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2627 jermar 1
/*
2793 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2627 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	fat_ops.c
35
 * @brief	Implementation of VFS operations for the FAT file system server.
36
 */
37
 
38
#include "fat.h"
3505 jermar 39
#include "fat_dentry.h"
40
#include "fat_fat.h"
2638 jermar 41
#include "../../vfs/vfs.h"
2793 jermar 42
#include <libfs.h>
3521 jermar 43
#include <libblock.h>
2627 jermar 44
#include <ipc/ipc.h>
3257 jermar 45
#include <ipc/services.h>
46
#include <ipc/devmap.h>
2627 jermar 47
#include <async.h>
48
#include <errno.h>
2793 jermar 49
#include <string.h>
2798 jermar 50
#include <byteorder.h>
4509 decky 51
#include <adt/hash_table.h>
52
#include <adt/list.h>
2831 jermar 53
#include <assert.h>
4552 jermar 54
#include <fibril_sync.h>
3257 jermar 55
#include <sys/mman.h>
3499 jermar 56
#include <align.h>
2627 jermar 57
 
4357 jermar 58
#define FAT_NODE(node)	((node) ? (fat_node_t *) (node)->data : NULL)
59
#define FS_NODE(node)	((node) ? (node)->bp : NULL)
60
 
4552 jermar 61
/** Mutex protecting the list of cached free FAT nodes. */
62
static FIBRIL_MUTEX_INITIALIZE(ffn_mutex);
2843 jermar 63
 
2951 jermar 64
/** List of cached free FAT nodes. */
65
static LIST_INITIALIZE(ffn_head);
66
 
2831 jermar 67
static void fat_node_initialize(fat_node_t *node)
2793 jermar 68
{
4552 jermar 69
	fibril_mutex_initialize(&node->lock);
4357 jermar 70
	node->bp = NULL;
2864 jermar 71
	node->idx = NULL;
2831 jermar 72
	node->type = 0;
73
	link_initialize(&node->ffn_link);
74
	node->size = 0;
75
	node->lnkcnt = 0;
76
	node->refcnt = 0;
77
	node->dirty = false;
2793 jermar 78
}
79
 
2893 jermar 80
static void fat_node_sync(fat_node_t *node)
2831 jermar 81
{
3530 jermar 82
	block_t *b;
83
	fat_bs_t *bs;
3519 jermar 84
	fat_dentry_t *d;
85
	uint16_t bps;
86
	unsigned dps;
87
 
88
	assert(node->dirty);
89
 
3530 jermar 90
	bs = block_bb_get(node->idx->dev_handle);
91
	bps = uint16_t_le2host(bs->bps);
3519 jermar 92
	dps = bps / sizeof(fat_dentry_t);
93
 
94
	/* Read the block that contains the dentry of interest. */
3530 jermar 95
	b = _fat_block_get(bs, node->idx->dev_handle, node->idx->pfc,
3595 jermar 96
	    (node->idx->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE);
3519 jermar 97
 
98
	d = ((fat_dentry_t *)b->data) + (node->idx->pdi % dps);
99
 
100
	d->firstc = host2uint16_t_le(node->firstc);
3629 jermar 101
	if (node->type == FAT_FILE) {
3519 jermar 102
		d->size = host2uint32_t_le(node->size);
3629 jermar 103
	} else if (node->type == FAT_DIRECTORY) {
104
		d->attr = FAT_ATTR_SUBDIR;
105
	}
3519 jermar 106
 
3629 jermar 107
	/* TODO: update other fields? (e.g time fields) */
108
 
3519 jermar 109
	b->dirty = true;		/* need to sync block */
110
	block_put(b);
2831 jermar 111
}
112
 
3574 jermar 113
static fat_node_t *fat_node_get_new(void)
114
{
4357 jermar 115
	fs_node_t *fn;
3574 jermar 116
	fat_node_t *nodep;
117
 
