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2645 jermar 1
/*
2685 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2645 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    tmpfs_ops.c
35
 * @brief   Implementation of VFS operations for the TMPFS file system
36
 *      server.
37
 */
38
 
39
#include "tmpfs.h"
40
#include "../../vfs/vfs.h"
41
#include <ipc/ipc.h>
42
#include <async.h>
43
#include <errno.h>
2655 jermar 44
#include <atomic.h>
45
#include <stdlib.h>
46
#include <string.h>
47
#include <stdio.h>
2699 jermar 48
#include <assert.h>
2658 jermar 49
#include <sys/types.h>
50
#include <libadt/hash_table.h>
51
#include <as.h>
2747 jermar 52
#include <libfs.h>
2645 jermar 53
 
2658 jermar 54
#define min(a, b)       ((a) < (b) ? (a) : (b))
55
#define max(a, b)       ((a) > (b) ? (a) : (b))
56
 
57
#define DENTRIES_BUCKETS    256
58
 
2760 jermar 59
#define NAMES_BUCKETS       4
60
 
2747 jermar 61
/*
62
 * For now, we don't distinguish between different dev_handles/instances. All
63
 * requests resolve to the only instance, rooted in the following variable.
64
 */
65
static tmpfs_dentry_t *root;
2730 jermar 66
 
3575 jermar 67
#define TMPFS_DEV       0   /**< Dummy device handle for TMPFS */
68
 
2747 jermar 69
/*
70
 * Implementation of the libfs interface.
71
 */
72
 
2742 jermar 73
/* Forward declarations of static functions. */
2791 jermar 74
static void *tmpfs_match(void *, const char *);
2863 jermar 75
static void *tmpfs_node_get(dev_handle_t, fs_index_t);
2852 jermar 76
static void tmpfs_node_put(void *);
3575 jermar 77
static void *tmpfs_create_node(dev_handle_t, int);
3625 jermar 78
static int tmpfs_link_node(void *, void *, const char *);
2758 jermar 79
static int tmpfs_unlink_node(void *, void *);
2858 jermar 80
static int tmpfs_destroy_node(void *);
2742 jermar 81
 
2747 jermar 82
/* Implementation of helper functions. */
2770 jermar 83
static fs_index_t tmpfs_index_get(void *nodep)
2747 jermar 84
{
85
    return ((tmpfs_dentry_t *) nodep)->index;
86
}
87
 
2770 jermar 88
static size_t tmpfs_size_get(void *nodep)
2747 jermar 89
{
90
    return ((tmpfs_dentry_t *) nodep)->size;
91
}
92
 
93
static unsigned tmpfs_lnkcnt_get(void *nodep)
94
{
2756 jermar 95
    return ((tmpfs_dentry_t *) nodep)->lnkcnt;
2747 jermar 96
}
97
 
2791 jermar 98
static bool tmpfs_has_children(void *nodep)
2747 jermar 99
{
2791 jermar 100
    return ((tmpfs_dentry_t *) nodep)->child != NULL;
2747 jermar 101
}
102
 
2844 jermar 103
static void *tmpfs_root_get(dev_handle_t dev_handle)
2747 jermar 104
{
105
    return root;
106
}
107
 
108
static char tmpfs_plb_get_char(unsigned pos)
109
{
110
    return tmpfs_reg.plb_ro[pos % PLB_SIZE];
111
}
112
 
113
static bool tmpfs_is_directory(void *nodep)
114
{
115
    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_DIRECTORY;
116
}
117
 
118
static bool tmpfs_is_file(void *nodep)
119
{
120
    return ((tmpfs_dentry_t *) nodep)->type == TMPFS_FILE;
121
}
122
 
