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2689 jermar 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
 
2763 jermar 38
#include "vfs.h"
2689 jermar 39
#include <ipc/ipc.h>
40
#include <async.h>
41
#include <errno.h>
42
#include <stdio.h>
43
#include <stdlib.h>
44
#include <string.h>
45
#include <bool.h>
46
#include <futex.h>
47
#include <rwlock.h>
48
#include <libadt/list.h>
49
#include <unistd.h>
50
#include <ctype.h>
2708 jermar 51
#include <fcntl.h>
2689 jermar 52
#include <assert.h>
2763 jermar 53
#include <vfs/canonify.h>
2689 jermar 54
 
2748 jermar 55
/* Forward declarations of static functions. */
2770 jermar 56
static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);
2748 jermar 57
 
2689 jermar 58
/**
59
 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
60
 * concurrent VFS operation which modifies the file system namespace.
61
 */
62
RWLOCK_INITIALIZE(namespace_rwlock);
63
 
2766 jermar 64
futex_t rootfs_futex = FUTEX_INITIALIZER;
3109 jermar 65
vfs_pair_t rootfs = {
2689 jermar 66
	.fs_handle = 0,
3109 jermar 67
	.dev_handle = 0
2689 jermar 68
};
69
 
70
void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
71
{
2770 jermar 72
	dev_handle_t dev_handle;
2689 jermar 73
	vfs_node_t *mp_node = NULL;
3255 jermar 74
	ipc_callid_t callid;
75
	ipc_call_t data;
2957 jermar 76
	int rc;
2958 jermar 77
	int phone;
3255 jermar 78
	size_t size;
2689 jermar 79
 
80
	/*
81
	 * We expect the library to do the device-name to device-handle
82
	 * translation for us, thus the device handle will arrive as ARG1
83
	 * in the request.
84
	 */
2770 jermar 85
	dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
2689 jermar 86
 
87
	/*
88
	 * For now, don't make use of ARG2 and ARG3, but they can be used to
89
	 * carry mount options in the future.
90
	 */
91
 
92
	/*
93
	 * Now, we expect the client to send us data with the name of the file
94
	 * system.
95
	 */
96
	if (!ipc_data_write_receive(&callid, &size)) {
97
		ipc_answer_0(callid, EINVAL);
98
		ipc_answer_0(rid, EINVAL);
99
		return;
100
	}
101
 
102
	/*
103
	 * Don't receive more than is necessary for storing a full file system
104
	 * name.
105
	 */
106
	if (size < 1 || size > FS_NAME_MAXLEN) {
107
		ipc_answer_0(callid, EINVAL);
108
		ipc_answer_0(rid, EINVAL);
109
		return;
110
	}
111
 
2707 jermar 112
	/* Deliver the file system name. */
2689 jermar 113
	char fs_name[FS_NAME_MAXLEN + 1];
114
	(void) ipc_data_write_finalize(callid, fs_name, size);
115
	fs_name[size] = '\0';
116
 
117
	/*
3255 jermar 118
	 * Wait for IPC_M_PING so that we can return an error if we don't know
119
	 * fs_name.
120
	 */
121
	callid = async_get_call(&data);
122
	if (IPC_GET_METHOD(data) != IPC_M_PING) {
123
		ipc_answer_0(callid, ENOTSUP);
124
		ipc_answer_0(rid, ENOTSUP);
125
		return;
126
	}
127
 
128
	/*
2689 jermar 129
	 * Check if we know a file system with the same name as is in fs_name.
130
	 * This will also give us its file system handle.
131
	 */
2770 jermar 132
	fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);
2689 jermar 133
	if (!fs_handle) {
3255 jermar 134
		ipc_answer_0(callid, ENOENT);
2689 jermar 135
		ipc_answer_0(rid, ENOENT);
136
		return;
137
	}
138
 
3255 jermar 139
	/* Acknowledge that we know fs_name. */
140
	ipc_answer_0(callid, EOK);
141
 
