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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
 * @{
4153 mejdrech 31
 */
2689 jermar 32
 
33
/**
4153 mejdrech 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>
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
 
4153 mejdrech 58
/** Pending mount structure. */
59
typedef struct {
60
    link_t link;
61
    char *fs_name;            /**< File system name */
62
    char *mp;                 /**< Mount point */
63
    ipc_callid_t callid;      /**< Call ID waiting for the mount */
64
    ipc_callid_t rid;         /**< Request ID */
65
    dev_handle_t dev_handle;  /**< Device handle */
66
} pending_req_t;
67
 
68
LIST_INITIALIZE(pending_req);
69
 
2689 jermar 70
/**
71
 * This rwlock prevents the race between a triplet-to-VFS-node resolution and a
72
 * concurrent VFS operation which modifies the file system namespace.
73
 */
74
RWLOCK_INITIALIZE(namespace_rwlock);
75
 
2766 jermar 76
futex_t rootfs_futex = FUTEX_INITIALIZER;
3109 jermar 77
vfs_pair_t rootfs = {
2689 jermar 78
    .fs_handle = 0,
3109 jermar 79
    .dev_handle = 0
2689 jermar 80
};
81
 
4153 mejdrech 82
static void vfs_mount_internal(ipc_callid_t rid, dev_handle_t dev_handle,
83
    fs_handle_t fs_handle, char *mp)
2689 jermar 84
{
4153 mejdrech 85
    /* Resolve the path to the mountpoint. */
86
    vfs_lookup_res_t mp_res;
2689 jermar 87
    vfs_node_t *mp_node = NULL;
2957 jermar 88
    int rc;
2958 jermar 89
    int phone;
2689 jermar 90
    futex_down(&rootfs_futex);
91
    if (rootfs.fs_handle) {
2707 jermar 92
        /* We already have the root FS. */
2689 jermar 93
        rwlock_write_lock(&namespace_rwlock);
4153 mejdrech 94
        if ((strlen(mp) == 1) && (mp[0] == '/')) {
2788 jermar 95
            /* Trying to mount root FS over root FS */
96
            rwlock_write_unlock(&namespace_rwlock);
97
            futex_up(&rootfs_futex);
98
            ipc_answer_0(rid, EBUSY);
99
            return;
100
        }
4153 mejdrech 101
 
102
        rc = vfs_lookup_internal(mp, L_DIRECTORY, &mp_res, NULL);
2689 jermar 103
        if (rc != EOK) {
2707 jermar 104
            /* The lookup failed for some reason. */
2689 jermar 105
            rwlock_write_unlock(&namespace_rwlock);
106
            futex_up(&rootfs_futex);
107
            ipc_answer_0(rid, rc);
108
            return;
109
        }
4153 mejdrech 110
 
2691 jermar 111
        mp_node = vfs_node_get(&mp_res);
2689 jermar 112
        if (!mp_node) {
113
            rwlock_write_unlock(&namespace_rwlock);
114
            futex_up(&rootfs_futex);
115
            ipc_answer_0(rid, ENOMEM);
116
            return;
117
        }
4153 mejdrech 118
 
2689 jermar 119
        /*
120
         * Now we hold a reference to mp_node.
121
         * It will be dropped upon the corresponding VFS_UNMOUNT.
122
         * This prevents the mount point from being deleted.
123
         */
124
        rwlock_write_unlock(&namespace_rwlock);
125
    } else {
2707 jermar 126
        /* We still don't have the root file system mounted. */
4153 mejdrech 127
        if ((strlen(mp) == 1) && (mp[0] == '/')) {
3352 jermar 128
            vfs_lookup_res_t mr_res;
129
            vfs_node_t *mr_node;
130
            ipcarg_t rindex;
131
            ipcarg_t rsize;
132
            ipcarg_t rlnkcnt;
4153 mejdrech 133
 
2958 jermar 134
            /*
135
             * For this simple, but important case,
136
             * we are almost done.
137
             */
138
 
3109 jermar 139
            /* Tell the mountee that it is being mounted. */
140
            phone = vfs_grab_phone(fs_handle);
3352 jermar 141
            rc = async_req_1_3(phone, VFS_MOUNTED,
142
                (ipcarg_t) dev_handle, &rindex, &rsize, &rlnkcnt);
2958 jermar 143
            vfs_release_phone(phone);
3352 jermar 144
 
145
            if (rc != EOK) {
146
                futex_up(&rootfs_futex);
147
                ipc_answer_0(rid, rc);
148
                return;
3109 jermar 149
            }
4153 mejdrech 150
 