123
/** libfs operations */
124
libfs_ops_t tmpfs_libfs_ops = {
125
    .match = tmpfs_match,
2763 jermar 126
    .node_get = tmpfs_node_get,
2852 jermar 127
    .node_put = tmpfs_node_put,
2747 jermar 128
    .create = tmpfs_create_node,
129
    .destroy = tmpfs_destroy_node,
130
    .link = tmpfs_link_node,
131
    .unlink = tmpfs_unlink_node,
132
    .index_get = tmpfs_index_get,
133
    .size_get = tmpfs_size_get,
134
    .lnkcnt_get = tmpfs_lnkcnt_get,
2791 jermar 135
    .has_children = tmpfs_has_children,
2747 jermar 136
    .root_get = tmpfs_root_get,
137
    .plb_get_char = tmpfs_plb_get_char,
138
    .is_directory = tmpfs_is_directory,
139
    .is_file = tmpfs_is_file
140
};
141
 
2742 jermar 142
/** Hash table of all directory entries. */
2658 jermar 143
hash_table_t dentries;
144
 
2760 jermar 145
/* Implementation of hash table interface for the dentries hash table. */
2658 jermar 146
static hash_index_t dentries_hash(unsigned long *key)
147
{
148
    return *key % DENTRIES_BUCKETS;
149
}
150
 
151
static int dentries_compare(unsigned long *key, hash_count_t keys,
152
    link_t *item)
153
{
154
    tmpfs_dentry_t *dentry = hash_table_get_instance(item, tmpfs_dentry_t,
155
        dh_link);
156
    return dentry->index == *key;
157
}
158
 
159
static void dentries_remove_callback(link_t *item)
160
{
161
}
162
 
163
/** TMPFS dentries hash table operations. */
164
hash_table_operations_t dentries_ops = {
165
    .hash = dentries_hash,
166
    .compare = dentries_compare,
167
    .remove_callback = dentries_remove_callback
168
};
169
 
2770 jermar 170
fs_index_t tmpfs_next_index = 1;
2655 jermar 171
 
2760 jermar 172
typedef struct {
173
    char *name;
174
    tmpfs_dentry_t *parent;
175
    link_t link;
176
} tmpfs_name_t;
177
 
178
/* Implementation of hash table interface for the names hash table. */
179
static hash_index_t names_hash(unsigned long *key)
2655 jermar 180
{
2760 jermar 181
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) *key;
182
    return dentry->index % NAMES_BUCKETS;
183
}
184
 
185
static int names_compare(unsigned long *key, hash_count_t keys, link_t *item)
186
{
187
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) *key;
188
    tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
189
        link);
190
    return dentry == namep->parent;
191
}
192
 
193
static void names_remove_callback(link_t *item)
194
{
195
    tmpfs_name_t *namep = hash_table_get_instance(item, tmpfs_name_t,
196
        link);
197
    free(namep->name);
198
    free(namep);
199
}
200
 
201
/** TMPFS node names hash table operations. */
202
static hash_table_operations_t names_ops = {
203
    .hash = names_hash,
204
    .compare = names_compare,
205
    .remove_callback = names_remove_callback
206
};
207
 
208
static void tmpfs_name_initialize(tmpfs_name_t *namep)
209
{
210
    namep->name = NULL;
211
    namep->parent = NULL;
212
    link_initialize(&namep->link);
213
}
214
 
215
static bool tmpfs_dentry_initialize(tmpfs_dentry_t *dentry)
216
{
2655 jermar 217
    dentry->index = 0;
218
    dentry->sibling = NULL;
219
    dentry->child = NULL;
220
    dentry->type = TMPFS_NONE;
2756 jermar 221
    dentry->lnkcnt = 0;
2655 jermar 222
    dentry->size = 0;
223
    dentry->data = NULL;
2658 jermar 224
    link_initialize(&dentry->dh_link);
2760 jermar 225
    return (bool)hash_table_create(&dentry->names, NAMES_BUCKETS, 1,
226
        &names_ops);
2655 jermar 227
}
228
 