2707 jermar 142
	/* Now, we want the client to send us the mount point. */
2689 jermar 143
	if (!ipc_data_write_receive(&callid, &size)) {
144
		ipc_answer_0(callid, EINVAL);
145
		ipc_answer_0(rid, EINVAL);
146
		return;
147
	}
148
 
2707 jermar 149
	/* Check whether size is reasonable wrt. the mount point. */
2689 jermar 150
	if (size < 1 || size > MAX_PATH_LEN) {
151
		ipc_answer_0(callid, EINVAL);
152
		ipc_answer_0(rid, EINVAL);
153
		return;
154
	}
2707 jermar 155
	/* Allocate buffer for the mount point data being received. */
3488 svoboda 156
	char *buf;
2752 jermar 157
	buf = malloc(size + 1);
2689 jermar 158
	if (!buf) {
159
		ipc_answer_0(callid, ENOMEM);
160
		ipc_answer_0(rid, ENOMEM);
161
		return;
162
	}
163
 
2707 jermar 164
	/* Deliver the mount point. */
2689 jermar 165
	(void) ipc_data_write_finalize(callid, buf, size);
2752 jermar 166
	buf[size] = '\0';
2689 jermar 167
 
3109 jermar 168
	/* Resolve the path to the mountpoint. */
2691 jermar 169
	vfs_lookup_res_t mp_res;
2689 jermar 170
	futex_down(&rootfs_futex);
171
	if (rootfs.fs_handle) {
2707 jermar 172
		/* We already have the root FS. */
2689 jermar 173
		rwlock_write_lock(&namespace_rwlock);
2788 jermar 174
		if ((size == 1) && (buf[0] == '/')) {
175
			/* Trying to mount root FS over root FS */
176
			rwlock_write_unlock(&namespace_rwlock);
177
			futex_up(&rootfs_futex);
178
			free(buf);
179
			ipc_answer_0(rid, EBUSY);
180
			return;
181
		}
2752 jermar 182
		rc = vfs_lookup_internal(buf, L_DIRECTORY, &mp_res, NULL);
2689 jermar 183
		if (rc != EOK) {
2707 jermar 184
			/* The lookup failed for some reason. */
2689 jermar 185
			rwlock_write_unlock(&namespace_rwlock);
186
			futex_up(&rootfs_futex);
187
			free(buf);
188
			ipc_answer_0(rid, rc);
189
			return;
190
		}
2691 jermar 191
		mp_node = vfs_node_get(&mp_res);
2689 jermar 192
		if (!mp_node) {
193
			rwlock_write_unlock(&namespace_rwlock);
194
			futex_up(&rootfs_futex);
195
			free(buf);
196
			ipc_answer_0(rid, ENOMEM);
197
			return;
198
		}
199
		/*
200
		 * Now we hold a reference to mp_node.
201
		 * It will be dropped upon the corresponding VFS_UNMOUNT.
202
		 * This prevents the mount point from being deleted.
203
		 */
204
		rwlock_write_unlock(&namespace_rwlock);
205
	} else {
2707 jermar 206
		/* We still don't have the root file system mounted. */
2689 jermar 207
		if ((size == 1) && (buf[0] == '/')) {
3352 jermar 208
			vfs_lookup_res_t mr_res;
209
			vfs_node_t *mr_node;
210
			ipcarg_t rindex;
211
			ipcarg_t rsize;
212
			ipcarg_t rlnkcnt;
213
 
2958 jermar 214
			/*
215
			 * For this simple, but important case,
216
			 * we are almost done.
217
			 */
218
			free(buf);
219
 
3109 jermar 220
			/* Tell the mountee that it is being mounted. */
221
			phone = vfs_grab_phone(fs_handle);
3352 jermar 222
			rc = async_req_1_3(phone, VFS_MOUNTED,
223
			    (ipcarg_t) dev_handle, &rindex, &rsize, &rlnkcnt);
2958 jermar 224
			vfs_release_phone(phone);
3352 jermar 225
 