3352 jermar 151
            mr_res.triplet.fs_handle = fs_handle;
152
            mr_res.triplet.dev_handle = dev_handle;
153
            mr_res.triplet.index = (fs_index_t) rindex;
154
            mr_res.size = (size_t) rsize;
155
            mr_res.lnkcnt = (unsigned) rlnkcnt;
4153 mejdrech 156
            mr_res.type = VFS_NODE_DIRECTORY;
157
 
3352 jermar 158
            rootfs.fs_handle = fs_handle;
159
            rootfs.dev_handle = dev_handle;
2689 jermar 160
            futex_up(&rootfs_futex);
4153 mejdrech 161
 
3352 jermar 162
            /* Add reference to the mounted root. */
163
            mr_node = vfs_node_get(&mr_res);
164
            assert(mr_node);
4153 mejdrech 165
 
2958 jermar 166
            ipc_answer_0(rid, rc);
2689 jermar 167
            return;
168
        } else {
169
            /*
170
             * We can't resolve this without the root filesystem
171
             * being mounted first.
172
             */
173
            futex_up(&rootfs_futex);
174
            ipc_answer_0(rid, ENOENT);
175
            return;
176
        }
177
    }
178
    futex_up(&rootfs_futex);
179
 
180
    /*
181
     * At this point, we have all necessary pieces: file system and device
3109 jermar 182
     * handles, and we know the mount point VFS node.
2689 jermar 183
     */
4153 mejdrech 184
 
2958 jermar 185
    phone = vfs_grab_phone(mp_res.triplet.fs_handle);
3109 jermar 186
    rc = async_req_4_0(phone, VFS_MOUNT,
2691 jermar 187
        (ipcarg_t) mp_res.triplet.dev_handle,
2957 jermar 188
        (ipcarg_t) mp_res.triplet.index,
3109 jermar 189
        (ipcarg_t) fs_handle,
190
        (ipcarg_t) dev_handle);
2689 jermar 191
    vfs_release_phone(phone);
4153 mejdrech 192
 
2957 jermar 193
    if (rc != EOK) {
3109 jermar 194
        /* Mount failed, drop reference to mp_node. */
2689 jermar 195
        if (mp_node)
196
            vfs_node_put(mp_node);
197
    }
198
 
2957 jermar 199
    ipc_answer_0(rid, rc);
2689 jermar 200
}
201
 
4153 mejdrech 202
/** Process pending mount requests */
203
void vfs_process_pending_mount()
204
{
205
    link_t *cur;
206
 
207
loop:
208
    for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
209
        pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
210
 
211
        fs_handle_t fs_handle = fs_name_to_handle(pr->fs_name, true);
212
        if (!fs_handle)
213
            continue;
214
 
215
        /* Acknowledge that we know fs_name. */
216
        ipc_answer_0(pr->callid, EOK);
217
 
218
        /* Do the mount */
219
        vfs_mount_internal(pr->rid, pr->dev_handle, fs_handle, pr->mp);
220
 
221
        free(pr->fs_name);
222
        free(pr->mp);
223
        list_remove(cur);
224
        free(pr);
225
        goto loop;
226
    }
227
}
228
 
229
void vfs_mount(ipc_callid_t rid, ipc_call_t *request)
230
{
231
    /*
232
     * We expect the library to do the device-name to device-handle
233
     * translation for us, thus the device handle will arrive as ARG1
234
     * in the request.
235
     */
236
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
237
 
238
    /*
239
     * Mount flags are passed as ARG2.
240
     */
241
    unsigned int flags = (unsigned int) IPC_GET_ARG2(*request);
242
 
243
    /*
244
     * For now, don't make use of ARG3, but it can be used to
245
     * carry mount options in the future.
246
     */
247
 
248
    /* We want the client to send us the mount point. */
249
    ipc_callid_t callid;
250
    size_t size;
251
    if (!ipc_data_write_receive(&callid, &size)) {
252
        ipc_answer_0(callid, EINVAL);
253
        ipc_answer_0(rid, EINVAL);
254
        return;
255
    }
256
 
257
    /* Check whether size is reasonable wrt. the mount point. */
258
    if ((size < 1) || (size > MAX_PATH_LEN)) {
259
        ipc_answer_0(callid, EINVAL);
260
        ipc_answer_0(rid, EINVAL);
261
        return;
262
    }
263
 
264
    /* Allocate buffer for the mount point data being received. */
265
    char *mp = malloc(size + 1);
266
    if (!mp) {
267
        ipc_answer_0(callid, ENOMEM);
268
        ipc_answer_0(rid, ENOMEM);
269
        return;
270
    }
271
 
