Subversion Repositories HelenOS

Rev

Rev 4389 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
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
 * @{
4345 svoboda 31
 */
2689 jermar 32
 
33
/**
4345 svoboda 34
 * @file vfs_ops.c
35
 * @brief Operations that VFS offers to its clients.
2689 jermar 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>
4691 svoboda 46
#include <fibril_sync.h>
47
#include <adt/list.h>
2689 jermar 48
#include <unistd.h>
49
#include <ctype.h>
2708 jermar 50
#include <fcntl.h>
2689 jermar 51
#include <assert.h>
2763 jermar 52
#include <vfs/canonify.h>
2689 jermar 53
 
2748 jermar 54
/* Forward declarations of static functions. */
2770 jermar 55
static int vfs_truncate_internal(fs_handle_t, dev_handle_t, fs_index_t, size_t);
2748 jermar 56
 
2689 jermar 57
/**
58
 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
59
 * concurrent VFS operation which modifies the file system namespace.
60
 */
4691 svoboda 61
FIBRIL_RWLOCK_INITIALIZE(namespace_rwlock);
2689 jermar 62
 
3153 svoboda 63
vfs_pair_t rootfs = {
2689 jermar 64
    .fs_handle = 0,
3153 svoboda 65
    .dev_handle = 0
2689 jermar 66
};
67
 
4345 svoboda 68
static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,
4348 svoboda 69
    fs_handle_t fs_handle, char *mp, char *opts)
2689 jermar 70
{
4345 svoboda 71
    vfs_lookup_res_t mp_res;
4691 svoboda 72
    vfs_lookup_res_t mr_res;
2689 jermar 73
    vfs_node_t *mp_node = NULL;
4691 svoboda 74
    vfs_node_t *mr_node;
75
    fs_index_t rindex;
76
    size_t rsize;
77
    unsigned rlnkcnt;
4348 svoboda 78
    ipcarg_t rc;
3009 svoboda 79
    int phone;
4348 svoboda 80
    aid_t msg;
81
    ipc_call_t answer;
4691 svoboda 82
 
4348 svoboda 83
    /* Resolve the path to the mountpoint. */
4691 svoboda 84
    fibril_rwlock_write_lock(&namespace_rwlock);
2689 jermar 85
    if (rootfs.fs_handle) {
2707 jermar 86
        /* We already have the root FS. */
4348 svoboda 87
        if (str_cmp(mp, "/") == 0) {
2788 jermar 88
            /* Trying to mount root FS over root FS */
4691 svoboda 89
            fibril_rwlock_write_unlock(&namespace_rwlock);
2788 jermar 90
            ipc_answer_0(rid, EBUSY);
91
            return;
92
        }
4345 svoboda 93
 
94
        rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);
2689 jermar 95
        if (rc != EOK) {
2707 jermar 96
            /* The lookup failed for some reason. */
4691 svoboda 97
            fibril_rwlock_write_unlock(&namespace_rwlock);
2689 jermar 98
            ipc_answer_0(rid, rc);
99
            return;
100
        }
4345 svoboda 101
 
2691 jermar 102
        mp_node = vfs_node_get(&mp_res);
2689 jermar 103
        if (!mp_node) {
4691 svoboda 104
            fibril_rwlock_write_unlock(&namespace_rwlock);
2689 jermar 105
            ipc_answer_0(rid, ENOMEM);
106
            return;
107
        }
4345 svoboda 108
 
2689 jermar 109
        /*
110
         * Now we hold a reference to mp_node.
4691 svoboda 111
         * It will be dropped upon the corresponding VFS_IN_UNMOUNT.
2689 jermar 112
         * This prevents the mount point from being deleted.
113
         */
114
    } else {
2707 jermar 115
        /* We still don't have the root file system mounted. */
4348 svoboda 116
        if (str_cmp(mp, "/") == 0) {
3009 svoboda 117
            /*
118
             * For this simple, but important case,
119
             * we are almost done.
120
             */
121
 
3153 svoboda 122
            /* Tell the mountee that it is being mounted. */
123
            phone = vfs_grab_phone(fs_handle);
4691 svoboda 124
            msg = async_send_1(phone, VFS_OUT_MOUNTED,
4348 svoboda 125
                (ipcarg_t) dev_handle, &answer);
126
            /* send the mount options */
127
            rc = ipc_data_write_start(phone, (void *)opts,
128
                str_size(opts));
129
            if (rc != EOK) {
130
                async_wait_for(msg, NULL);
131
                vfs_release_phone(phone);
4691 svoboda 132
                fibril_rwlock_write_unlock(&namespace_rwlock);
4348 svoboda 133
                ipc_answer_0(rid, rc);
134
                return;
135
            }
136
            async_wait_for(msg, &rc);
3009 svoboda 137
            vfs_release_phone(phone);
3403 svoboda 138
 
139
            if (rc != EOK) {
4691 svoboda 140
                fibril_rwlock_write_unlock(&namespace_rwlock);
3403 svoboda 141
                ipc_answer_0(rid, rc);
142
                return;
3153 svoboda 143
            }
4348 svoboda 144
 
145
            rindex = (fs_index_t) IPC_GET_ARG1(answer);
146
            rsize = (size_t) IPC_GET_ARG2(answer);
147
            rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
4345 svoboda 148
 
3403 svoboda 149
            mr_res.triplet.fs_handle = fs_handle;
150
            mr_res.triplet.dev_handle = dev_handle;
4348 svoboda 151
            mr_res.triplet.index = rindex;
152
            mr_res.size = rsize;
153
            mr_res.lnkcnt = rlnkcnt;
3674 svoboda 154
            mr_res.type = VFS_NODE_DIRECTORY;
4345 svoboda 155
 
3403 svoboda 156
            rootfs.fs_handle = fs_handle;
157
            rootfs.dev_handle = dev_handle;
4345 svoboda 158
 
3403 svoboda 159
            /* Add reference to the mounted root. */
160
            mr_node = vfs_node_get(&mr_res);
161
            assert(mr_node);
4345 svoboda 162
 
4691 svoboda 163
            fibril_rwlock_write_unlock(&namespace_rwlock);
3009 svoboda 164
            ipc_answer_0(rid, rc);
2689 jermar 165
            return;
166
        } else {
167
            /*
168
             * We can't resolve this without the root filesystem
169
             * being mounted first.
170
             */
4691 svoboda 171
            fibril_rwlock_write_unlock(&namespace_rwlock);
2689 jermar 172
            ipc_answer_0(rid, ENOENT);
173
            return;
174
        }
175
    }
176
 
