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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;
3424 svoboda 65
vfs_pair_t rootfs = {
2689 jermar 66
    .fs_handle = 0,
3424 svoboda 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;
3425 svoboda 74
    ipc_callid_t callid;
75
    ipc_call_t data;
3011 svoboda 76
    int rc;
77
    int phone;
3425 svoboda 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
    /*
3425 svoboda 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) {
3425 svoboda 134
        ipc_answer_0(callid, ENOENT);
2689 jermar 135
        ipc_answer_0(rid, ENOENT);
136
        return;
137
    }
138
 
3425 svoboda 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. */
3536 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
 
3424 svoboda 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);
2925 svoboda 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] == '/')) {
3425 svoboda 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
 
3011 svoboda 214
            /*
215
             * For this simple, but important case,
216
             * we are almost done.
217
             */
218
            free(buf);
219
 
3424 svoboda 220
            /* Tell the mountee that it is being mounted. */
221
            phone = vfs_grab_phone(fs_handle);
3425 svoboda 222
            rc = async_req_1_3(phone, VFS_MOUNTED,
223
                (ipcarg_t) dev_handle, &rindex, &rsize, &rlnkcnt);
3011 svoboda 224
            vfs_release_phone(phone);
3425 svoboda 225
 
226
            if (rc != EOK) {
227
                futex_up(&rootfs_futex);
228
                ipc_answer_0(rid, rc);
229
                return;
3424 svoboda 230
            }
3011 svoboda 231
 
3425 svoboda 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;
3675 svoboda 237
            mr_res.type = VFS_NODE_DIRECTORY;
3425 svoboda 238
 
239
            rootfs.fs_handle = fs_handle;
240
            rootfs.dev_handle = dev_handle;
2689 jermar 241
            futex_up(&rootfs_futex);
3425 svoboda 242
 
243
            /* Add reference to the mounted root. */
244
            mr_node = vfs_node_get(&mr_res);
245
            assert(mr_node);
246
 
3011 svoboda 247
            ipc_answer_0(rid, rc);
2689 jermar 248
            return;
249
        } else {
250
            /*
251
             * We can't resolve this without the root filesystem
252
             * being mounted first.
253
             */
254
            futex_up(&rootfs_futex);
255
            free(buf);
256
            ipc_answer_0(rid, ENOENT);
257
            return;
258
        }
259
    }
260
    futex_up(&rootfs_futex);
261
 
262
    free(buf);  /* The buffer is not needed anymore. */
263
 
264
    /*
265
     * At this point, we have all necessary pieces: file system and device
3424 svoboda 266
     * handles, and we know the mount point VFS node.
2689 jermar 267
     */
268
 
3011 svoboda 269
    phone = vfs_grab_phone(mp_res.triplet.fs_handle);
3424 svoboda 270
    rc = async_req_4_0(phone, VFS_MOUNT,
2691 jermar 271
        (ipcarg_t) mp_res.triplet.dev_handle,
3011 svoboda 272
        (ipcarg_t) mp_res.triplet.index,
3424 svoboda 273
        (ipcarg_t) fs_handle,
274
        (ipcarg_t) dev_handle);
2689 jermar 275
    vfs_release_phone(phone);
276
 
3011 svoboda 277
    if (rc != EOK) {
3424 svoboda 278
        /* Mount failed, drop reference to mp_node. */
2689 jermar 279
        if (mp_node)
280
            vfs_node_put(mp_node);
281
    }
282
 
3011 svoboda 283
    ipc_answer_0(rid, rc);
2689 jermar 284
}
285
 
286
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
287
{
288
    if (!vfs_files_init()) {
289
        ipc_answer_0(rid, ENOMEM);
290
        return;
291
    }
292
 
293
    /*
2700 jermar 294
     * The POSIX interface is open(path, oflag, mode).
295
     * We can receive oflags and mode along with the VFS_OPEN call; the path
2689 jermar 296
     * will need to arrive in another call.
2700 jermar 297
     *
298
     * We also receive one private, non-POSIX set of flags called lflag
299
     * used to pass information to vfs_lookup_internal().
2689 jermar 300
     */
2700 jermar 301
    int lflag = IPC_GET_ARG1(*request);
302
    int oflag = IPC_GET_ARG2(*request);
303
    int mode = IPC_GET_ARG3(*request);
2689 jermar 304
    size_t len;
305
 