272
    /* Deliver the mount point. */
273
    ipcarg_t retval = ipc_data_write_finalize(callid, mp, size);
274
    if (retval != EOK) {
275
        ipc_answer_0(rid, EREFUSED);
276
        free(mp);
277
        return;
278
    }
279
    mp[size] = '\0';
280
 
281
    /*
282
     * Now, we expect the client to send us data with the name of the file
283
     * system.
284
     */
285
    if (!ipc_data_write_receive(&callid, &size)) {
286
        ipc_answer_0(callid, EINVAL);
287
        ipc_answer_0(rid, EINVAL);
288
        free(mp);
289
        return;
290
    }
291
 
292
    /*
293
     * Don't receive more than is necessary for storing a full file system
294
     * name.
295
     */
296
    if ((size < 1) || (size > FS_NAME_MAXLEN)) {
297
        ipc_answer_0(callid, EINVAL);
298
        ipc_answer_0(rid, EINVAL);
299
        free(mp);
300
        return;
301
    }
302
 
303
    /*
304
     * Allocate buffer for file system name.
305
     */
306
    char *fs_name = (char *) malloc(size + 1);
307
    if (fs_name == NULL) {
308
        ipc_answer_0(callid, ENOMEM);
309
        ipc_answer_0(rid, EREFUSED);
310
        free(mp);
311
        return;
312
    }
313
 
314
    /* Deliver the file system name. */
315
    retval = ipc_data_write_finalize(callid, fs_name, size);
316
    if (retval != EOK) {
317
        ipc_answer_0(rid, EREFUSED);
318
        free(mp);
319
        free(fs_name);
320
        return;
321
    }
322
    fs_name[size] = '\0';
323
 
324
    /*
325
     * Check if we know a file system with the same name as is in fs_name.
326
     * This will also give us its file system handle.
327
     */
328
    fs_handle_t fs_handle = fs_name_to_handle(fs_name, true);
329
    if (!fs_handle) {
330
        if (flags & IPC_FLAG_BLOCKING) {
331
            /* Blocking mount, add to pending list */
332
            pending_req_t *pr = (pending_req_t *) malloc(sizeof(pending_req_t));
333
            if (!pr) {
334
                ipc_answer_0(callid, ENOMEM);
335
                ipc_answer_0(rid, ENOMEM);
336
                free(mp);
337
                free(fs_name);
338
                return;
339
            }
340
 
341
            pr->fs_name = fs_name;
342
            pr->mp = mp;
343
            pr->callid = callid;
344
            pr->rid = rid;
345
            pr->dev_handle = dev_handle;
346
            list_append(&pr->link, &pending_req);
347
            return;
348
        }
349
 
350
        ipc_answer_0(callid, ENOENT);
351
        ipc_answer_0(rid, ENOENT);
352
        free(mp);
353
        free(fs_name);
354
        return;
355
    }
356
 
357
    /* Acknowledge that we know fs_name. */
358
    ipc_answer_0(callid, EOK);
359
 
360
    /* Do the mount */
361
    vfs_mount_internal(rid, dev_handle, fs_handle, mp);
362
    free(mp);
363
    free(fs_name);
364
}
365
 
2689 jermar 366
void vfs_open(ipc_callid_t rid, ipc_call_t *request)
367
{
368
    if (!vfs_files_init()) {
369
        ipc_answer_0(rid, ENOMEM);
370
        return;
371
    }
372
 
373
    /*
2700 jermar 374
     * The POSIX interface is open(path, oflag, mode).
375
     * We can receive oflags and mode along with the VFS_OPEN call; the path
2689 jermar 376
     * will need to arrive in another call.
2700 jermar 377
     *
378
     * We also receive one private, non-POSIX set of flags called lflag
379
     * used to pass information to vfs_lookup_internal().
2689 jermar 380
     */
2700 jermar 381
    int lflag = IPC_GET_ARG1(*request);
382
    int oflag = IPC_GET_ARG2(*request);
383
    int mode = IPC_GET_ARG3(*request);
2689 jermar 384
    size_t len;
385
 
4153 mejdrech 386
    /*
387
     * Make sure that we are called with exactly one of L_FILE and
388
     * L_DIRECTORY.
389
     */
390
    if ((lflag & (L_FILE | L_DIRECTORY)) == 0 ||
391
        (lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) {
392
        ipc_answer_0(rid, EINVAL);
393
        return;
394
    }
395
 
