source: mainline/uspace/srv/vfs/vfs_ops.c@ fadc76f

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since fadc76f was fadc76f, checked in by Ji?? Z?rev?cky <zarevucky.jiri@…>, 12 years ago

Remove MKDIR from server.
  • Property mode set to 100644
File size: 33.8 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(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(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, cur) {
551 mtab_ent_t *mtab_ent = list_get_instance(cur, mtab_ent_t,
552 link);
553
554 if (str_cmp(mtab_ent->mp, mp) == 0) {
555 list_remove(&mtab_ent->link);
556 mtab_size--;
557 free(mtab_ent);
558 found = 1;
559 break;
560 }
561 }
562 assert(found);
563 fibril_mutex_unlock(&mtab_list_lock);
564
565 free(mp);
566
567 async_answer_0(rid, EOK);
568}
569
570static inline bool walk_flags_valid(int flags)
571{
572 if ((flags&~WALK_ALL_FLAGS) != 0) {
573 return false;
574 }
575 if ((flags&WALK_MAY_CREATE) && (flags&WALK_MUST_CREATE)) {
576 return false;
577 }
578 if ((flags&WALK_REGULAR) && (flags&WALK_DIRECTORY)) {
579 return false;
580 }
581 if ((flags&WALK_MAY_CREATE) || (flags&WALK_MUST_CREATE)) {
582 if (!(flags&WALK_DIRECTORY) && !(flags&WALK_REGULAR)) {
583 return false;
584 }
585 }
586 return true;
587}
588
589static inline int walk_lookup_flags(int flags)
590{
591 int lflags = 0;
592 if (flags&WALK_MAY_CREATE || flags&WALK_MUST_CREATE) {
593 lflags |= L_CREATE;
594 }
595 if (flags&WALK_MUST_CREATE) {
596 lflags |= L_EXCLUSIVE;
597 }
598 if (flags&WALK_REGULAR) {
599 lflags |= L_FILE;
600 }
601 if (flags&WALK_DIRECTORY) {
602 lflags |= L_DIRECTORY;
603 }
604 return lflags;
605}
606
607void vfs_walk(ipc_callid_t rid, ipc_call_t *request)
608{
609 /*
610 * Parent is our relative root for file lookup.
611 * For defined flags, see <ipc/vfs.h>.
612 */
613 int parentfd = IPC_GET_ARG1(*request);
614 int flags = IPC_GET_ARG2(*request);
615
616 if (!walk_flags_valid(flags)) {
617 async_answer_0(rid, EINVAL);
618 return;
619 }
620
621 char *path;
622 int rc = async_data_write_accept((void **)&path, true, 0, 0, 0, NULL);
623
624 /* Lookup the file structure corresponding to the file descriptor. */
625 vfs_file_t *parent = NULL;
626 vfs_pair_t *parent_node = NULL;
627 // TODO: Client-side root.
