source: mainline/uspace/srv/vfs/vfs_ops.c@ 8ebc5b8a

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 8ebc5b8a was d2c8533, checked in by Jiri Svoboda <jiri@…>, 8 years ago

File system probing groundwork. Only MFS can do it for now.
  • Property mode set to 100644
File size: 21.1 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 <ctype.h>
50#include <assert.h>
51#include <vfs/canonify.h>
52
53/* Forward declarations of static functions. */
54static int vfs_truncate_internal(fs_handle_t, service_id_t, fs_index_t,
55 aoff64_t);
56
57/**
58 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
59 * concurrent VFS operation which modifies the file system namespace.
60 */
61FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);
62
63static size_t shared_path(char *a, char *b)
64{
65 size_t res = 0;
66
67 while (a[res] == b[res] && a[res] != 0)
68 res++;
69
70 if (a[res] == b[res])
71 return res;
72
73 res--;
74 while (a[res] != '/')
75 res--;
76 return res;
77}
78
79/* This call destroys the file if and only if there are no hard links left. */
80static void out_destroy(vfs_triplet_t *file)
81{
82 async_exch_t *exch = vfs_exchange_grab(file->fs_handle);
83 async_msg_2(exch, VFS_OUT_DESTROY, (sysarg_t) file->service_id,
84 (sysarg_t) file->index);
85 vfs_exchange_release(exch);
86}
87
88int vfs_op_clone(int oldfd, int newfd, bool desc)
89{
90 int rc;
91
92 /* If the file descriptors are the same, do nothing. */
93 if (oldfd == newfd)
94 return EOK;
95
96 /* Lookup the file structure corresponding to fd. */
97 vfs_file_t *oldfile = vfs_file_get(oldfd);
98 if (oldfile == NULL)
99 return EBADF;
100
101 assert(oldfile->node != NULL);
102
103 if (newfd != -1) {
104 /* Make sure newfd is closed. */
105 (void) vfs_fd_free(newfd);
106 /* Assign the old file to newfd. */
107 rc = vfs_fd_assign(oldfile, newfd);
108 } else {
109 vfs_file_t *newfile;
110 int newfd = vfs_fd_alloc(&newfile, desc);
111 if (newfd >= 0) {
112 newfile->node = oldfile->node;
113 newfile->permissions = oldfile->permissions;
114 vfs_node_addref(newfile->node);
115
116 vfs_file_put(newfile);
117 }
118 rc = newfd;
119 }
120 vfs_file_put(oldfile);
121
122 return rc;
123}
124
125int vfs_op_put(int fd)
126{
127 return vfs_fd_free(fd);
128}
129
130static int vfs_connect_internal(service_id_t service_id, unsigned flags,
131 unsigned instance, const char *options, const char *fsname,
132 vfs_node_t **root)
133{
134 fs_handle_t fs_handle = 0;
135
136 fibril_mutex_lock(&fs_list_lock);
137 while (true) {
138 fs_handle = fs_name_to_handle(instance, fsname, false);
139
140 if (fs_handle != 0 || !(flags & VFS_MOUNT_BLOCKING))
141 break;
142
143 fibril_condvar_wait(&fs_list_cv, &fs_list_lock);
144 }
145 fibril_mutex_unlock(&fs_list_lock);
146
147 if (fs_handle == 0)
148 return ENOFS;
149
150 /* Tell the mountee that it is being mounted. */
151 ipc_call_t answer;
152 async_exch_t *exch = vfs_exchange_grab(fs_handle);
153 aid_t msg = async_send_1(exch, VFS_OUT_MOUNTED, (sysarg_t) service_id,
154 &answer);
155 /* Send the mount options */
156 sysarg_t rc = async_data_write_start(exch, options, str_size(options));
157 if (rc != EOK) {
158 async_forget(msg);
159 vfs_exchange_release(exch);