2708 jermar 396
    if (oflag & O_CREAT)
397
        lflag |= L_CREATE;
398
    if (oflag & O_EXCL)
399
        lflag |= L_EXCLUSIVE;
400
 
2689 jermar 401
    ipc_callid_t callid;
402
 
403
    if (!ipc_data_write_receive(&callid, &len)) {
404
        ipc_answer_0(callid, EINVAL);
405
        ipc_answer_0(rid, EINVAL);
406
        return;
407
    }
2752 jermar 408
    char *path = malloc(len + 1);
2689 jermar 409
    if (!path) {
410
        ipc_answer_0(callid, ENOMEM);
411
        ipc_answer_0(rid, ENOMEM);
412
        return;
413
    }
414
    int rc;
415
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
416
        ipc_answer_0(rid, rc);
417
        free(path);
418
        return;
419
    }
2752 jermar 420
    path[len] = '\0';
2689 jermar 421
 
422
    /*
423
     * Avoid the race condition in which the file can be deleted before we
424
     * find/create-and-lock the VFS node corresponding to the looked-up
425
     * triplet.
426
     */
2708 jermar 427
    if (lflag & L_CREATE)
428
        rwlock_write_lock(&namespace_rwlock);
429
    else
430
        rwlock_read_lock(&namespace_rwlock);
2689 jermar 431
 
2707 jermar 432
    /* The path is now populated and we can call vfs_lookup_internal(). */
2691 jermar 433
    vfs_lookup_res_t lr;
2752 jermar 434
    rc = vfs_lookup_internal(path, lflag, &lr, NULL);
2689 jermar 435
    if (rc) {
2708 jermar 436
        if (lflag & L_CREATE)
437
            rwlock_write_unlock(&namespace_rwlock);
438
        else
439
            rwlock_read_unlock(&namespace_rwlock);
2689 jermar 440
        ipc_answer_0(rid, rc);
441
        free(path);
442
        return;
443
    }
444
 
2748 jermar 445
    /* Path is no longer needed. */
2689 jermar 446
    free(path);
447
 
2691 jermar 448
    vfs_node_t *node = vfs_node_get(&lr);
2708 jermar 449
    if (lflag & L_CREATE)
450
        rwlock_write_unlock(&namespace_rwlock);
451
    else
452
        rwlock_read_unlock(&namespace_rwlock);
2689 jermar 453
 
2748 jermar 454
    /* Truncate the file if requested and if necessary. */
455
    if (oflag & O_TRUNC) {
2749 jermar 456
        rwlock_write_lock(&node->contents_rwlock);
2748 jermar 457
        if (node->size) {
458
            rc = vfs_truncate_internal(node->fs_handle,
459
                node->dev_handle, node->index, 0);
460
            if (rc) {
2749 jermar 461
                rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 462
                vfs_node_put(node);
463
                ipc_answer_0(rid, rc);
464
                return;
465
            }
466
            node->size = 0;
467
        }
2749 jermar 468
        rwlock_write_unlock(&node->contents_rwlock);
2748 jermar 469
    }
470
 
2689 jermar 471
    /*
472
     * Get ourselves a file descriptor and the corresponding vfs_file_t
473
     * structure.
474
     */
475
    int fd = vfs_fd_alloc();
476
    if (fd < 0) {
477
        vfs_node_put(node);
478
        ipc_answer_0(rid, fd);
479
        return;
480
    }
481
    vfs_file_t *file = vfs_file_get(fd);
482
    file->node = node;
2710 jermar 483
    if (oflag & O_APPEND)
2709 jermar 484
        file->append = true;
2689 jermar 485
 
486
    /*
487
     * The following increase in reference count is for the fact that the
488
     * file is being opened and that a file structure is pointing to it.
489
     * It is necessary so that the file will not disappear when
490
     * vfs_node_put() is called. The reference will be dropped by the
491
     * respective VFS_CLOSE.
492
     */
493
    vfs_node_addref(node);
494
    vfs_node_put(node);
495
 
2707 jermar 496
    /* Success! Return the new file descriptor to the client. */
2689 jermar 497
    ipc_answer_1(rid, EOK, fd);
498
}
499
 
2734 jermar 500
void vfs_close(ipc_callid_t rid, ipc_call_t *request)
501
{
502
    int fd = IPC_GET_ARG1(*request);
3215 jermar 503
    int rc = vfs_fd_free(fd);
504
    ipc_answer_0(rid, rc);
2734 jermar 505
}
506
 