628 if (parentfd != -1) {
629 parent = vfs_file_get(parentfd);
630 if (!parent) {
631 free(path);
632 async_answer_0(rid, EBADF);
633 return;
634 }
635 parent_node = (vfs_pair_t *)parent->node;
636 }
637
638 fibril_rwlock_read_lock(&namespace_rwlock);
639
640 vfs_lookup_res_t lr;
641 rc = vfs_lookup_internal(path, walk_lookup_flags(flags), &lr, parent_node);
642 free(path);
643
644 if (rc != EOK) {
645 fibril_rwlock_read_unlock(&namespace_rwlock);
646 if (parent) {
647 vfs_file_put(parent);
648 }
649 async_answer_0(rid, rc);
650 return;
651 }
652
653 vfs_node_t *node = vfs_node_get(&lr);
654
655 int fd = vfs_fd_alloc(false);
656 if (fd < 0) {
657 vfs_node_put(node);
658 if (parent) {
659 vfs_file_put(parent);
660 }
661 async_answer_0(rid, fd);
662 return;
663 }
664
665 vfs_file_t *file = vfs_file_get(fd);
666 assert(file != NULL);
667
668 file->node = node;
669 if (parent) {
670 file->permissions = parent->permissions;
671 } else {
672 file->permissions = MODE_READ | MODE_WRITE | MODE_APPEND;
673 }
674 file->open_read = false;
675 file->open_write = false;
676
677 vfs_node_addref(node);
678 vfs_node_put(node);
679 vfs_file_put(file);
680 if (parent) {
681 vfs_file_put(parent);
682 }
683
684 fibril_rwlock_read_unlock(&namespace_rwlock);
685
686 async_answer_1(rid, EOK, fd);
687}
688
689void vfs_open2(ipc_callid_t rid, ipc_call_t *request)
690{
691 int fd = IPC_GET_ARG1(*request);
692 int flags = IPC_GET_ARG2(*request);
693
694 if (flags == 0) {
695 async_answer_0(rid, EINVAL);
696 return;
697 }
698
699 vfs_file_t *file = vfs_file_get(fd);
700 if (!file) {
701 async_answer_0(rid, EBADF);
702 return;
703 }
704
705 if ((flags & ~file->permissions) != 0) {
706 vfs_file_put(file);
707 async_answer_0(rid, EPERM);
708 return;
709 }
710
711 file->open_read = (flags & MODE_READ) != 0;
712 file->open_write = (flags & (MODE_WRITE | MODE_APPEND)) != 0;
713 file->append = (flags & MODE_APPEND) != 0;
714
715 if (!file->open_read && !file->open_write) {
716 vfs_file_put(file);
717 async_answer_0(rid, EINVAL);
718 return;
719 }
720
721 if (file->node->type == VFS_NODE_DIRECTORY && file->open_write) {
722 file->open_read = file->open_write = false;
723 vfs_file_put(file);
724 async_answer_0(rid, EINVAL);
725 return;
726 }
727
728 int rc = vfs_open_node_remote(file->node);
729 if (rc != EOK) {
730 file->open_read = file->open_write = false;
731 vfs_file_put(file);
732 async_answer_0(rid, rc);
733 return;
734 }
735
736 vfs_file_put(file);
737 async_answer_0(rid, EOK);
738}
739
740void vfs_sync(ipc_callid_t rid, ipc_call_t *request)
741{
742 int fd = IPC_GET_ARG1(*request);
743
744 /* Lookup the file structure corresponding to the file descriptor. */
745 vfs_file_t *file = vfs_file_get(fd);
746 if (!file) {
747 async_answer_0(rid, ENOENT);
748 return;
749 }
750
751 /*
752 * Lock the open file structure so that no other thread can manipulate
753 * the same open file at a time.
754 */
755 fibril_mutex_lock(&file->lock);
756 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
757
758 /* Make a VFS_OUT_SYMC request at the destination FS server. */
759 aid_t msg;
760 ipc_call_t answer;
761 msg = async_send_2(fs_exch, VFS_OUT_SYNC, file->node->service_id,
762 file->node->index, &answer);
763
764 vfs_exchange_release(fs_exch);
765
766 /* Wait for reply from the FS server. */
767 sysarg_t rc;
768 async_wait_for(msg, &rc);
769
770 fibril_mutex_unlock(&file->lock);
771
772 vfs_file_put(file);
773 async_answer_0(rid, rc);
774}
775
776void vfs_close(ipc_callid_t rid, ipc_call_t *request)
777{
778 int fd = IPC_GET_ARG1(*request);
779 int ret = vfs_fd_free(fd);
780 async_answer_0(rid, ret);
781}
782
783static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
784{
785 /*
786 * The following code strongly depends on the fact that the files data
787 * structure can be only accessed by a single fibril and all file
788 * operations are serialized (i.e. the reads and writes cannot
789 * interleave and a file cannot be closed while it is being read).
790 *
791 * Additional synchronization needs to be added once the table of
792 * open files supports parallel access!
793 */
794
795 int fd = IPC_GET_ARG1(*request);
796
797 /* Lookup the file structure corresponding to the file descriptor. */
798 vfs_file_t *file = vfs_file_get(fd);
799 if (!file) {
800 async_answer_0(rid, ENOENT);
801 return;
802 }
803
804 /*
805 * Lock the open file structure so that no other thread can manipulate
806 * the same open file at a time.