229
static bool tmpfs_init(void)
230
{
2658 jermar 231
    if (!hash_table_create(&dentries, DENTRIES_BUCKETS, 1, &dentries_ops))
232
        return false;
3575 jermar 233
    root = (tmpfs_dentry_t *) tmpfs_create_node(TMPFS_DEV, L_DIRECTORY);
2760 jermar 234
    if (!root) {
235
        hash_table_destroy(&dentries);
236
        return false;
237
    }
3352 jermar 238
    root->lnkcnt = 0;   /* FS root is not linked */
2760 jermar 239
    return true;
2655 jermar 240
}
241
 
2645 jermar 242
/** Compare one component of path to a directory entry.
243
 *
2791 jermar 244
 * @param parentp   Pointer to node from which we descended.
245
 * @param childp    Pointer to node to compare the path component with.
2705 jermar 246
 * @param component Array of characters holding component name.
2645 jermar 247
 *
2705 jermar 248
 * @return      True on match, false otherwise.
2645 jermar 249
 */
2791 jermar 250
static bool
251
tmpfs_match_one(tmpfs_dentry_t *parentp, tmpfs_dentry_t *childp,
252
    const char *component)
2645 jermar 253
{
2760 jermar 254
    unsigned long key = (unsigned long) parentp;
255
    link_t *hlp = hash_table_find(&childp->names, &key);
256
    assert(hlp);
257
    tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t, link);
4264 svoboda 258
    return !str_cmp(namep->name, component);
2705 jermar 259
}
2655 jermar 260
 
2791 jermar 261
void *tmpfs_match(void *prnt, const char *component)
262
{
263
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
264
    tmpfs_dentry_t *childp = parentp->child;
265
 
266
    while (childp && !tmpfs_match_one(parentp, childp, component))
267
        childp = childp->sibling;
268
 
269
    return (void *) childp;
270
}
271
 
2770 jermar 272
void *
2863 jermar 273
tmpfs_node_get(dev_handle_t dev_handle, fs_index_t index)
2763 jermar 274
{
2770 jermar 275
    unsigned long key = index;
276
    link_t *lnk = hash_table_find(&dentries, &key);
2763 jermar 277
    if (!lnk)
278
        return NULL;
279
    return hash_table_get_instance(lnk, tmpfs_dentry_t, dh_link);
280
}
281
 
2852 jermar 282
void tmpfs_node_put(void *node)
283
{
284
    /* nothing to do */
285
}
286
 
3575 jermar 287
void *tmpfs_create_node(dev_handle_t dev_handle, int lflag)
2705 jermar 288
{
2707 jermar 289
    assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
290
 
291
    tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
292
    if (!node)
2730 jermar 293
        return NULL;
2707 jermar 294
 
2760 jermar 295
    if (!tmpfs_dentry_initialize(node)) {
296
        free(node);
297
        return NULL;
298
    }
2707 jermar 299
    node->index = tmpfs_next_index++;
300
    if (lflag & L_DIRECTORY)
301
        node->type = TMPFS_DIRECTORY;
302
    else
303
        node->type = TMPFS_FILE;
304
 
2742 jermar 305
    /* Insert the new node into the dentry hash table. */
2770 jermar 306
    unsigned long key = node->index;
307
    hash_table_insert(&dentries, &key, &node->dh_link);
2742 jermar 308
    return (void *) node;
309
}
310
 
3625 jermar 311
int tmpfs_link_node(void *prnt, void *chld, const char *nm)
2742 jermar 312
{
313
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *) prnt;
314
    tmpfs_dentry_t *childp = (tmpfs_dentry_t *) chld;
315
 
316
    assert(parentp->type == TMPFS_DIRECTORY);
317
 
2760 jermar 318
    tmpfs_name_t *namep = malloc(sizeof(tmpfs_name_t));
319
    if (!namep)
3625 jermar 320
        return ENOMEM;
2760 jermar 321
    tmpfs_name_initialize(namep);
4264 svoboda 322
    size_t size = str_size(nm);
323
    namep->name = malloc(size + 1);
2760 jermar 324
    if (!namep->name) {
325
        free(namep);
3625 jermar 326
        return ENOMEM;
2760 jermar 327
    }
4268 svoboda 328
    str_cpy(namep->name, size + 1, nm);
2760 jermar 329
    namep->parent = parentp;
2756 jermar 330
 