177
    /*
178
     * At this point, we have all necessary pieces: file system and device
3153 svoboda 179
     * handles, and we know the mount point VFS node.
2689 jermar 180
     */
4345 svoboda 181
 
4691 svoboda 182
    int mountee_phone = vfs_grab_phone(fs_handle);
183
    assert(mountee_phone >= 0);
184
 
3009 svoboda 185
    phone = vfs_grab_phone(mp_res.triplet.fs_handle);
4691 svoboda 186
    msg = async_send_4(phone, VFS_OUT_MOUNT,
2691 jermar 187
        (ipcarg_t) mp_res.triplet.dev_handle,
3009 svoboda 188
        (ipcarg_t) mp_res.triplet.index,
3153 svoboda 189
        (ipcarg_t) fs_handle,
4348 svoboda 190
        (ipcarg_t) dev_handle, &answer);
4691 svoboda 191
 
192
    /* send connection */
193
    rc = async_req_1_0(phone, IPC_M_CONNECTION_CLONE, mountee_phone);
194
    if (rc != EOK) {
195
        async_wait_for(msg, NULL);
196
        vfs_release_phone(mountee_phone);
197
        vfs_release_phone(phone);
198
        /* Mount failed, drop reference to mp_node. */
199
        if (mp_node)
200
            vfs_node_put(mp_node);
201
        ipc_answer_0(rid, rc);
202
        fibril_rwlock_write_unlock(&namespace_rwlock);
203
        return;
204
    }
205
 
206
    vfs_release_phone(mountee_phone);
207
 
4348 svoboda 208
    /* send the mount options */
209
    rc = ipc_data_write_start(phone, (void *)opts, str_size(opts));
210
    if (rc != EOK) {
211
        async_wait_for(msg, NULL);
212
        vfs_release_phone(phone);
213
        /* Mount failed, drop reference to mp_node. */
214
        if (mp_node)
215
            vfs_node_put(mp_node);
4691 svoboda 216
        fibril_rwlock_write_unlock(&namespace_rwlock);
4348 svoboda 217
        ipc_answer_0(rid, rc);
218
        return;
219
    }
220
    async_wait_for(msg, &rc);
2689 jermar 221
    vfs_release_phone(phone);
4345 svoboda 222
 
4691 svoboda 223
    if (rc == EOK) {
224
        rindex = (fs_index_t) IPC_GET_ARG1(answer);
225
        rsize = (size_t) IPC_GET_ARG2(answer);
226
        rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
227
 
228
        mr_res.triplet.fs_handle = fs_handle;
229
        mr_res.triplet.dev_handle = dev_handle;
230
        mr_res.triplet.index = rindex;
231
        mr_res.size = rsize;
232
        mr_res.lnkcnt = rlnkcnt;
233
        mr_res.type = VFS_NODE_DIRECTORY;
234
 
235
        /* Add reference to the mounted root. */
236
        mr_node = vfs_node_get(&mr_res);
237
        assert(mr_node);
238
    } else {
3153 svoboda 239
        /* Mount failed, drop reference to mp_node. */
2689 jermar 240
        if (mp_node)
241
            vfs_node_put(mp_node);
242
    }
4691 svoboda 243
 
3009 svoboda 244
    ipc_answer_0(rid, rc);
4691 svoboda 245
    fibril_rwlock_write_unlock(&namespace_rwlock);
2689 jermar 246
}
247
 
4345 svoboda 248
void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
249
{
250
    /*
251
     * We expect the library to do the device-name to device-handle
252
     * translation for us, thus the device handle will arrive as ARG1
253
     * in the request.
254
     */
255
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
256
 
257
    /*
258
     * Mount flags are passed as ARG2.
259
     */
260
    unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
261
 
262
    /*
263
     * For now, don't make use of ARG3, but it can be used to
264
     * carry mount options in the future.
265
     */
266
 
267
    /* We want the client to send us the mount point. */
268
    ipc_callid_t callid;
269
    size_t size;
270
    if (!ipc_data_write_receive(&callid, &size)) {
271
        ipc_answer_0(callid, EINVAL);
272
        ipc_answer_0(rid, EINVAL);
273
        return;
274
    }
275
 
276
    /* Check whether size is reasonable wrt. the mount point. */
277
    if ((size < 1) || (size > MAX_PATH_LEN)) {
278
        ipc_answer_0(callid, EINVAL);
279
        ipc_answer_0(rid, EINVAL);
280
        return;
281
    }
282
 
283
    /* Allocate buffer for the mount point data being received. */
284
    char *mp = malloc(size + 1);
285
    if (!mp) {
286
        ipc_answer_0(callid, ENOMEM);
287
        ipc_answer_0(rid, ENOMEM);
288
        return;
289
    }
290
 
291
    /* Deliver the mount point. */
292
    ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);
293
    if (retval != EOK) {
4348 svoboda 294
        ipc_answer_0(rid, retval);
4345 svoboda 295
        free(mp);
296
        return;
297
    }
298
    mp[size] = '\0';
299
 
4348 svoboda 300
    /* Now we expect to receive the mount options. */
301
    if (!ipc_data_write_receive(&callid, &size)) {
302
        ipc_answer_0(callid, EINVAL);
303
        ipc_answer_0(rid, EINVAL);
304
        free(mp);
305
        return;
306
    }
307
 
308
    /* Check the offered options size. */
4691 svoboda 309
    if (size > MAX_MNTOPTS_LEN) {
4348 svoboda 310
        ipc_answer_0(callid, EINVAL);
311
        ipc_answer_0(rid, EINVAL);
312
        free(mp);
313
        return;
314
    }
315
 
316
    /* Allocate buffer for the mount options. */
317
    char *opts = (char *) malloc(size + 1);
318
    if (!opts) {
319
        ipc_answer_0(callid, ENOMEM);
320
        ipc_answer_0(rid, ENOMEM);
321
        free(mp);
322
        return;
323
    }
324
 
325
    /* Deliver the mount options. */
326
    retval = ipc_data_write_finalize(callid, opts, size);
327
    if (retval != EOK) {
328
        ipc_answer_0(rid, retval);
329
        free(mp);
330
        free(opts);
331
        return;
332
    }
333
    opts[size] = '\0';
334
 
4345 svoboda 335
    /*
336
     * Now, we expect the client to send us data with the name of the file
337
     * system.
338
     */
339
    if (!ipc_data_write_receive(&callid, &size)) {
340
        ipc_answer_0(callid, EINVAL);
341
        ipc_answer_0(rid, EINVAL);
342
        free(mp);
4348 svoboda 343
        free(opts);
4345 svoboda 344
        return;
345
    }
346
 