807 */
808 fibril_mutex_lock(&file->lock);
809
810 if ((read && !file->open_read) || (!read && !file->open_write)) {
811 fibril_mutex_unlock(&file->lock);
812 async_answer_0(rid, EINVAL);
813 return;
814 }
815
816 vfs_info_t *fs_info = fs_handle_to_info(file->node->fs_handle);
817 assert(fs_info);
818
819 /*
820 * Lock the file's node so that no other client can read/write to it at
821 * the same time unless the FS supports concurrent reads/writes and its
822 * write implementation does not modify the file size.
823 */
824 if ((read) ||
825 ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
826 fibril_rwlock_read_lock(&file->node->contents_rwlock);
827 else
828 fibril_rwlock_write_lock(&file->node->contents_rwlock);
829
830 if (file->node->type == VFS_NODE_DIRECTORY) {
831 /*
832 * Make sure that no one is modifying the namespace
833 * while we are in readdir().
834 */
835 assert(read);
836 fibril_rwlock_read_lock(&namespace_rwlock);
837 }
838
839 async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
840
841 /*
842 * Make a VFS_READ/VFS_WRITE request at the destination FS server
843 * and forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
844 * destination FS server. The call will be routed as if sent by
845 * ourselves. Note that call arguments are immutable in this case so we
846 * don't have to bother.
847 */
848 sysarg_t rc;
849 ipc_call_t answer;
850 if (read) {
851 rc = async_data_read_forward_4_1(fs_exch, VFS_OUT_READ,
852 file->node->service_id, file->node->index,
853 LOWER32(file->pos), UPPER32(file->pos), &answer);
854 } else {
855 if (file->append)
856 file->pos = file->node->size;
857
858 rc = async_data_write_forward_4_1(fs_exch, VFS_OUT_WRITE,
859 file->node->service_id, file->node->index,
860 LOWER32(file->pos), UPPER32(file->pos), &answer);
861 }
862
863 vfs_exchange_release(fs_exch);
864
865 size_t bytes = IPC_GET_ARG1(answer);
866
867 if (file->node->type == VFS_NODE_DIRECTORY)
868 fibril_rwlock_read_unlock(&namespace_rwlock);
869
870 /* Unlock the VFS node. */
871 if ((read) ||
872 ((fs_info->concurrent_read_write) && (fs_info->write_retains_size)))
873 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
874 else {
875 /* Update the cached version of node's size. */
876 if (rc == EOK)
877 file->node->size = MERGE_LOUP32(IPC_GET_ARG2(answer),
878 IPC_GET_ARG3(answer));
879 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
880 }
881
882 /* Update the position pointer and unlock the open file. */
883 if (rc == EOK)
884 file->pos += bytes;
885 fibril_mutex_unlock(&file->lock);
886 vfs_file_put(file);
887
888 /*
889 * FS server's reply is the final result of the whole operation we
890 * return to the client.
