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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;
2689 jermar 65
vfs_triplet_t rootfs = {
66
    .fs_handle = 0,
67
    .dev_handle = 0,
68
    .index = 0,
69
};
70
 
2770 jermar 71
static int
72
lookup_root(fs_handle_t fs_handle, dev_handle_t dev_handle,
73
    vfs_lookup_res_t *result)
2689 jermar 74
{
75
    vfs_pair_t altroot = {
76
        .fs_handle = fs_handle,
77
        .dev_handle = dev_handle,
78
    };
79
 
2752 jermar 80
    return vfs_lookup_internal("/", L_DIRECTORY, result, &altroot);
2689 jermar 81
}
82
 
83
void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
84
{
2770 jermar 85
    dev_handle_t dev_handle;
2689 jermar 86
    vfs_node_t *mp_node = NULL;
2957 jermar 87
    int rc;
2958 jermar 88
    int phone;
2689 jermar 89
 
90
    /*
91
     * We expect the library to do the device-name to device-handle
92
     * translation for us, thus the device handle will arrive as ARG1
93
     * in the request.
94
     */
2770 jermar 95
    dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
2689 jermar 96
 
97
    /*
98
     * For now, don't make use of ARG2 and ARG3, but they can be used to
99
     * carry mount options in the future.
100
     */
101
 
102
    ipc_callid_t callid;
103
    size_t size;
104
 
105
    /*
106
     * Now, we expect the client to send us data with the name of the file
107
     * system.
108
     */
109
    if (!ipc_data_write_receive(&callid, &size)) {
110
        ipc_answer_0(callid, EINVAL);
111
        ipc_answer_0(rid, EINVAL);
112
        return;
113
    }
114
 
115
    /*
116
     * Don't receive more than is necessary for storing a full file system
117
     * name.
118
     */
119
    if (size < 1 || size > FS_NAME_MAXLEN) {
120
        ipc_answer_0(callid, EINVAL);
121
        ipc_answer_0(rid, EINVAL);
122
        return;
123
    }
124
 
2707 jermar 125
    /* Deliver the file system name. */
2689 jermar 126
    char fs_name[FS_NAME_MAXLEN + 1];
127
    (void) ipc_data_write_finalize(callid, fs_name, size);
128
    fs_name[size] = '\0';
129
 
130
    /*
131
     * Check if we know a file system with the same name as is in fs_name.
132
     * This will also give us its file system handle.
133
     */
2770 jermar 134
    fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);
2689 jermar 135
    if (!fs_handle) {
136
        ipc_answer_0(rid, ENOENT);
137
        return;
138
    }
139
 
2707 jermar 140
    /* Now, we want the client to send us the mount point. */
2689 jermar 141
    if (!ipc_data_write_receive(&callid, &size)) {
142
        ipc_answer_0(callid, EINVAL);
143
        ipc_answer_0(rid, EINVAL);
144
        return;
145
    }
146
 
2707 jermar 147
    /* Check whether size is reasonable wrt. the mount point. */
2689 jermar 148
    if (size < 1 || size > MAX_PATH_LEN) {
149
        ipc_answer_0(callid, EINVAL);
150
        ipc_answer_0(rid, EINVAL);
151
        return;
152
    }
2707 jermar 153
    /* Allocate buffer for the mount point data being received. */
2689 jermar 154
    uint8_t *buf;
2752 jermar 155
    buf = malloc(size + 1);
2689 jermar 156
    if (!buf) {
157
        ipc_answer_0(callid, ENOMEM);
158
        ipc_answer_0(rid, ENOMEM);
159
        return;
160
    }
161
 
2707 jermar 162
    /* Deliver the mount point. */
2689 jermar 163
    (void) ipc_data_write_finalize(callid, buf, size);
2752 jermar 164
    buf[size] = '\0';
2689 jermar 165
 
166
    /*
167
     * Lookup the root node of the filesystem being mounted.
168
     * In this case, we don't need to take the namespace_futex as the root
169
     * node cannot be removed. However, we do take a reference to it so
170
     * that we can track how many times it has been mounted.
171
     */
2691 jermar 172
    vfs_lookup_res_t mr_res;
173
    rc = lookup_root(fs_handle, dev_handle, &mr_res);
2689 jermar 174
    if (rc != EOK) {
175
        free(buf);
176
        ipc_answer_0(rid, rc);
177
        return;
178
    }
2691 jermar 179
    vfs_node_t *mr_node = vfs_node_get(&mr_res);
2689 jermar 180
    if (!mr_node) {
181
        free(buf);
182
        ipc_answer_0(rid, ENOMEM);
183
        return;
184
    }
185
 