160 return rc;
161 }
162
163 async_wait_for(msg, &rc);
164 if (rc != EOK) {
165 vfs_exchange_release(exch);
166 return rc;
167 }
168
169 vfs_lookup_res_t res;
170 res.triplet.fs_handle = fs_handle;
171 res.triplet.service_id = service_id;
172 res.triplet.index = (fs_index_t) IPC_GET_ARG1(answer);
173 res.size = (int64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
174 IPC_GET_ARG3(answer));
175 res.type = VFS_NODE_DIRECTORY;
176
177 /* Add reference to the mounted root. */
178 *root = vfs_node_get(&res);
179 if (!*root) {
180 aid_t msg = async_send_1(exch, VFS_OUT_UNMOUNTED,
181 (sysarg_t) service_id, NULL);
182 async_forget(msg);
183 vfs_exchange_release(exch);
184 return ENOMEM;
185 }
186
187 vfs_exchange_release(exch);
188
189 return EOK;
190}
191
192int vfs_op_fsprobe(const char *fs_name, service_id_t sid,
193 vfs_fs_probe_info_t *info)
194{
195 fs_handle_t fs_handle = 0;
196 sysarg_t rc;
197 int retval;
198
199 fibril_mutex_lock(&fs_list_lock);
200 fs_handle = fs_name_to_handle(0, fs_name, false);
201 fibril_mutex_unlock(&fs_list_lock);
202
203 if (fs_handle == 0)
204 return ENOFS;
205
206 /* Send probe request to the file system server */
207 ipc_call_t answer;
208 async_exch_t *exch = vfs_exchange_grab(fs_handle);
209 aid_t msg = async_send_1(exch, VFS_OUT_FSPROBE, (sysarg_t) sid,
210 &answer);
211 if (msg == 0)
212 return EINVAL;
213
214 /* Read probe information */
215 retval = async_data_read_start(exch, info, sizeof(*info));
216 if (retval != EOK) {
217 async_forget(msg);
218 return retval;
219 }
220
221 async_wait_for(msg, &rc);
222 vfs_exchange_release(exch);
223 return rc;
224}
225
226int vfs_op_mount(int mpfd, unsigned service_id, unsigned flags,
227 unsigned instance, const char *opts, const char *fs_name, int *outfd)
228{
229 int rc;
230 vfs_file_t *mp = NULL;
231 vfs_file_t *file = NULL;
232 int fd = -1;
233
234 if (!(flags & VFS_MOUNT_CONNECT_ONLY)) {
235 mp = vfs_file_get(mpfd);
236 if (mp == NULL) {
237 rc = EBADF;
238 goto out;
239 }
240
241 if (mp->node->mount != NULL) {
242 rc = EBUSY;
243 goto out;
244 }
245
246 if (mp->node->type != VFS_NODE_DIRECTORY) {
247 rc = ENOTDIR;
248 goto out;
249 }
250
251 if (vfs_node_has_children(mp->node)) {
252 rc = ENOTEMPTY;
253 goto out;
254 }
255 }
256
257 if (!(flags & VFS_MOUNT_NO_REF)) {
258 fd = vfs_fd_alloc(&file, false);
259 if (fd < 0) {
260 rc = fd;
261 goto out;
262 }
263 }
264
265 vfs_node_t *root = NULL;
266
267 fibril_rwlock_write_lock(&namespace_rwlock);
268
269 rc = vfs_connect_internal(service_id, flags, instance, opts, fs_name,
270 &root);
271 if (rc == EOK && !(flags & VFS_MOUNT_CONNECT_ONLY)) {
272 vfs_node_addref(mp->node);
273 vfs_node_addref(root);
274 mp->node->mount = root;
275 }
276
277 fibril_rwlock_write_unlock(&namespace_rwlock);
278
279 if (rc != EOK)
280 goto out;
281
282 if (flags & VFS_MOUNT_NO_REF) {
283 vfs_node_delref(root);
284 } else {
285 assert(file != NULL);
286
287 file->node = root;
288 file->permissions = MODE_READ | MODE_WRITE | MODE_APPEND;
289 file->open_read = false;
290 file->open_write = false;
291 }
292
293out:
294 if (mp)
295 vfs_file_put(mp);
296 if (file)
297 vfs_file_put(file);
298
299 if (rc != EOK && fd >= 0) {
300 vfs_fd_free(fd);