891 */
892 async_answer_1(rid, rc, bytes);
893}
894
895void vfs_read(ipc_callid_t rid, ipc_call_t *request)
896{
897 vfs_rdwr(rid, request, true);
898}
899
900void vfs_write(ipc_callid_t rid, ipc_call_t *request)
901{
902 vfs_rdwr(rid, request, false);
903}
904
905void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
906{
907 int fd = (int) IPC_GET_ARG1(*request);
908 off64_t off = (off64_t) MERGE_LOUP32(IPC_GET_ARG2(*request),
909 IPC_GET_ARG3(*request));
910 int whence = (int) IPC_GET_ARG4(*request);
911
912 /* Lookup the file structure corresponding to the file descriptor. */
913 vfs_file_t *file = vfs_file_get(fd);
914 if (!file) {
915 async_answer_0(rid, ENOENT);
916 return;
917 }
918
919 fibril_mutex_lock(&file->lock);
920
921 off64_t newoff;
922 switch (whence) {
923 case SEEK_SET:
924 if (off >= 0) {
925 file->pos = (aoff64_t) off;
926 fibril_mutex_unlock(&file->lock);
927 vfs_file_put(file);
928 async_answer_1(rid, EOK, off);
929 return;
930 }
931 break;
932 case SEEK_CUR:
933 if ((off >= 0) && (file->pos + off < file->pos)) {
934 fibril_mutex_unlock(&file->lock);
935 vfs_file_put(file);
936 async_answer_0(rid, EOVERFLOW);
937 return;
938 }
939
940 if ((off < 0) && (file->pos < (aoff64_t) -off)) {
941 fibril_mutex_unlock(&file->lock);
942 vfs_file_put(file);
943 async_answer_0(rid, EOVERFLOW);
944 return;
945 }
946
947 file->pos += off;
948 newoff = (file->pos > OFF64_MAX) ? OFF64_MAX : file->pos;
949
950 fibril_mutex_unlock(&file->lock);
951 vfs_file_put(file);
952 async_answer_2(rid, EOK, LOWER32(newoff),
953 UPPER32(newoff));
954 return;
955 case SEEK_END:
956 fibril_rwlock_read_lock(&file->node->contents_rwlock);
957 aoff64_t size = file->node->size;
958
959 if ((off >= 0) && (size + off < size)) {
960 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
961 fibril_mutex_unlock(&file->lock);
962 vfs_file_put(file);
963 async_answer_0(rid, EOVERFLOW);
964 return;
965 }
966
967 if ((off < 0) && (size < (aoff64_t) -off)) {
968 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
969 fibril_mutex_unlock(&file->lock);
970 vfs_file_put(file);
971 async_answer_0(rid, EOVERFLOW);
972 return;
973 }
974
975 file->pos = size + off;
976 newoff = (file->pos > OFF64_MAX) ? OFF64_MAX : file->pos;
977
978 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
979 fibril_mutex_unlock(&file->lock);
980 vfs_file_put(file);
981 async_answer_2(rid, EOK, LOWER32(newoff), UPPER32(newoff));
982 return;
983 }
984
985 fibril_mutex_unlock(&file->lock);
986 vfs_file_put(file);
987 async_answer_0(rid, EINVAL);
988}
989
990int vfs_truncate_internal(fs_handle_t fs_handle, service_id_t service_id,
991 fs_index_t index, aoff64_t size)
992{
993 async_exch_t *exch = vfs_exchange_grab(fs_handle);
994 sysarg_t rc = async_req_4_0(exch, VFS_OUT_TRUNCATE,
995 (sysarg_t) service_id, (sysarg_t) index, LOWER32(size),
996 UPPER32(size));
997 vfs_exchange_release(exch);
998
999 return (int) rc;
1000}
1001
1002void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
1003{
1004 int fd = IPC_GET_ARG1(*request);
1005 aoff64_t size = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(*request),
1006 IPC_GET_ARG3(*request));
1007 int rc;
1008
1009 vfs_file_t *file = vfs_file_get(fd);
1010 if (!file) {
1011 async_answer_0(rid, ENOENT);
1012 return;
1013 }
1014 fibril_mutex_lock(&file->lock);
1015
1016 fibril_rwlock_write_lock(&file->node->contents_rwlock);
1017 rc = vfs_truncate_internal(file->node->fs_handle,