3675 svoboda 306
    /*
307
     * Make sure that we are called with exactly one of L_FILE and
308
     * L_DIRECTORY.
309
     */
310
    if ((lflag & (L_FILE | L_DIRECTORY)) == 0 ||
311
        (lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) {
312
        ipc_answer_0(rid, EINVAL);
313
        return;
314
    }
315
 
2708 jermar 316
    if (oflag & O_CREAT)
317
        lflag |= L_CREATE;
318
    if (oflag & O_EXCL)
319
        lflag |= L_EXCLUSIVE;
320
 
2689 jermar 321
    ipc_callid_t callid;
322
 
323
    if (!ipc_data_write_receive(&callid, &len)) {
324
        ipc_answer_0(callid, EINVAL);
325
        ipc_answer_0(rid, EINVAL);
326
        return;
327
    }
2752 jermar 328
    char *path = malloc(len + 1);
2689 jermar 329
    if (!path) {
330
        ipc_answer_0(callid, ENOMEM);
331
        ipc_answer_0(rid, ENOMEM);
332
        return;
333
    }
334
    int rc;
335
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
336
        ipc_answer_0(rid, rc);
337
        free(path);
338
        return;
339
    }
2752 jermar 340
    path[len] = '\0';
2689 jermar 341
 
342
    /*
343
     * Avoid the race condition in which the file can be deleted before we
344
     * find/create-and-lock the VFS node corresponding to the looked-up
345
     * triplet.
346
     */
2708 jermar 347
    if (lflag & L_CREATE)
348
        rwlock_write_lock(&namespace_rwlock);
349
    else
350
        rwlock_read_lock(&namespace_rwlock);
2689 jermar 351
 
2707 jermar 352
    /* The path is now populated and we can call vfs_lookup_internal(). */
2691 jermar 353
    vfs_lookup_res_t lr;
2752 jermar 354
    rc = vfs_lookup_internal(path, lflag, &lr, NULL);
2689 jermar 355
    if (rc) {
2708 jermar 356
        if (lflag & L_CREATE)
357
            rwlock_write_unlock(&namespace_rwlock);
358
        else
359
            rwlock_read_unlock(&namespace_rwlock);
2689 jermar 360
        ipc_answer_0(rid, rc);
361
        free(path);
362
        return;
363
    }
364
 
2748 jermar 365
    /* Path is no longer needed. */
2689 jermar 366
    free(path);
367
 
2691 jermar 368
    vfs_node_t *node = vfs_node_get(&lr);
2708 jermar 369
    if (lflag & L_CREATE)
370
        rwlock_write_unlock(&namespace_rwlock);
371
    else
372
        rwlock_read_unlock(&namespace_rwlock);
2689 jermar 373
 
2748 jermar 374
    /* Truncate the file if requested and if necessary. */
375
    if (oflag & O_TRUNC) {
2749 jermar 376
        rwlock_write_lock(&node->contents_rwlock);
2748 jermar 377
        if (node->size) {
378
            rc = vfs_truncate_internal(node->fs_handle,
379
                node->dev_handle, node->index, 0);
380
            if (rc) {
2749 jermar 381
                rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 382
                vfs_node_put(node);
383
                ipc_answer_0(rid, rc);
384
                return;
385
            }
386
            node->size = 0;
387
        }
2749 jermar 388
        rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 389
    }
390
 
2689 jermar 391
    /*
392
     * Get ourselves a file descriptor and the corresponding vfs_file_t
393
     * structure.
394
     */
395
    int fd = vfs_fd_alloc();
396
    if (fd < 0) {
397
        vfs_node_put(node);
398
        ipc_answer_0(rid, fd);
399
        return;
400
    }
401
    vfs_file_t *file = vfs_file_get(fd);
402
    file->node = node;
2710 jermar 403
    if (oflag & O_APPEND)
2709 jermar 404
        file->append = true;
2689 jermar 405
 
406
    /*
407
     * The following increase in reference count is for the fact that the
408
     * file is being opened and that a file structure is pointing to it.
409
     * It is necessary so that the file will not disappear when
410
     * vfs_node_put() is called. The reference will be dropped by the
411
     * respective VFS_CLOSE.
412
     */
413
    vfs_node_addref(node);
414
    vfs_node_put(node);
415
 