301 fd = 0;
302 }
303
304 *outfd = fd;
305 return rc;
306}
307
308int vfs_op_open(int fd, int mode)
309{
310 if (mode == 0)
311 return EINVAL;
312
313 vfs_file_t *file = vfs_file_get(fd);
314 if (!file)
315 return EBADF;
316
317 if ((mode & ~file->permissions) != 0) {
318 vfs_file_put(file);
319 return EPERM;
320 }
321
322 if (file->open_read || file->open_write) {
323 vfs_file_put(file);
324 return EBUSY;
325 }
326
327 file->open_read = (mode & MODE_READ) != 0;
328 file->open_write = (mode & (MODE_WRITE | MODE_APPEND)) != 0;
329 file->append = (mode & MODE_APPEND) != 0;
330
331 if (!file->open_read && !file->open_write) {
332 vfs_file_put(file);
333 return EINVAL;
334 }
335
336 if (file->node->type == VFS_NODE_DIRECTORY && file->open_write) {
337 file->open_read = file->open_write = false;
338 vfs_file_put(file);
339 return EINVAL;
340 }
341
342 int rc = vfs_open_node_remote(file->node);
343 if (rc != EOK) {
344 file->open_read = file->open_write = false;
345 vfs_file_put(file);
346 return rc;
347 }
348
349 vfs_file_put(file);
350 return EOK;
351}
352
353typedef int (* rdwr_ipc_cb_t)(async_exch_t *, vfs_file_t *, aoff64_t,
354 ipc_call_t *, bool, void *);
355
356static int rdwr_ipc_client(async_exch_t *exch, vfs_file_t *file, aoff64_t pos,
357 ipc_call_t *answer, bool read, void *data)
358{
359 size_t *bytes = (size_t *) data;
360 int rc;
361
362 /*
363 * Make a VFS_READ/VFS_WRITE request at the destination FS server
364 * and forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
365 * destination FS server. The call will be routed as if sent by
366 * ourselves. Note that call arguments are immutable in this case so we
367 * don't have to bother.
368 */
369
370 if (read) {
371 rc = async_data_read_forward_4_1(exch, VFS_OUT_READ,
372 file->node->service_id, file->node->index,
373 LOWER32(pos), UPPER32(pos), answer);
374 } else {
375 rc = async_data_write_forward_4_1(exch, VFS_OUT_WRITE,
376 file->node->service_id, file->node->index,
377 LOWER32(pos), UPPER32(pos), answer);
378 }
379
380 *bytes = IPC_GET_ARG1(*answer);
381 return rc;
382}
383
384static int rdwr_ipc_internal(async_exch_t *exch, vfs_file_t *file, aoff64_t pos,
385 ipc_call_t *answer, bool read, void *data)
386{
387 rdwr_io_chunk_t *chunk = (rdwr_io_chunk_t *) data;
388
389 if (exch == NULL)
390 return ENOENT;
391
392 aid_t msg = async_send_fast(exch, read ? VFS_OUT_READ : VFS_OUT_WRITE,
393 file->node->service_id, file->node->index, LOWER32(pos),
394 UPPER32(pos), answer);
395 if (msg == 0)
396 return EINVAL;
397
398 int retval = async_data_read_start(exch, chunk->buffer, chunk->size);
399 if (retval != EOK) {
400 async_forget(msg);
401 return retval;
402 }
403
404 sysarg_t rc;
405 async_wait_for(msg, &rc);
406
407 chunk->size = IPC_GET_ARG1(*answer);
408
409 return (int) rc;
410}
411
412static int vfs_rdwr(int fd, aoff64_t pos, bool read, rdwr_ipc_cb_t ipc_cb,
413 void *ipc_cb_data)
414{
415 /*
416 * The following code strongly depends on the fact that the files data
417 * structure can be only accessed by a single fibril and all file
418 * operations are serialized (i.e. the reads and writes cannot
419 * interleave and a file cannot be closed while it is being read).
