source: mainline/uspace/srv/vfs/vfs_ops.c@ 8a36bc1e

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 8a36bc1e was 6f2c1ff, checked in by Jakub Jermar <jakub@…>, 9 years ago

vfs: Sanitize the case when vfs_node_get() returns NULL in vfs_open()
  • Property mode set to 100644
File size: 36.2 KB
Line 
1/*
2 * Copyright (c) 2008 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup fs
30 * @{
31 */
32
33/**
34 * @file vfs_ops.c
35 * @brief Operations that VFS offers to its clients.
36 */
37
38#include "vfs.h"
39#include <macros.h>
40#include <stdint.h>
41#include <async.h>
42#include <errno.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <str.h>
46#include <stdbool.h>
47#include <fibril_synch.h>
48#include <adt/list.h>
49#include <unistd.h>
50#include <ctype.h>
51#include <fcntl.h>
52#include <assert.h>
53#include <vfs/canonify.h>
54#include <vfs/vfs_mtab.h>
55
56FIBRIL_MUTEX_INITIALIZE(mtab_list_lock);
57LIST_INITIALIZE(mtab_list);
58static size_t mtab_size = 0;
59
60/* Forward declarations of static functions. */
61static int vfs_truncate_internal(fs_handle_t, service_id_t, fs_index_t,
62 aoff64_t);
63
64/**
65 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
66 * concurrent VFS operation which modifies the file system namespace.
67 */
68FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);
69
70vfs_pair_t rootfs = {
71 .fs_handle = 0,
72 .service_id = 0
73};
74
75static int vfs_mount_internal(ipc_callid_t rid, service_id_t service_id,
76 fs_handle_t fs_handle, char *mp, char *opts)
77{
78 vfs_lookup_res_t mp_res;
79 vfs_lookup_res_t mr_res;
80 vfs_node_t *mp_node = NULL;
81 vfs_node_t *mr_node;
82 fs_index_t rindex;
83 aoff64_t rsize;
84 unsigned rlnkcnt;
85 async_exch_t *exch;
86 sysarg_t rc;
87 aid_t msg;
88 ipc_call_t answer;
89
90 /* Resolve the path to the mountpoint. */
91 fibril_rwlock_write_lock(&namespace_rwlock);
92 if (rootfs.fs_handle) {
93 /* We already have the root FS. */
94 if (str_cmp(mp, "/") == 0) {
95 /* Trying to mount root FS over root FS */
96 fibril_rwlock_write_unlock(&namespace_rwlock);
97 async_answer_0(rid, EBUSY);
98 return EBUSY;
99 }
100
101 rc = vfs_lookup_internal(mp, L_MP, &mp_res, NULL);
102 if (rc != EOK) {
103 /* The lookup failed for some reason. */
104 fibril_rwlock_write_unlock(&namespace_rwlock);
105 async_answer_0(rid, rc);
106 return rc;
107 }
108
109 mp_node = vfs_node_get(&mp_res);
110 if (!mp_node) {
111 fibril_rwlock_write_unlock(&namespace_rwlock);
112 async_answer_0(rid, ENOMEM);
113 return ENOMEM;
114 }
115
116 /*
117 * Now we hold a reference to mp_node.
118 * It will be dropped upon the corresponding VFS_IN_UNMOUNT.
119 * This prevents the mount point from being deleted.
120 */
121 } else {
122 /* We still don't have the root file system mounted. */
123 if (str_cmp(mp, "/") == 0) {
124 /*
125 * For this simple, but important case,
126 * we are almost done.
127 */
128
129 /* Tell the mountee that it is being mounted. */
130 exch = vfs_exchange_grab(fs_handle);
131 msg = async_send_1(exch, VFS_OUT_MOUNTED,
132 (sysarg_t) service_id, &answer);
133 /* Send the mount options */
134 rc = async_data_write_start(exch, (void *)opts,
135 str_size(opts));
136 vfs_exchange_release(exch);
137
138 if (rc != EOK) {
139 async_forget(msg);
140 fibril_rwlock_write_unlock(&namespace_rwlock);
141 async_answer_0(rid, rc);
142 return rc;
143 }
144 async_wait_for(msg, &rc);
145
146 if (rc != EOK) {
147 fibril_rwlock_write_unlock(&namespace_rwlock);
148 async_answer_0(rid, rc);
149 return rc;
150 }
151
152 rindex = (fs_index_t) IPC_GET_ARG1(answer);
153 rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
154 IPC_GET_ARG3(answer));
155 rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
156
157 mr_res.triplet.fs_handle = fs_handle;
158 mr_res.triplet.service_id = service_id;
159 mr_res.triplet.index = rindex;
160 mr_res.size = rsize;
161 mr_res.lnkcnt = rlnkcnt;
162 mr_res.type = VFS_NODE_DIRECTORY;
163
164 rootfs.fs_handle = fs_handle;
165 rootfs.service_id = service_id;
166
167 /* Add reference to the mounted root. */
168 mr_node = vfs_node_get(&mr_res);
169 assert(mr_node);
170
171 fibril_rwlock_write_unlock(&namespace_rwlock);
172 async_answer_0(rid, rc);
173 return rc;
174 } else {
175 /*
176 * We can't resolve this without the root filesystem
177 * being mounted first.
178 */
179 fibril_rwlock_write_unlock(&namespace_rwlock);
180 async_answer_0(rid, ENOENT);
181 return ENOENT;
182 }
183 }
184
185 /*
186 * At this point, we have all necessary pieces: file system handle
187 * and service ID, and we know the mount point VFS node.