2689 jermar 507
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
508
{
509
 
510
    /*
511
     * The following code strongly depends on the fact that the files data
512
     * structure can be only accessed by a single fibril and all file
513
     * operations are serialized (i.e. the reads and writes cannot
514
     * interleave and a file cannot be closed while it is being read).
515
     *
516
     * Additional synchronization needs to be added once the table of
517
     * open files supports parallel access!
518
     */
519
 
520
    int fd = IPC_GET_ARG1(*request);
3079 decky 521
 
2707 jermar 522
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 523
    vfs_file_t *file = vfs_file_get(fd);
524
    if (!file) {
525
        ipc_answer_0(rid, ENOENT);
526
        return;
527
    }
3079 decky 528
 
2689 jermar 529
    /*
530
     * Now we need to receive a call with client's
531
     * IPC_M_DATA_READ/IPC_M_DATA_WRITE request.
532
     */
533
    ipc_callid_t callid;
534
    int res;
535
    if (read)
536
        res = ipc_data_read_receive(&callid, NULL);
537
    else
538
        res = ipc_data_write_receive(&callid, NULL);
539
    if (!res) {
540
        ipc_answer_0(callid, EINVAL);
541
        ipc_answer_0(rid, EINVAL);
542
        return;
543
    }
3079 decky 544
 
2689 jermar 545
    /*
546
     * Lock the open file structure so that no other thread can manipulate
547
     * the same open file at a time.
548
     */
549
    futex_down(&file->lock);
4153 mejdrech 550
 
2689 jermar 551
    /*
552
     * Lock the file's node so that no other client can read/write to it at
553
     * the same time.
554
     */
555
    if (read)
556
        rwlock_read_lock(&file->node->contents_rwlock);
557
    else
558
        rwlock_write_lock(&file->node->contents_rwlock);
4153 mejdrech 559
 
560
    if (file->node->type == VFS_NODE_DIRECTORY) {
561
        /*
562
         * Make sure that no one is modifying the namespace
563
         * while we are in readdir().
564
         */
565
        assert(read);
566
        rwlock_read_lock(&namespace_rwlock);
567
    }
3079 decky 568
 
2689 jermar 569
    int fs_phone = vfs_grab_phone(file->node->fs_handle);  
570
 
2707 jermar 571
    /* Make a VFS_READ/VFS_WRITE request at the destination FS server. */
2689 jermar 572
    aid_t msg;
573
    ipc_call_t answer;
2709 jermar 574
    if (!read && file->append)
575
        file->pos = file->node->size;
2689 jermar 576
    msg = async_send_3(fs_phone, IPC_GET_METHOD(*request),
577
        file->node->dev_handle, file->node->index, file->pos, &answer);
578
 
579
    /*
580
     * Forward the IPC_M_DATA_READ/IPC_M_DATA_WRITE request to the
581
     * destination FS server. The call will be routed as if sent by
582
     * ourselves. Note that call arguments are immutable in this case so we
583
     * don't have to bother.
584
     */
585
    ipc_forward_fast(callid, fs_phone, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
3079 decky 586
 
2689 jermar 587
    vfs_release_phone(fs_phone);
3079 decky 588
 
2707 jermar 589
    /* Wait for reply from the FS server. */
2689 jermar 590
    ipcarg_t rc;
591
    async_wait_for(msg, &rc);
592
    size_t bytes = IPC_GET_ARG1(answer);
4153 mejdrech 593
 
594
    if (file->node->type == VFS_NODE_DIRECTORY)
595
        rwlock_read_unlock(&namespace_rwlock);
3079 decky 596
 
2707 jermar 597
    /* Unlock the VFS node. */
2689 jermar 598
    if (read)
599
        rwlock_read_unlock(&file->node->contents_rwlock);
600
    else {
601
        /* Update the cached version of node's size. */
2710 jermar 602
        if (rc == EOK)
603
            file->node->size = IPC_GET_ARG2(answer);
2689 jermar 604
        rwlock_write_unlock(&file->node->contents_rwlock);
605
    }
3079 decky 606
 
2707 jermar 607
    /* Update the position pointer and unlock the open file. */
2710 jermar 608
    if (rc == EOK)
609
        file->pos += bytes;
2689 jermar 610
    futex_up(&file->lock);
3079 decky 611
 
2689 jermar 612
    /*
613
     * FS server's reply is the final result of the whole operation we
614
     * return to the client.
615
     */
616
    ipc_answer_1(rid, rc, bytes);
617
}
618
 
619
void vfs_read(ipc_callid_t rid, ipc_call_t *request)
620
{
621
    vfs_rdwr(rid, request, true);
622
}
623
 