2707 jermar 186
    /* Finally, we need to resolve the path to the mountpoint. */
2691 jermar 187
    vfs_lookup_res_t mp_res;
2689 jermar 188
    futex_down(&rootfs_futex);
189
    if (rootfs.fs_handle) {
2707 jermar 190
        /* We already have the root FS. */
2689 jermar 191
        rwlock_write_lock(&namespace_rwlock);
2788 jermar 192
        if ((size == 1) && (buf[0] == '/')) {
193
            /* Trying to mount root FS over root FS */
194
            rwlock_write_unlock(&namespace_rwlock);
195
            futex_up(&rootfs_futex);
196
            vfs_node_put(mr_node);
197
            free(buf);
198
            ipc_answer_0(rid, EBUSY);
199
            return;
200
        }
2752 jermar 201
        rc = vfs_lookup_internal(buf, L_DIRECTORY, &mp_res, NULL);
2689 jermar 202
        if (rc != EOK) {
2707 jermar 203
            /* The lookup failed for some reason. */
2689 jermar 204
            rwlock_write_unlock(&namespace_rwlock);
205
            futex_up(&rootfs_futex);
206
            vfs_node_put(mr_node);  /* failed -> drop reference */
207
            free(buf);
208
            ipc_answer_0(rid, rc);
209
            return;
210
        }
2691 jermar 211
        mp_node = vfs_node_get(&mp_res);
2689 jermar 212
        if (!mp_node) {
213
            rwlock_write_unlock(&namespace_rwlock);
214
            futex_up(&rootfs_futex);
215
            vfs_node_put(mr_node);  /* failed -> drop reference */
216
            free(buf);
217
            ipc_answer_0(rid, ENOMEM);
218
            return;
219
        }
220
        /*
221
         * Now we hold a reference to mp_node.
222
         * It will be dropped upon the corresponding VFS_UNMOUNT.
223
         * This prevents the mount point from being deleted.
224
         */
225
        rwlock_write_unlock(&namespace_rwlock);
226
    } else {
2707 jermar 227
        /* We still don't have the root file system mounted. */
2689 jermar 228
        if ((size == 1) && (buf[0] == '/')) {
2958 jermar 229
            /*
230
             * For this simple, but important case,
231
             * we are almost done.
232
             */
233
            free(buf);
234
 
235
            /* Inform the mount point about the root mount. */
236
            phone = vfs_grab_phone(mr_res.triplet.fs_handle);
237
            rc = async_req_5_0(phone, VFS_MOUNT,
238
                (ipcarg_t) mr_res.triplet.dev_handle,
239
                (ipcarg_t) mr_res.triplet.index,
240
                (ipcarg_t) mr_res.triplet.fs_handle,
241
                (ipcarg_t) mr_res.triplet.dev_handle,
242
                (ipcarg_t) mr_res.triplet.index);
243
            vfs_release_phone(phone);
244
 
245
            if (rc == EOK)
246
                rootfs = mr_res.triplet;
247
            else
248
                vfs_node_put(mr_node);
249
 
2689 jermar 250
            futex_up(&rootfs_futex);
2958 jermar 251
            ipc_answer_0(rid, rc);
2689 jermar 252
            return;
253
        } else {
254
            /*
255
             * We can't resolve this without the root filesystem
256
             * being mounted first.
257
             */
258
            futex_up(&rootfs_futex);
259
            free(buf);
260
            vfs_node_put(mr_node);  /* failed -> drop reference */
261
            ipc_answer_0(rid, ENOENT);
262
            return;
263
        }
264
    }
265
    futex_up(&rootfs_futex);
266
 
267
    free(buf);  /* The buffer is not needed anymore. */
268
 
269
    /*
270
     * At this point, we have all necessary pieces: file system and device
271
     * handles, and we know the mount point VFS node and also the root node
272
     * of the file system being mounted.
273
     */
274
 