1018 file->node->service_id, file->node->index, size);
1019 if (rc == EOK)
1020 file->node->size = size;
1021 fibril_rwlock_write_unlock(&file->node->contents_rwlock);
1022
1023 fibril_mutex_unlock(&file->lock);
1024 vfs_file_put(file);
1025 async_answer_0(rid, (sysarg_t)rc);
1026}
1027
1028void vfs_fstat(ipc_callid_t rid, ipc_call_t *request)
1029{
1030 int fd = IPC_GET_ARG1(*request);
1031 sysarg_t rc;
1032
1033 vfs_file_t *file = vfs_file_get(fd);
1034 if (!file) {
1035 async_answer_0(rid, ENOENT);
1036 return;
1037 }
1038
1039 ipc_callid_t callid;
1040 if (!async_data_read_receive(&callid, NULL)) {
1041 vfs_file_put(file);
1042 async_answer_0(callid, EINVAL);
1043 async_answer_0(rid, EINVAL);
1044 return;
1045 }
1046
1047 fibril_mutex_lock(&file->lock);
1048
1049 async_exch_t *exch = vfs_exchange_grab(file->node->fs_handle);
1050
1051 aid_t msg;
1052 msg = async_send_3(exch, VFS_OUT_STAT, file->node->service_id,
1053 file->node->index, true, NULL);
1054 async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
1055
1056 vfs_exchange_release(exch);
1057
1058 async_wait_for(msg, &rc);
1059
1060 fibril_mutex_unlock(&file->lock);
1061 vfs_file_put(file);
1062 async_answer_0(rid, rc);
1063}
1064
1065void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
1066{
1067 int lflag = IPC_GET_ARG1(*request);
1068
1069 char *path;
1070 int rc = async_data_write_accept((void **) &path, true, 0, 0, 0, NULL);
1071 if (rc != EOK) {
1072 async_answer_0(rid, rc);
1073 return;
1074 }
1075
1076 fibril_rwlock_write_lock(&namespace_rwlock);
1077 lflag &= L_DIRECTORY; /* sanitize lflag */
1078 vfs_lookup_res_t lr;
1079 rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
1080 free(path);
1081 if (rc != EOK) {
1082 fibril_rwlock_write_unlock(&namespace_rwlock);
1083 async_answer_0(rid, rc);
1084 return;
1085 }
1086
1087 /*
1088 * The name has already been unlinked by vfs_lookup_internal().
1089 * We have to get and put the VFS node to ensure that it is
1090 * VFS_OUT_DESTROY'ed after the last reference to it is dropped.
1091 */
1092 vfs_node_t *node = vfs_node_get(&lr);
1093 fibril_mutex_lock(&nodes_mutex);
1094 node->lnkcnt--;
1095 fibril_mutex_unlock(&nodes_mutex);
1096 fibril_rwlock_write_unlock(&namespace_rwlock);
1097 vfs_node_put(node);
1098 async_answer_0(rid, EOK);
1099}
1100
1101void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
1102{
1103 /* Retrieve the old path. */
1104 char *old;
1105 int rc = async_data_write_accept((void **) &old, true, 0, 0, 0, NULL);
1106 if (rc != EOK) {
1107 async_answer_0(rid, rc);
1108 return;
1109 }
1110
1111 /* Retrieve the new path. */
1112 char *new;
1113 rc = async_data_write_accept((void **) &new, true, 0, 0, 0, NULL);
1114 if (rc != EOK) {
1115 free(old);
1116 async_answer_0(rid, rc);
1117 return;
1118 }
1119
1120 size_t olen;
1121 size_t nlen;
1122 char *oldc = canonify(old, &olen);
1123 char *newc = canonify(new, &nlen);
1124
1125 if ((!oldc) || (!newc)) {
1126 async_answer_0(rid, EINVAL);
1127 free(old);
1128 free(new);
1129 return;
1130 }
1131
1132 oldc[olen] = '\0';
1133 newc[nlen] = '\0';
1134
1135 if ((!str_lcmp(newc, oldc, str_length(oldc))) &&
1136 ((newc[str_length(oldc)] == '/') ||
1137 (str_length(oldc) == 1) ||
1138 (str_length(oldc) == str_length(newc)))) {
1139 /*
1140 * oldc is a prefix of newc and either
1141 * - newc continues with a / where oldc ends, or
1142 * - oldc was / itself, or
1143 * - oldc and newc are equal.
