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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. */
2689 jermar 156
    uint8_t *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
 */