4552 jermar 118
	fibril_mutex_lock(&ffn_mutex);
3574 jermar 119
	if (!list_empty(&ffn_head)) {
120
		/* Try to use a cached free node structure. */
121
		fat_idx_t *idxp_tmp;
122
		nodep = list_get_instance(ffn_head.next, fat_node_t, ffn_link);
4552 jermar 123
		if (!fibril_mutex_trylock(&nodep->lock))
3574 jermar 124
			goto skip_cache;
125
		idxp_tmp = nodep->idx;
4552 jermar 126
		if (!fibril_mutex_trylock(&idxp_tmp->lock)) {
127
			fibril_mutex_unlock(&nodep->lock);
3574 jermar 128
			goto skip_cache;
129
		}
130
		list_remove(&nodep->ffn_link);
4552 jermar 131
		fibril_mutex_unlock(&ffn_mutex);
3574 jermar 132
		if (nodep->dirty)
133
			fat_node_sync(nodep);
134
		idxp_tmp->nodep = NULL;
4552 jermar 135
		fibril_mutex_unlock(&nodep->lock);
136
		fibril_mutex_unlock(&idxp_tmp->lock);
4357 jermar 137
		fn = FS_NODE(nodep);
3574 jermar 138
	} else {
139
skip_cache:
140
		/* Try to allocate a new node structure. */
4552 jermar 141
		fibril_mutex_unlock(&ffn_mutex);
4357 jermar 142
		fn = (fs_node_t *)malloc(sizeof(fs_node_t));
143
		if (!fn)
144
			return NULL;
3574 jermar 145
		nodep = (fat_node_t *)malloc(sizeof(fat_node_t));
4357 jermar 146
		if (!nodep) {
147
			free(fn);
3574 jermar 148
			return NULL;
4357 jermar 149
		}
3574 jermar 150
	}
151
	fat_node_initialize(nodep);
4409 jermar 152
	fs_node_initialize(fn);
4357 jermar 153
	fn->data = nodep;
154
	nodep->bp = fn;
3574 jermar 155
 
156
	return nodep;
157
}
158
 
2951 jermar 159
/** Internal version of fat_node_get().
160
 *
161
 * @param idxp		Locked index structure.
162
 */
4357 jermar 163
static fat_node_t *fat_node_get_core(fat_idx_t *idxp)
2831 jermar 164
{
3530 jermar 165
	block_t *b;
166
	fat_bs_t *bs;
2891 jermar 167
	fat_dentry_t *d;
3312 jermar 168
	fat_node_t *nodep = NULL;
2891 jermar 169
	unsigned bps;
3550 jermar 170
	unsigned spc;
2891 jermar 171
	unsigned dps;
172
 
2951 jermar 173
	if (idxp->nodep) {
2891 jermar 174
		/*
175
		 * We are lucky.
176
		 * The node is already instantiated in memory.
177
		 */
4552 jermar 178
		fibril_mutex_lock(&idxp->nodep->lock);
2951 jermar 179
		if (!idxp->nodep->refcnt++)
3312 jermar 180
			list_remove(&idxp->nodep->ffn_link);
4552 jermar 181
		fibril_mutex_unlock(&idxp->nodep->lock);
2951 jermar 182
		return idxp->nodep;
2891 jermar 183
	}
184
 
185
	/*
186
	 * We must instantiate the node from the file system.
187
	 */
188
 
2951 jermar 189
	assert(idxp->pfc);
2891 jermar 190
 
3574 jermar 191
	nodep = fat_node_get_new();
192
	if (!nodep)
193
		return NULL;
2891 jermar 194
 
3530 jermar 195
	bs = block_bb_get(idxp->dev_handle);
196
	bps = uint16_t_le2host(bs->bps);
3550 jermar 197
	spc = bs->spc;
2891 jermar 198
	dps = bps / sizeof(fat_dentry_t);
199
 
2893 jermar 200
	/* Read the block that contains the dentry of interest. */
3530 jermar 201
	b = _fat_block_get(bs, idxp->dev_handle, idxp->pfc,
3595 jermar 202
	    (idxp->pdi * sizeof(fat_dentry_t)) / bps, BLOCK_FLAGS_NONE);
2891 jermar 203
	assert(b);
204
 