420 *
421 * Additional synchronization needs to be added once the table of
422 * open files supports parallel access!
423 */
424
425 /* Lookup the file structure corresponding to the file descriptor. */
426 vfs_file_t *file = vfs_file_get(fd);
427 if (!file)
428 return EBADF;
429
430 if ((read && !file->open_read) || (!read && !file->open_write)) {
431 vfs_file_put(file);
432 return EINVAL;
433 }
434
435 vfs_info_t *fs_info = fs_handle_to_info(file->node->fs_handle);
436 assert(fs_info);
437
438 bool rlock = read ||
439 (fs_info->concurrent_read_write && fs_info->write_retains_size);
440
441 /*
442 * Lock the file's node so that no other client can read/write to it at
443 * the same time unless the FS supports concurrent reads/writes and its
444 * write implementation does not modify the file size.
445 */
446 if (rlock)
447 fibril_rwlock_read_lock(&file->node->contents_rwlock);
448 else
449 fibril_rwlock_write_lock(&file->node->contents_rwlock);
450
451 if (file->node->type == VFS_NODE_DIRECTORY) {
452 /*
453 * Make sure that no one is modifying the namespace
454 * while we are in readdir().
455 */
456
457 if (!read) {
458 if (rlock) {
459 fibril_rwlock_read_unlock(
460 &file->node->contents_rwlock);
461 } else {
462 fibril_rwlock_write_unlock(
463 &file->node->contents_rwlock);
464 }
465 vfs_file_put(file);
466 return EINVAL;
467 }
468
469 fibril_rwlock_read_lock(&namespace_rwlock);
470 }
471
472 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
473
474 if (!read && file->append)
475 pos = file->node->size;
476
477 /*
478 * Handle communication with the endpoint FS.
479 */
480 ipc_call_t answer;
481 int rc = ipc_cb(fs_exch, file, pos, &answer, read, ipc_cb_data);
482
483 vfs_exchange_release(fs_exch);
484
485 if (file->node->type == VFS_NODE_DIRECTORY)
486 fibril_rwlock_read_unlock(&namespace_rwlock);
487
488 /* Unlock the VFS node. */
489 if (rlock) {
490 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
491 } else {
492 /* Update the cached version of node's size. */
493 if (rc == EOK) {
494 file->node->size = MERGE_LOUP32(IPC_GET_ARG2(answer),
495 IPC_GET_ARG3(answer));
496 }
497 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
498 }
499
500 vfs_file_put(file);
501
502 return rc;
503}
504
505int vfs_rdwr_internal(int fd, aoff64_t pos, bool read, rdwr_io_chunk_t *chunk)
506{
507 return vfs_rdwr(fd, pos, read, rdwr_ipc_internal, chunk);
508}
509
510int vfs_op_read(int fd, aoff64_t pos, size_t *out_bytes)
511{
512 return vfs_rdwr(fd, pos, true, rdwr_ipc_client, out_bytes);
513}
514
515int vfs_op_rename(int basefd, char *old, char *new)
516{
517 vfs_file_t *base_file = vfs_file_get(basefd);
518 if (!base_file)
519 return EBADF;
520
521 vfs_node_t *base = base_file->node;
522 vfs_node_addref(base);
523 vfs_file_put(base_file);
524
525 vfs_lookup_res_t base_lr;
526 vfs_lookup_res_t old_lr;
527 vfs_lookup_res_t new_lr_orig;
528 bool orig_unlinked = false;
529
530 int rc;
531
532 size_t shared = shared_path(old, new);
533
534 /* Do not allow one path to be a prefix of the other. */
535 if (old[shared] == 0 || new[shared] == 0) {
536 vfs_node_put(base);
537 return EINVAL;
538 }
539 assert(old[shared] == '/');