226
			if (rc != EOK) {
227
				futex_up(&rootfs_futex);
228
				ipc_answer_0(rid, rc);
229
				return;
3109 jermar 230
			}
2958 jermar 231
 
3352 jermar 232
			mr_res.triplet.fs_handle = fs_handle;
233
			mr_res.triplet.dev_handle = dev_handle;
234
			mr_res.triplet.index = (fs_index_t) rindex;
235
			mr_res.size = (size_t) rsize;
236
			mr_res.lnkcnt = (unsigned) rlnkcnt;
237
 
238
			rootfs.fs_handle = fs_handle;
239
			rootfs.dev_handle = dev_handle;
2689 jermar 240
			futex_up(&rootfs_futex);
3352 jermar 241
 
242
			/* Add reference to the mounted root. */
243
			mr_node = vfs_node_get(&mr_res); 
244
			assert(mr_node);
245
 
2958 jermar 246
			ipc_answer_0(rid, rc);
2689 jermar 247
			return;
248
		} else {
249
			/*
250
			 * We can't resolve this without the root filesystem
251
			 * being mounted first.
252
			 */
253
			futex_up(&rootfs_futex);
254
			free(buf);
255
			ipc_answer_0(rid, ENOENT);
256
			return;
257
		}
258
	}
259
	futex_up(&rootfs_futex);
260
 
261
	free(buf);	/* The buffer is not needed anymore. */
262
 
263
	/*
264
	 * At this point, we have all necessary pieces: file system and device
3109 jermar 265
	 * handles, and we know the mount point VFS node.
2689 jermar 266
	 */
267
 
2958 jermar 268
	phone = vfs_grab_phone(mp_res.triplet.fs_handle);
3109 jermar 269
	rc = async_req_4_0(phone, VFS_MOUNT,
2691 jermar 270
	    (ipcarg_t) mp_res.triplet.dev_handle,
2957 jermar 271
	    (ipcarg_t) mp_res.triplet.index,
3109 jermar 272
	    (ipcarg_t) fs_handle,
273
	    (ipcarg_t) dev_handle);
2689 jermar 274
	vfs_release_phone(phone);
275
 
2957 jermar 276
	if (rc != EOK) {
3109 jermar 277
		/* Mount failed, drop reference to mp_node. */
2689 jermar 278
		if (mp_node)
279
			vfs_node_put(mp_node);
280
	}
281
 
2957 jermar 282
	ipc_answer_0(rid, rc);
2689 jermar 283
}
284
 
285
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
286
{
287
	if (!vfs_files_init()) {
288
		ipc_answer_0(rid, ENOMEM);
289
		return;
290
	}
291
 
292
	/*
2700 jermar 293
	 * The POSIX interface is open(path, oflag, mode).
294
	 * We can receive oflags and mode along with the VFS_OPEN call; the path
2689 jermar 295
	 * will need to arrive in another call.
2700 jermar 296
	 *
297
	 * We also receive one private, non-POSIX set of flags called lflag
298
	 * used to pass information to vfs_lookup_internal().
2689 jermar 299
	 */
2700 jermar 300
	int lflag = IPC_GET_ARG1(*request);
301
	int oflag = IPC_GET_ARG2(*request);
302
	int mode = IPC_GET_ARG3(*request);
2689 jermar 303
	size_t len;
304
 
2708 jermar 305
	if (oflag & O_CREAT)
306
		lflag |= L_CREATE;
307
	if (oflag & O_EXCL)
308
		lflag |= L_EXCLUSIVE;
309
 
2689 jermar 310
	ipc_callid_t callid;
311
 
312
	if (!ipc_data_write_receive(&callid, &len)) {
313
		ipc_answer_0(callid, EINVAL);
314
		ipc_answer_0(rid, EINVAL);
315
		return;
316
	}
2752 jermar 317
	char *path = malloc(len + 1);
2689 jermar 318
	if (!path) {
319
		ipc_answer_0(callid, ENOMEM);
320
		ipc_answer_0(rid, ENOMEM);
321
		return;
322
	}
323
	int rc;
324
	if ((rc = ipc_data_write_finalize(callid, path, len))) {
325
		ipc_answer_0(rid, rc);
326
		free(path);
327
		return;
328
	}
2752 jermar 329
	path[len] = '\0';
2689 jermar 330
 