1144 */
1145 async_answer_0(rid, EINVAL);
1146 free(old);
1147 free(new);
1148 return;
1149 }
1150
1151 vfs_lookup_res_t old_lr;
1152 vfs_lookup_res_t new_lr;
1153 vfs_lookup_res_t new_par_lr;
1154 fibril_rwlock_write_lock(&namespace_rwlock);
1155
1156 /* Lookup the node belonging to the old file name. */
1157 rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
1158 if (rc != EOK) {
1159 fibril_rwlock_write_unlock(&namespace_rwlock);
1160 async_answer_0(rid, rc);
1161 free(old);
1162 free(new);
1163 return;
1164 }
1165
1166 vfs_node_t *old_node = vfs_node_get(&old_lr);
1167 if (!old_node) {
1168 fibril_rwlock_write_unlock(&namespace_rwlock);
1169 async_answer_0(rid, ENOMEM);
1170 free(old);
1171 free(new);
1172 return;
1173 }
1174
1175 /* Determine the path to the parent of the node with the new name. */
1176 char *parentc = str_dup(newc);
1177 if (!parentc) {
1178 fibril_rwlock_write_unlock(&namespace_rwlock);
1179 vfs_node_put(old_node);
1180 async_answer_0(rid, rc);
1181 free(old);
1182 free(new);
1183 return;
1184 }
1185
1186 char *lastsl = str_rchr(parentc + 1, '/');
1187 if (lastsl)
1188 *lastsl = '\0';
1189 else
1190 parentc[1] = '\0';
1191
1192 /* Lookup parent of the new file name. */
1193 rc = vfs_lookup_internal(parentc, L_NONE, &new_par_lr, NULL);
1194 free(parentc); /* not needed anymore */
1195 if (rc != EOK) {
1196 fibril_rwlock_write_unlock(&namespace_rwlock);
1197 vfs_node_put(old_node);
1198 async_answer_0(rid, rc);
1199 free(old);
1200 free(new);
1201 return;
1202 }
1203
1204 /* Check whether linking to the same file system instance. */
1205 if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
1206 (old_node->service_id != new_par_lr.triplet.service_id)) {
1207 fibril_rwlock_write_unlock(&namespace_rwlock);
1208 vfs_node_put(old_node);
1209 async_answer_0(rid, EXDEV); /* different file systems */
1210 free(old);
1211 free(new);
1212 return;
1213 }
1214
1215 /* Destroy the old link for the new name. */
1216 vfs_node_t *new_node = NULL;
1217 rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
1218
1219 switch (rc) {
1220 case ENOENT:
1221 /* simply not in our way */
1222 break;
1223 case EOK:
1224 new_node = vfs_node_get(&new_lr);
1225 if (!new_node) {
1226 fibril_rwlock_write_unlock(&namespace_rwlock);
1227 vfs_node_put(old_node);
1228 async_answer_0(rid, ENOMEM);
1229 free(old);
1230 free(new);
1231 return;
1232 }
1233 fibril_mutex_lock(&nodes_mutex);
1234 new_node->lnkcnt--;
1235 fibril_mutex_unlock(&nodes_mutex);
1236 break;
1237 default:
1238 fibril_rwlock_write_unlock(&namespace_rwlock);
1239 vfs_node_put(old_node);
1240 async_answer_0(rid, ENOTEMPTY);
1241 free(old);
1242 free(new);
1243 return;
1244 }
1245
1246 /* Create the new link for the new name. */
1247 rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
1248 if (rc != EOK) {
1249 fibril_rwlock_write_unlock(&namespace_rwlock);
1250 vfs_node_put(old_node);
1251 if (new_node)
1252 vfs_node_put(new_node);
1253 async_answer_0(rid, rc);
1254 free(old);
1255 free(new);
1256 return;
1257 }
1258
1259 fibril_mutex_lock(&nodes_mutex);
1260 old_node->lnkcnt++;
1261 fibril_mutex_unlock(&nodes_mutex);
1262
1263 /* Destroy the link for the old name. */
1264 rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
1265 if (rc != EOK) {
1266 fibril_rwlock_write_unlock(&namespace_rwlock);
1267 vfs_node_put(old_node);
1268 if (new_node)
1269 vfs_node_put(new_node);
1270 async_answer_0(rid, rc);
1271 free(old);
1272 free(new);
1273 return;
1274 }
1275
1276 fibril_mutex_lock(&nodes_mutex);
1277 old_node->lnkcnt--;
1278 fibril_mutex_unlock(&nodes_mutex);
1279 fibril_rwlock_write_unlock(&namespace_rwlock);
1280 vfs_node_put(old_node);
1281
1282 if (new_node)
1283 vfs_node_put(new_node);
1284
1285 free(old);
1286 free(new);
1287 async_answer_0(rid, EOK);
1288}
1289
1290void vfs_dup(ipc_callid_t rid, ipc_call_t *request)
1291{
1292 int oldfd = IPC_GET_ARG1(*request);
1293 int newfd = IPC_GET_ARG2(*request);
1294
1295 /* If the file descriptors are the same, do nothing. */
1296 if (oldfd == newfd) {
1297 async_answer_1(rid, EOK, newfd);
1298 return;
1299 }
1300
1301 /* Lookup the file structure corresponding to oldfd. */
1302 vfs_file_t *oldfile = vfs_file_get(oldfd);
1303 if (!oldfile) {
1304 async_answer_0(rid, EBADF);
1305 return;
1306 }
1307
1308 /*
1309 * Lock the open file structure so that no other thread can manipulate
1310 * the same open file at a time.