331
    childp->lnkcnt++;
2742 jermar 332
 
2760 jermar 333
    unsigned long key = (unsigned long) parentp;
334
    hash_table_insert(&childp->names, &key, &namep->link);
335
 
2707 jermar 336
    /* Insert the new node into the namespace. */
2742 jermar 337
    if (parentp->child) {
338
        tmpfs_dentry_t *tmp = parentp->child;
2707 jermar 339
        while (tmp->sibling)
340
            tmp = tmp->sibling;
2742 jermar 341
        tmp->sibling = childp;
2707 jermar 342
    } else {
2742 jermar 343
        parentp->child = childp;
2707 jermar 344
    }
345
 
3625 jermar 346
    return EOK;
2705 jermar 347
}
2655 jermar 348
 
2758 jermar 349
int tmpfs_unlink_node(void *prnt, void *chld)
2705 jermar 350
{
2758 jermar 351
    tmpfs_dentry_t *parentp = (tmpfs_dentry_t *)prnt;
352
    tmpfs_dentry_t *childp = (tmpfs_dentry_t *)chld;
2733 jermar 353
 
2758 jermar 354
    if (!parentp)
355
        return EBUSY;
356
 
357
    if (childp->child)
2733 jermar 358
        return ENOTEMPTY;
359
 
2758 jermar 360
    if (parentp->child == childp) {
361
        parentp->child = childp->sibling;
2733 jermar 362
    } else {
363
        /* TODO: consider doubly linked list for organizing siblings. */
2758 jermar 364
        tmpfs_dentry_t *tmp = parentp->child;
365
        while (tmp->sibling != childp)
2733 jermar 366
            tmp = tmp->sibling;
2758 jermar 367
        tmp->sibling = childp->sibling;
2733 jermar 368
    }
2758 jermar 369
    childp->sibling = NULL;
2733 jermar 370
 
2760 jermar 371
    unsigned long key = (unsigned long) parentp;
372
    hash_table_remove(&childp->names, &key, 1);
2742 jermar 373
 
2758 jermar 374
    childp->lnkcnt--;
2756 jermar 375
 
2733 jermar 376
    return EOK;
2645 jermar 377
}
378
 
2858 jermar 379
int tmpfs_destroy_node(void *nodep)
2742 jermar 380
{
381
    tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
382
 
2756 jermar 383
    assert(!dentry->lnkcnt);
2742 jermar 384
    assert(!dentry->child);
385
    assert(!dentry->sibling);
386
 
2770 jermar 387
    unsigned long key = dentry->index;
388
    hash_table_remove(&dentries, &key, 1);
2742 jermar 389
 
2760 jermar 390
    hash_table_destroy(&dentry->names);
391
 
2742 jermar 392
    if (dentry->type == TMPFS_FILE)
393
        free(dentry->data);
394
    free(dentry);
2858 jermar 395
    return EOK;
2742 jermar 396
}
397
 
3109 jermar 398
void tmpfs_mounted(ipc_callid_t rid, ipc_call_t *request)
399
{
400
    dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
401
 
402
    /* Initialize TMPFS. */
403
    if (!root && !tmpfs_init()) {
404
        ipc_answer_0(rid, ENOMEM);
405
        return;
406
    }
407
 
408
    if (dev_handle >= 0) {
409
        if (tmpfs_restore(dev_handle))
3352 jermar 410
            ipc_answer_3(rid, EOK, root->index, root->size,
411
                root->lnkcnt);
3109 jermar 412
        else
413
            ipc_answer_0(rid, ELIMIT);
414
    } else {
3352 jermar 415
        ipc_answer_3(rid, EOK, root->index, root->size, root->lnkcnt);
3109 jermar 416
    }
417
}
418
 