624
void vfs_write(ipc_callid_t rid, ipc_call_t *request)
625
{
626
    vfs_rdwr(rid, request, false);
627
}
628
 
629
void vfs_seek(ipc_callid_t rid, ipc_call_t *request)
630
{
631
    int fd = (int) IPC_GET_ARG1(*request);
632
    off_t off = (off_t) IPC_GET_ARG2(*request);
633
    int whence = (int) IPC_GET_ARG3(*request);
634
 
635
 
2707 jermar 636
    /* Lookup the file structure corresponding to the file descriptor. */
2689 jermar 637
    vfs_file_t *file = vfs_file_get(fd);
638
    if (!file) {
639
        ipc_answer_0(rid, ENOENT);
640
        return;
641
    }
642
 
643
    off_t newpos;
644
    futex_down(&file->lock);
645
    if (whence == SEEK_SET) {
646
        file->pos = off;
647
        futex_up(&file->lock);
648
        ipc_answer_1(rid, EOK, off);
649
        return;
650
    }
651
    if (whence == SEEK_CUR) {
652
        if (file->pos + off < file->pos) {
653
            futex_up(&file->lock);
654
            ipc_answer_0(rid, EOVERFLOW);
655
            return;
656
        }
657
        file->pos += off;
658
        newpos = file->pos;
659
        futex_up(&file->lock);
660
        ipc_answer_1(rid, EOK, newpos);
661
        return;
662
    }
663
    if (whence == SEEK_END) {
664
        rwlock_read_lock(&file->node->contents_rwlock);
665
        size_t size = file->node->size;
666
        rwlock_read_unlock(&file->node->contents_rwlock);
667
        if (size + off < size) {
668
            futex_up(&file->lock);
669
            ipc_answer_0(rid, EOVERFLOW);
670
            return;
671
        }
672
        newpos = size + off;
673
        futex_up(&file->lock);
674
        ipc_answer_1(rid, EOK, newpos);
675
        return;
676
    }
677
    futex_up(&file->lock);
678
    ipc_answer_0(rid, EINVAL);
679
}
680
 
2770 jermar 681
int
682
vfs_truncate_internal(fs_handle_t fs_handle, dev_handle_t dev_handle,
683
    fs_index_t index, size_t size)
2748 jermar 684
{
685
    ipcarg_t rc;
686
    int fs_phone;
687
 
688
    fs_phone = vfs_grab_phone(fs_handle);
689
    rc = async_req_3_0(fs_phone, VFS_TRUNCATE, (ipcarg_t)dev_handle,
690
        (ipcarg_t)index, (ipcarg_t)size);
691
    vfs_release_phone(fs_phone);
692
    return (int)rc;
693
}
694
 
2693 jermar 695
void vfs_truncate(ipc_callid_t rid, ipc_call_t *request)
696
{
697
    int fd = IPC_GET_ARG1(*request);
698
    size_t size = IPC_GET_ARG2(*request);
2748 jermar 699
    int rc;
2693 jermar 700
 
701
    vfs_file_t *file = vfs_file_get(fd);
702
    if (!file) {
703
        ipc_answer_0(rid, ENOENT);
704
        return;
705
    }
706
    futex_down(&file->lock);
707
 
708
    rwlock_write_lock(&file->node->contents_rwlock);
2748 jermar 709
    rc = vfs_truncate_internal(file->node->fs_handle,
710
        file->node->dev_handle, file->node->index, size);
2693 jermar 711
    if (rc == EOK)
712
        file->node->size = size;
713
    rwlock_write_unlock(&file->node->contents_rwlock);
714
 
715
    futex_up(&file->lock);
2748 jermar 716
    ipc_answer_0(rid, (ipcarg_t)rc);
2693 jermar 717
}
718
 
2707 jermar 719
void vfs_mkdir(ipc_callid_t rid, ipc_call_t *request)
720
{
721
    int mode = IPC_GET_ARG1(*request);
2735 jermar 722
 
2707 jermar 723
    size_t len;
724
    ipc_callid_t callid;
725
 
726
    if (!ipc_data_write_receive(&callid, &len)) {
727
        ipc_answer_0(callid, EINVAL);
728
        ipc_answer_0(rid, EINVAL);
729
        return;
730
    }
2752 jermar 731
    char *path = malloc(len + 1);
2707 jermar 732
    if (!path) {
733
        ipc_answer_0(callid, ENOMEM);
734
        ipc_answer_0(rid, ENOMEM);
735
        return;
736
    }
737
    int rc;
738
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
739
        ipc_answer_0(rid, rc);
740
        free(path);
741
        return;
742
    }
2752 jermar 743
    path[len] = '\0';
2707 jermar 744
 