2957 jermar 275
    /**
276
     * @todo
277
     * Add more IPC parameters so that we can send mount mode/flags.
278
     */
2958 jermar 279
    phone = vfs_grab_phone(mp_res.triplet.fs_handle);
2957 jermar 280
    rc = async_req_5_0(phone, VFS_MOUNT,
2691 jermar 281
        (ipcarg_t) mp_res.triplet.dev_handle,
2957 jermar 282
        (ipcarg_t) mp_res.triplet.index,
2691 jermar 283
        (ipcarg_t) mr_res.triplet.fs_handle,
284
        (ipcarg_t) mr_res.triplet.dev_handle,
2957 jermar 285
        (ipcarg_t) mr_res.triplet.index);
2689 jermar 286
    vfs_release_phone(phone);
287
 
2957 jermar 288
    if (rc != EOK) {
2689 jermar 289
        /* Mount failed, drop references to mr_node and mp_node. */
290
        vfs_node_put(mr_node);
291
        if (mp_node)
292
            vfs_node_put(mp_node);
293
    }
294
 
2957 jermar 295
    ipc_answer_0(rid, rc);
2689 jermar 296
}
297
 
298
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
299
{
300
    if (!vfs_files_init()) {
301
        ipc_answer_0(rid, ENOMEM);
302
        return;
303
    }
304
 
305
    /*
2700 jermar 306
     * The POSIX interface is open(path, oflag, mode).
307
     * We can receive oflags and mode along with the VFS_OPEN call; the path
2689 jermar 308
     * will need to arrive in another call.
2700 jermar 309
     *
310
     * We also receive one private, non-POSIX set of flags called lflag
311
     * used to pass information to vfs_lookup_internal().
2689 jermar 312
     */
2700 jermar 313
    int lflag = IPC_GET_ARG1(*request);
314
    int oflag = IPC_GET_ARG2(*request);
315
    int mode = IPC_GET_ARG3(*request);
2689 jermar 316
    size_t len;
317
 
2708 jermar 318
    if (oflag & O_CREAT)
319
        lflag |= L_CREATE;
320
    if (oflag & O_EXCL)
321
        lflag |= L_EXCLUSIVE;
322
 
2689 jermar 323
    ipc_callid_t callid;
324
 
325
    if (!ipc_data_write_receive(&callid, &len)) {
326
        ipc_answer_0(callid, EINVAL);
327
        ipc_answer_0(rid, EINVAL);
328
        return;
329
    }
2752 jermar 330
    char *path = malloc(len + 1);
2689 jermar 331
    if (!path) {
332
        ipc_answer_0(callid, ENOMEM);
333
        ipc_answer_0(rid, ENOMEM);
334
        return;
335
    }
336
    int rc;
337
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
338
        ipc_answer_0(rid, rc);
339
        free(path);
340
        return;
341
    }
2752 jermar 342
    path[len] = '\0';
2689 jermar 343
 
344
    /*
345
     * Avoid the race condition in which the file can be deleted before we
346
     * find/create-and-lock the VFS node corresponding to the looked-up
347
     * triplet.
348
     */
2708 jermar 349
    if (lflag & L_CREATE)
350
        rwlock_write_lock(&namespace_rwlock);
351
    else
352
        rwlock_read_lock(&namespace_rwlock);
2689 jermar 353
 
2707 jermar 354
    /* The path is now populated and we can call vfs_lookup_internal(). */
2691 jermar 355
    vfs_lookup_res_t lr;
2752 jermar 356
    rc = vfs_lookup_internal(path, lflag, &lr, NULL);
2689 jermar 357
    if (rc) {
2708 jermar 358
        if (lflag & L_CREATE)
359
            rwlock_write_unlock(&namespace_rwlock);
360
        else
361
            rwlock_read_unlock(&namespace_rwlock);
2689 jermar 362
        ipc_answer_0(rid, rc);
363
        free(path);
364
        return;
365
    }
366
 
2748 jermar 367
    /* Path is no longer needed. */
2689 jermar 368
    free(path);
369
 
2691 jermar 370
    vfs_node_t *node = vfs_node_get(&lr);
2708 jermar 371
    if (lflag & L_CREATE)
372
        rwlock_write_unlock(&namespace_rwlock);
373
    else
374
        rwlock_read_unlock(&namespace_rwlock);
2689 jermar 375
 