2951 jermar 205
	d = ((fat_dentry_t *)b->data) + (idxp->pdi % dps);
2893 jermar 206
	if (d->attr & FAT_ATTR_SUBDIR) {
207
		/* 
208
		 * The only directory which does not have this bit set is the
209
		 * root directory itself. The root directory node is handled
210
		 * and initialized elsewhere.
211
		 */
212
		nodep->type = FAT_DIRECTORY;
3282 jermar 213
		/*
3325 jermar 214
		 * Unfortunately, the 'size' field of the FAT dentry is not
215
		 * defined for the directory entry type. We must determine the
216
		 * size of the directory by walking the FAT.
3282 jermar 217
		 */
3550 jermar 218
		nodep->size = bps * spc * fat_clusters_get(bs, idxp->dev_handle,
219
		    uint16_t_le2host(d->firstc));
2893 jermar 220
	} else {
221
		nodep->type = FAT_FILE;
3282 jermar 222
		nodep->size = uint32_t_le2host(d->size);
2893 jermar 223
	}
224
	nodep->firstc = uint16_t_le2host(d->firstc);
225
	nodep->lnkcnt = 1;
226
	nodep->refcnt = 1;
227
 
228
	block_put(b);
229
 
230
	/* Link the idx structure with the node structure. */
2951 jermar 231
	nodep->idx = idxp;
232
	idxp->nodep = nodep;
2893 jermar 233
 
234
	return nodep;
2831 jermar 235
}
236
 
3621 jermar 237
/*
238
 * Forward declarations of FAT libfs operations.
239
 */
4357 jermar 240
static fs_node_t *fat_node_get(dev_handle_t, fs_index_t);
241
static void fat_node_put(fs_node_t *);
242
static fs_node_t *fat_create_node(dev_handle_t, int);
243
static int fat_destroy_node(fs_node_t *);
244
static int fat_link(fs_node_t *, fs_node_t *, const char *);
4370 jermar 245
static int fat_unlink(fs_node_t *, fs_node_t *, const char *);
4357 jermar 246
static fs_node_t *fat_match(fs_node_t *, const char *);
247
static fs_index_t fat_index_get(fs_node_t *);
248
static size_t fat_size_get(fs_node_t *);
249
static unsigned fat_lnkcnt_get(fs_node_t *);
250
static bool fat_has_children(fs_node_t *);
251
static fs_node_t *fat_root_get(dev_handle_t);
3621 jermar 252
static char fat_plb_get_char(unsigned);
4357 jermar 253
static bool fat_is_directory(fs_node_t *);
254
static bool fat_is_file(fs_node_t *node);
3621 jermar 255
 
256
/*
257
 * FAT libfs operations.
258
 */
259
 
2951 jermar 260
/** Instantiate a FAT in-core node. */
4357 jermar 261
fs_node_t *fat_node_get(dev_handle_t dev_handle, fs_index_t index)
2951 jermar 262
{
4357 jermar 263
	fat_node_t *nodep;
2951 jermar 264
	fat_idx_t *idxp;
265
 
266
	idxp = fat_idx_get_by_index(dev_handle, index);
267
	if (!idxp)
268
		return NULL;
269
	/* idxp->lock held */
4357 jermar 270
	nodep = fat_node_get_core(idxp);
4552 jermar 271
	fibril_mutex_unlock(&idxp->lock);
4357 jermar 272
	return FS_NODE(nodep);
2951 jermar 273
}
274
 
4357 jermar 275
void fat_node_put(fs_node_t *fn)
2852 jermar 276
{
4357 jermar 277
	fat_node_t *nodep = FAT_NODE(fn);
3609 jermar 278
	bool destroy = false;
2910 jermar 279
 
4552 jermar 280
	fibril_mutex_lock(&nodep->lock);
2910 jermar 281
	if (!--nodep->refcnt) {
3609 jermar 282
		if (nodep->idx) {
4552 jermar 283
			fibril_mutex_lock(&ffn_mutex);
3609 jermar 284
			list_append(&nodep->ffn_link, &ffn_head);
4552 jermar 285
			fibril_mutex_unlock(&ffn_mutex);
3609 jermar 286
		} else {
287
			/*
288
			 * The node does not have any index structure associated
289
			 * with itself. This can only mean that we are releasing
290
			 * the node after a failed attempt to allocate the index
291
			 * structure for it.
292
			 */
293
			destroy = true;
294
		}
2910 jermar 295
	}
4552 jermar 296
	fibril_mutex_unlock(&nodep->lock);
4357 jermar 297
	if (destroy) {
298
		free(nodep->bp);
299
		free(nodep);
300
	}
2852 jermar 301
}
302
 
