sizeof(struct stat));
699 }
700 if (task->ret < 0) {
701 error_report("NFS Error: %s", nfs_get_error(nfs));
702 }
703 task->complete = 1;
704 bdrv_wakeup(task->bs);
705 }
706
707 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
708 {
709 NFSClient *client = bs->opaque;
710 NFSRPC task = {0};
711 struct stat st;
712
713 if (bdrv_is_read_only(bs) &&
714 !(bs->open_flags & BDRV_O_NOCACHE)) {
715 return client->st_blocks * 512;
716 }
717
718 task.bs = bs;
719 task.st = &st;
720 if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
721 &task) != 0) {
722 return -ENOMEM;
723 }
724
725 nfs_set_events(client);
726 BDRV_POLL_WHILE(bs, !task.complete);
727
728 return (task.ret < 0 ? task.ret : st.st_blocks * 512);
729 }
730
731 static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
732 {
733 NFSClient *client = bs->opaque;
734 return nfs_ftruncate(client->context, client->fh, offset);
735 }
736
737 /* Note that this will not re-establish a connection with the NFS server
738 * - it is effectively a NOP. */
739 static int nfs_reopen_prepare(BDRVReopenState *state,
740 BlockReopenQueue *queue, Error **errp)
741 {
742 NFSClient *client = state->bs->opaque;
743 struct stat st;
744 int ret = 0;
745
746 if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
747 error_setg(errp, "Cannot open a read-only mount as read-write");
748 return -EACCES;
749 }
750
751 if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
752 error_setg(errp, "Cannot disable cache if libnfs readahead or"
753 " pagecache is enabled");
754 return -EINVAL;
755 }
756
757 /* Update cache for read-only reopens */
758 if (!(state->flags & BDRV_O_RDWR)) {
759 ret = nfs_fstat(client->context, client->fh, &st);
760 if (ret < 0) {
761 error_setg(errp, "Failed to fstat file: %s",
762 nfs_get_error(client->context));
763 return ret;
764 }
765 client->st_blocks = st.st_blocks;
766 }
767
768 return 0;
769 }
770
771 static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
772 {
773 NFSClient *client = bs->opaque;
774 QDict *opts = qdict_new();
775 QObject *server_qdict;
776 Visitor *ov;
777
778 qdict_put(opts, "driver", qstring_from_str("nfs"));
779
780 if (client->uid && !client->gid) {
781 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
782 "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
783 client->uid);
784 } else if (!client->uid && client->gid) {
785 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
786 "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
787 client->gid);
788 } else if (client->uid && client->gid) {
789 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
790 "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
791 client->server->host, client->path, client->uid, client->gid);
792 } else {
793 snprintf(bs->exact_filename, sizeof(bs->exact_filename),
794 "nfs://%s%s", client->server->host, client->path);
795 }
796
797 ov = qobject_output_visitor_new(&server_qdict);
798 visit_type_NFSServer(ov, NULL, &client->server, &error_abort);
799 visit_complete(ov, &server_qdict);
800 assert(qobject_type(server_qdict) == QTYPE_QDICT);
801
802 qdict_put_obj(opts, "server", server_qdict);
803 qdict_put(opts, "path", qstring_from_str(client->path));
804
805 if (client->uid) {
806 qdict_put(opts, "uid", qint_from_int(client->uid));
807 }
808 if (client->gid) {
809 qdict_put(opts, "gid", qint_from_int(client->gid));
810 }
811 if (client->tcp_syncnt) {
812 qdict_put(opts, "tcp-syncnt",
813 qint_from_int(client->tcp_syncnt));
814 }
815 if (client->readahead) {
816 qdict_put(opts, "readahead",
817 qint_from_int(client->readahead));
818 }
819 if (client->pagecache) {
820 qdict_put(opts, "pagecache",
821 qint_from_int(client->pagecache));
822 }
823 if (client->debug) {
824 qdict_put(opts, "debug", qint_from_int(client->debug));
825 }
826
827 visit_free(ov);
828 qdict_flatten(opts);
829 bs->full_open_options = opts;
830 }
831
832 #ifdef LIBNFS_FEATURE_PAGECACHE
833 static void nfs_invalidate_cache(BlockDriverState *bs,
834 Error **errp)
835 {
836 NFSClient *client = bs->opaque;
837 nfs_pagecache_invalidate(client->context, client->fh);
838 }
839 #endif
840
841 static BlockDriver bdrv_nfs = {
842 .format_name = "nfs",
843 .protocol_name = "nfs",
844
845 .instance_size = sizeof(NFSClient),
846 .bdrv_parse_filename = nfs_parse_filename,
847 .create_opts = &nfs_create_opts,
848
849 .bdrv_has_zero_init = nfs_has_zero_init,
850 .bdrv_get_allocated_file_size = nfs_get_allocated_file_size,
851 .bdrv_truncate = nfs_file_truncate,
852
853 .bdrv_file_open = nfs_file_open,
854 .bdrv_close = nfs_file_close,
855 .bdrv_create = nfs_file_create,
856 .bdrv_reopen_prepare = nfs_reopen_prepare,
857
858 .bdrv_co_readv = nfs_co_readv,
859 .bdrv_co_writev = nfs_co_writev,
860 .bdrv_co_flush_to_disk = nfs_co_flush,
861
862 .bdrv_detach_aio_context = nfs_detach_aio_context,
863 .bdrv_attach_aio_context = nfs_attach_aio_context,
864 .bdrv_refresh_filename = nfs_refresh_filename,
865
866 #ifdef LIBNFS_FEATURE_PAGECACHE
867 .bdrv_invalidate_cache = nfs_invalidate_cache,
868 #endif
869 };
870
871 static void nfs_block_init(void)
872 {
873 bdrv_register(&bdrv_nfs);
874 }
875
876 block_init(nfs_block_init);