347
    /*
348
     * Don't receive more than is necessary for storing a full file system
349
     * name.
350
     */
351
    if ((size < 1) || (size > FS_NAME_MAXLEN)) {
352
        ipc_answer_0(callid, EINVAL);
353
        ipc_answer_0(rid, EINVAL);
354
        free(mp);
4348 svoboda 355
        free(opts);
4345 svoboda 356
        return;
357
    }
358
 
359
    /*
360
     * Allocate buffer for file system name.
361
     */
362
    char *fs_name = (char *) malloc(size + 1);
363
    if (fs_name == NULL) {
364
        ipc_answer_0(callid, ENOMEM);
4348 svoboda 365
        ipc_answer_0(rid, ENOMEM);
4345 svoboda 366
        free(mp);
4348 svoboda 367
        free(opts);
4345 svoboda 368
        return;
369
    }
370
 
371
    /* Deliver the file system name. */
372
    retval = ipc_data_write_finalize(callid, fs_name, size);
373
    if (retval != EOK) {
4348 svoboda 374
        ipc_answer_0(rid, retval);
4345 svoboda 375
        free(mp);
4348 svoboda 376
        free(opts);
4345 svoboda 377
        free(fs_name);
378
        return;
379
    }
380
    fs_name[size] = '\0';
4348 svoboda 381
 
4345 svoboda 382
    /*
4348 svoboda 383
     * Wait for IPC_M_PING so that we can return an error if we don't know
384
     * fs_name.
385
     */
386
    ipc_call_t data;
387
    callid = async_get_call(&data);
388
    if (IPC_GET_METHOD(data) != IPC_M_PING) {
389
        ipc_answer_0(callid, ENOTSUP);
390
        ipc_answer_0(rid, ENOTSUP);
391
        free(mp);
392
        free(opts);
393
        free(fs_name);
394
        return;
395
    }
396
 
397
    /*
4345 svoboda 398
     * Check if we know a file system with the same name as is in fs_name.
399
     * This will also give us its file system handle.
400
     */
4691 svoboda 401
    fibril_mutex_lock(&fs_head_lock);
402
    fs_handle_t fs_handle;
403
recheck:
404
    fs_handle = fs_name_to_handle(fs_name, false);
4345 svoboda 405
    if (!fs_handle) {
406
        if (flags & IPC_FLAG_BLOCKING) {
4691 svoboda 407
            fibril_condvar_wait(&fs_head_cv, &fs_head_lock);
408
            goto recheck;
4345 svoboda 409
        }
410
 
4691 svoboda 411
        fibril_mutex_unlock(&fs_head_lock);
4345 svoboda 412
        ipc_answer_0(callid, ENOENT);
413
        ipc_answer_0(rid, ENOENT);
414
        free(mp);
415
        free(fs_name);
4348 svoboda 416
        free(opts);
4345 svoboda 417
        return;
418
    }
4691 svoboda 419
    fibril_mutex_unlock(&fs_head_lock);
4345 svoboda 420
 
421
    /* Acknowledge that we know fs_name. */
422
    ipc_answer_0(callid, EOK);
423
 
424
    /* Do the mount */
4348 svoboda 425
    vfs_mount_internal(rid, dev_handle, fs_handle, mp, opts);
4345 svoboda 426
    free(mp);
427
    free(fs_name);
4348 svoboda 428
    free(opts);
4345 svoboda 429
}
430
 
2689 jermar 431
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
432
{
433
    if (!vfs_files_init()) {
434
        ipc_answer_0(rid, ENOMEM);
435
        return;
436
    }
4691 svoboda 437
 
2689 jermar 438
    /*
2700 jermar 439
     * The POSIX interface is open(path, oflag, mode).
4691 svoboda 440
     * We can receive oflags and mode along with the VFS_IN_OPEN call;
441
     * the path will need to arrive in another call.
2700 jermar 442
     *
443
     * We also receive one private, non-POSIX set of flags called lflag
444
     * used to pass information to vfs_lookup_internal().
2689 jermar 445
     */
2700 jermar 446
    int lflag = IPC_GET_ARG1(*request);
447
    int oflag = IPC_GET_ARG2(*request);
448
    int mode = IPC_GET_ARG3(*request);
2689 jermar 449
    size_t len;
450
 
4691 svoboda 451
    /* Ignore mode for now. */
452
    (void) mode;
453
 
3674 svoboda 454
    /*
455
     * Make sure that we are called with exactly one of L_FILE and
4691 svoboda 456
     * L_DIRECTORY. Make sure that the user does not pass L_OPEN.
3674 svoboda 457
     */
4691 svoboda 458
    if (((lflag & (L_FILE | L_DIRECTORY)) == 0) ||
459
        ((lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) ||
460
        ((lflag & L_OPEN) != 0)) {
3674 svoboda 461
        ipc_answer_0(rid, EINVAL);
462
        return;
463
    }
4691 svoboda 464
 
2708 jermar 465
    if (oflag & O_CREAT)
466
        lflag |= L_CREATE;
467
    if (oflag & O_EXCL)
468
        lflag |= L_EXCLUSIVE;
4691 svoboda 469
 
2689 jermar 470
    ipc_callid_t callid;
471
    if (!ipc_data_write_receive(&callid, &len)) {
472
        ipc_answer_0(callid, EINVAL);
473
        ipc_answer_0(rid, EINVAL);
474
        return;
475
    }
4691 svoboda 476
 
2752 jermar 477
    char *path = malloc(len + 1);
2689 jermar 478
    if (!path) {
479
        ipc_answer_0(callid, ENOMEM);
480
        ipc_answer_0(rid, ENOMEM);
481
        return;
482
    }
4691 svoboda 483
 
2689 jermar 484
    int rc;
485
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
486
        ipc_answer_0(rid, rc);
487
        free(path);
488
        return;
489
    }
2752 jermar 490
    path[len] = '\0';
2689 jermar 491
 
492
    /*
493
     * Avoid the race condition in which the file can be deleted before we
494
     * find/create-and-lock the VFS node corresponding to the looked-up
495
     * triplet.
496
     */
2708 jermar 497
    if (lflag & L_CREATE)
4691 svoboda 498
        fibril_rwlock_write_lock(&namespace_rwlock);
2708 jermar 499
    else
4691 svoboda 500
        fibril_rwlock_read_lock(&namespace_rwlock);
501
 