2958 jermar 419
void tmpfs_mount(ipc_callid_t rid, ipc_call_t *request)
420
{
3109 jermar 421
    dev_handle_t mp_dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
422
    fs_index_t mp_index = (fs_index_t) IPC_GET_ARG2(*request);
423
    fs_handle_t mr_fs_handle = (fs_handle_t) IPC_GET_ARG3(*request);
424
    dev_handle_t mr_dev_handle = (dev_handle_t) IPC_GET_ARG4(*request);
3087 decky 425
 
3109 jermar 426
    ipc_answer_0(rid, ENOTSUP);
2958 jermar 427
}
428
 
2645 jermar 429
void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
430
{
2747 jermar 431
    libfs_lookup(&tmpfs_libfs_ops, tmpfs_reg.fs_handle, rid, request);
2645 jermar 432
}
433
 
2658 jermar 434
void tmpfs_read(ipc_callid_t rid, ipc_call_t *request)
435
{
2770 jermar 436
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
437
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
438
    off_t pos = (off_t)IPC_GET_ARG3(*request);
2658 jermar 439
 
440
    /*
441
     * Lookup the respective dentry.
442
     */
443
    link_t *hlp;
2770 jermar 444
    unsigned long key = index;
445
    hlp = hash_table_find(&dentries, &key);
2658 jermar 446
    if (!hlp) {
447
        ipc_answer_0(rid, ENOENT);
448
        return;
449
    }
450
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
451
        dh_link);
452
 
453
    /*
2663 jermar 454
     * Receive the read request.
2658 jermar 455
     */
456
    ipc_callid_t callid;
4264 svoboda 457
    size_t size;
458
    if (!ipc_data_read_receive(&callid, &size)) {
2658 jermar 459
        ipc_answer_0(callid, EINVAL);  
460
        ipc_answer_0(rid, EINVAL);
461
        return;
462
    }
463
 
2699 jermar 464
    size_t bytes;
465
    if (dentry->type == TMPFS_FILE) {
4264 svoboda 466
        bytes = max(0, min(dentry->size - pos, size));
2699 jermar 467
        (void) ipc_data_read_finalize(callid, dentry->data + pos,
468
            bytes);
469
    } else {
470
        int i;
2739 jermar 471
        tmpfs_dentry_t *cur;
2699 jermar 472
 
473
        assert(dentry->type == TMPFS_DIRECTORY);
474
 
475
        /*
476
         * Yes, we really use O(n) algorithm here.
477
         * If it bothers someone, it could be fixed by introducing a
478
         * hash table.
479
         */
480
        for (i = 0, cur = dentry->child; i < pos && cur; i++,
481
            cur = cur->sibling)
482
            ;
2664 jermar 483
 
2699 jermar 484
        if (!cur) {
485
            ipc_answer_0(callid, ENOENT);
486
            ipc_answer_1(rid, ENOENT, 0);
487
            return;
488
        }
489
 
2760 jermar 490
        unsigned long key = (unsigned long) dentry;
491
        link_t *hlp = hash_table_find(&cur->names, &key);
492
        assert(hlp);
493
        tmpfs_name_t *namep = hash_table_get_instance(hlp, tmpfs_name_t,
494
            link);
495
 
496
        (void) ipc_data_read_finalize(callid, namep->name,
4264 svoboda 497
            str_size(namep->name) + 1);
2699 jermar 498
        bytes = 1;
499
    }
500
 
2664 jermar 501
    /*
502
     * Answer the VFS_READ call.
503
     */
504
    ipc_answer_1(rid, EOK, bytes);
2658 jermar 505
}
506
 
2666 jermar 507
void tmpfs_write(ipc_callid_t rid, ipc_call_t *request)
508
{
2770 jermar 509
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
510
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
511
    off_t pos = (off_t)IPC_GET_ARG3(*request);
2666 jermar 512
 
513
    /*
514
     * Lookup the respective dentry.
515
     */
516
    link_t *hlp;
2770 jermar 517
    unsigned long key = index;
518
    hlp = hash_table_find(&dentries, &key);
2666 jermar 519
    if (!hlp) {
520
        ipc_answer_0(rid, ENOENT);
521
        return;
522
    }
523
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
524
        dh_link);
525
 