1311 */
1312 fibril_mutex_lock(&oldfile->lock);
1313
1314 /* Make sure newfd is closed. */
1315 (void) vfs_fd_free(newfd);
1316
1317 /* Assign the old file to newfd. */
1318 int ret = vfs_fd_assign(oldfile, newfd);
1319 fibril_mutex_unlock(&oldfile->lock);
1320 vfs_file_put(oldfile);
1321
1322 if (ret != EOK)
1323 async_answer_0(rid, ret);
1324 else
1325 async_answer_1(rid, EOK, newfd);
1326}
1327
1328void vfs_wait_handle(ipc_callid_t rid, ipc_call_t *request)
1329{
1330 int fd = vfs_wait_handle_internal();
1331 async_answer_1(rid, EOK, fd);
1332}
1333
1334void vfs_get_mtab(ipc_callid_t rid, ipc_call_t *request)
1335{
1336 ipc_callid_t callid;
1337 ipc_call_t data;
1338 sysarg_t rc = EOK;
1339 size_t len;
1340
1341 fibril_mutex_lock(&mtab_list_lock);
1342
1343 /* Send to the caller the number of mounted filesystems */
1344 callid = async_get_call(&data);
1345 if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
1346 rc = ENOTSUP;
1347 async_answer_0(callid, rc);
1348 goto exit;
1349 }
1350 async_answer_1(callid, EOK, mtab_size);
1351
1352 list_foreach(mtab_list, cur) {
1353 mtab_ent_t *mtab_ent = list_get_instance(cur, mtab_ent_t,
1354 link);
1355
1356 rc = ENOTSUP;
1357
1358 if (!async_data_read_receive(&callid, &len)) {
1359 async_answer_0(callid, rc);
1360 goto exit;
1361 }
1362
1363 (void) async_data_read_finalize(callid, mtab_ent->mp,
1364 str_size(mtab_ent->mp));
1365
1366 if (!async_data_read_receive(&callid, &len)) {
1367 async_answer_0(callid, rc);
1368 goto exit;
1369 }
1370
1371 (void) async_data_read_finalize(callid, mtab_ent->opts,
1372 str_size(mtab_ent->opts));
1373
1374 if (!async_data_read_receive(&callid, &len)) {
1375 async_answer_0(callid, rc);
1376 goto exit;
1377 }
1378
1379 (void) async_data_read_finalize(callid, mtab_ent->fs_name,
1380 str_size(mtab_ent->fs_name));
1381
1382 callid = async_get_call(&data);
1383
1384 if (IPC_GET_IMETHOD(data) != VFS_IN_PING) {
1385 async_answer_0(callid, rc);
1386 goto exit;
1387 }
1388
1389 rc = EOK;
1390 async_answer_2(callid, rc, mtab_ent->instance,
1391 mtab_ent->service_id);
1392 }
1393
1394exit:
1395 fibril_mutex_unlock(&mtab_list_lock);
1396 async_answer_0(rid, rc);
1397}
1398
1399/**
1400 * @}
1401 */
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