188 */
189
190 async_exch_t *mountee_exch = vfs_exchange_grab(fs_handle);
191 assert(mountee_exch);
192
193 exch = vfs_exchange_grab(mp_res.triplet.fs_handle);
194 msg = async_send_4(exch, VFS_OUT_MOUNT,
195 (sysarg_t) mp_res.triplet.service_id,
196 (sysarg_t) mp_res.triplet.index,
197 (sysarg_t) fs_handle,
198 (sysarg_t) service_id, &answer);
199
200 /* Send connection */
201 rc = async_exchange_clone(exch, mountee_exch);
202 vfs_exchange_release(mountee_exch);
203
204 if (rc != EOK) {
205 vfs_exchange_release(exch);
206 async_forget(msg);
207
208 /* Mount failed, drop reference to mp_node. */
209 if (mp_node)
210 vfs_node_put(mp_node);
211
212 async_answer_0(rid, rc);
213 fibril_rwlock_write_unlock(&namespace_rwlock);
214 return rc;
215 }
216
217 /* send the mount options */
218 rc = async_data_write_start(exch, (void *) opts, str_size(opts));
219 if (rc != EOK) {
220 vfs_exchange_release(exch);
221 async_forget(msg);
222
223 /* Mount failed, drop reference to mp_node. */
224 if (mp_node)
225 vfs_node_put(mp_node);
226
227 fibril_rwlock_write_unlock(&namespace_rwlock);
228 async_answer_0(rid, rc);
229 return rc;
230 }
231
232 /*
233 * Wait for the answer before releasing the exchange to avoid deadlock
234 * in case the answer depends on further calls to the same file system.
235 * Think of a case when mounting a FS on a file_bd backed by a file on
236 * the same FS.
237 */
238 async_wait_for(msg, &rc);
239 vfs_exchange_release(exch);
240
241 if (rc == EOK) {
242 rindex = (fs_index_t) IPC_GET_ARG1(answer);
243 rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
244 IPC_GET_ARG3(answer));
245 rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
246
247 mr_res.triplet.fs_handle = fs_handle;
248 mr_res.triplet.service_id = service_id;
249 mr_res.triplet.index = rindex;
250 mr_res.size = rsize;
251 mr_res.lnkcnt = rlnkcnt;
252 mr_res.type = VFS_NODE_DIRECTORY;
253
254 /* Add reference to the mounted root. */
255 mr_node = vfs_node_get(&mr_res);
256 assert(mr_node);
257 } else {
258 /* Mount failed, drop reference to mp_node. */
259 if (mp_node)
260 vfs_node_put(mp_node);
261 }
262
263 async_answer_0(rid, rc);
264 fibril_rwlock_write_unlock(&namespace_rwlock);
265 return rc;
266}
267
268void vfs_mount_srv(ipc_callid_t rid, ipc_call_t *request)
269{
270 service_id_t service_id;
271
272 /*
273 * We expect the library to do the device-name to device-handle
274 * translation for us, thus the device handle will arrive as ARG1
275 * in the request.
276 */
277 service_id = (service_id_t) IPC_GET_ARG1(*request);
278
279 /*
280 * Mount flags are passed as ARG2.
281 */
282 unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
283
284 /*
285 * Instance number is passed as ARG3.
286 */
287 unsigned int instance = IPC_GET_ARG3(*request);
288
289 /* We want the client to send us the mount point. */
290 char *mp;
291 int rc = async_data_write_accept((void **) &mp, true, 0, MAX_PATH_LEN,
292 0, NULL);
293 if (rc != EOK) {
294 async_answer_0(rid, rc);
295 return;
296 }
297
298 /* Now we expect to receive the mount options. */
299 char *opts;
300 rc = async_data_write_accept((void **) &opts, true, 0, MAX_MNTOPTS_LEN,
301 0, NULL);
302 if (rc != EOK) {
303 free(mp);
304 async_answer_0(rid, rc);
305 return;
306 }
307
308 /*
309 * Now, we expect the client to send us data with the name of the file
310 * system.
311 */
312 char *fs_name;
313 rc = async_data_write_accept((void **) &fs_name, true, 0,
314 FS_NAME_MAXLEN, 0, NULL);
315 if (rc != EOK) {
316 free(mp);
317 free(opts);
318 async_answer_0(rid, rc);
319 return;
320 }
321
322 /*
323 * Wait for VFS_IN_PING so that we can return an error if we don't know
324 * fs_name.
325 */
326 ipc_call_t data;
327 ipc_callid_t callid = async_get_call(&data);
328 if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
329 async_answer_0(callid, ENOTSUP);
330 async_answer_0(rid, ENOTSUP);
331 free(mp);
332 free(opts);
333 free(fs_name);
334 return;
335 }
336
337 /*
338 * Check if we know a file system with the same name as is in fs_name.
339 * This will also give us its file system handle.
340 */
341 fibril_mutex_lock(&fs_list_lock);
342 fs_handle_t fs_handle;
343recheck:
344 fs_handle = fs_name_to_handle(instance, fs_name, false);
345 if (!fs_handle) {
346 if (flags & IPC_FLAG_BLOCKING) {
347 fibril_condvar_wait(&fs_list_cv, &fs_list_lock);
348 goto recheck;
349 }
350
351 fibril_mutex_unlock(&fs_list_lock);
352 async_answer_0(callid, ENOENT);
353 async_answer_0(rid, ENOENT);
354 free(mp);
355 free(fs_name);
356 free(opts);
357 return;
358 }
359 fibril_mutex_unlock(&fs_list_lock);
360
361 /* Add the filesystem info to the list of mounted filesystems */
362 mtab_ent_t *mtab_ent = malloc(sizeof(mtab_ent_t));
363 if (!mtab_ent) {
364 async_answer_0(callid, ENOMEM);
365 async_answer_0(rid, ENOMEM);
366 free(mp);
367 free(fs_name);
368 free(opts);
369 return;
370 }
371
372 /* Do the mount */
373 rc = vfs_mount_internal(rid, service_id, fs_handle, mp, opts);
374 if (rc != EOK) {
375 async_answer_0(callid, ENOTSUP);
376 async_answer_0(rid, ENOTSUP);
377 free(mtab_ent);
378 free(mp);
379 free(opts);
380 free(fs_name);
381 return;
382 }
383
384 /* Add the filesystem info to the list of mounted filesystems */
385
386 str_cpy(mtab_ent->mp, MAX_PATH_LEN, mp);
387 str_cpy(mtab_ent->fs_name, FS_NAME_MAXLEN, fs_name);
388 str_cpy(mtab_ent->opts, MAX_MNTOPTS_LEN, opts);
389 mtab_ent->instance = instance;
390 mtab_ent->service_id = service_id;
391
392 link_initialize(&mtab_ent->link);
393
394 fibril_mutex_lock(&mtab_list_lock);
395 list_append(&mtab_ent->link, &mtab_list);
396 mtab_size++;
397 fibril_mutex_unlock(&mtab_list_lock);
398
399 free(mp);
400 free(fs_name);
401 free(opts);
402
403 /* Acknowledge that we know fs_name. */
404 async_answer_0(callid, EOK);
405}
406
407void vfs_unmount_srv(ipc_callid_t rid, ipc_call_t *request)
408{
409 int rc;
410 char *mp;
411 vfs_lookup_res_t mp_res;
412 vfs_lookup_res_t mr_res;
413 vfs_node_t *mr_node;
414 async_exch_t *exch;
415
416 /*
417 * Receive the mount point path.