2707 jermar 502
    /* The path is now populated and we can call vfs_lookup_internal(). */
2691 jermar 503
    vfs_lookup_res_t lr;
4691 svoboda 504
    rc = vfs_lookup_internal(path, lflag | L_OPEN, &lr, NULL);
505
    if (rc != EOK) {
2708 jermar 506
        if (lflag & L_CREATE)
4691 svoboda 507
            fibril_rwlock_write_unlock(&namespace_rwlock);
2708 jermar 508
        else
4691 svoboda 509
            fibril_rwlock_read_unlock(&namespace_rwlock);
2689 jermar 510
        ipc_answer_0(rid, rc);
511
        free(path);
512
        return;
513
    }
4691 svoboda 514
 
2748 jermar 515
    /* Path is no longer needed. */
2689 jermar 516
    free(path);
4691 svoboda 517
 
2691 jermar 518
    vfs_node_t *node = vfs_node_get(&lr);
2708 jermar 519
    if (lflag & L_CREATE)
4691 svoboda 520
        fibril_rwlock_write_unlock(&namespace_rwlock);
2708 jermar 521
    else
4691 svoboda 522
        fibril_rwlock_read_unlock(&namespace_rwlock);
523
 
2748 jermar 524
    /* Truncate the file if requested and if necessary. */
525
    if (oflag & O_TRUNC) {
4691 svoboda 526
        fibril_rwlock_write_lock(&node->contents_rwlock);
2748 jermar 527
        if (node->size) {
528
            rc = vfs_truncate_internal(node->fs_handle,
529
                node->dev_handle, node->index, 0);
530
            if (rc) {
4691 svoboda 531
                fibril_rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 532
                vfs_node_put(node);
533
                ipc_answer_0(rid, rc);
534
                return;
535
            }
536
            node->size = 0;
537
        }
4691 svoboda 538
        fibril_rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 539
    }
4691 svoboda 540
 
2689 jermar 541
    /*
542
     * Get ourselves a file descriptor and the corresponding vfs_file_t
543
     * structure.
544
     */
545
    int fd = vfs_fd_alloc();
546
    if (fd < 0) {
547
        vfs_node_put(node);
548
        ipc_answer_0(rid, fd);
549
        return;
550
    }
551
    vfs_file_t *file = vfs_file_get(fd);
552
    file->node = node;
4691 svoboda 553
    if (oflag & O_APPEND)
2709 jermar 554
        file->append = true;
4691 svoboda 555
 
556
    /*
557
     * The following increase in reference count is for the fact that the
558
     * file is being opened and that a file structure is pointing to it.
559
     * It is necessary so that the file will not disappear when
560
     * vfs_node_put() is called. The reference will be dropped by the
561
     * respective VFS_IN_CLOSE.
562
     */
563
    vfs_node_addref(node);
564
    vfs_node_put(node);
565
 
566
    /* Success! Return the new file descriptor to the client. */
567
    ipc_answer_1(rid, EOK, fd);
568
}
2689 jermar 569
 
4691 svoboda 570
void vfs_open_node(ipc_callid_t rid, ipc_call_t *request)
571
{
572
    // FIXME: check for sanity of the supplied fs, dev and index
573
 
574
    if (!vfs_files_init()) {
575
        ipc_answer_0(rid, ENOMEM);
576
        return;
577
    }
578
 
2689 jermar 579
    /*
4691 svoboda 580
     * The interface is open_node(fs, dev, index, oflag).
581
     */
582
    vfs_lookup_res_t lr;
583
 
584
    lr.triplet.fs_handle = IPC_GET_ARG1(*request);
585
    lr.triplet.dev_handle = IPC_GET_ARG2(*request);
586
    lr.triplet.index = IPC_GET_ARG3(*request);
587
    int oflag = IPC_GET_ARG4(*request);
588
 
589
    fibril_rwlock_read_lock(&namespace_rwlock);
590
 
591
    int rc = vfs_open_node_internal(&lr);
592
    if (rc != EOK) {
593
        fibril_rwlock_read_unlock(&namespace_rwlock);
594
        ipc_answer_0(rid, rc);
595
        return;
596
    }
597
 
598
    vfs_node_t *node = vfs_node_get(&lr);
599
    fibril_rwlock_read_unlock(&namespace_rwlock);
600
 
601
    /* Truncate the file if requested and if necessary. */
602
    if (oflag & O_TRUNC) {
603
        fibril_rwlock_write_lock(&node->contents_rwlock);
604
        if (node->size) {
605
            rc = vfs_truncate_internal(node->fs_handle,
606
                node->dev_handle, node->index, 0);
607
            if (rc) {
608
                fibril_rwlock_write_unlock(&node->contents_rwlock);
609
                vfs_node_put(node);
610
                ipc_answer_0(rid, rc);
611
                return;
612
            }
613
            node->size = 0;
614
        }
615
        fibril_rwlock_write_unlock(&node->contents_rwlock);
616
    }
617
 
618
    /*
619
     * Get ourselves a file descriptor and the corresponding vfs_file_t
620
     * structure.
621
     */
622
    int fd = vfs_fd_alloc();
623
    if (fd < 0) {
624
        vfs_node_put(node);
625
        ipc_answer_0(rid, fd);
626
        return;
627
    }
628
    vfs_file_t *file = vfs_file_get(fd);
629
    file->node = node;
630
    if (oflag & O_APPEND)
631
        file->append = true;
632
 
633
    /*
2689 jermar 634
     * The following increase in reference count is for the fact that the
635
     * file is being opened and that a file structure is pointing to it.
636
     * It is necessary so that the file will not disappear when
637
     * vfs_node_put() is called. The reference will be dropped by the
4691 svoboda 638
     * respective VFS_IN_CLOSE.
2689 jermar 639
     */
640
    vfs_node_addref(node);
641
    vfs_node_put(node);
4691 svoboda 642
 
2707 jermar 643
    /* Success! Return the new file descriptor to the client. */
2689 jermar 644
    ipc_answer_1(rid, EOK, fd);
645
}
646
 
4691 svoboda 647
void vfs_sync(ipc_callid_t rid, ipc_call_t *request)
2734 jermar 648
{
649
    int fd = IPC_GET_ARG1(*request);
4691 svoboda 650
 
651
    /* Lookup the file structure corresponding to the file descriptor. */
652
    vfs_file_t *file = vfs_file_get(fd);
653
    if (!file) {
654
        ipc_answer_0(rid, ENOENT);
655
        return;
656
    }
657
 