331
	/*
332
	 * Avoid the race condition in which the file can be deleted before we
333
	 * find/create-and-lock the VFS node corresponding to the looked-up
334
	 * triplet.
335
	 */
2708 jermar 336
	if (lflag & L_CREATE)
337
		rwlock_write_lock(&namespace_rwlock);
338
	else
339
		rwlock_read_lock(&namespace_rwlock);
2689 jermar 340
 
2707 jermar 341
	/* The path is now populated and we can call vfs_lookup_internal(). */
2691 jermar 342
	vfs_lookup_res_t lr;
2752 jermar 343
	rc = vfs_lookup_internal(path, lflag, &lr, NULL);
2689 jermar 344
	if (rc) {
2708 jermar 345
		if (lflag & L_CREATE)
346
			rwlock_write_unlock(&namespace_rwlock);
347
		else
348
			rwlock_read_unlock(&namespace_rwlock);
2689 jermar 349
		ipc_answer_0(rid, rc);
350
		free(path);
351
		return;
352
	}
353
 
2748 jermar 354
	/* Path is no longer needed. */
2689 jermar 355
	free(path);
356
 
2691 jermar 357
	vfs_node_t *node = vfs_node_get(&lr);
2708 jermar 358
	if (lflag & L_CREATE)
359
		rwlock_write_unlock(&namespace_rwlock);
360
	else
361
		rwlock_read_unlock(&namespace_rwlock);
2689 jermar 362
 
2748 jermar 363
	/* Truncate the file if requested and if necessary. */
364
	if (oflag & O_TRUNC) {
2749 jermar 365
		rwlock_write_lock(&node->contents_rwlock);
2748 jermar 366
		if (node->size) {
367
			rc = vfs_truncate_internal(node->fs_handle,
368
			    node->dev_handle, node->index, 0);
369
			if (rc) {
2749 jermar 370
				rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 371
				vfs_node_put(node);
372
				ipc_answer_0(rid, rc);
373
				return;
374
			}
375
			node->size = 0;
376
		}
2749 jermar 377
		rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 378
	}
379
 
2689 jermar 380
	/*
381
	 * Get ourselves a file descriptor and the corresponding vfs_file_t
382
	 * structure.
383
	 */
384
	int fd = vfs_fd_alloc();
385
	if (fd < 0) {
386
		vfs_node_put(node);
387
		ipc_answer_0(rid, fd);
388
		return;
389
	}
390
	vfs_file_t *file = vfs_file_get(fd);
391
	file->node = node;
2710 jermar 392
	if (oflag & O_APPEND) 
2709 jermar 393
		file->append = true;
2689 jermar 394
 
395
	/*
396
	 * The following increase in reference count is for the fact that the
397
	 * file is being opened and that a file structure is pointing to it.
398
	 * It is necessary so that the file will not disappear when
399
	 * vfs_node_put() is called. The reference will be dropped by the
400
	 * respective VFS_CLOSE.
401
	 */
402
	vfs_node_addref(node);
403
	vfs_node_put(node);
404
 
2707 jermar 405
	/* Success! Return the new file descriptor to the client. */
2689 jermar 406
	ipc_answer_1(rid, EOK, fd);
407
}
408
 
2734 jermar 409
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
410
{
411
	int fd = IPC_GET_ARG1(*request);
3215 jermar 412
	int rc = vfs_fd_free(fd);
413
	ipc_answer_0(rid, rc);
2734 jermar 414
}
415
 
2689 jermar 416
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
417
{
418
 
419
	/*
420
	 * The following code strongly depends on the fact that the files data
421
	 * structure can be only accessed by a single fibril and all file
422
	 * operations are serialized (i.e. the reads and writes cannot
423
	 * interleave and a file cannot be closed while it is being read).
424
	 *
425
	 * Additional synchronization needs to be added once the table of
426
	 * open files supports parallel access!
427
	 */
428
 