4357 jermar 303
fs_node_t *fat_create_node(dev_handle_t dev_handle, int flags)
2857 jermar 304
{
3609 jermar 305
	fat_idx_t *idxp;
306
	fat_node_t *nodep;
3633 jermar 307
	fat_bs_t *bs;
308
	fat_cluster_t mcl, lcl;
309
	uint16_t bps;
310
	int rc;
3609 jermar 311
 
3633 jermar 312
	bs = block_bb_get(dev_handle);
313
	bps = uint16_t_le2host(bs->bps);
314
	if (flags & L_DIRECTORY) {
315
		/* allocate a cluster */
316
		rc = fat_alloc_clusters(bs, dev_handle, 1, &mcl, &lcl);
317
		if (rc != EOK) 
318
			return NULL;
319
	}
320
 
3609 jermar 321
	nodep = fat_node_get_new();
3633 jermar 322
	if (!nodep) {
323
		fat_free_clusters(bs, dev_handle, mcl);	
3609 jermar 324
		return NULL;
3633 jermar 325
	}
3609 jermar 326
	idxp = fat_idx_get_new(dev_handle);
327
	if (!idxp) {
3633 jermar 328
		fat_free_clusters(bs, dev_handle, mcl);	
4357 jermar 329
		fat_node_put(FS_NODE(nodep));
3609 jermar 330
		return NULL;
331
	}
332
	/* idxp->lock held */
333
	if (flags & L_DIRECTORY) {
3633 jermar 334
		int i;
335
		block_t *b;
336
 
337
		/*
338
		 * Populate the new cluster with unused dentries.
339
		 */
340
		for (i = 0; i < bs->spc; i++) {
341
			b = _fat_block_get(bs, dev_handle, mcl, i,
342
			    BLOCK_FLAGS_NOREAD);
343
			/* mark all dentries as never-used */
344
			memset(b->data, 0, bps);
345
			b->dirty = false;
346
			block_put(b);
347
		}
3609 jermar 348
		nodep->type = FAT_DIRECTORY;
3633 jermar 349
		nodep->firstc = mcl;
350
		nodep->size = bps * bs->spc;
3609 jermar 351
	} else {
352
		nodep->type = FAT_FILE;
3633 jermar 353
		nodep->firstc = FAT_CLST_RES0;
354
		nodep->size = 0;
3609 jermar 355
	}
356
	nodep->lnkcnt = 0;	/* not linked anywhere */
357
	nodep->refcnt = 1;
3633 jermar 358
	nodep->dirty = true;
3609 jermar 359
 
360
	nodep->idx = idxp;
361
	idxp->nodep = nodep;
362
 
4552 jermar 363
	fibril_mutex_unlock(&idxp->lock);
4357 jermar 364
	return FS_NODE(nodep);
2857 jermar 365
}
366
 
4357 jermar 367
int fat_destroy_node(fs_node_t *fn)
2857 jermar 368
{
4357 jermar 369
	fat_node_t *nodep = FAT_NODE(fn);
3621 jermar 370
	fat_bs_t *bs;
371
 
372
	/*
373
	 * The node is not reachable from the file system. This means that the
374
	 * link count should be zero and that the index structure cannot be
375
	 * found in the position hash. Obviously, we don't need to lock the node
376
	 * nor its index structure.
377
	 */
378
	assert(nodep->lnkcnt == 0);
379
 
380
	/*
381
	 * The node may not have any children.
382
	 */
4357 jermar 383
	assert(fat_has_children(fn) == false);
3621 jermar 384
 
385
	bs = block_bb_get(nodep->idx->dev_handle);
386
	if (nodep->firstc != FAT_CLST_RES0) {
387
		assert(nodep->size);
388
		/* Free all clusters allocated to the node. */
389
		fat_free_clusters(bs, nodep->idx->dev_handle, nodep->firstc);
390
	}
391
 
392
	fat_idx_destroy(nodep->idx);
4357 jermar 393
	free(nodep->bp);
3621 jermar 394
	free(nodep);
395
	return EOK;
2857 jermar 396
}
397
 
4357 jermar 398
int fat_link(fs_node_t *pfn, fs_node_t *cfn, const char *name)
2857 jermar 399
{
4357 jermar 400
	fat_node_t *parentp = FAT_NODE(pfn);
401
	fat_node_t *childp = FAT_NODE(cfn);
3628 jermar 402
	fat_dentry_t *d;
403
	fat_bs_t *bs;
404
	block_t *b;
4680 svoboda 405
	unsigned i, j;
3628 jermar 406
	uint16_t bps;
407
	unsigned dps;
408
	unsigned blocks;
3700 jermar 409
	fat_cluster_t mcl, lcl;
410
	int rc;
3628 jermar 411
 