658
    /*
659
     * Lock the open file structure so that no other thread can manipulate
660
     * the same open file at a time.
661
     */
662
    fibril_mutex_lock(&file->lock);
663
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
664
 
665
    /* Make a VFS_OUT_SYMC request at the destination FS server. */
666
    aid_t msg;
667
    ipc_call_t answer;
668
    msg = async_send_2(fs_phone, VFS_OUT_SYNC, file->node->dev_handle,
669
        file->node->index, &answer);
670
 
671
    /* Wait for reply from the FS server. */
672
    ipcarg_t rc;
673
    async_wait_for(msg, &rc);
674
 
675
    vfs_release_phone(fs_phone);
676
    fibril_mutex_unlock(&file->lock);
677
 
3219 svoboda 678
    ipc_answer_0(rid, rc);
2734 jermar 679
}
680
 
4691 svoboda 681
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
682
{
683
    int fd = IPC_GET_ARG1(*request);
684
 
685
    /* Lookup the file structure corresponding to the file descriptor. */
686
    vfs_file_t *file = vfs_file_get(fd);
687
    if (!file) {
688
        ipc_answer_0(rid, ENOENT);
689
        return;
690
    }
691
 
692
    /*
693
     * Lock the open file structure so that no other thread can manipulate
694
     * the same open file at a time.
695
     */
696
    fibril_mutex_lock(&file->lock);
697
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
698
 
699
    /* Make a VFS_OUT_CLOSE request at the destination FS server. */
700
    aid_t msg;
701
    ipc_call_t answer;
702
    msg = async_send_2(fs_phone, VFS_OUT_CLOSE, file->node->dev_handle,
703
        file->node->index, &answer);
704
 
705
    /* Wait for reply from the FS server. */
706
    ipcarg_t rc;
707
    async_wait_for(msg, &rc);
708
 
709
    vfs_release_phone(fs_phone);
710
    fibril_mutex_unlock(&file->lock);
711
 
712
    int retval = IPC_GET_ARG1(answer);
713
    if (retval != EOK)
714
        ipc_answer_0(rid, retval);
715
 
716
    retval = vfs_fd_free(fd);
717
    ipc_answer_0(rid, retval);
718
}
719
 
2689 jermar 720
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
721
{
722
 
723
    /*
724
     * The following code strongly depends on the fact that the files data
725
     * structure can be only accessed by a single fibril and all file
726
     * operations are serialized (i.e. the reads and writes cannot
727
     * interleave and a file cannot be closed while it is being read).
728
     *
729
     * Additional synchronization needs to be added once the table of
730
     * open files supports parallel access!
731
     */
732
 
733
    int fd = IPC_GET_ARG1(*request);
3150 svoboda 734
 
2707 jermar 735
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 736
    vfs_file_t *file = vfs_file_get(fd);
737
    if (!file) {
738
        ipc_answer_0(rid, ENOENT);
739
        return;
740
    }
3150 svoboda 741
 
2689 jermar 742
    /*
743
     * Now we need to receive a call with client's
744
     * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
745
     */
746
    ipc_callid_t callid;
747
    int res;
748
    if (read)
749
        res = ipc_data_read_receive(&callid, NULL);
750
    else
751
        res = ipc_data_write_receive(&callid, NULL);
752
    if (!res) {
753
        ipc_answer_0(callid, EINVAL);
754
        ipc_answer_0(rid, EINVAL);
755
        return;
756
    }
3150 svoboda 757
 
2689 jermar 758
    /*
759
     * Lock the open file structure so that no other thread can manipulate
760
     * the same open file at a time.
761
     */
4691 svoboda 762
    fibril_mutex_lock(&file->lock);
3674 svoboda 763
 
2689 jermar 764
    /*
765
     * Lock the file's node so that no other client can read/write to it at
766
     * the same time.
767
     */
768
    if (read)
4691 svoboda 769
        fibril_rwlock_read_lock(&file->node->contents_rwlock);
2689 jermar 770
    else
4691 svoboda 771
        fibril_rwlock_write_lock(&file->node->contents_rwlock);
3674 svoboda 772
 
773
    if (file->node->type == VFS_NODE_DIRECTORY) {
774
        /*
775
         * Make sure that no one is modifying the namespace
776
         * while we are in readdir().
777
         */
778
        assert(read);
4691 svoboda 779
        fibril_rwlock_read_lock(&namespace_rwlock);
3674 svoboda 780
    }
3150 svoboda 781
 
2689 jermar 782
    int fs_phone = vfs_grab_phone(file->node->fs_handle);  
783
 
2707 jermar 784
    /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
2689 jermar 785
    aid_t msg;
786
    ipc_call_t answer;
2709 jermar 787
    if (!read && file->append)
788
        file->pos = file->node->size;
4691 svoboda 789
    msg = async_send_3(fs_phone, read ? VFS_OUT_READ : VFS_OUT_WRITE,
2689 jermar 790
        file->node->dev_handle, file->node->index, file->pos, &answer);
791
 
792
    /*
793
     * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
794
     * destination FS server. The call will be routed as if sent by
795
     * ourselves. Note that call arguments are immutable in this case so we
796
     * don't have to bother.
797
     */
798
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
4691 svoboda 799
 
800
    /* Wait for reply from the FS server. */
801
    ipcarg_t rc;
802
    async_wait_for(msg, &rc);
3150 svoboda 803
 
2689 jermar 804
    vfs_release_phone(fs_phone);
3150 svoboda 805
 
2689 jermar 806
    size_t bytes = IPC_GET_ARG1(answer);
3674 svoboda 807
 
808
    if (file->node->type == VFS_NODE_DIRECTORY)
4691 svoboda 809
        fibril_rwlock_read_unlock(&namespace_rwlock);
3150 svoboda 810
 
2707 jermar 811
    /* Unlock the VFS node. */
2689 jermar 812
    if (read)
4691 svoboda 813
        fibril_rwlock_read_unlock(&file->node->contents_rwlock);
2689 jermar 814
    else {
815
        /* Update the cached version of node's size. */
2710 jermar 816
        if (rc == EOK)
817
            file->node->size = IPC_GET_ARG2(answer);
4691 svoboda 818
        fibril_rwlock_write_unlock(&file->node->contents_rwlock);
2689 jermar 819
    }
3150 svoboda 820
 
2707 jermar 821
    /* Update the position pointer and unlock the open file. */
2710 jermar 822
    if (rc == EOK)
823
        file->pos += bytes;
4691 svoboda 824
    fibril_mutex_unlock(&file->lock);
3150 svoboda 825
 