429
	int fd = IPC_GET_ARG1(*request);
3079 decky 430
 
2707 jermar 431
	/* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 432
	vfs_file_t *file = vfs_file_get(fd);
433
	if (!file) {
434
		ipc_answer_0(rid, ENOENT);
435
		return;
436
	}
3079 decky 437
 
2689 jermar 438
	/*
439
	 * Now we need to receive a call with client's
440
	 * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
441
	 */
442
	ipc_callid_t callid;
443
	int res;
444
	if (read)
445
		res = ipc_data_read_receive(&callid, NULL);
446
	else 
447
		res = ipc_data_write_receive(&callid, NULL);
448
	if (!res) {
449
		ipc_answer_0(callid, EINVAL);
450
		ipc_answer_0(rid, EINVAL);
451
		return;
452
	}
3079 decky 453
 
2689 jermar 454
	/*
455
	 * Lock the open file structure so that no other thread can manipulate
456
	 * the same open file at a time.
457
	 */
458
	futex_down(&file->lock);
3079 decky 459
 
2689 jermar 460
	/*
461
	 * Lock the file's node so that no other client can read/write to it at
462
	 * the same time.
463
	 */
464
	if (read)
465
		rwlock_read_lock(&file->node->contents_rwlock);
466
	else
467
		rwlock_write_lock(&file->node->contents_rwlock);
3079 decky 468
 
2689 jermar 469
	int fs_phone = vfs_grab_phone(file->node->fs_handle);	
470
 
2707 jermar 471
	/* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
2689 jermar 472
	aid_t msg;
473
	ipc_call_t answer;
2709 jermar 474
	if (!read && file->append)
475
		file->pos = file->node->size;
2689 jermar 476
	msg = async_send_3(fs_phone, IPC_GET_METHOD(*request),
477
	    file->node->dev_handle, file->node->index, file->pos, &answer);
478
 
479
	/*
480
	 * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
481
	 * destination FS server. The call will be routed as if sent by
482
	 * ourselves. Note that call arguments are immutable in this case so we
483
	 * don't have to bother.
484
	 */
485
	ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
3079 decky 486
 
2689 jermar 487
	vfs_release_phone(fs_phone);
3079 decky 488
 
2707 jermar 489
	/* Wait for reply from the FS server. */
2689 jermar 490
	ipcarg_t rc;
491
	async_wait_for(msg, &rc);
492
	size_t bytes = IPC_GET_ARG1(answer);
3079 decky 493
 
2707 jermar 494
	/* Unlock the VFS node. */
2689 jermar 495
	if (read)
496
		rwlock_read_unlock(&file->node->contents_rwlock);
497
	else {
498
		/* Update the cached version of node's size. */
2710 jermar 499
		if (rc == EOK)
500
			file->node->size = IPC_GET_ARG2(answer); 
2689 jermar 501
		rwlock_write_unlock(&file->node->contents_rwlock);
502
	}
3079 decky 503
 
2707 jermar 504
	/* Update the position pointer and unlock the open file. */
2710 jermar 505
	if (rc == EOK)
506
		file->pos += bytes;
2689 jermar 507
	futex_up(&file->lock);
3079 decky 508
 
2689 jermar 509
	/*
510
	 * FS server's reply is the final result of the whole operation we
511
	 * return to the client.
512
	 */
513
	ipc_answer_1(rid, rc, bytes);
514
}
515
 
516
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
517
{
518
	vfs_rdwr(rid, request, true);
519
}
520
 
521
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
522
{
523
	vfs_rdwr(rid, request, false);
524
}
525
 
526
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
527
{
528
	int fd = (int) IPC_GET_ARG1(*request);
529
	off_t off = (off_t) IPC_GET_ARG2(*request);
530
	int whence = (int) IPC_GET_ARG3(*request);
531
 
532
 
2707 jermar 533
	/* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 534
	vfs_file_t *file = vfs_file_get(fd);
535
	if (!file) {
536
		ipc_answer_0(rid, ENOENT);
537
		return;
538
	}
539
 