418 */
419 rc = async_data_write_accept((void **) &mp, true, 0, MAX_PATH_LEN,
420 0, NULL);
421 if (rc != EOK)
422 async_answer_0(rid, rc);
423
424 /*
425 * Taking the namespace lock will do two things for us. First, it will
426 * prevent races with other lookup operations. Second, it will stop new
427 * references to already existing VFS nodes and creation of new VFS
428 * nodes. This is because new references are added as a result of some
429 * lookup operation or at least of some operation which is protected by
430 * the namespace lock.
431 */
432 fibril_rwlock_write_lock(&namespace_rwlock);
433
434 /*
435 * Lookup the mounted root and instantiate it.
436 */
437 rc = vfs_lookup_internal(mp, L_ROOT, &mr_res, NULL);
438 if (rc != EOK) {
439 fibril_rwlock_write_unlock(&namespace_rwlock);
440 free(mp);
441 async_answer_0(rid, rc);
442 return;
443 }
444 mr_node = vfs_node_get(&mr_res);
445 if (!mr_node) {
446 fibril_rwlock_write_unlock(&namespace_rwlock);
447 free(mp);
448 async_answer_0(rid, ENOMEM);
449 return;
450 }
451
452 /*
453 * Count the total number of references for the mounted file system. We
454 * are expecting at least two. One which we got above and one which we
455 * got when the file system was mounted. If we find more, it means that
456 * the file system cannot be gracefully unmounted at the moment because
457 * someone is working with it.
458 */
459 if (vfs_nodes_refcount_sum_get(mr_node->fs_handle,
460 mr_node->service_id) != 2) {
461 fibril_rwlock_write_unlock(&namespace_rwlock);
462 vfs_node_put(mr_node);
463 free(mp);
464 async_answer_0(rid, EBUSY);
465 return;
466 }
467
468 if (str_cmp(mp, "/") == 0) {
469
470 /*
471 * Unmounting the root file system.
472 *
473 * In this case, there is no mount point node and we send
474 * VFS_OUT_UNMOUNTED directly to the mounted file system.
475 */
476
477 exch = vfs_exchange_grab(mr_node->fs_handle);
478 rc = async_req_1_0(exch, VFS_OUT_UNMOUNTED,
479 mr_node->service_id);
480 vfs_exchange_release(exch);
481
482 if (rc != EOK) {
483 fibril_rwlock_write_unlock(&namespace_rwlock);
484 free(mp);
485 vfs_node_put(mr_node);
486 async_answer_0(rid, rc);
487 return;
488 }
489
490 rootfs.fs_handle = 0;
491 rootfs.service_id = 0;
492 } else {
493
494 /*
495 * Unmounting a non-root file system.
496 *
497 * We have a regular mount point node representing the parent
498 * file system, so we delegate the operation to it.
499 */
500
501 rc = vfs_lookup_internal(mp, L_MP, &mp_res, NULL);
502 if (rc != EOK) {
503 fibril_rwlock_write_unlock(&namespace_rwlock);
504 free(mp);
505 vfs_node_put(mr_node);
506 async_answer_0(rid, rc);
507 return;
508 }
509
510 vfs_node_t *mp_node = vfs_node_get(&mp_res);
511 if (!mp_node) {
512 fibril_rwlock_write_unlock(&namespace_rwlock);
513 free(mp);
514 vfs_node_put(mr_node);
515 async_answer_0(rid, ENOMEM);
516 return;
517 }
518
519 exch = vfs_exchange_grab(mp_node->fs_handle);
520 rc = async_req_2_0(exch, VFS_OUT_UNMOUNT,
521 mp_node->service_id, mp_node->index);
522 vfs_exchange_release(exch);
523
524 if (rc != EOK) {
525 fibril_rwlock_write_unlock(&namespace_rwlock);
526 free(mp);
527 vfs_node_put(mp_node);
528 vfs_node_put(mr_node);
529 async_answer_0(rid, rc);
530 return;
531 }
532
533 /* Drop the reference we got above. */
534 vfs_node_put(mp_node);
535 /* Drop the reference from when the file system was mounted. */
536 vfs_node_put(mp_node);
537 }
538
539 /*
540 * All went well, the mounted file system was successfully unmounted.
541 * The only thing left is to forget the unmounted root VFS node.
542 */
543 vfs_node_forget(mr_node);
544 fibril_rwlock_write_unlock(&namespace_rwlock);
545
546 fibril_mutex_lock(&mtab_list_lock);
547
548 int found = 0;
549
550 list_foreach(mtab_list, link, mtab_ent_t, mtab_ent) {
551 if (str_cmp(mtab_ent->mp, mp) == 0) {
552 list_remove(&mtab_ent->link);
553 mtab_size--;
554 free(mtab_ent);
555 found = 1;
556 break;
557 }
558 }
559 assert(found);
560 fibril_mutex_unlock(&mtab_list_lock);
561
562 free(mp);
563
564 async_answer_0(rid, EOK);
565}
566
567void vfs_open(ipc_callid_t rid, ipc_call_t *request)
568{
569 /*
570 * The POSIX interface is open(path, oflag, mode).