2707 jermar 416
    /* Success! Return the new file descriptor to the client. */
2689 jermar 417
    ipc_answer_1(rid, EOK, fd);
418
}
419
 
2734 jermar 420
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
421
{
422
    int fd = IPC_GET_ARG1(*request);
3425 svoboda 423
    int rc = vfs_fd_free(fd);
424
    ipc_answer_0(rid, rc);
2734 jermar 425
}
426
 
2689 jermar 427
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
428
{
429
 
430
    /*
431
     * The following code strongly depends on the fact that the files data
432
     * structure can be only accessed by a single fibril and all file
433
     * operations are serialized (i.e. the reads and writes cannot
434
     * interleave and a file cannot be closed while it is being read).
435
     *
436
     * Additional synchronization needs to be added once the table of
437
     * open files supports parallel access!
438
     */
439
 
440
    int fd = IPC_GET_ARG1(*request);
3424 svoboda 441
 
2707 jermar 442
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 443
    vfs_file_t *file = vfs_file_get(fd);
444
    if (!file) {
445
        ipc_answer_0(rid, ENOENT);
446
        return;
447
    }
3424 svoboda 448
 
2689 jermar 449
    /*
450
     * Now we need to receive a call with client's
451
     * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
452
     */
453
    ipc_callid_t callid;
454
    int res;
455
    if (read)
456
        res = ipc_data_read_receive(&callid, NULL);
457
    else
458
        res = ipc_data_write_receive(&callid, NULL);
459
    if (!res) {
460
        ipc_answer_0(callid, EINVAL);
461
        ipc_answer_0(rid, EINVAL);
462
        return;
463
    }
3424 svoboda 464
 
2689 jermar 465
    /*
466
     * Lock the open file structure so that no other thread can manipulate
467
     * the same open file at a time.
468
     */
469
    futex_down(&file->lock);
3675 svoboda 470
 
2689 jermar 471
    /*
472
     * Lock the file's node so that no other client can read/write to it at
473
     * the same time.
474
     */
475
    if (read)
476
        rwlock_read_lock(&file->node->contents_rwlock);
477
    else
478
        rwlock_write_lock(&file->node->contents_rwlock);
3675 svoboda 479
 
480
    if (file->node->type == VFS_NODE_DIRECTORY) {
481
        /*
482
         * Make sure that no one is modifying the namespace
483
         * while we are in readdir().
484
         */
485
        assert(read);
486
        rwlock_read_lock(&namespace_rwlock);
487
    }
3424 svoboda 488
 
2689 jermar 489
    int fs_phone = vfs_grab_phone(file->node->fs_handle);  
490
 
2707 jermar 491
    /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
2689 jermar 492
    aid_t msg;
493
    ipc_call_t answer;
2709 jermar 494
    if (!read && file->append)
495
        file->pos = file->node->size;
2689 jermar 496
    msg = async_send_3(fs_phone, IPC_GET_METHOD(*request),
497
        file->node->dev_handle, file->node->index, file->pos, &answer);
498
 
499
    /*
500
     * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
501
     * destination FS server. The call will be routed as if sent by
502
     * ourselves. Note that call arguments are immutable in this case so we
503
     * don't have to bother.
504
     */
505
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
3424 svoboda 506
 
2689 jermar 507
    vfs_release_phone(fs_phone);
3424 svoboda 508
 
2707 jermar 509
    /* Wait for reply from the FS server. */
2689 jermar 510
    ipcarg_t rc;
511
    async_wait_for(msg, &rc);
512
    size_t bytes = IPC_GET_ARG1(answer);
3675 svoboda 513
 
514
    if (file->node->type == VFS_NODE_DIRECTORY)
515
        rwlock_read_unlock(&namespace_rwlock);
3424 svoboda 516
 
2707 jermar 517
    /* Unlock the VFS node. */
2689 jermar 518
    if (read)
519
        rwlock_read_unlock(&file->node->contents_rwlock);
520
    else {
521
        /* Update the cached version of node's size. */
2710 jermar 522
        if (rc == EOK)
523
            file->node->size = IPC_GET_ARG2(answer);
2689 jermar 524
        rwlock_write_unlock(&file->node->contents_rwlock);
525
    }
3424 svoboda 526
 