540
	off_t newpos;
541
	futex_down(&file->lock);
542
	if (whence == SEEK_SET) {
543
		file->pos = off;
544
		futex_up(&file->lock);
545
		ipc_answer_1(rid, EOK, off);
546
		return;
547
	}
548
	if (whence == SEEK_CUR) {
549
		if (file->pos + off < file->pos) {
550
			futex_up(&file->lock);
551
			ipc_answer_0(rid, EOVERFLOW);
552
			return;
553
		}
554
		file->pos += off;
555
		newpos = file->pos;
556
		futex_up(&file->lock);
557
		ipc_answer_1(rid, EOK, newpos);
558
		return;
559
	}
560
	if (whence == SEEK_END) {
561
		rwlock_read_lock(&file->node->contents_rwlock);
562
		size_t size = file->node->size;
563
		rwlock_read_unlock(&file->node->contents_rwlock);
564
		if (size + off < size) {
565
			futex_up(&file->lock);
566
			ipc_answer_0(rid, EOVERFLOW);
567
			return;
568
		}
569
		newpos = size + off;
570
		futex_up(&file->lock);
571
		ipc_answer_1(rid, EOK, newpos);
572
		return;
573
	}
574
	futex_up(&file->lock);
575
	ipc_answer_0(rid, EINVAL);
576
}
577
 
2770 jermar 578
int
579
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
580
    fs_index_t index, size_t size)
2748 jermar 581
{
582
	ipcarg_t rc;
583
	int fs_phone;
584
 
585
	fs_phone = vfs_grab_phone(fs_handle);
586
	rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle,
587
	    (ipcarg_t)index, (ipcarg_t)size);
588
	vfs_release_phone(fs_phone);
589
	return (int)rc;
590
}
591
 
2693 jermar 592
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
593
{
594
	int fd = IPC_GET_ARG1(*request);
595
	size_t size = IPC_GET_ARG2(*request);
2748 jermar 596
	int rc;
2693 jermar 597
 
598
	vfs_file_t *file = vfs_file_get(fd);
599
	if (!file) {
600
		ipc_answer_0(rid, ENOENT);
601
		return;
602
	}
603
	futex_down(&file->lock);
604
 
605
	rwlock_write_lock(&file->node->contents_rwlock);
2748 jermar 606
	rc = vfs_truncate_internal(file->node->fs_handle,
607
	    file->node->dev_handle, file->node->index, size);
2693 jermar 608
	if (rc == EOK)
609
		file->node->size = size;
610
	rwlock_write_unlock(&file->node->contents_rwlock);
611
 
612
	futex_up(&file->lock);
2748 jermar 613
	ipc_answer_0(rid, (ipcarg_t)rc);
2693 jermar 614
}
615
 
2707 jermar 616
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
617
{
618
	int mode = IPC_GET_ARG1(*request);
2735 jermar 619
 
2707 jermar 620
	size_t len;
621
	ipc_callid_t callid;
622
 
623
	if (!ipc_data_write_receive(&callid, &len)) {
624
		ipc_answer_0(callid, EINVAL);
625
		ipc_answer_0(rid, EINVAL);
626
		return;
627
	}
2752 jermar 628
	char *path = malloc(len + 1);
2707 jermar 629
	if (!path) {
630
		ipc_answer_0(callid, ENOMEM);
631
		ipc_answer_0(rid, ENOMEM);
632
		return;
633
	}
634
	int rc;
635
	if ((rc = ipc_data_write_finalize(callid, path, len))) {
636
		ipc_answer_0(rid, rc);
637
		free(path);
638
		return;
639
	}
2752 jermar 640
	path[len] = '\0';
2707 jermar 641
 
642
	rwlock_write_lock(&namespace_rwlock);
643
	int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
2752 jermar 644
	rc = vfs_lookup_internal(path, lflag, NULL, NULL);
2707 jermar 645
	rwlock_write_unlock(&namespace_rwlock);
646
	free(path);
647
	ipc_answer_0(rid, rc);
648
}
649
 