571 * We can receive oflags and mode along with the VFS_IN_OPEN call;
572 * the path will need to arrive in another call.
573 *
574 * We also receive one private, non-POSIX set of flags called lflag
575 * used to pass information to vfs_lookup_internal().
576 */
577 int lflag = IPC_GET_ARG1(*request);
578 int oflag = IPC_GET_ARG2(*request);
579 int mode = IPC_GET_ARG3(*request);
580
581 /* Ignore mode for now. */
582 (void) mode;
583
584 /*
585 * Make sure that we are called with exactly one of L_FILE and
586 * L_DIRECTORY. Make sure that the user does not pass L_OPEN,
587 * L_ROOT or L_MP.
588 */
589 if (((lflag & (L_FILE | L_DIRECTORY)) == 0) ||
590 ((lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) ||
591 (lflag & (L_OPEN | L_ROOT | L_MP))) {
592 async_answer_0(rid, EINVAL);
593 return;
594 }
595
596 if (oflag & O_CREAT)
597 lflag |= L_CREATE;
598 if (oflag & O_EXCL)
599 lflag |= L_EXCLUSIVE;
600
601 char *path;
602 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
603 if (rc != EOK) {
604 async_answer_0(rid, rc);
605 return;
606 }
607
608 /*
609 * Avoid the race condition in which the file can be deleted before we
610 * find/create-and-lock the VFS node corresponding to the looked-up
611 * triplet.
612 */
613 if (lflag & L_CREATE)
614 fibril_rwlock_write_lock(&namespace_rwlock);
615 else
616 fibril_rwlock_read_lock(&namespace_rwlock);
617
618 /* The path is now populated and we can call vfs_lookup_internal(). */
619 vfs_lookup_res_t lr;
620 rc = vfs_lookup_internal(path, lflag | L_OPEN, &lr, NULL);
621 if (rc != EOK) {
622 if (lflag & L_CREATE)
623 fibril_rwlock_write_unlock(&namespace_rwlock);
624 else
625 fibril_rwlock_read_unlock(&namespace_rwlock);
626 async_answer_0(rid, rc);
627 free(path);
628 return;
629 }
630
631 /* Path is no longer needed. */
632 free(path);
633
634 vfs_node_t *node = vfs_node_get(&lr);
635 if (lflag & L_CREATE)
636 fibril_rwlock_write_unlock(&namespace_rwlock);
637 else
638 fibril_rwlock_read_unlock(&namespace_rwlock);
639
640 if (!node) {
641 async_answer_0(rid, ENOMEM);
642 return;
643 }
644
645 /* Truncate the file if requested and if necessary. */
646 if (oflag & O_TRUNC) {
647 fibril_rwlock_write_lock(&node->contents_rwlock);
648 if (node->size) {
649 rc = vfs_truncate_internal(node->fs_handle,
650 node->service_id, node->index, 0);
651 if (rc) {
652 fibril_rwlock_write_unlock(&node->contents_rwlock);
653 vfs_node_put(node);
654 async_answer_0(rid, rc);
655 return;
656 }
657 node->size = 0;
658 }
659 fibril_rwlock_write_unlock(&node->contents_rwlock);
660 }
661
662 /*
663 * Get ourselves a file descriptor and the corresponding vfs_file_t
664 * structure.
665 */
666 int fd = vfs_fd_alloc((oflag & O_DESC) != 0);
667 if (fd < 0) {
668 vfs_node_put(node);
669 async_answer_0(rid, fd);
670 return;
671 }
672 vfs_file_t *file = vfs_file_get(fd);
673 assert(file);
674 file->node = node;
675 if (oflag & O_APPEND)
676 file->append = true;
677
678 /*
679 * The following increase in reference count is for the fact that the
680 * file is being opened and that a file structure is pointing to it.
681 * It is necessary so that the file will not disappear when
682 * vfs_node_put() is called. The reference will be dropped by the
683 * respective VFS_IN_CLOSE.
684 */
685 vfs_node_addref(node);
686 vfs_node_put(node);
687 vfs_file_put(file);
688
689 /* Success! Return the new file descriptor to the client. */
690 async_answer_1(rid, EOK, fd);
691}
692
693void vfs_sync(ipc_callid_t rid, ipc_call_t *request)
694{
695 int fd = IPC_GET_ARG1(*request);
696
697 /* Lookup the file structure corresponding to the file descriptor. */
698 vfs_file_t *file = vfs_file_get(fd);
699 if (!file) {
700 async_answer_0(rid, ENOENT);
701 return;
702 }
703
704 /*
705 * Lock the open file structure so that no other thread can manipulate
706 * the same open file at a time.
707 */
708 fibril_mutex_lock(&file->lock);
709 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
710
711 /* Make a VFS_OUT_SYMC request at the destination FS server. */
712 aid_t msg;
713 ipc_call_t answer;
714 msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->service_id,
715 file->node->index, &answer);
716
717 vfs_exchange_release(fs_exch);
718
719 /* Wait for reply from the FS server. */
720 sysarg_t rc;
721 async_wait_for(msg, &rc);
722
723 fibril_mutex_unlock(&file->lock);
724
725 vfs_file_put(file);
726 async_answer_0(rid, rc);
727}
728
729void vfs_close(ipc_callid_t rid, ipc_call_t *request)
730{
731 int fd = IPC_GET_ARG1(*request);
732 int ret = vfs_fd_free(fd);
733 async_answer_0(rid, ret);
734}
735
736static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
737{
738 /*
739 * The following code strongly depends on the fact that the files data
740 * structure can be only accessed by a single fibril and all file
741 * operations are serialized (i.e. the reads and writes cannot
742 * interleave and a file cannot be closed while it is being read).
743 *
744 * Additional synchronization needs to be added once the table of
745 * open files supports parallel access!