540 assert(new[shared] == '/');
541
542 fibril_rwlock_write_lock(&namespace_rwlock);
543
544 /* Resolve the shared portion of the path first. */
545 if (shared != 0) {
546 old[shared] = 0;
547 rc = vfs_lookup_internal(base, old, L_DIRECTORY, &base_lr);
548 if (rc != EOK) {
549 vfs_node_put(base);
550 fibril_rwlock_write_unlock(&namespace_rwlock);
551 return rc;
552 }
553
554 vfs_node_put(base);
555 base = vfs_node_get(&base_lr);
556 if (!base) {
557 fibril_rwlock_write_unlock(&namespace_rwlock);
558 return ENOMEM;
559 }
560 old[shared] = '/';
561 old += shared;
562 new += shared;
563 }
564
565 rc = vfs_lookup_internal(base, old, L_DISABLE_MOUNTS, &old_lr);
566 if (rc != EOK) {
567 vfs_node_put(base);
568 fibril_rwlock_write_unlock(&namespace_rwlock);
569 return rc;
570 }
571
572 rc = vfs_lookup_internal(base, new, L_UNLINK | L_DISABLE_MOUNTS,
573 &new_lr_orig);
574 if (rc == EOK) {
575 orig_unlinked = true;
576 } else if (rc != ENOENT) {
577 vfs_node_put(base);
578 fibril_rwlock_write_unlock(&namespace_rwlock);
579 return rc;
580 }
581
582 rc = vfs_link_internal(base, new, &old_lr.triplet);
583 if (rc != EOK) {
584 vfs_link_internal(base, old, &old_lr.triplet);
585 if (orig_unlinked)
586 vfs_link_internal(base, new, &new_lr_orig.triplet);
587 vfs_node_put(base);
588 fibril_rwlock_write_unlock(&namespace_rwlock);
589 return rc;
590 }
591
592 rc = vfs_lookup_internal(base, old, L_UNLINK | L_DISABLE_MOUNTS,
593 &old_lr);
594 if (rc != EOK) {
595 if (orig_unlinked)
596 vfs_link_internal(base, new, &new_lr_orig.triplet);
597 vfs_node_put(base);
598 fibril_rwlock_write_unlock(&namespace_rwlock);
599 return rc;
600 }
601
602 /* If the node is not held by anyone, try to destroy it. */
603 if (orig_unlinked) {
604 vfs_node_t *node = vfs_node_peek(&new_lr_orig);
605 if (!node)
606 out_destroy(&new_lr_orig.triplet);
607 else
608 vfs_node_put(node);
609 }
610
611 vfs_node_put(base);
612 fibril_rwlock_write_unlock(&namespace_rwlock);
613 return EOK;
614}
615
616int vfs_op_resize(int fd, int64_t size)
617{
618 vfs_file_t *file = vfs_file_get(fd);
619 if (!file)
620 return EBADF;
621
622 fibril_rwlock_write_lock(&file->node->contents_rwlock);
623
624 int rc = vfs_truncate_internal(file->node->fs_handle,
625 file->node->service_id, file->node->index, size);
626 if (rc == EOK)
627 file->node->size = size;
628
629 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
630 vfs_file_put(file);
631 return rc;
632}
633
634int vfs_op_stat(int fd)
635{
636 vfs_file_t *file = vfs_file_get(fd);
637 if (!file)
638 return EBADF;
639
640 vfs_node_t *node = file->node;
641
642 async_exch_t *exch = vfs_exchange_grab(node->fs_handle);
643 int rc = async_data_read_forward_fast(exch, VFS_OUT_STAT,
644 node->service_id, node->index, true, 0, NULL);
645 vfs_exchange_release(exch);
646
647 vfs_file_put(file);
648 return rc;
649}
650
651int vfs_op_statfs(int fd)
652{
653 vfs_file_t *file = vfs_file_get(fd);
654 if (!file)
655 return EBADF;
656
657 vfs_node_t *node = file->node;
658
659 async_exch_t *exch = vfs_exchange_grab(node->fs_handle);
660 int rc = async_data_read_forward_fast(exch, VFS_OUT_STATFS,
661 node->service_id, node->index, false, 0, NULL);