2735 jermar 650
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
651
{
652
	int lflag = IPC_GET_ARG1(*request);
653
 
654
	size_t len;
655
	ipc_callid_t callid;
656
 
657
	if (!ipc_data_write_receive(&callid, &len)) {
658
		ipc_answer_0(callid, EINVAL);
659
		ipc_answer_0(rid, EINVAL);
660
		return;
661
	}
2752 jermar 662
	char *path = malloc(len + 1);
2735 jermar 663
	if (!path) {
664
		ipc_answer_0(callid, ENOMEM);
665
		ipc_answer_0(rid, ENOMEM);
666
		return;
667
	}
668
	int rc;
669
	if ((rc = ipc_data_write_finalize(callid, path, len))) {
670
		ipc_answer_0(rid, rc);
671
		free(path);
672
		return;
673
	}
2752 jermar 674
	path[len] = '\0';
2735 jermar 675
 
676
	rwlock_write_lock(&namespace_rwlock);
677
	lflag &= L_DIRECTORY;	/* sanitize lflag */
678
	vfs_lookup_res_t lr;
2763 jermar 679
	rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
2735 jermar 680
	free(path);
681
	if (rc != EOK) {
682
		rwlock_write_unlock(&namespace_rwlock);
683
		ipc_answer_0(rid, rc);
684
		return;
685
	}
686
 
687
	/*
688
	 * The name has already been unlinked by vfs_lookup_internal().
689
	 * We have to get and put the VFS node to ensure that it is
2742 jermar 690
	 * VFS_DESTROY'ed after the last reference to it is dropped.
2735 jermar 691
	 */
692
	vfs_node_t *node = vfs_node_get(&lr);
2766 jermar 693
	futex_down(&nodes_futex);
2735 jermar 694
	node->lnkcnt--;
2766 jermar 695
	futex_up(&nodes_futex);
2735 jermar 696
	rwlock_write_unlock(&namespace_rwlock);
697
	vfs_node_put(node);
698
	ipc_answer_0(rid, EOK);
699
}
700
 
2763 jermar 701
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
702
{
703
	size_t len;
704
	ipc_callid_t callid;
705
	int rc;
706
 
707
	/* Retrieve the old path. */
708
	if (!ipc_data_write_receive(&callid, &len)) {
709
		ipc_answer_0(callid, EINVAL);
710
		ipc_answer_0(rid, EINVAL);
711
		return;
712
	}
713
	char *old = malloc(len + 1);
714
	if (!old) {
715
		ipc_answer_0(callid, ENOMEM);
716
		ipc_answer_0(rid, ENOMEM);
717
		return;
718
	}
719
	if ((rc = ipc_data_write_finalize(callid, old, len))) {
720
		ipc_answer_0(rid, rc);
721
		free(old);
722
		return;
723
	}
724
	old[len] = '\0';
725
 
726
	/* Retrieve the new path. */
727
	if (!ipc_data_write_receive(&callid, &len)) {
728
		ipc_answer_0(callid, EINVAL);
729
		ipc_answer_0(rid, EINVAL);
730
		free(old);
731
		return;
732
	}
733
	char *new = malloc(len + 1);
734
	if (!new) {
735
		ipc_answer_0(callid, ENOMEM);
736
		ipc_answer_0(rid, ENOMEM);
737
		free(old);
738
		return;
739
	}
740
	if ((rc = ipc_data_write_finalize(callid, new, len))) {
741
		ipc_answer_0(rid, rc);
742
		free(old);
743
		free(new);
744
		return;
745
	}
746
	new[len] = '\0';
747
 
748
	char *oldc = canonify(old, &len);
749
	char *newc = canonify(new, NULL);
750
	if (!oldc || !newc) {
751
		ipc_answer_0(rid, EINVAL);
752
		free(old);
753
		free(new);
754
		return;
755
	}
756
	if (!strncmp(newc, oldc, len)) {
757
		/* oldc is a prefix of newc */
758
		ipc_answer_0(rid, EINVAL);
759
		free(old);
760
		free(new);
761
		return;
762
	}
763
 