2707 jermar 527
    /* Update the position pointer and unlock the open file. */
2710 jermar 528
    if (rc == EOK)
529
        file->pos += bytes;
2689 jermar 530
    futex_up(&file->lock);
3424 svoboda 531
 
2689 jermar 532
    /*
533
     * FS server's reply is the final result of the whole operation we
534
     * return to the client.
535
     */
536
    ipc_answer_1(rid, rc, bytes);
537
}
538
 
539
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
540
{
541
    vfs_rdwr(rid, request, true);
542
}
543
 
544
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
545
{
546
    vfs_rdwr(rid, request, false);
547
}
548
 
549
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
550
{
551
    int fd = (int) IPC_GET_ARG1(*request);
552
    off_t off = (off_t) IPC_GET_ARG2(*request);
553
    int whence = (int) IPC_GET_ARG3(*request);
554
 
555
 
2707 jermar 556
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 557
    vfs_file_t *file = vfs_file_get(fd);
558
    if (!file) {
559
        ipc_answer_0(rid, ENOENT);
560
        return;
561
    }
562
 
563
    off_t newpos;
564
    futex_down(&file->lock);
565
    if (whence == SEEK_SET) {
566
        file->pos = off;
567
        futex_up(&file->lock);
568
        ipc_answer_1(rid, EOK, off);
569
        return;
570
    }
571
    if (whence == SEEK_CUR) {
572
        if (file->pos + off < file->pos) {
573
            futex_up(&file->lock);
574
            ipc_answer_0(rid, EOVERFLOW);
575
            return;
576
        }
577
        file->pos += off;
578
        newpos = file->pos;
579
        futex_up(&file->lock);
580
        ipc_answer_1(rid, EOK, newpos);
581
        return;
582
    }
583
    if (whence == SEEK_END) {
584
        rwlock_read_lock(&file->node->contents_rwlock);
585
        size_t size = file->node->size;
586
        rwlock_read_unlock(&file->node->contents_rwlock);
587
        if (size + off < size) {
588
            futex_up(&file->lock);
589
            ipc_answer_0(rid, EOVERFLOW);
590
            return;
591
        }
592
        newpos = size + off;
593
        futex_up(&file->lock);
594
        ipc_answer_1(rid, EOK, newpos);
595
        return;
596
    }
597
    futex_up(&file->lock);
598
    ipc_answer_0(rid, EINVAL);
599
}
600
 
2770 jermar 601
int
602
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
603
    fs_index_t index, size_t size)
2748 jermar 604
{
605
    ipcarg_t rc;
606
    int fs_phone;
607
 
608
    fs_phone = vfs_grab_phone(fs_handle);
609
    rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle,
610
        (ipcarg_t)index, (ipcarg_t)size);
611
    vfs_release_phone(fs_phone);
612
    return (int)rc;
613
}
614
 
2693 jermar 615
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
616
{
617
    int fd = IPC_GET_ARG1(*request);
618
    size_t size = IPC_GET_ARG2(*request);
2748 jermar 619
    int rc;
2693 jermar 620
 
621
    vfs_file_t *file = vfs_file_get(fd);
622
    if (!file) {
623
        ipc_answer_0(rid, ENOENT);
624
        return;
625
    }
626
    futex_down(&file->lock);
627
 
628
    rwlock_write_lock(&file->node->contents_rwlock);
2748 jermar 629
    rc = vfs_truncate_internal(file->node->fs_handle,
630
        file->node->dev_handle, file->node->index, size);
2693 jermar 631
    if (rc == EOK)
632
        file->node->size = size;
633
    rwlock_write_unlock(&file->node->contents_rwlock);
634
 
635
    futex_up(&file->lock);
2748 jermar 636
    ipc_answer_0(rid, (ipcarg_t)rc);
2693 jermar 637
}
638
 
2707 jermar 639
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
640
{
641
    int mode = IPC_GET_ARG1(*request);
2735 jermar 642
 