2748 jermar 376
    /* Truncate the file if requested and if necessary. */
377
    if (oflag & O_TRUNC) {
2749 jermar 378
        rwlock_write_lock(&node->contents_rwlock);
2748 jermar 379
        if (node->size) {
380
            rc = vfs_truncate_internal(node->fs_handle,
381
                node->dev_handle, node->index, 0);
382
            if (rc) {
2749 jermar 383
                rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 384
                vfs_node_put(node);
385
                ipc_answer_0(rid, rc);
386
                return;
387
            }
388
            node->size = 0;
389
        }
2749 jermar 390
        rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 391
    }
392
 
2689 jermar 393
    /*
394
     * Get ourselves a file descriptor and the corresponding vfs_file_t
395
     * structure.
396
     */
397
    int fd = vfs_fd_alloc();
398
    if (fd < 0) {
399
        vfs_node_put(node);
400
        ipc_answer_0(rid, fd);
401
        return;
402
    }
403
    vfs_file_t *file = vfs_file_get(fd);
404
    file->node = node;
2710 jermar 405
    if (oflag & O_APPEND)
2709 jermar 406
        file->append = true;
2689 jermar 407
 
408
    /*
409
     * The following increase in reference count is for the fact that the
410
     * file is being opened and that a file structure is pointing to it.
411
     * It is necessary so that the file will not disappear when
412
     * vfs_node_put() is called. The reference will be dropped by the
413
     * respective VFS_CLOSE.
414
     */
415
    vfs_node_addref(node);
416
    vfs_node_put(node);
417
 
2707 jermar 418
    /* Success! Return the new file descriptor to the client. */
2689 jermar 419
    ipc_answer_1(rid, EOK, fd);
420
}
421
 
2734 jermar 422
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
423
{
424
    int fd = IPC_GET_ARG1(*request);
425
    if (fd >= MAX_OPEN_FILES) {
426
        ipc_answer_0(rid, EBADF);
427
        return;
428
    }
429
    vfs_fd_free(fd);
430
    ipc_answer_0(rid, EOK);
431
}
432
 
2689 jermar 433
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
434
{
435
 
436
    /*
437
     * The following code strongly depends on the fact that the files data
438
     * structure can be only accessed by a single fibril and all file
439
     * operations are serialized (i.e. the reads and writes cannot
440
     * interleave and a file cannot be closed while it is being read).
441
     *
442
     * Additional synchronization needs to be added once the table of
443
     * open files supports parallel access!
444
     */
445
 
446
    int fd = IPC_GET_ARG1(*request);
447
 
2707 jermar 448
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 449
    vfs_file_t *file = vfs_file_get(fd);
450
    if (!file) {
451
        ipc_answer_0(rid, ENOENT);
452
        return;
453
    }
454
 
455
    /*
456
     * Now we need to receive a call with client's
457
     * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
458
     */
459
    ipc_callid_t callid;
460
    int res;
461
    if (read)
462
        res = ipc_data_read_receive(&callid, NULL);
463
    else
464
        res = ipc_data_write_receive(&callid, NULL);
465
    if (!res) {
466
        ipc_answer_0(callid, EINVAL);
467
        ipc_answer_0(rid, EINVAL);
468
        return;
469
    }
470
 
471
    /*
472
     * Lock the open file structure so that no other thread can manipulate
473
     * the same open file at a time.
474
     */
475
    futex_down(&file->lock);
476
 
477
    /*
478
     * Lock the file's node so that no other client can read/write to it at
479
     * the same time.
480
     */
481
    if (read)
482
        rwlock_read_lock(&file->node->contents_rwlock);
483
    else
484
        rwlock_write_lock(&file->node->contents_rwlock);
485
 
486
    int fs_phone = vfs_grab_phone(file->node->fs_handle);  
487
 
2707 jermar 488
    /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
2689 jermar 489
    aid_t msg;
490
    ipc_call_t answer;
2709 jermar 491
    if (!read && file->append)
492
        file->pos = file->node->size;
2689 jermar 493
    msg = async_send_3(fs_phone, IPC_GET_METHOD(*request),
494
        file->node->dev_handle, file->node->index, file->pos, &answer);
495
 
496
    /*
497
     * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
498
     * destination FS server. The call will be routed as if sent by
499
     * ourselves. Note that call arguments are immutable in this case so we
500
     * don't have to bother.
501
     */
502
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
503
 
504
    vfs_release_phone(fs_phone);
505
 
2707 jermar 506
    /* Wait for reply from the FS server. */
2689 jermar 507
    ipcarg_t rc;
508
    async_wait_for(msg, &rc);
509
    size_t bytes = IPC_GET_ARG1(answer);
510
 