746 */
747
748 int fd = IPC_GET_ARG1(*request);
749
750 /* Lookup the file structure corresponding to the file descriptor. */
751 vfs_file_t *file = vfs_file_get(fd);
752 if (!file) {
753 async_answer_0(rid, ENOENT);
754 return;
755 }
756
757 /*
758 * Lock the open file structure so that no other thread can manipulate
759 * the same open file at a time.
760 */
761 fibril_mutex_lock(&file->lock);
762
763 vfs_info_t *fs_info = fs_handle_to_info(file->node->fs_handle);
764 assert(fs_info);
765
766 /*
767 * Lock the file's node so that no other client can read/write to it at
768 * the same time unless the FS supports concurrent reads/writes and its
769 * write implementation does not modify the file size.
770 */
771 if ((read) ||
772 ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
773 fibril_rwlock_read_lock(&file->node->contents_rwlock);
774 else
775 fibril_rwlock_write_lock(&file->node->contents_rwlock);
776
777 if (file->node->type == VFS_NODE_DIRECTORY) {
778 /*
779 * Make sure that no one is modifying the namespace
780 * while we are in readdir().
781 */
782 assert(read);
783 fibril_rwlock_read_lock(&namespace_rwlock);
784 }
785
786 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
787
788 /*
789 * Make a VFS_READ/VFS_WRITE request at the destination FS server
790 * and forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
791 * destination FS server. The call will be routed as if sent by
792 * ourselves. Note that call arguments are immutable in this case so we
793 * don't have to bother.
794 */
795 sysarg_t rc;
796 ipc_call_t answer;
797 if (read) {
798 rc = async_data_read_forward_4_1(fs_exch, VFS_OUT_READ,
799 file->node->service_id, file->node->index,
800 LOWER32(file->pos), UPPER32(file->pos), &answer);
801 } else {
802 if (file->append)
803 file->pos = file->node->size;
804
805 rc = async_data_write_forward_4_1(fs_exch, VFS_OUT_WRITE,
806 file->node->service_id, file->node->index,
807 LOWER32(file->pos), UPPER32(file->pos), &answer);
808 }
809
810 vfs_exchange_release(fs_exch);
811
812 size_t bytes = IPC_GET_ARG1(answer);
813
814 if (file->node->type == VFS_NODE_DIRECTORY)
815 fibril_rwlock_read_unlock(&namespace_rwlock);
816
817 /* Unlock the VFS node. */
818 if ((read) ||
819 ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
820 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
821 else {
822 /* Update the cached version of node's size. */
823 if (rc == EOK)
824 file->node->size = MERGE_LOUP32(IPC_GET_ARG2(answer),
825 IPC_GET_ARG3(answer));
826 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
827 }
828
829 /* Update the position pointer and unlock the open file. */
830 if (rc == EOK)
831 file->pos += bytes;
832 fibril_mutex_unlock(&file->lock);
833 vfs_file_put(file);
834
835 /*
836 * FS server's reply is the final result of the whole operation we
837 * return to the client.
838 */
839 async_answer_1(rid, rc, bytes);
840}
841
842void vfs_read(ipc_callid_t rid, ipc_call_t *request)
843{
844 vfs_rdwr(rid, request, true);
845}
846
847void vfs_write(ipc_callid_t rid, ipc_call_t *request)
848{
849 vfs_rdwr(rid, request, false);
850}
851
852void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
853{
854 int fd = (int) IPC_GET_ARG1(*request);
855 off64_t off = (off64_t) MERGE_LOUP32(IPC_GET_ARG2(*request),
856 IPC_GET_ARG3(*request));
857 int whence = (int) IPC_GET_ARG4(*request);
858
859 /* Lookup the file structure corresponding to the file descriptor. */
860 vfs_file_t *file = vfs_file_get(fd);
861 if (!file) {
862 async_answer_0(rid, ENOENT);
863 return;
864 }
865
866 fibril_mutex_lock(&file->lock);
867
868 off64_t newoff;
869 switch (whence) {
870 case SEEK_SET:
871 if (off >= 0) {
872 file->pos = (aoff64_t) off;
873 fibril_mutex_unlock(&file->lock);
874 vfs_file_put(file);
875 async_answer_1(rid, EOK, off);
876 return;
877 }
878 break;
879 case SEEK_CUR:
880 if ((off >= 0) && (file->pos + off < file->pos)) {
881 fibril_mutex_unlock(&file->lock);
882 vfs_file_put(file);
883 async_answer_0(rid, EOVERFLOW);
884 return;
885 }
886
887 if ((off < 0) && (file->pos < (aoff64_t) -off)) {
888 fibril_mutex_unlock(&file->lock);
889 vfs_file_put(file);
890 async_answer_0(rid, EOVERFLOW);
891 return;
892 }
893
894 file->pos += off;
895 newoff = (file->pos > OFF64_MAX) ? OFF64_MAX : file->pos;
896
897 fibril_mutex_unlock(&file->lock);
898 vfs_file_put(file);
899 async_answer_2(rid, EOK, LOWER32(newoff),
900 UPPER32(newoff));
901 return;
902 case SEEK_END:
903 fibril_rwlock_read_lock(&file->node->contents_rwlock);
904 aoff64_t size = file->node->size;
905
906 if ((off >= 0) && (size + off < size)) {
907 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
908 fibril_mutex_unlock(&file->lock);
909 vfs_file_put(file);
910 async_answer_0(rid, EOVERFLOW);
911 return;
912 }
913
914 if ((off < 0) && (size < (aoff64_t) -off)) {
915 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
916 fibril_mutex_unlock(&file->lock);
917 vfs_file_put(file);
918 async_answer_0(rid, EOVERFLOW);
919 return;
920 }
921
922 file->pos = size + off;
923 newoff = (file->pos > OFF64_MAX) ? OFF64_MAX : file->pos;
924