4552 jermar 412
	fibril_mutex_lock(&childp->lock);
3628 jermar 413
	if (childp->lnkcnt == 1) {
414
		/*
415
		 * On FAT, we don't support multiple hard links.
416
		 */
4552 jermar 417
		fibril_mutex_unlock(&childp->lock);
3628 jermar 418
		return EMLINK;
419
	}
420
	assert(childp->lnkcnt == 0);
4552 jermar 421
	fibril_mutex_unlock(&childp->lock);
3628 jermar 422
 
423
	if (!fat_dentry_name_verify(name)) {
424
		/*
425
		 * Attempt to create unsupported name.
426
		 */
427
		return ENOTSUP;
428
	}
429
 
430
	/*
431
	 * Get us an unused parent node's dentry or grow the parent and allocate
432
	 * a new one.
433
	 */
434
 
4552 jermar 435
	fibril_mutex_lock(&parentp->idx->lock);
3628 jermar 436
	bs = block_bb_get(parentp->idx->dev_handle);
437
	bps = uint16_t_le2host(bs->bps);
438
	dps = bps / sizeof(fat_dentry_t);
439
 
440
	blocks = parentp->size / bps;
441
 
442
	for (i = 0; i < blocks; i++) {
443
		b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE);
444
		for (j = 0; j < dps; j++) {
445
			d = ((fat_dentry_t *)b->data) + j;
446
			switch (fat_classify_dentry(d)) {
447
			case FAT_DENTRY_SKIP:
448
			case FAT_DENTRY_VALID:
449
				/* skipping used and meta entries */
450
				continue;
451
			case FAT_DENTRY_FREE:
452
			case FAT_DENTRY_LAST:
453
				/* found an empty slot */
454
				goto hit;
455
			}
456
		}
457
		block_put(b);
458
	}
3701 jermar 459
	j = 0;
3628 jermar 460
 
461
	/*
462
	 * We need to grow the parent in order to create a new unused dentry.
463
	 */
3700 jermar 464
	if (parentp->idx->pfc == FAT_CLST_ROOT) {
465
		/* Can't grow the root directory. */
4552 jermar 466
		fibril_mutex_unlock(&parentp->idx->lock);
3700 jermar 467
		return ENOSPC;
468
	}
469
	rc = fat_alloc_clusters(bs, parentp->idx->dev_handle, 1, &mcl, &lcl);
470
	if (rc != EOK) {
4552 jermar 471
		fibril_mutex_unlock(&parentp->idx->lock);
3700 jermar 472
		return rc;
473
	}
474
	fat_append_clusters(bs, parentp, mcl);
475
	b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NOREAD);
476
	d = (fat_dentry_t *)b->data;
477
	/*
478
	 * Clear all dentries in the block except for the first one (the first
479
	 * dentry will be cleared in the next step).
480
	 */
481
	memset(d + 1, 0, bps - sizeof(fat_dentry_t));
3628 jermar 482
 
483
hit:
484
	/*
485
	 * At this point we only establish the link between the parent and the
486
	 * child.  The dentry, except of the name and the extension, will remain
3700 jermar 487
	 * uninitialized until the corresponding node is synced. Thus the valid
488
	 * dentry data is kept in the child node structure.
3628 jermar 489
	 */
490
	memset(d, 0, sizeof(fat_dentry_t));
491
	fat_dentry_name_set(d, name);
492
	b->dirty = true;		/* need to sync block */
493
	block_put(b);
4552 jermar 494
	fibril_mutex_unlock(&parentp->idx->lock);
3628 jermar 495
 