745
    rwlock_write_lock(&namespace_rwlock);
746
    int lflag = L_DIRECTORY | L_CREATE | L_EXCLUSIVE;
2752 jermar 747
    rc = vfs_lookup_internal(path, lflag, NULL, NULL);
2707 jermar 748
    rwlock_write_unlock(&namespace_rwlock);
749
    free(path);
750
    ipc_answer_0(rid, rc);
751
}
752
 
2735 jermar 753
void vfs_unlink(ipc_callid_t rid, ipc_call_t *request)
754
{
755
    int lflag = IPC_GET_ARG1(*request);
756
 
757
    size_t len;
758
    ipc_callid_t callid;
759
 
760
    if (!ipc_data_write_receive(&callid, &len)) {
761
        ipc_answer_0(callid, EINVAL);
762
        ipc_answer_0(rid, EINVAL);
763
        return;
764
    }
2752 jermar 765
    char *path = malloc(len + 1);
2735 jermar 766
    if (!path) {
767
        ipc_answer_0(callid, ENOMEM);
768
        ipc_answer_0(rid, ENOMEM);
769
        return;
770
    }
771
    int rc;
772
    if ((rc = ipc_data_write_finalize(callid, path, len))) {
773
        ipc_answer_0(rid, rc);
774
        free(path);
775
        return;
776
    }
2752 jermar 777
    path[len] = '\0';
2735 jermar 778
 
779
    rwlock_write_lock(&namespace_rwlock);
780
    lflag &= L_DIRECTORY;   /* sanitize lflag */
781
    vfs_lookup_res_t lr;
2763 jermar 782
    rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
2735 jermar 783
    free(path);
784
    if (rc != EOK) {
785
        rwlock_write_unlock(&namespace_rwlock);
786
        ipc_answer_0(rid, rc);
787
        return;
788
    }
789
 
790
    /*
791
     * The name has already been unlinked by vfs_lookup_internal().
792
     * We have to get and put the VFS node to ensure that it is
2742 jermar 793
     * VFS_DESTROY'ed after the last reference to it is dropped.
2735 jermar 794
     */
795
    vfs_node_t *node = vfs_node_get(&lr);
2766 jermar 796
    futex_down(&nodes_futex);
2735 jermar 797
    node->lnkcnt--;
2766 jermar 798
    futex_up(&nodes_futex);
2735 jermar 799
    rwlock_write_unlock(&namespace_rwlock);
800
    vfs_node_put(node);
801
    ipc_answer_0(rid, EOK);
802
}
803
 
2763 jermar 804
void vfs_rename(ipc_callid_t rid, ipc_call_t *request)
805
{
806
    size_t len;
807
    ipc_callid_t callid;
808
    int rc;
809
 
810
    /* Retrieve the old path. */
811
    if (!ipc_data_write_receive(&callid, &len)) {
812
        ipc_answer_0(callid, EINVAL);
813
        ipc_answer_0(rid, EINVAL);
814
        return;
815
    }
816
    char *old = malloc(len + 1);
817
    if (!old) {
818
        ipc_answer_0(callid, ENOMEM);
819
        ipc_answer_0(rid, ENOMEM);
820
        return;
821
    }
822
    if ((rc = ipc_data_write_finalize(callid, old, len))) {
823
        ipc_answer_0(rid, rc);
824
        free(old);
825
        return;
826
    }
827
    old[len] = '\0';
828
 
829
    /* Retrieve the new path. */
830
    if (!ipc_data_write_receive(&callid, &len)) {
831
        ipc_answer_0(callid, EINVAL);
832
        ipc_answer_0(rid, EINVAL);
833
        free(old);
834
        return;
835
    }
836
    char *new = malloc(len + 1);
837
    if (!new) {
838
        ipc_answer_0(callid, ENOMEM);
839
        ipc_answer_0(rid, ENOMEM);
840
        free(old);
841
        return;
842
    }
843
    if ((rc = ipc_data_write_finalize(callid, new, len))) {
844
        ipc_answer_0(rid, rc);
845
        free(old);
846
        free(new);
847
        return;
848
    }
849
    new[len] = '\0';
850
 
851
    char *oldc = canonify(old, &len);
852
    char *newc = canonify(new, NULL);
853
    if (!oldc || !newc) {
854
        ipc_answer_0(rid, EINVAL);
855
        free(old);
856
        free(new);
857
        return;
858
    }
859
    if (!strncmp(newc, oldc, len)) {
860
        /* oldc is a prefix of newc */
861
        ipc_answer_0(rid, EINVAL);
862
        free(old);
863
        free(new);
864
        return;
865
    }
866
 