925 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
926 fibril_mutex_unlock(&file->lock);
927 vfs_file_put(file);
928 async_answer_2(rid, EOK, LOWER32(newoff), UPPER32(newoff));
929 return;
930 }
931
932 fibril_mutex_unlock(&file->lock);
933 vfs_file_put(file);
934 async_answer_0(rid, EINVAL);
935}
936
937int vfs_truncate_internal(fs_handle_t fs_handle, service_id_t service_id,
938 fs_index_t index, aoff64_t size)
939{
940 async_exch_t *exch = vfs_exchange_grab(fs_handle);
941 sysarg_t rc = async_req_4_0(exch, VFS_OUT_TRUNCATE,
942 (sysarg_t) service_id, (sysarg_t) index, LOWER32(size),
943 UPPER32(size));
944 vfs_exchange_release(exch);
945
946 return (int) rc;
947}
948
949void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
950{
951 int fd = IPC_GET_ARG1(*request);
952 aoff64_t size = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(*request),
953 IPC_GET_ARG3(*request));
954 int rc;
955
956 vfs_file_t *file = vfs_file_get(fd);
957 if (!file) {
958 async_answer_0(rid, ENOENT);
959 return;
960 }
961 fibril_mutex_lock(&file->lock);
962
963 fibril_rwlock_write_lock(&file->node->contents_rwlock);
964 rc = vfs_truncate_internal(file->node->fs_handle,
965 file->node->service_id, file->node->index, size);
966 if (rc == EOK)
967 file->node->size = size;
968 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
969
970 fibril_mutex_unlock(&file->lock);
971 vfs_file_put(file);
972 async_answer_0(rid, (sysarg_t)rc);
973}
974
975void vfs_fstat(ipc_callid_t rid, ipc_call_t *request)
976{
977 int fd = IPC_GET_ARG1(*request);
978 sysarg_t rc;
979
980 vfs_file_t *file = vfs_file_get(fd);
981 if (!file) {
982 async_answer_0(rid, ENOENT);
983 return;
984 }
985
986 ipc_callid_t callid;
987 if (!async_data_read_receive(&callid, NULL)) {
988 vfs_file_put(file);
989 async_answer_0(callid, EINVAL);
990 async_answer_0(rid, EINVAL);
991 return;
992 }
993
994 fibril_mutex_lock(&file->lock);
995
996 async_exch_t *exch = vfs_exchange_grab(file->node->fs_handle);
997
998 aid_t msg;
999 msg = async_send_3(exch, VFS_OUT_STAT, file->node->service_id,
1000 file->node->index, true, NULL);
1001 async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
1002
1003 vfs_exchange_release(exch);
1004
1005 async_wait_for(msg, &rc);
1006
1007 fibril_mutex_unlock(&file->lock);
1008 vfs_file_put(file);
1009 async_answer_0(rid, rc);
1010}
1011
1012void vfs_stat(ipc_callid_t rid, ipc_call_t *request)
1013{
1014 char *path;
1015 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
1016 if (rc != EOK) {
1017 async_answer_0(rid, rc);
1018 return;
1019 }
1020
1021 ipc_callid_t callid;
1022 if (!async_data_read_receive(&callid, NULL)) {
1023 free(path);
1024 async_answer_0(callid, EINVAL);
1025 async_answer_0(rid, EINVAL);
1026 return;
1027 }
1028
1029 vfs_lookup_res_t lr;
1030 fibril_rwlock_read_lock(&namespace_rwlock);
1031 rc = vfs_lookup_internal(path, L_NONE, &lr, NULL);
1032 free(path);
1033 if (rc != EOK) {
1034 fibril_rwlock_read_unlock(&namespace_rwlock);
1035 async_answer_0(callid, rc);
1036 async_answer_0(rid, rc);
1037 return;
1038 }
1039 vfs_node_t *node = vfs_node_get(&lr);
1040 if (!node) {
1041 fibril_rwlock_read_unlock(&namespace_rwlock);
1042 async_answer_0(callid, ENOMEM);
1043 async_answer_0(rid, ENOMEM);
1044 return;
1045 }
1046
1047 fibril_rwlock_read_unlock(&namespace_rwlock);
1048
1049 async_exch_t *exch = vfs_exchange_grab(node->fs_handle);
1050
1051 aid_t msg;
1052 msg = async_send_3(exch, VFS_OUT_STAT, node->service_id,
1053 node->index, false, NULL);
1054 async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
1055
1056 vfs_exchange_release(exch);
1057
1058 sysarg_t rv;
1059 async_wait_for(msg, &rv);
1060
1061 async_answer_0(rid, rv);
1062
1063 vfs_node_put(node);
1064}
1065
1066void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
1067{
1068 int mode = IPC_GET_ARG1(*request);
1069
1070 char *path;
1071 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
1072 if (rc != EOK) {
1073 async_answer_0(rid, rc);
1074 return;
1075 }
1076
1077 /* Ignore mode for now. */
1078 (void) mode;
1079
1080 fibril_rwlock_write_lock(&namespace_rwlock);
1081 int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
1082 rc = vfs_lookup_internal(path, lflag, NULL, NULL);
1083 fibril_rwlock_write_unlock(&namespace_rwlock);
1084 free(path);
1085 async_answer_0(rid, rc);
1086}
1087
1088void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
1089{
1090 int lflag = IPC_GET_ARG1(*request);
1091
1092 char *path;
1093 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
1094 if (rc != EOK) {
1095 async_answer_0(rid, rc);
1096 return;
1097 }
1098
1099 fibril_rwlock_write_lock(&namespace_rwlock);
1100 lflag &= L_DIRECTORY; /* sanitize lflag */
1101 vfs_lookup_res_t lr;
1102 rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
1103 free(path);
1104 if (rc != EOK) {
1105 fibril_rwlock_write_unlock(&namespace_rwlock);
1106 async_answer_0(rid, rc);
1107 return;
1108 }
1109
1110 /*
1111 * The name has already been unlinked by vfs_lookup_internal().
1112 * We have to get and put the VFS node to ensure that it is
1113 * VFS_OUT_DESTROY'ed after the last reference to it is dropped.