2689 jermar 826
    /*
827
     * FS server's reply is the final result of the whole operation we
828
     * return to the client.
829
     */
830
    ipc_answer_1(rid, rc, bytes);
831
}
832
 
833
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
834
{
835
    vfs_rdwr(rid, request, true);
836
}
837
 
838
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
839
{
840
    vfs_rdwr(rid, request, false);
841
}
842
 
843
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
844
{
845
    int fd = (int) IPC_GET_ARG1(*request);
846
    off_t off = (off_t) IPC_GET_ARG2(*request);
847
    int whence = (int) IPC_GET_ARG3(*request);
848
 
849
 
2707 jermar 850
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 851
    vfs_file_t *file = vfs_file_get(fd);
852
    if (!file) {
853
        ipc_answer_0(rid, ENOENT);
854
        return;
855
    }
856
 
857
    off_t newpos;
4691 svoboda 858
    fibril_mutex_lock(&file->lock);
2689 jermar 859
    if (whence == SEEK_SET) {
860
        file->pos = off;
4691 svoboda 861
        fibril_mutex_unlock(&file->lock);
2689 jermar 862
        ipc_answer_1(rid, EOK, off);
863
        return;
864
    }
865
    if (whence == SEEK_CUR) {
866
        if (file->pos + off < file->pos) {
4691 svoboda 867
            fibril_mutex_unlock(&file->lock);
2689 jermar 868
            ipc_answer_0(rid, EOVERFLOW);
869
            return;
870
        }
871
        file->pos += off;
872
        newpos = file->pos;
4691 svoboda 873
        fibril_mutex_unlock(&file->lock);
2689 jermar 874
        ipc_answer_1(rid, EOK, newpos);
875
        return;
876
    }
877
    if (whence == SEEK_END) {
4691 svoboda 878
        fibril_rwlock_read_lock(&file->node->contents_rwlock);
2689 jermar 879
        size_t size = file->node->size;
4691 svoboda 880
        fibril_rwlock_read_unlock(&file->node->contents_rwlock);
2689 jermar 881
        if (size + off < size) {
4691 svoboda 882
            fibril_mutex_unlock(&file->lock);
2689 jermar 883
            ipc_answer_0(rid, EOVERFLOW);
884
            return;
885
        }
886
        newpos = size + off;
4691 svoboda 887
        fibril_mutex_unlock(&file->lock);
2689 jermar 888
        ipc_answer_1(rid, EOK, newpos);
889
        return;
890
    }
4691 svoboda 891
    fibril_mutex_unlock(&file->lock);
2689 jermar 892
    ipc_answer_0(rid, EINVAL);
893
}
894
 
2770 jermar 895
int
896
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
897
    fs_index_t index, size_t size)
2748 jermar 898
{
899
    ipcarg_t rc;
900
    int fs_phone;
901
 
902
    fs_phone = vfs_grab_phone(fs_handle);
4691 svoboda 903
    rc = async_req_3_0(fs_phone, VFS_OUT_TRUNCATE, (ipcarg_t)dev_handle,
2748 jermar 904
        (ipcarg_t)index, (ipcarg_t)size);
905
    vfs_release_phone(fs_phone);
906
    return (int)rc;
907
}
908
 
2693 jermar 909
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
910
{
911
    int fd = IPC_GET_ARG1(*request);
912
    size_t size = IPC_GET_ARG2(*request);
2748 jermar 913
    int rc;
2693 jermar 914
 
915
    vfs_file_t *file = vfs_file_get(fd);
916
    if (!file) {
917
        ipc_answer_0(rid, ENOENT);
918
        return;
919
    }
4691 svoboda 920
    fibril_mutex_lock(&file->lock);
2693 jermar 921
 
4691 svoboda 922
    fibril_rwlock_write_lock(&file->node->contents_rwlock);
2748 jermar 923
    rc = vfs_truncate_internal(file->node->fs_handle,
924
        file->node->dev_handle, file->node->index, size);
2693 jermar 925
    if (rc == EOK)
926
        file->node->size = size;
4691 svoboda 927
    fibril_rwlock_write_unlock(&file->node->contents_rwlock);
2693 jermar 928
 
4691 svoboda 929
    fibril_mutex_unlock(&file->lock);
2748 jermar 930
    ipc_answer_0(rid, (ipcarg_t)rc);
2693 jermar 931
}
932
 
4691 svoboda 933
void vfs_fstat(ipc_callid_t rid, ipc_call_t *request)
934
{
935
    int fd = IPC_GET_ARG1(*request);
936
    size_t size = IPC_GET_ARG2(*request);
937
    ipcarg_t rc;
938
 
939
    vfs_file_t *file = vfs_file_get(fd);
940
    if (!file) {
941
        ipc_answer_0(rid, ENOENT);
942
        return;
943
    }
944
 
945
    ipc_callid_t callid;
946
    if (!ipc_data_read_receive(&callid, NULL)) {
947
        ipc_answer_0(callid, EINVAL);
948
        ipc_answer_0(rid, EINVAL);
949
        return;
950
    }
951
 
952
    fibril_mutex_lock(&file->lock);
953
 
954
    int fs_phone = vfs_grab_phone(file->node->fs_handle);
955
 
956
    aid_t msg;
957
    msg = async_send_3(fs_phone, VFS_OUT_STAT, file->node->dev_handle,
958
        file->node->index, true, NULL);
959
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
960
    async_wait_for(msg, &rc);
961
    vfs_release_phone(fs_phone);
962
 
963
    fibril_mutex_unlock(&file->lock);
964
    ipc_answer_0(rid, rc);
965
}
966
 
967
void vfs_stat(ipc_callid_t rid, ipc_call_t *request)
968
{
969
    size_t len;
970
    ipc_callid_t callid;
971
 
972
    if (!ipc_data_write_receive(&callid, &len)) {
973
        ipc_answer_0(callid, EINVAL);
974
        ipc_answer_0(rid, EINVAL);
975
        return;
976
    }
977
    char *path = malloc(len + 1);
978
    if (!path) {
979
        ipc_answer_0(callid, ENOMEM);
980
        ipc_answer_0(rid, ENOMEM);
981
        return;
982
    }
983
    int rc;
984
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
985
        ipc_answer_0(rid, rc);
986
        free(path);
987
        return;
988
    }
989
    path[len] = '\0';
990
 
991
    if (!ipc_data_read_receive(&callid, NULL)) {
992
        free(path);
993
        ipc_answer_0(callid, EINVAL);
994
        ipc_answer_0(rid, EINVAL);
995
        return;
996
    }
997
 