2707 jermar 511
    /* Unlock the VFS node. */
2689 jermar 512
    if (read)
513
        rwlock_read_unlock(&file->node->contents_rwlock);
514
    else {
515
        /* Update the cached version of node's size. */
2710 jermar 516
        if (rc == EOK)
517
            file->node->size = IPC_GET_ARG2(answer);
2689 jermar 518
        rwlock_write_unlock(&file->node->contents_rwlock);
519
    }
520
 
2707 jermar 521
    /* Update the position pointer and unlock the open file. */
2710 jermar 522
    if (rc == EOK)
523
        file->pos += bytes;
2689 jermar 524
    futex_up(&file->lock);
525
 
526
    /*
527
     * FS server's reply is the final result of the whole operation we
528
     * return to the client.
529
     */
530
    ipc_answer_1(rid, rc, bytes);
531
}
532
 
533
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
534
{
535
    vfs_rdwr(rid, request, true);
536
}
537
 
538
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
539
{
540
    vfs_rdwr(rid, request, false);
541
}
542
 
543
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
544
{
545
    int fd = (int) IPC_GET_ARG1(*request);
546
    off_t off = (off_t) IPC_GET_ARG2(*request);
547
    int whence = (int) IPC_GET_ARG3(*request);
548
 
549
 
2707 jermar 550
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 551
    vfs_file_t *file = vfs_file_get(fd);
552
    if (!file) {
553
        ipc_answer_0(rid, ENOENT);
554
        return;
555
    }
556
 
557
    off_t newpos;
558
    futex_down(&file->lock);
559
    if (whence == SEEK_SET) {
560
        file->pos = off;
561
        futex_up(&file->lock);
562
        ipc_answer_1(rid, EOK, off);
563
        return;
564
    }
565
    if (whence == SEEK_CUR) {
566
        if (file->pos + off < file->pos) {
567
            futex_up(&file->lock);
568
            ipc_answer_0(rid, EOVERFLOW);
569
            return;
570
        }
571
        file->pos += off;
572
        newpos = file->pos;
573
        futex_up(&file->lock);
574
        ipc_answer_1(rid, EOK, newpos);
575
        return;
576
    }
577
    if (whence == SEEK_END) {
578
        rwlock_read_lock(&file->node->contents_rwlock);
579
        size_t size = file->node->size;
580
        rwlock_read_unlock(&file->node->contents_rwlock);
581
        if (size + off < size) {
582
            futex_up(&file->lock);
583
            ipc_answer_0(rid, EOVERFLOW);
584
            return;
585
        }
586
        newpos = size + off;
587
        futex_up(&file->lock);
588
        ipc_answer_1(rid, EOK, newpos);
589
        return;
590
    }
591
    futex_up(&file->lock);
592
    ipc_answer_0(rid, EINVAL);
593
}
594
 
2770 jermar 595
int
596
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
597
    fs_index_t index, size_t size)
2748 jermar 598
{
599
    ipcarg_t rc;
600
    int fs_phone;
601
 
602
    fs_phone = vfs_grab_phone(fs_handle);
603
    rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle,
604
        (ipcarg_t)index, (ipcarg_t)size);
605
    vfs_release_phone(fs_phone);
606
    return (int)rc;
607
}
608
 
2693 jermar 609
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
610
{
611
    int fd = IPC_GET_ARG1(*request);
612
    size_t size = IPC_GET_ARG2(*request);
2748 jermar 613
    int rc;
2693 jermar 614
 
615
    vfs_file_t *file = vfs_file_get(fd);
616
    if (!file) {
617
        ipc_answer_0(rid, ENOENT);
618
        return;
619
    }
620
    futex_down(&file->lock);
621
 
622
    rwlock_write_lock(&file->node->contents_rwlock);
2748 jermar 623
    rc = vfs_truncate_internal(file->node->fs_handle,
624
        file->node->dev_handle, file->node->index, size);
2693 jermar 625
    if (rc == EOK)
626
        file->node->size = size;
627
    rwlock_write_unlock(&file->node->contents_rwlock);
628
 
629
    futex_up(&file->lock);
2748 jermar 630
    ipc_answer_0(rid, (ipcarg_t)rc);
2693 jermar 631
}
632
 
2707 jermar 633
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
634
{
635
    int mode = IPC_GET_ARG1(*request);
2735 jermar 636
 