1114 */
1115 vfs_node_t *node = vfs_node_get(&lr);
1116 fibril_mutex_lock(&nodes_mutex);
1117 node->lnkcnt--;
1118 fibril_mutex_unlock(&nodes_mutex);
1119 fibril_rwlock_write_unlock(&namespace_rwlock);
1120 vfs_node_put(node);
1121 async_answer_0(rid, EOK);
1122}
1123
1124void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
1125{
1126 /* Retrieve the old path. */
1127 char *old;
1128 int rc = async_data_write_accept((void **) &old, true, 0, 0, 0, NULL);
1129 if (rc != EOK) {
1130 async_answer_0(rid, rc);
1131 return;
1132 }
1133
1134 /* Retrieve the new path. */
1135 char *new;
1136 rc = async_data_write_accept((void **) &new, true, 0, 0, 0, NULL);
1137 if (rc != EOK) {
1138 free(old);
1139 async_answer_0(rid, rc);
1140 return;
1141 }
1142
1143 size_t olen;
1144 size_t nlen;
1145 char *oldc = canonify(old, &olen);
1146 char *newc = canonify(new, &nlen);
1147
1148 if ((!oldc) || (!newc)) {
1149 async_answer_0(rid, EINVAL);
1150 free(old);
1151 free(new);
1152 return;
1153 }
1154
1155 oldc[olen] = '\0';
1156 newc[nlen] = '\0';
1157
1158 if ((!str_lcmp(newc, oldc, str_length(oldc))) &&
1159 ((newc[str_length(oldc)] == '/') ||
1160 (str_length(oldc) == 1) ||
1161 (str_length(oldc) == str_length(newc)))) {
1162 /*
1163 * oldc is a prefix of newc and either
1164 * - newc continues with a / where oldc ends, or
1165 * - oldc was / itself, or
1166 * - oldc and newc are equal.
1167 */
1168 async_answer_0(rid, EINVAL);
1169 free(old);
1170 free(new);
1171 return;
1172 }
1173
1174 vfs_lookup_res_t old_lr;
1175 vfs_lookup_res_t new_lr;
1176 vfs_lookup_res_t new_par_lr;
1177 fibril_rwlock_write_lock(&namespace_rwlock);
1178
1179 /* Lookup the node belonging to the old file name. */
1180 rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
1181 if (rc != EOK) {
1182 fibril_rwlock_write_unlock(&namespace_rwlock);
1183 async_answer_0(rid, rc);
1184 free(old);
1185 free(new);
1186 return;
1187 }
1188
1189 vfs_node_t *old_node = vfs_node_get(&old_lr);
1190 if (!old_node) {
1191 fibril_rwlock_write_unlock(&namespace_rwlock);
1192 async_answer_0(rid, ENOMEM);
1193 free(old);
1194 free(new);
1195 return;
1196 }
1197
1198 /* Determine the path to the parent of the node with the new name. */
1199 char *parentc = str_dup(newc);
1200 if (!parentc) {
1201 fibril_rwlock_write_unlock(&namespace_rwlock);
1202 vfs_node_put(old_node);
1203 async_answer_0(rid, rc);
1204 free(old);
1205 free(new);
1206 return;
1207 }
1208
1209 char *lastsl = str_rchr(parentc + 1, '/');
1210 if (lastsl)
1211 *lastsl = '\0';
1212 else
1213 parentc[1] = '\0';
1214
1215 /* Lookup parent of the new file name. */
1216 rc = vfs_lookup_internal(parentc, L_NONE, &new_par_lr, NULL);
1217 free(parentc); /* not needed anymore */
1218 if (rc != EOK) {
1219 fibril_rwlock_write_unlock(&namespace_rwlock);
1220 vfs_node_put(old_node);
1221 async_answer_0(rid, rc);
1222 free(old);
1223 free(new);
1224 return;
1225 }
1226
1227 /* Check whether linking to the same file system instance. */
1228 if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
1229 (old_node->service_id != new_par_lr.triplet.service_id)) {
1230 fibril_rwlock_write_unlock(&namespace_rwlock);
1231 vfs_node_put(old_node);
1232 async_answer_0(rid, EXDEV); /* different file systems */
1233 free(old);
1234 free(new);
1235 return;
1236 }
1237
1238 /* Destroy the old link for the new name. */
1239 vfs_node_t *new_node = NULL;
1240 rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
1241
1242 switch (rc) {
1243 case ENOENT:
1244 /* simply not in our way */
1245 break;
1246 case EOK:
1247 new_node = vfs_node_get(&new_lr);
1248 if (!new_node) {
1249 fibril_rwlock_write_unlock(&namespace_rwlock);
1250 vfs_node_put(old_node);
1251 async_answer_0(rid, ENOMEM);
1252 free(old);
1253 free(new);
1254 return;
1255 }
1256 fibril_mutex_lock(&nodes_mutex);
1257 new_node->lnkcnt--;
1258 fibril_mutex_unlock(&nodes_mutex);
1259 break;
1260 default:
1261 fibril_rwlock_write_unlock(&namespace_rwlock);
1262 vfs_node_put(old_node);
1263 async_answer_0(rid, ENOTEMPTY);
1264 free(old);
1265 free(new);
1266 return;
1267 }
1268
1269 /* Create the new link for the new name. */
1270 rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
1271 if (rc != EOK) {
1272 fibril_rwlock_write_unlock(&namespace_rwlock);
1273 vfs_node_put(old_node);
1274 if (new_node)
1275 vfs_node_put(new_node);
1276 async_answer_0(rid, rc);
1277 free(old);
1278 free(new);
1279 return;
1280 }
1281
1282 fibril_mutex_lock(&nodes_mutex);
1283 old_node->lnkcnt++;
1284 fibril_mutex_unlock(&nodes_mutex);
1285
1286 /* Destroy the link for the old name. */
1287 rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
1288 if (rc != EOK) {
1289 fibril_rwlock_write_unlock(&namespace_rwlock);
1290 vfs_node_put(old_node);
1291 if (new_node)
1292 vfs_node_put(new_node);
1293 async_answer_0(rid, rc);
1294 free(old);
1295 free(new);
1296 return;
1297 }
1298
1299 fibril_mutex_lock(&nodes_mutex);
1300 old_node->lnkcnt--;
1301 fibril_mutex_unlock(&nodes_mutex);
1302 fibril_rwlock_write_unlock(&namespace_rwlock);
1303 vfs_node_put(old_node);
1304
1305 if (new_node)
1306 vfs_node_put(new_node);
1307
1308 free(old);
1309 free(new);
1310 async_answer_0(rid, EOK);
1311}
1312
1313void vfs_dup(ipc_callid_t rid, ipc_call_t *request)
1314{
1315 int oldfd = IPC_GET_ARG1(*request);
1316 int newfd = IPC_GET_ARG2(*request);
1317
1318 /* If the file descriptors are the same, do nothing. */
1319 if (oldfd == newfd) {
1320 async_answer_1(rid, EOK, newfd);
1321 return;
1322 }
1323
1324 /* Lookup the file structure corresponding to oldfd. */
1325 vfs_file_t *oldfile = vfs_file_get(oldfd);
1326 if (!oldfile) {
1327 async_answer_0(rid, EBADF);
1328 return;
1329 }
1330
1331 /*
1332 * Lock the open file structure so that no other thread can manipulate
1333 * the same open file at a time.