2707 jermar 643
    size_t len;
644
    ipc_callid_t callid;
645
 
646
    if (!ipc_data_write_receive(&callid, &len)) {
647
        ipc_answer_0(callid, EINVAL);
648
        ipc_answer_0(rid, EINVAL);
649
        return;
650
    }
2752 jermar 651
    char *path = malloc(len + 1);
2707 jermar 652
    if (!path) {
653
        ipc_answer_0(callid, ENOMEM);
654
        ipc_answer_0(rid, ENOMEM);
655
        return;
656
    }
657
    int rc;
658
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
659
        ipc_answer_0(rid, rc);
660
        free(path);
661
        return;
662
    }
2752 jermar 663
    path[len] = '\0';
2707 jermar 664
 
665
    rwlock_write_lock(&namespace_rwlock);
666
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
2752 jermar 667
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
2707 jermar 668
    rwlock_write_unlock(&namespace_rwlock);
669
    free(path);
670
    ipc_answer_0(rid, rc);
671
}
672
 
2735 jermar 673
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
674
{
675
    int lflag = IPC_GET_ARG1(*request);
676
 
677
    size_t len;
678
    ipc_callid_t callid;
679
 
680
    if (!ipc_data_write_receive(&callid, &len)) {
681
        ipc_answer_0(callid, EINVAL);
682
        ipc_answer_0(rid, EINVAL);
683
        return;
684
    }
2752 jermar 685
    char *path = malloc(len + 1);
2735 jermar 686
    if (!path) {
687
        ipc_answer_0(callid, ENOMEM);
688
        ipc_answer_0(rid, ENOMEM);
689
        return;
690
    }
691
    int rc;
692
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
693
        ipc_answer_0(rid, rc);
694
        free(path);
695
        return;
696
    }
2752 jermar 697
    path[len] = '\0';
2735 jermar 698
 
699
    rwlock_write_lock(&namespace_rwlock);
700
    lflag &= L_DIRECTORY;   /* sanitize lflag */
701
    vfs_lookup_res_t lr;
2763 jermar 702
    rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
2735 jermar 703
    free(path);
704
    if (rc != EOK) {
705
        rwlock_write_unlock(&namespace_rwlock);
706
        ipc_answer_0(rid, rc);
707
        return;
708
    }
709
 
710
    /*
711
     * The name has already been unlinked by vfs_lookup_internal().
712
     * We have to get and put the VFS node to ensure that it is
2742 jermar 713
     * VFS_DESTROY'ed after the last reference to it is dropped.
2735 jermar 714
     */
715
    vfs_node_t *node = vfs_node_get(&lr);
2766 jermar 716
    futex_down(&nodes_futex);
2735 jermar 717
    node->lnkcnt--;
2766 jermar 718
    futex_up(&nodes_futex);
2735 jermar 719
    rwlock_write_unlock(&namespace_rwlock);
720
    vfs_node_put(node);
721
    ipc_answer_0(rid, EOK);
722
}
723
 
2763 jermar 724
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
725
{
726
    size_t len;
727
    ipc_callid_t callid;
728
    int rc;
729
 
730
    /* Retrieve the old path. */
731
    if (!ipc_data_write_receive(&callid, &len)) {
732
        ipc_answer_0(callid, EINVAL);
733
        ipc_answer_0(rid, EINVAL);
734
        return;
735
    }
736
    char *old = malloc(len + 1);
737
    if (!old) {
738
        ipc_answer_0(callid, ENOMEM);
739
        ipc_answer_0(rid, ENOMEM);
740
        return;
741
    }
742
    if ((rc = ipc_data_write_finalize(callid, old, len))) {
743
        ipc_answer_0(rid, rc);
744
        free(old);
745
        return;
746
    }
747
    old[len] = '\0';
748
 
749
    /* Retrieve the new path. */
750
    if (!ipc_data_write_receive(&callid, &len)) {
751
        ipc_answer_0(callid, EINVAL);
752
        ipc_answer_0(rid, EINVAL);
753
        free(old);
754
        return;
755
    }
756
    char *new = malloc(len + 1);
757
    if (!new) {
758
        ipc_answer_0(callid, ENOMEM);
759
        ipc_answer_0(rid, ENOMEM);
760
        free(old);
761
        return;
762
    }
763
    if ((rc = ipc_data_write_finalize(callid, new, len))) {
764
        ipc_answer_0(rid, rc);
765
        free(old);
766
        free(new);
767
        return;
768
    }
769
    new[len] = '\0';
770
 