662 vfs_exchange_release(exch);
663
664 vfs_file_put(file);
665 return rc;
666}
667
668int vfs_op_sync(int fd)
669{
670 vfs_file_t *file = vfs_file_get(fd);
671 if (!file)
672 return EBADF;
673
674 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
675
676 aid_t msg;
677 ipc_call_t answer;
678 msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->service_id,
679 file->node->index, &answer);
680
681 vfs_exchange_release(fs_exch);
682
683 sysarg_t rc;
684 async_wait_for(msg, &rc);
685
686 vfs_file_put(file);
687 return rc;
688
689}
690
691static int vfs_truncate_internal(fs_handle_t fs_handle, service_id_t service_id,
692 fs_index_t index, aoff64_t size)
693{
694 async_exch_t *exch = vfs_exchange_grab(fs_handle);
695 sysarg_t rc = async_req_4_0(exch, VFS_OUT_TRUNCATE,
696 (sysarg_t) service_id, (sysarg_t) index, LOWER32(size),
697 UPPER32(size));
698 vfs_exchange_release(exch);
699
700 return (int) rc;
701}
702
703int vfs_op_unlink(int parentfd, int expectfd, char *path)
704{
705 int rc = EOK;
706 vfs_file_t *parent = NULL;
707 vfs_file_t *expect = NULL;
708
709 if (parentfd == expectfd)
710 return EINVAL;
711
712 fibril_rwlock_write_lock(&namespace_rwlock);
713
714 /*
715 * Files are retrieved in order of file descriptors, to prevent
716 * deadlock.
717 */
718 if (parentfd < expectfd) {
719 parent = vfs_file_get(parentfd);
720 if (!parent) {
721 rc = EBADF;
722 goto exit;
723 }
724 }
725
726 if (expectfd >= 0) {
727 expect = vfs_file_get(expectfd);
728 if (!expect) {
729 rc = EBADF;
730 goto exit;
731 }
732 }
733
734 if (parentfd > expectfd) {
735 parent = vfs_file_get(parentfd);
736 if (!parent) {
737 rc = EBADF;
738 goto exit;
739 }
740 }
741
742 assert(parent != NULL);
743
744 if (expectfd >= 0) {
745 vfs_lookup_res_t lr;
746 rc = vfs_lookup_internal(parent->node, path, 0, &lr);
747 if (rc != EOK)
748 goto exit;
749
750 vfs_node_t *found_node = vfs_node_peek(&lr);
751 vfs_node_put(found_node);
752 if (expect->node != found_node) {
753 rc = ENOENT;
754 goto exit;
755 }
756
757 vfs_file_put(expect);
758 expect = NULL;
759 }
760
761 vfs_lookup_res_t lr;
762 rc = vfs_lookup_internal(parent->node, path, L_UNLINK, &lr);
763 if (rc != EOK)
764 goto exit;
765
766 /* If the node is not held by anyone, try to destroy it. */
767 vfs_node_t *node = vfs_node_peek(&lr);
768 if (!node)
769 out_destroy(&lr.triplet);
770 else
771 vfs_node_put(node);
772
773exit:
774 if (path)
775 free(path);
776 if (parent)
777 vfs_file_put(parent);
778 if (expect)
779 vfs_file_put(expect);
780 fibril_rwlock_write_unlock(&namespace_rwlock);
781 return rc;
782}
783
784int vfs_op_unmount(int mpfd)
785{
786 vfs_file_t *mp = vfs_file_get(mpfd);
787 if (mp == NULL)
788 return EBADF;
789
790 if (mp->node->mount == NULL) {
791 vfs_file_put(mp);
792 return ENOENT;
793 }
794
795 fibril_rwlock_write_lock(&namespace_rwlock);
796
797 /*
798 * Count the total number of references for the mounted file system. We
799 * are expecting at least one, which is held by the mount point.
800 * If we find more, it means that
801 * the file system cannot be gracefully unmounted at the moment because
802 * someone is working with it.