1334 */
1335 fibril_mutex_lock(&oldfile->lock);
1336
1337 /* Make sure newfd is closed. */
1338 (void) vfs_fd_free(newfd);
1339
1340 /* Assign the old file to newfd. */
1341 int ret = vfs_fd_assign(oldfile, newfd);
1342 fibril_mutex_unlock(&oldfile->lock);
1343 vfs_file_put(oldfile);
1344
1345 if (ret != EOK)
1346 async_answer_0(rid, ret);
1347 else
1348 async_answer_1(rid, EOK, newfd);
1349}
1350
1351void vfs_wait_handle(ipc_callid_t rid, ipc_call_t *request)
1352{
1353 int fd = vfs_wait_handle_internal();
1354 async_answer_1(rid, EOK, fd);
1355}
1356
1357void vfs_get_mtab(ipc_callid_t rid, ipc_call_t *request)
1358{
1359 ipc_callid_t callid;
1360 ipc_call_t data;
1361 sysarg_t rc = EOK;
1362 size_t len;
1363
1364 fibril_mutex_lock(&mtab_list_lock);
1365
1366 /* Send to the caller the number of mounted filesystems */
1367 callid = async_get_call(&data);
1368 if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
1369 rc = ENOTSUP;
1370 async_answer_0(callid, rc);
1371 goto exit;
1372 }
1373 async_answer_1(callid, EOK, mtab_size);
1374
1375 list_foreach(mtab_list, link, mtab_ent_t, mtab_ent) {
1376 rc = ENOTSUP;
1377
1378 if (!async_data_read_receive(&callid, &len)) {
1379 async_answer_0(callid, rc);
1380 goto exit;
1381 }
1382
1383 (void) async_data_read_finalize(callid, mtab_ent->mp,
1384 str_size(mtab_ent->mp));
1385
1386 if (!async_data_read_receive(&callid, &len)) {
1387 async_answer_0(callid, rc);
1388 goto exit;
1389 }
1390
1391 (void) async_data_read_finalize(callid, mtab_ent->opts,
1392 str_size(mtab_ent->opts));
1393
1394 if (!async_data_read_receive(&callid, &len)) {
1395 async_answer_0(callid, rc);
1396 goto exit;
1397 }
1398
1399 (void) async_data_read_finalize(callid, mtab_ent->fs_name,
1400 str_size(mtab_ent->fs_name));
1401
1402 callid = async_get_call(&data);
1403
1404 if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
1405 async_answer_0(callid, rc);
1406 goto exit;
1407 }
1408
1409 rc = EOK;
1410 async_answer_2(callid, rc, mtab_ent->instance,
1411 mtab_ent->service_id);
1412 }
1413
1414exit:
1415 fibril_mutex_unlock(&mtab_list_lock);
1416 async_answer_0(rid, rc);
1417}
1418
1419void vfs_statfs(ipc_callid_t rid, ipc_call_t *request)
1420{
1421 char *path;
1422 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
1423 if (rc != EOK) {
1424 async_answer_0(rid, rc);
1425 return;
1426 }
1427
1428 ipc_callid_t callid;
1429 if (!async_data_read_receive(&callid, NULL)) {
1430 free(path);
1431 async_answer_0(callid, EINVAL);
1432 async_answer_0(rid, EINVAL);
1433 return;
1434 }
1435
1436 vfs_lookup_res_t lr;
1437 fibril_rwlock_read_lock(&namespace_rwlock);
1438 rc = vfs_lookup_internal(path, L_NONE, &lr, NULL);
1439 free(path);
1440 if (rc != EOK) {
1441 fibril_rwlock_read_unlock(&namespace_rwlock);
1442 async_answer_0(callid, rc);
1443 async_answer_0(rid, rc);
1444 return;
1445 }
1446 vfs_node_t *node = vfs_node_get(&lr);
1447 if (!node) {
1448 fibril_rwlock_read_unlock(&namespace_rwlock);
1449 async_answer_0(callid, ENOMEM);
1450 async_answer_0(rid, ENOMEM);
1451 return;
1452 }
1453
1454 fibril_rwlock_read_unlock(&namespace_rwlock);
1455
1456 async_exch_t *exch = vfs_exchange_grab(node->fs_handle);
1457
1458 aid_t msg;
1459 msg = async_send_3(exch, VFS_OUT_STATFS, node->service_id,
1460 node->index, false, NULL);
1461 async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
1462
1463 vfs_exchange_release(exch);
1464
1465 sysarg_t rv;
1466 async_wait_for(msg, &rv);
1467
1468 async_answer_0(rid, rv);
1469
1470 vfs_node_put(node);
1471}
1472
1473/**
1474 * @}
1475 */
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