4552 jermar 496
	fibril_mutex_lock(&childp->idx->lock);
3660 jermar 497
 
498
	/*
499
	 * If possible, create the Sub-directory Identifier Entry and the
500
	 * Sub-directory Parent Pointer Entry (i.e. "." and ".."). These entries
501
	 * are not mandatory according to Standard ECMA-107 and HelenOS VFS does
502
	 * not use them anyway, so this is rather a sign of our good will.
503
	 */
504
	b = fat_block_get(bs, childp, 0, BLOCK_FLAGS_NONE);
505
	d = (fat_dentry_t *)b->data;
506
	if (fat_classify_dentry(d) == FAT_DENTRY_LAST ||
4264 svoboda 507
	    str_cmp(d->name, FAT_NAME_DOT) == 0) {
3660 jermar 508
	   	memset(d, 0, sizeof(fat_dentry_t));
4268 svoboda 509
	   	str_cpy(d->name, 8, FAT_NAME_DOT);
510
		str_cpy(d->ext, 3, FAT_EXT_PAD);
3660 jermar 511
		d->attr = FAT_ATTR_SUBDIR;
512
		d->firstc = host2uint16_t_le(childp->firstc);
513
		/* TODO: initialize also the date/time members. */
514
	}
515
	d++;
516
	if (fat_classify_dentry(d) == FAT_DENTRY_LAST ||
4264 svoboda 517
	    str_cmp(d->name, FAT_NAME_DOT_DOT) == 0) {
3660 jermar 518
		memset(d, 0, sizeof(fat_dentry_t));
4268 svoboda 519
		str_cpy(d->name, 8, FAT_NAME_DOT_DOT);
520
		str_cpy(d->ext, 3, FAT_EXT_PAD);
3660 jermar 521
		d->attr = FAT_ATTR_SUBDIR;
522
		d->firstc = (parentp->firstc == FAT_CLST_ROOT) ?
523
		    host2uint16_t_le(FAT_CLST_RES0) :
524
		    host2uint16_t_le(parentp->firstc);
525
		/* TODO: initialize also the date/time members. */
526
	}
527
	b->dirty = true;		/* need to sync block */
528
	block_put(b);
529
 
3628 jermar 530
	childp->idx->pfc = parentp->firstc;
531
	childp->idx->pdi = i * dps + j;
4552 jermar 532
	fibril_mutex_unlock(&childp->idx->lock);
3628 jermar 533
 
4552 jermar 534
	fibril_mutex_lock(&childp->lock);
3628 jermar 535
	childp->lnkcnt = 1;
536
	childp->dirty = true;		/* need to sync node */
4552 jermar 537
	fibril_mutex_unlock(&childp->lock);
3628 jermar 538
 
539
	/*
540
	 * Hash in the index structure into the position hash.
541
	 */
542
	fat_idx_hashin(childp->idx);
543
 
544
	return EOK;
2857 jermar 545
}
546
 
4370 jermar 547
int fat_unlink(fs_node_t *pfn, fs_node_t *cfn, const char *nm)
2857 jermar 548
{
4357 jermar 549
	fat_node_t *parentp = FAT_NODE(pfn);
550
	fat_node_t *childp = FAT_NODE(cfn);
3638 jermar 551
	fat_bs_t *bs;
552
	fat_dentry_t *d;
553
	uint16_t bps;
554
	block_t *b;
555
 
4358 jermar 556
	if (!parentp)
557
		return EBUSY;
4359 jermar 558
 
559
	if (fat_has_children(cfn))
560
		return ENOTEMPTY;
4358 jermar 561
 
4552 jermar 562
	fibril_mutex_lock(&parentp->lock);
563
	fibril_mutex_lock(&childp->lock);
3638 jermar 564
	assert(childp->lnkcnt == 1);
4552 jermar 565
	fibril_mutex_lock(&childp->idx->lock);
3638 jermar 566
	bs = block_bb_get(childp->idx->dev_handle);
567
	bps = uint16_t_le2host(bs->bps);
568
 
569
	b = _fat_block_get(bs, childp->idx->dev_handle, childp->idx->pfc,
570
	    (childp->idx->pdi * sizeof(fat_dentry_t)) / bps,
571
	    BLOCK_FLAGS_NONE);
572
	d = (fat_dentry_t *)b->data +
573
	    (childp->idx->pdi % (bps / sizeof(fat_dentry_t)));
574
	/* mark the dentry as not-currently-used */
575
	d->name[0] = FAT_DENTRY_ERASED;
576
	b->dirty = true;		/* need to sync block */
577
	block_put(b);
578
 