803 */
804 if (vfs_nodes_refcount_sum_get(mp->node->mount->fs_handle,
805 mp->node->mount->service_id) != 1) {
806 vfs_file_put(mp);
807 fibril_rwlock_write_unlock(&namespace_rwlock);
808 return EBUSY;
809 }
810
811 async_exch_t *exch = vfs_exchange_grab(mp->node->mount->fs_handle);
812 int rc = async_req_1_0(exch, VFS_OUT_UNMOUNTED,
813 mp->node->mount->service_id);
814 vfs_exchange_release(exch);
815
816 if (rc != EOK) {
817 vfs_file_put(mp);
818 fibril_rwlock_write_unlock(&namespace_rwlock);
819 return rc;
820 }
821
822 vfs_node_forget(mp->node->mount);
823 vfs_node_put(mp->node);
824 mp->node->mount = NULL;
825
826 fibril_rwlock_write_unlock(&namespace_rwlock);
827
828 vfs_file_put(mp);
829 return EOK;
830}
831
832int vfs_op_wait_handle(bool high_fd)
833{
834 return vfs_wait_handle_internal(high_fd);
835}
836
837static inline bool walk_flags_valid(int flags)
838{
839 if ((flags & ~WALK_ALL_FLAGS) != 0)
840 return false;
841 if ((flags & WALK_MAY_CREATE) && (flags & WALK_MUST_CREATE))
842 return false;
843 if ((flags & WALK_REGULAR) && (flags & WALK_DIRECTORY))
844 return false;
845 if ((flags & WALK_MAY_CREATE) || (flags & WALK_MUST_CREATE)) {
846 if (!(flags & WALK_DIRECTORY) && !(flags & WALK_REGULAR))
847 return false;
848 }
849 return true;
850}
851
852static inline int walk_lookup_flags(int flags)
853{
854 int lflags = 0;
855 if ((flags & WALK_MAY_CREATE) || (flags & WALK_MUST_CREATE))
856 lflags |= L_CREATE;
857 if (flags & WALK_MUST_CREATE)
858 lflags |= L_EXCLUSIVE;
859 if (flags & WALK_REGULAR)
860 lflags |= L_FILE;
861 if (flags & WALK_DIRECTORY)
862 lflags |= L_DIRECTORY;
863 if (flags & WALK_MOUNT_POINT)
864 lflags |= L_MP;
865 return lflags;
866}
867
868int vfs_op_walk(int parentfd, int flags, char *path, int *out_fd)
869{
870 if (!walk_flags_valid(flags))
871 return EINVAL;
872
873 vfs_file_t *parent = vfs_file_get(parentfd);
874 if (!parent)
875 return EBADF;
876
877 fibril_rwlock_read_lock(&namespace_rwlock);
878
879 vfs_lookup_res_t lr;
880 int rc = vfs_lookup_internal(parent->node, path,
881 walk_lookup_flags(flags), &lr);
882 if (rc != EOK) {
883 fibril_rwlock_read_unlock(&namespace_rwlock);
884 vfs_file_put(parent);
885 return rc;
886 }
887
888 vfs_node_t *node = vfs_node_get(&lr);
889 if (!node) {
890 fibril_rwlock_read_unlock(&namespace_rwlock);
891 vfs_file_put(parent);
892 return ENOMEM;
893 }
894
895 vfs_file_t *file;
896 int fd = vfs_fd_alloc(&file, false);
897 if (fd < 0) {
898 vfs_node_put(node);
899 vfs_file_put(parent);
900 return fd;
901 }
902 assert(file != NULL);
903
904 file->node = node;
905 file->permissions = parent->permissions;
906 file->open_read = false;
907 file->open_write = false;
908
909 vfs_file_put(file);
910 vfs_file_put(parent);
911
912 fibril_rwlock_read_unlock(&namespace_rwlock);
913
914 *out_fd = fd;
915 return EOK;
916}
917
918int vfs_op_write(int fd, aoff64_t pos, size_t *out_bytes)
919{
920 return vfs_rdwr(fd, pos, false, rdwr_ipc_client, out_bytes);
921}
922
923/**
924 * @}
925 */
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