771
    char *oldc = canonify(old, &len);
772
    char *newc = canonify(new, NULL);
773
    if (!oldc || !newc) {
774
        ipc_answer_0(rid, EINVAL);
775
        free(old);
776
        free(new);
777
        return;
778
    }
779
    if (!strncmp(newc, oldc, len)) {
780
        /* oldc is a prefix of newc */
781
        ipc_answer_0(rid, EINVAL);
782
        free(old);
783
        free(new);
784
        return;
785
    }
786
 
787
    vfs_lookup_res_t old_lr;
788
    vfs_lookup_res_t new_lr;
789
    vfs_lookup_res_t new_par_lr;
790
    rwlock_write_lock(&namespace_rwlock);
791
    /* Lookup the node belonging to the old file name. */
792
    rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
793
    if (rc != EOK) {
794
        rwlock_write_unlock(&namespace_rwlock);
795
        ipc_answer_0(rid, rc);
796
        free(old);
797
        free(new);
798
        return;
799
    }
800
    vfs_node_t *old_node = vfs_node_get(&old_lr);
801
    if (!old_node) {
802
        rwlock_write_unlock(&namespace_rwlock);
803
        ipc_answer_0(rid, ENOMEM);
804
        free(old);
805
        free(new);
806
        return;
807
    }
808
    /* Lookup parent of the new file name. */
809
    rc = vfs_lookup_internal(newc, L_PARENT, &new_par_lr, NULL);
810
    if (rc != EOK) {
811
        rwlock_write_unlock(&namespace_rwlock);
812
        ipc_answer_0(rid, rc);
813
        free(old);
814
        free(new);
815
        return;
816
    }
817
    /* Check whether linking to the same file system instance. */
818
    if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
819
        (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
820
        rwlock_write_unlock(&namespace_rwlock);
821
        ipc_answer_0(rid, EXDEV);   /* different file systems */
822
        free(old);
823
        free(new);
824
        return;
825
    }
826
    /* Destroy the old link for the new name. */
827
    vfs_node_t *new_node = NULL;
828
    rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
829
    switch (rc) {
830
    case ENOENT:
831
        /* simply not in our way */
832
        break;
833
    case EOK:
834
        new_node = vfs_node_get(&new_lr);
835
        if (!new_node) {
836
            rwlock_write_unlock(&namespace_rwlock);
837
            ipc_answer_0(rid, ENOMEM);
838
            free(old);
839
            free(new);
840
            return;
841
        }
2766 jermar 842
        futex_down(&nodes_futex);
2763 jermar 843
        new_node->lnkcnt--;
2766 jermar 844
        futex_up(&nodes_futex);
2763 jermar 845
        break;
846
    default:
847
        rwlock_write_unlock(&namespace_rwlock);
848
        ipc_answer_0(rid, ENOTEMPTY);
849
        free(old);
850
        free(new);
851
        return;
852
    }
853
    /* Create the new link for the new name. */
854
    rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
855
    if (rc != EOK) {
856
        rwlock_write_unlock(&namespace_rwlock);
857
        if (new_node)
858
            vfs_node_put(new_node);
859
        ipc_answer_0(rid, rc);
860
        free(old);
861
        free(new);
862
        return;
863
    }
2766 jermar 864
    futex_down(&nodes_futex);
2763 jermar 865
    old_node->lnkcnt++;
2766 jermar 866
    futex_up(&nodes_futex);
2763 jermar 867
    /* Destroy the link for the old name. */
868
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
869
    if (rc != EOK) {
870
        rwlock_write_unlock(&namespace_rwlock);
871
        vfs_node_put(old_node);
872
        if (new_node)
873
            vfs_node_put(new_node);
874
        ipc_answer_0(rid, rc);
875
        free(old);
876
        free(new);
877
        return;
878
    }
2766 jermar 879
    futex_down(&nodes_futex);
2763 jermar 880
    old_node->lnkcnt--;
2766 jermar 881
    futex_up(&nodes_futex);
2763 jermar 882
    rwlock_write_unlock(&namespace_rwlock);
883
    vfs_node_put(old_node);
884
    if (new_node)
885
        vfs_node_put(new_node);
886
    free(old);
887
    free(new);
888
    ipc_answer_0(rid, EOK);
889
}
890
 
2689 jermar 891
/**
892
 * @}
893
 */