579
	/* remove the index structure from the position hash */
580
	fat_idx_hashout(childp->idx);
581
	/* clear position information */
582
	childp->idx->pfc = FAT_CLST_RES0;
583
	childp->idx->pdi = 0;
4552 jermar 584
	fibril_mutex_unlock(&childp->idx->lock);
3638 jermar 585
	childp->lnkcnt = 0;
586
	childp->dirty = true;
4552 jermar 587
	fibril_mutex_unlock(&childp->lock);
588
	fibril_mutex_unlock(&parentp->lock);
3638 jermar 589
 
590
	return EOK;
2857 jermar 591
}
592
 
4357 jermar 593
fs_node_t *fat_match(fs_node_t *pfn, const char *component)
2793 jermar 594
{
3530 jermar 595
	fat_bs_t *bs;
4357 jermar 596
	fat_node_t *parentp = FAT_NODE(pfn);
2793 jermar 597
	char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
2822 jermar 598
	unsigned i, j;
2828 jermar 599
	unsigned bps;		/* bytes per sector */
2822 jermar 600
	unsigned dps;		/* dentries per sector */
601
	unsigned blocks;
2793 jermar 602
	fat_dentry_t *d;
3530 jermar 603
	block_t *b;
2793 jermar 604
 
4552 jermar 605
	fibril_mutex_lock(&parentp->idx->lock);
3530 jermar 606
	bs = block_bb_get(parentp->idx->dev_handle);
607
	bps = uint16_t_le2host(bs->bps);
2828 jermar 608
	dps = bps / sizeof(fat_dentry_t);
3526 jermar 609
	blocks = parentp->size / bps;
2822 jermar 610
	for (i = 0; i < blocks; i++) {
3595 jermar 611
		b = fat_block_get(bs, parentp, i, BLOCK_FLAGS_NONE);
3526 jermar 612
		for (j = 0; j < dps; j++) { 
2822 jermar 613
			d = ((fat_dentry_t *)b->data) + j;
2845 jermar 614
			switch (fat_classify_dentry(d)) {
615
			case FAT_DENTRY_SKIP:
3628 jermar 616
			case FAT_DENTRY_FREE:
2822 jermar 617
				continue;
2845 jermar 618
			case FAT_DENTRY_LAST:
2822 jermar 619
				block_put(b);
4552 jermar 620
				fibril_mutex_unlock(&parentp->idx->lock);
2822 jermar 621
				return NULL;
2845 jermar 622
			default:
623
			case FAT_DENTRY_VALID:
3628 jermar 624
				fat_dentry_name_get(d, name);
2845 jermar 625
				break;
2822 jermar 626
			}
3634 jermar 627
			if (fat_dentry_namecmp(name, component) == 0) {
2822 jermar 628
				/* hit */
4357 jermar 629
				fat_node_t *nodep;
2953 jermar 630
				/*
631
				 * Assume tree hierarchy for locking.  We
632
				 * already have the parent and now we are going
633
				 * to lock the child.  Never lock in the oposite
634
				 * order.
635
				 */
2890 jermar 636
				fat_idx_t *idx = fat_idx_get_by_pos(
2881 jermar 637
				    parentp->idx->dev_handle, parentp->firstc,
2864 jermar 638
				    i * dps + j);
4552 jermar 639
				fibril_mutex_unlock(&parentp->idx->lock);
2890 jermar 640
				if (!idx) {
641
					/*
642
					 * Can happen if memory is low or if we
643
					 * run out of 32-bit indices.
644
					 */
645
					block_put(b);
646
					return NULL;
647
				}
4357 jermar 648
				nodep = fat_node_get_core(idx);
4552 jermar 649
				fibril_mutex_unlock(&idx->lock);
2822 jermar 650
				block_put(b);
4357 jermar 651
				return FS_NODE(nodep);
2822 jermar 652
			}
2793 jermar 653
		}
2822 jermar 654
		block_put(b);
2639 jermar 655
	}
3516 jermar 656
 
4552 jermar 657
	fibril_mutex_unlock(&parentp->idx->lock);
2793 jermar 658
	return NULL;
2638 jermar 659
}
660
 
4357 jermar 661
fs_index_t fat_index_get(fs_node_t *fn)
2831 jermar 662
{
4357 jermar 663
	return FAT_NODE(fn)->idx->index;
2831 jermar 664
}
665
 
4357 jermar 666
size_t fat_size_get(fs_node_t *fn)
2831 jermar 667
{
4357 jermar 668
	return FAT_NODE(fn)->size;
2831 jermar 669
}
670
 