2707 jermar 637
    size_t len;
638
    ipc_callid_t callid;
639
 
640
    if (!ipc_data_write_receive(&callid, &len)) {
641
        ipc_answer_0(callid, EINVAL);
642
        ipc_answer_0(rid, EINVAL);
643
        return;
644
    }
2752 jermar 645
    char *path = malloc(len + 1);
2707 jermar 646
    if (!path) {
647
        ipc_answer_0(callid, ENOMEM);
648
        ipc_answer_0(rid, ENOMEM);
649
        return;
650
    }
651
    int rc;
652
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
653
        ipc_answer_0(rid, rc);
654
        free(path);
655
        return;
656
    }
2752 jermar 657
    path[len] = '\0';
2707 jermar 658
 
659
    rwlock_write_lock(&namespace_rwlock);
660
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
2752 jermar 661
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
2707 jermar 662
    rwlock_write_unlock(&namespace_rwlock);
663
    free(path);
664
    ipc_answer_0(rid, rc);
665
}
666
 
2735 jermar 667
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
668
{
669
    int lflag = IPC_GET_ARG1(*request);
670
 
671
    size_t len;
672
    ipc_callid_t callid;
673
 
674
    if (!ipc_data_write_receive(&callid, &len)) {
675
        ipc_answer_0(callid, EINVAL);
676
        ipc_answer_0(rid, EINVAL);
677
        return;
678
    }
2752 jermar 679
    char *path = malloc(len + 1);
2735 jermar 680
    if (!path) {
681
        ipc_answer_0(callid, ENOMEM);
682
        ipc_answer_0(rid, ENOMEM);
683
        return;
684
    }
685
    int rc;
686
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
687
        ipc_answer_0(rid, rc);
688
        free(path);
689
        return;
690
    }
2752 jermar 691
    path[len] = '\0';
2735 jermar 692
 
693
    rwlock_write_lock(&namespace_rwlock);
694
    lflag &= L_DIRECTORY;   /* sanitize lflag */
695
    vfs_lookup_res_t lr;
2763 jermar 696
    rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
2735 jermar 697
    free(path);
698
    if (rc != EOK) {
699
        rwlock_write_unlock(&namespace_rwlock);
700
        ipc_answer_0(rid, rc);
701
        return;
702
    }
703
 
704
    /*
705
     * The name has already been unlinked by vfs_lookup_internal().
706
     * We have to get and put the VFS node to ensure that it is
2742 jermar 707
     * VFS_DESTROY'ed after the last reference to it is dropped.
2735 jermar 708
     */
709
    vfs_node_t *node = vfs_node_get(&lr);
2766 jermar 710
    futex_down(&nodes_futex);
2735 jermar 711
    node->lnkcnt--;
2766 jermar 712
    futex_up(&nodes_futex);
2735 jermar 713
    rwlock_write_unlock(&namespace_rwlock);
714
    vfs_node_put(node);
715
    ipc_answer_0(rid, EOK);
716
}
717
 
2763 jermar 718
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
719
{
720
    size_t len;
721
    ipc_callid_t callid;
722
    int rc;
723
 
724
    /* Retrieve the old path. */
725
    if (!ipc_data_write_receive(&callid, &len)) {
726
        ipc_answer_0(callid, EINVAL);
727
        ipc_answer_0(rid, EINVAL);
728
        return;
729
    }
730
    char *old = malloc(len + 1);
731
    if (!old) {
732
        ipc_answer_0(callid, ENOMEM);
733
        ipc_answer_0(rid, ENOMEM);
734
        return;
735
    }
736
    if ((rc = ipc_data_write_finalize(callid, old, len))) {
737
        ipc_answer_0(rid, rc);
738
        free(old);
739
        return;
740
    }
741
    old[len] = '\0';
742
 
743
    /* Retrieve the new path. */
744
    if (!ipc_data_write_receive(&callid, &len)) {
745
        ipc_answer_0(callid, EINVAL);
746
        ipc_answer_0(rid, EINVAL);
747
        free(old);
748
        return;
749
    }
750
    char *new = malloc(len + 1);
751
    if (!new) {
752
        ipc_answer_0(callid, ENOMEM);
753
        ipc_answer_0(rid, ENOMEM);
754
        free(old);
755
        return;
756
    }
757
    if ((rc = ipc_data_write_finalize(callid, new, len))) {
758
        ipc_answer_0(rid, rc);
759
        free(old);
760
        free(new);
761
        return;
762
    }
763
    new[len] = '\0';
764
 