998
    vfs_lookup_res_t lr;
999
    fibril_rwlock_read_lock(&namespace_rwlock);
1000
    rc = vfs_lookup_internal(path, L_NONE, &lr, NULL);
1001
    free(path);
1002
    if (rc != EOK) {
1003
        fibril_rwlock_read_unlock(&namespace_rwlock);
1004
        ipc_answer_0(callid, rc);
1005
        ipc_answer_0(rid, rc);
1006
        return;
1007
    }
1008
    vfs_node_t *node = vfs_node_get(&lr);
1009
    if (!node) {
1010
        fibril_rwlock_read_unlock(&namespace_rwlock);
1011
        ipc_answer_0(callid, ENOMEM);
1012
        ipc_answer_0(rid, ENOMEM);
1013
        return;
1014
    }
1015
 
1016
    fibril_rwlock_read_unlock(&namespace_rwlock);
1017
 
1018
    int fs_phone = vfs_grab_phone(node->fs_handle);
1019
    aid_t msg;
1020
    msg = async_send_3(fs_phone, VFS_OUT_STAT, node->dev_handle,
1021
        node->index, false, NULL);
1022
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
1023
 
1024
    ipcarg_t rv;
1025
    async_wait_for(msg, &rv);
1026
    vfs_release_phone(fs_phone);
1027
 
1028
    ipc_answer_0(rid, rv);
1029
 
1030
    vfs_node_put(node);
1031
}
1032
 
2707 jermar 1033
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
1034
{
1035
    int mode = IPC_GET_ARG1(*request);
2735 jermar 1036
 
2707 jermar 1037
    size_t len;
1038
    ipc_callid_t callid;
1039
 
1040
    if (!ipc_data_write_receive(&callid, &len)) {
1041
        ipc_answer_0(callid, EINVAL);
1042
        ipc_answer_0(rid, EINVAL);
1043
        return;
1044
    }
2752 jermar 1045
    char *path = malloc(len + 1);
2707 jermar 1046
    if (!path) {
1047
        ipc_answer_0(callid, ENOMEM);
1048
        ipc_answer_0(rid, ENOMEM);
1049
        return;
1050
    }
1051
    int rc;
1052
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
1053
        ipc_answer_0(rid, rc);
1054
        free(path);
1055
        return;
1056
    }
2752 jermar 1057
    path[len] = '\0';
4691 svoboda 1058
 
1059
    /* Ignore mode for now. */
1060
    (void) mode;
2707 jermar 1061
 
4691 svoboda 1062
    fibril_rwlock_write_lock(&namespace_rwlock);
2707 jermar 1063
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
2752 jermar 1064
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
4691 svoboda 1065
    fibril_rwlock_write_unlock(&namespace_rwlock);
2707 jermar 1066
    free(path);
1067
    ipc_answer_0(rid, rc);
1068
}
1069
 
2735 jermar 1070
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
1071
{
1072
    int lflag = IPC_GET_ARG1(*request);
1073
 
1074
    size_t len;
1075
    ipc_callid_t callid;
1076
 
1077
    if (!ipc_data_write_receive(&callid, &len)) {
1078
        ipc_answer_0(callid, EINVAL);
1079
        ipc_answer_0(rid, EINVAL);
1080
        return;
1081
    }
2752 jermar 1082
    char *path = malloc(len + 1);
2735 jermar 1083
    if (!path) {
1084
        ipc_answer_0(callid, ENOMEM);
1085
        ipc_answer_0(rid, ENOMEM);
1086
        return;
1087
    }
1088
    int rc;
1089
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
1090
        ipc_answer_0(rid, rc);
1091
        free(path);
1092
        return;
1093
    }
2752 jermar 1094
    path[len] = '\0';
2735 jermar 1095
 
4691 svoboda 1096
    fibril_rwlock_write_lock(&namespace_rwlock);
2735 jermar 1097
    lflag &= L_DIRECTORY;   /* sanitize lflag */
1098
    vfs_lookup_res_t lr;
2763 jermar 1099
    rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
2735 jermar 1100
    free(path);
1101
    if (rc != EOK) {
4691 svoboda 1102
        fibril_rwlock_write_unlock(&namespace_rwlock);
2735 jermar 1103
        ipc_answer_0(rid, rc);
1104
        return;
1105
    }
1106
 
1107
    /*
1108
     * The name has already been unlinked by vfs_lookup_internal().
1109
     * We have to get and put the VFS node to ensure that it is
4691 svoboda 1110
     * VFS_OUT_DESTROY'ed after the last reference to it is dropped.
2735 jermar 1111
     */
1112
    vfs_node_t *node = vfs_node_get(&lr);
4691 svoboda 1113
    fibril_mutex_lock(&nodes_mutex);
2735 jermar 1114
    node->lnkcnt--;
4691 svoboda 1115
    fibril_mutex_unlock(&nodes_mutex);
1116
    fibril_rwlock_write_unlock(&namespace_rwlock);
2735 jermar 1117
    vfs_node_put(node);
1118
    ipc_answer_0(rid, EOK);
1119
}
1120
 
2763 jermar 1121
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
1122
{
4348 svoboda 1123
    size_t olen, nlen;
2763 jermar 1124
    ipc_callid_t callid;
1125
    int rc;
1126
 
1127
    /* Retrieve the old path. */
4348 svoboda 1128
    if (!ipc_data_write_receive(&callid, &olen)) {
2763 jermar 1129
        ipc_answer_0(callid, EINVAL);
1130
        ipc_answer_0(rid, EINVAL);
1131
        return;
1132
    }
4348 svoboda 1133
    char *old = malloc(olen + 1);
2763 jermar 1134
    if (!old) {
1135
        ipc_answer_0(callid, ENOMEM);
1136
        ipc_answer_0(rid, ENOMEM);
1137
        return;
1138
    }
4348 svoboda 1139
    if ((rc = ipc_data_write_finalize(callid, old, olen))) {
2763 jermar 1140
        ipc_answer_0(rid, rc);
1141
        free(old);
1142
        return;
1143
    }
4348 svoboda 1144
    old[olen] = '\0';
2763 jermar 1145
 