526
    /*
527
     * Receive the write request.
528
     */
529
    ipc_callid_t callid;
4264 svoboda 530
    size_t size;
531
    if (!ipc_data_write_receive(&callid, &size)) {
2666 jermar 532
        ipc_answer_0(callid, EINVAL);  
533
        ipc_answer_0(rid, EINVAL);
534
        return;
535
    }
536
 
537
    /*
2667 jermar 538
     * Check whether the file needs to grow.
539
     */
4264 svoboda 540
    if (pos + size <= dentry->size) {
2667 jermar 541
        /* The file size is not changing. */
4264 svoboda 542
        (void) ipc_data_write_finalize(callid, dentry->data + pos, size);
543
        ipc_answer_2(rid, EOK, size, dentry->size);
2667 jermar 544
        return;
545
    }
4264 svoboda 546
    size_t delta = (pos + size) - dentry->size;
2667 jermar 547
    /*
2666 jermar 548
     * At this point, we are deliberately extremely straightforward and
2667 jermar 549
     * simply realloc the contents of the file on every write that grows the
550
     * file. In the end, the situation might not be as bad as it may look:
551
     * our heap allocator can save us and just grow the block whenever
552
     * possible.
2666 jermar 553
     */
2667 jermar 554
    void *newdata = realloc(dentry->data, dentry->size + delta);
2666 jermar 555
    if (!newdata) {
556
        ipc_answer_0(callid, ENOMEM);
2710 jermar 557
        ipc_answer_2(rid, EOK, 0, dentry->size);
2666 jermar 558
        return;
559
    }
2693 jermar 560
    /* Clear any newly allocated memory in order to emulate gaps. */
2686 jermar 561
    memset(newdata + dentry->size, 0, delta);
2667 jermar 562
    dentry->size += delta;
2666 jermar 563
    dentry->data = newdata;
4264 svoboda 564
    (void) ipc_data_write_finalize(callid, dentry->data + pos, size);
565
    ipc_answer_2(rid, EOK, size, dentry->size);
2666 jermar 566
}
567
 
2693 jermar 568
void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request)
569
{
2770 jermar 570
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
571
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
572
    size_t size = (off_t)IPC_GET_ARG3(*request);
2693 jermar 573
 
574
    /*
575
     * Lookup the respective dentry.
576
     */
577
    link_t *hlp;
2770 jermar 578
    unsigned long key = index;
579
    hlp = hash_table_find(&dentries, &key);
2693 jermar 580
    if (!hlp) {
581
        ipc_answer_0(rid, ENOENT);
582
        return;
583
    }
584
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
585
        dh_link);
586
 
587
    if (size == dentry->size) {
588
        ipc_answer_0(rid, EOK);
589
        return;
590
    }
591
 
592
    void *newdata = realloc(dentry->data, size);
593
    if (!newdata) {
594
        ipc_answer_0(rid, ENOMEM);
595
        return;
596
    }
597
    if (size > dentry->size) {
598
        size_t delta = size - dentry->size;
599
        memset(newdata + dentry->size, 0, delta);
600
    }
601
    dentry->size = size;
602
    dentry->data = newdata;
603
    ipc_answer_0(rid, EOK);
604
}
605
 
2742 jermar 606
void tmpfs_destroy(ipc_callid_t rid, ipc_call_t *request)
2731 jermar 607
{
2770 jermar 608
    dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
609
    fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
2858 jermar 610
    int rc;
2731 jermar 611
 
612
    link_t *hlp;
2770 jermar 613
    unsigned long key = index;
614
    hlp = hash_table_find(&dentries, &key);
2731 jermar 615
    if (!hlp) {
616
        ipc_answer_0(rid, ENOENT);
617
        return;
618
    }
619
    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,
620
        dh_link);
2858 jermar 621
    rc = tmpfs_destroy_node(dentry);
622
    ipc_answer_0(rid, rc);
2731 jermar 623
}
624
 
2645 jermar 625
/**
626
 * @}
627
 */