765
    char *oldc = canonify(old, &len);
766
    char *newc = canonify(new, NULL);
767
    if (!oldc || !newc) {
768
        ipc_answer_0(rid, EINVAL);
769
        free(old);
770
        free(new);
771
        return;
772
    }
773
    if (!strncmp(newc, oldc, len)) {
774
        /* oldc is a prefix of newc */
775
        ipc_answer_0(rid, EINVAL);
776
        free(old);
777
        free(new);
778
        return;
779
    }
780
 
781
    vfs_lookup_res_t old_lr;
782
    vfs_lookup_res_t new_lr;
783
    vfs_lookup_res_t new_par_lr;
784
    rwlock_write_lock(&namespace_rwlock);
785
    /* Lookup the node belonging to the old file name. */
786
    rc = vfs_lookup_internal(oldc, L_NONE, &old_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
    vfs_node_t *old_node = vfs_node_get(&old_lr);
795
    if (!old_node) {
796
        rwlock_write_unlock(&namespace_rwlock);
797
        ipc_answer_0(rid, ENOMEM);
798
        free(old);
799
        free(new);
800
        return;
801
    }
802
    /* Lookup parent of the new file name. */
803
    rc = vfs_lookup_internal(newc, L_PARENT, &new_par_lr, NULL);
804
    if (rc != EOK) {
805
        rwlock_write_unlock(&namespace_rwlock);
806
        ipc_answer_0(rid, rc);
807
        free(old);
808
        free(new);
809
        return;
810
    }
811
    /* Check whether linking to the same file system instance. */
812
    if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
813
        (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
814
        rwlock_write_unlock(&namespace_rwlock);
815
        ipc_answer_0(rid, EXDEV);   /* different file systems */
816
        free(old);
817
        free(new);
818
        return;
819
    }
820
    /* Destroy the old link for the new name. */
821
    vfs_node_t *new_node = NULL;
822
    rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
823
    switch (rc) {
824
    case ENOENT:
825
        /* simply not in our way */
826
        break;
827
    case EOK:
828
        new_node = vfs_node_get(&new_lr);
829
        if (!new_node) {
830
            rwlock_write_unlock(&namespace_rwlock);
831
            ipc_answer_0(rid, ENOMEM);
832
            free(old);
833
            free(new);
834
            return;
835
        }
2766 jermar 836
        futex_down(&nodes_futex);
2763 jermar 837
        new_node->lnkcnt--;
2766 jermar 838
        futex_up(&nodes_futex);
2763 jermar 839
        break;
840
    default:
841
        rwlock_write_unlock(&namespace_rwlock);
842
        ipc_answer_0(rid, ENOTEMPTY);
843
        free(old);
844
        free(new);
845
        return;
846
    }
847
    /* Create the new link for the new name. */
848
    rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
849
    if (rc != EOK) {
850
        rwlock_write_unlock(&namespace_rwlock);
851
        if (new_node)
852
            vfs_node_put(new_node);
853
        ipc_answer_0(rid, rc);
854
        free(old);
855
        free(new);
856
        return;
857
    }
2766 jermar 858
    futex_down(&nodes_futex);
2763 jermar 859
    old_node->lnkcnt++;
2766 jermar 860
    futex_up(&nodes_futex);
2763 jermar 861
    /* Destroy the link for the old name. */
862
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
863
    if (rc != EOK) {
864
        rwlock_write_unlock(&namespace_rwlock);
865
        vfs_node_put(old_node);
866
        if (new_node)
867
            vfs_node_put(new_node);
868
        ipc_answer_0(rid, rc);
869
        free(old);
870
        free(new);
871
        return;
872
    }
2766 jermar 873
    futex_down(&nodes_futex);
2763 jermar 874
    old_node->lnkcnt--;
2766 jermar 875
    futex_up(&nodes_futex);
2763 jermar 876
    rwlock_write_unlock(&namespace_rwlock);
877
    vfs_node_put(old_node);
878
    if (new_node)
879
        vfs_node_put(new_node);
880
    free(old);
881
    free(new);
882
    ipc_answer_0(rid, EOK);
883
}
884
 
2689 jermar 885
/**
886
 * @}
887
 */