867
    vfs_lookup_res_t old_lr;
868
    vfs_lookup_res_t new_lr;
869
    vfs_lookup_res_t new_par_lr;
870
    rwlock_write_lock(&namespace_rwlock);
871
    /* Lookup the node belonging to the old file name. */
872
    rc = vfs_lookup_internal(oldc, L_NONE, &old_lr, NULL);
873
    if (rc != EOK) {
874
        rwlock_write_unlock(&namespace_rwlock);
875
        ipc_answer_0(rid, rc);
876
        free(old);
877
        free(new);
878
        return;
879
    }
880
    vfs_node_t *old_node = vfs_node_get(&old_lr);
881
    if (!old_node) {
882
        rwlock_write_unlock(&namespace_rwlock);
883
        ipc_answer_0(rid, ENOMEM);
884
        free(old);
885
        free(new);
886
        return;
887
    }
888
    /* Lookup parent of the new file name. */
889
    rc = vfs_lookup_internal(newc, L_PARENT, &new_par_lr, NULL);
890
    if (rc != EOK) {
891
        rwlock_write_unlock(&namespace_rwlock);
892
        ipc_answer_0(rid, rc);
893
        free(old);
894
        free(new);
895
        return;
896
    }
897
    /* Check whether linking to the same file system instance. */
898
    if ((old_node->fs_handle != new_par_lr.triplet.fs_handle) ||
899
        (old_node->dev_handle != new_par_lr.triplet.dev_handle)) {
900
        rwlock_write_unlock(&namespace_rwlock);
901
        ipc_answer_0(rid, EXDEV);   /* different file systems */
902
        free(old);
903
        free(new);
904
        return;
905
    }
906
    /* Destroy the old link for the new name. */
907
    vfs_node_t *new_node = NULL;
908
    rc = vfs_lookup_internal(newc, L_UNLINK, &new_lr, NULL);
909
    switch (rc) {
910
    case ENOENT:
911
        /* simply not in our way */
912
        break;
913
    case EOK:
914
        new_node = vfs_node_get(&new_lr);
915
        if (!new_node) {
916
            rwlock_write_unlock(&namespace_rwlock);
917
            ipc_answer_0(rid, ENOMEM);
918
            free(old);
919
            free(new);
920
            return;
921
        }
2766 jermar 922
        futex_down(&nodes_futex);
2763 jermar 923
        new_node->lnkcnt--;
2766 jermar 924
        futex_up(&nodes_futex);
2763 jermar 925
        break;
926
    default:
927
        rwlock_write_unlock(&namespace_rwlock);
928
        ipc_answer_0(rid, ENOTEMPTY);
929
        free(old);
930
        free(new);
931
        return;
932
    }
933
    /* Create the new link for the new name. */
934
    rc = vfs_lookup_internal(newc, L_LINK, NULL, NULL, old_node->index);
935
    if (rc != EOK) {
936
        rwlock_write_unlock(&namespace_rwlock);
937
        if (new_node)
938
            vfs_node_put(new_node);
939
        ipc_answer_0(rid, rc);
940
        free(old);
941
        free(new);
942
        return;
943
    }
2766 jermar 944
    futex_down(&nodes_futex);
2763 jermar 945
    old_node->lnkcnt++;
2766 jermar 946
    futex_up(&nodes_futex);
2763 jermar 947
    /* Destroy the link for the old name. */
948
    rc = vfs_lookup_internal(oldc, L_UNLINK, NULL, NULL);
949
    if (rc != EOK) {
950
        rwlock_write_unlock(&namespace_rwlock);
951
        vfs_node_put(old_node);
952
        if (new_node)
953
            vfs_node_put(new_node);
954
        ipc_answer_0(rid, rc);
955
        free(old);
956
        free(new);
957
        return;
958
    }
2766 jermar 959
    futex_down(&nodes_futex);
2763 jermar 960
    old_node->lnkcnt--;
2766 jermar 961
    futex_up(&nodes_futex);
2763 jermar 962
    rwlock_write_unlock(&namespace_rwlock);
963
    vfs_node_put(old_node);
964
    if (new_node)
965
        vfs_node_put(new_node);
966
    free(old);
967
    free(new);
968
    ipc_answer_0(rid, EOK);
969
}
970
 
2689 jermar 971
/**
972
 * @}
973
 */