1146
    /* Retrieve the new path. */
4348 svoboda 1147
    if (!ipc_data_write_receive(&callid, &nlen)) {
2763 jermar 1148
        ipc_answer_0(callid, EINVAL);
1149
        ipc_answer_0(rid, EINVAL);
1150
        free(old);
1151
        return;
1152
    }
4348 svoboda 1153
    char *new = malloc(nlen + 1);
2763 jermar 1154
    if (!new) {
1155
        ipc_answer_0(callid, ENOMEM);
1156
        ipc_answer_0(rid, ENOMEM);
1157
        free(old);
1158
        return;
1159
    }
4348 svoboda 1160
    if ((rc = ipc_data_write_finalize(callid, new, nlen))) {
2763 jermar 1161
        ipc_answer_0(rid, rc);
1162
        free(old);
1163
        free(new);
1164
        return;
1165
    }
4348 svoboda 1166
    new[nlen] = '\0';
2763 jermar 1167
 
4348 svoboda 1168
    char *oldc = canonify(old, &olen);
1169
    char *newc = canonify(new, &nlen);
2763 jermar 1170
    if (!oldc || !newc) {
1171
        ipc_answer_0(rid, EINVAL);
1172
        free(old);
1173
        free(new);
1174
        return;
1175
    }
4348 svoboda 1176
    oldc[olen] = '\0';
1177
    newc[nlen] = '\0';
4389 svoboda 1178
    if ((!str_lcmp(newc, oldc, str_length(oldc))) &&
1179
        ((newc[str_length(oldc)] == '/') ||
1180
        (str_length(oldc) == 1) ||
1181
        (str_length(oldc) == str_length(newc)))) {
1182
            /*
1183
         * oldc is a prefix of newc and either
1184
         * - newc continues with a / where oldc ends, or
1185
         * - oldc was / itself, or
1186
         * - oldc and newc are equal.
1187
         */
2763 jermar 1188
        ipc_answer_0(rid, EINVAL);
1189
        free(old);
1190
        free(new);
1191
        return;
1192
    }
1193
 
1194
    vfs_lookup_res_t old_lr;
1195
    vfs_lookup_res_t new_lr;
1196
    vfs_lookup_res_t new_par_lr;
4691 svoboda 1197
    fibril_rwlock_write_lock(&namespace_rwlock);
2763 jermar 1198
    /* Lookup the node belonging to the old file name. */
1199
    rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
1200
    if (rc != EOK) {
4691 svoboda 1201
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1202
        ipc_answer_0(rid, rc);
1203
        free(old);
1204
        free(new);
1205
        return;
1206
    }
1207
    vfs_node_t *old_node = vfs_node_get(&old_lr);
1208
    if (!old_node) {
4691 svoboda 1209
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1210
        ipc_answer_0(rid, ENOMEM);
1211
        free(old);
1212
        free(new);
1213
        return;
1214
    }
4389 svoboda 1215
    /* Determine the path to the parent of the node with the new name. */
1216
    char *parentc = str_dup(newc);
1217
    if (!parentc) {
4691 svoboda 1218
        fibril_rwlock_write_unlock(&namespace_rwlock);
4389 svoboda 1219
        ipc_answer_0(rid, rc);
1220
        free(old);
1221
        free(new);
1222
        return;
1223
    }
4691 svoboda 1224
    char *lastsl = str_rchr(parentc + 1, '/');
4389 svoboda 1225
    if (lastsl)
1226
        *lastsl = '\0';
1227
    else
1228
        parentc[1] = '\0';
2763 jermar 1229
    /* Lookup parent of the new file name. */
4389 svoboda 1230
    rc = vfs_lookup_internal(parentc, L_NONE, &new_par_lr, NULL);
1231
    free(parentc);  /* not needed anymore */
2763 jermar 1232
    if (rc != EOK) {
4691 svoboda 1233
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1234
        ipc_answer_0(rid, rc);
1235
        free(old);
1236
        free(new);
1237
        return;
1238
    }
1239
    /* Check whether linking to the same file system instance. */
1240
    if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
1241
        (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
4691 svoboda 1242
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1243
        ipc_answer_0(rid, EXDEV);   /* different file systems */
1244
        free(old);
1245
        free(new);
1246
        return;
1247
    }
1248
    /* Destroy the old link for the new name. */
1249
    vfs_node_t *new_node = NULL;
1250
    rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
1251
    switch (rc) {
1252
    case ENOENT:
1253
        /* simply not in our way */
1254
        break;
1255
    case EOK:
1256
        new_node = vfs_node_get(&new_lr);
1257
        if (!new_node) {
4691 svoboda 1258
            fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1259
            ipc_answer_0(rid, ENOMEM);
1260
            free(old);
1261
            free(new);
1262
            return;
1263
        }
4691 svoboda 1264
        fibril_mutex_lock(&nodes_mutex);
2763 jermar 1265
        new_node->lnkcnt--;
4691 svoboda 1266
        fibril_mutex_unlock(&nodes_mutex);
2763 jermar 1267
        break;
1268
    default:
4691 svoboda 1269
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1270
        ipc_answer_0(rid, ENOTEMPTY);
1271
        free(old);
1272
        free(new);
1273
        return;
1274
    }
1275
    /* Create the new link for the new name. */
1276
    rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
1277
    if (rc != EOK) {
4691 svoboda 1278
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1279
        if (new_node)
1280
            vfs_node_put(new_node);
1281
        ipc_answer_0(rid, rc);
1282
        free(old);
1283
        free(new);
1284
        return;
1285
    }
4691 svoboda 1286
    fibril_mutex_lock(&nodes_mutex);
2763 jermar 1287
    old_node->lnkcnt++;
4691 svoboda 1288
    fibril_mutex_unlock(&nodes_mutex);
2763 jermar 1289
    /* Destroy the link for the old name. */
1290
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
1291
    if (rc != EOK) {
4691 svoboda 1292
        fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1293
        vfs_node_put(old_node);
1294
        if (new_node)
1295
            vfs_node_put(new_node);
1296
        ipc_answer_0(rid, rc);
1297
        free(old);
1298
        free(new);
1299
        return;
1300
    }
4691 svoboda 1301
    fibril_mutex_lock(&nodes_mutex);
2763 jermar 1302
    old_node->lnkcnt--;
4691 svoboda 1303
    fibril_mutex_unlock(&nodes_mutex);
1304
    fibril_rwlock_write_unlock(&namespace_rwlock);
2763 jermar 1305
    vfs_node_put(old_node);
1306
    if (new_node)
1307
        vfs_node_put(new_node);
1308
    free(old);
1309
    free(new);
1310
    ipc_answer_0(rid, EOK);
1311
}
1312
 
2689 jermar 1313
/**
1314
 * @}
4691 svoboda 1315
 */