764
	vfs_lookup_res_t old_lr;
765
	vfs_lookup_res_t new_lr;
766
	vfs_lookup_res_t new_par_lr;
767
	rwlock_write_lock(&namespace_rwlock);
768
	/* Lookup the node belonging to the old file name. */
769
	rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
770
	if (rc != EOK) {
771
		rwlock_write_unlock(&namespace_rwlock);
772
		ipc_answer_0(rid, rc);
773
		free(old);
774
		free(new);
775
		return;
776
	}
777
	vfs_node_t *old_node = vfs_node_get(&old_lr);
778
	if (!old_node) {
779
		rwlock_write_unlock(&namespace_rwlock);
780
		ipc_answer_0(rid, ENOMEM);
781
		free(old);
782
		free(new);
783
		return;
784
	}
785
	/* Lookup parent of the new file name. */
786
	rc = vfs_lookup_internal(newc, L_PARENT, &new_par_lr, NULL);
787
	if (rc != EOK) {
788
		rwlock_write_unlock(&namespace_rwlock);
789
		ipc_answer_0(rid, rc);
790
		free(old);
791
		free(new);
792
		return;
793
	}
794
	/* Check whether linking to the same file system instance. */
795
	if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
796
	    (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
797
		rwlock_write_unlock(&namespace_rwlock);
798
		ipc_answer_0(rid, EXDEV);	/* different file systems */
799
		free(old);
800
		free(new);
801
		return;
802
	}
803
	/* Destroy the old link for the new name. */
804
	vfs_node_t *new_node = NULL;
805
	rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
806
	switch (rc) {
807
	case ENOENT:
808
		/* simply not in our way */
809
		break;
810
	case EOK:
811
		new_node = vfs_node_get(&new_lr);
812
		if (!new_node) {
813
			rwlock_write_unlock(&namespace_rwlock);
814
			ipc_answer_0(rid, ENOMEM);
815
			free(old);
816
			free(new);
817
			return;
818
		}
2766 jermar 819
		futex_down(&nodes_futex);
2763 jermar 820
		new_node->lnkcnt--;
2766 jermar 821
		futex_up(&nodes_futex);
2763 jermar 822
		break;
823
	default:
824
		rwlock_write_unlock(&namespace_rwlock);
825
		ipc_answer_0(rid, ENOTEMPTY);
826
		free(old);
827
		free(new);
828
		return;
829
	}
830
	/* Create the new link for the new name. */
831
	rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
832
	if (rc != EOK) {
833
		rwlock_write_unlock(&namespace_rwlock);
834
		if (new_node)
835
			vfs_node_put(new_node);
836
		ipc_answer_0(rid, rc);
837
		free(old);
838
		free(new);
839
		return;
840
	}
2766 jermar 841
	futex_down(&nodes_futex);
2763 jermar 842
	old_node->lnkcnt++;
2766 jermar 843
	futex_up(&nodes_futex);
2763 jermar 844
	/* Destroy the link for the old name. */
845
	rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
846
	if (rc != EOK) {
847
		rwlock_write_unlock(&namespace_rwlock);
848
		vfs_node_put(old_node);
849
		if (new_node)
850
			vfs_node_put(new_node);
851
		ipc_answer_0(rid, rc);
852
		free(old);
853
		free(new);
854
		return;
855
	}
2766 jermar 856
	futex_down(&nodes_futex);
2763 jermar 857
	old_node->lnkcnt--;
2766 jermar 858
	futex_up(&nodes_futex);
2763 jermar 859
	rwlock_write_unlock(&namespace_rwlock);
860
	vfs_node_put(old_node);
861
	if (new_node)
862
		vfs_node_put(new_node);
863
	free(old);
864
	free(new);
865
	ipc_answer_0(rid, EOK);
866
}
867
 
2689 jermar 868
/**
869
 * @}
870
 */