4357 jermar 671
unsigned fat_lnkcnt_get(fs_node_t *fn)
2831 jermar 672
{
4357 jermar 673
	return FAT_NODE(fn)->lnkcnt;
2831 jermar 674
}
675
 
4357 jermar 676
bool fat_has_children(fs_node_t *fn)
2845 jermar 677
{
3530 jermar 678
	fat_bs_t *bs;
4357 jermar 679
	fat_node_t *nodep = FAT_NODE(fn);
2845 jermar 680
	unsigned bps;
681
	unsigned dps;
682
	unsigned blocks;
3530 jermar 683
	block_t *b;
2845 jermar 684
	unsigned i, j;
685
 
686
	if (nodep->type != FAT_DIRECTORY)
687
		return false;
3526 jermar 688
 
4552 jermar 689
	fibril_mutex_lock(&nodep->idx->lock);
3530 jermar 690
	bs = block_bb_get(nodep->idx->dev_handle);
691
	bps = uint16_t_le2host(bs->bps);
2845 jermar 692
	dps = bps / sizeof(fat_dentry_t);
693
 
3526 jermar 694
	blocks = nodep->size / bps;
2845 jermar 695
 
696
	for (i = 0; i < blocks; i++) {
697
		fat_dentry_t *d;
698
 
3595 jermar 699
		b = fat_block_get(bs, nodep, i, BLOCK_FLAGS_NONE);
3526 jermar 700
		for (j = 0; j < dps; j++) {
2845 jermar 701
			d = ((fat_dentry_t *)b->data) + j;
702
			switch (fat_classify_dentry(d)) {
703
			case FAT_DENTRY_SKIP:
3628 jermar 704
			case FAT_DENTRY_FREE:
2845 jermar 705
				continue;
706
			case FAT_DENTRY_LAST:
707
				block_put(b);
4552 jermar 708
				fibril_mutex_unlock(&nodep->idx->lock);
2845 jermar 709
				return false;
710
			default:
711
			case FAT_DENTRY_VALID:
712
				block_put(b);
4552 jermar 713
				fibril_mutex_unlock(&nodep->idx->lock);
2845 jermar 714
				return true;
715
			}
716
			block_put(b);
4552 jermar 717
			fibril_mutex_unlock(&nodep->idx->lock);
2845 jermar 718
			return true;
719
		}
720
		block_put(b);
721
	}
722
 
4552 jermar 723
	fibril_mutex_unlock(&nodep->idx->lock);
2845 jermar 724
	return false;
725
}
726
 
4357 jermar 727
fs_node_t *fat_root_get(dev_handle_t dev_handle)
2844 jermar 728
{
3119 jermar 729
	return fat_node_get(dev_handle, 0);
2844 jermar 730
}
731
 
3621 jermar 732
char fat_plb_get_char(unsigned pos)
2844 jermar 733
{
734
	return fat_reg.plb_ro[pos % PLB_SIZE];
735
}
736
 
4357 jermar 737
bool fat_is_directory(fs_node_t *fn)
2831 jermar 738
{
4357 jermar 739
	return FAT_NODE(fn)->type == FAT_DIRECTORY;
2831 jermar 740
}
741
 
4357 jermar 742
bool fat_is_file(fs_node_t *fn)
2831 jermar 743
{
4357 jermar 744
	return FAT_NODE(fn)->type == FAT_FILE;
2831 jermar 745
}
746
 
2793 jermar 747
/** libfs operations */
748
libfs_ops_t fat_libfs_ops = {
749
	.match = fat_match,
750
	.node_get = fat_node_get,
2852 jermar 751
	.node_put = fat_node_put,
3609 jermar 752
	.create = fat_create_node,
753
	.destroy = fat_destroy_node,
2857 jermar 754
	.link = fat_link,
755
	.unlink = fat_unlink,
2831 jermar 756
	.index_get = fat_index_get,
757
	.size_get = fat_size_get,
758
	.lnkcnt_get = fat_lnkcnt_get,
2845 jermar 759
	.has_children = fat_has_children,
2844 jermar 760
	.root_get = fat_root_get,
761
	.plb_get_char =	fat_plb_get_char,
2831 jermar 762
	.is_directory = fat_is_directory,
763
	.is_file = fat_is_file
2793 jermar 764
};
765
 
3625 jermar 766
/*
767
 * VFS operations.
768
 */
769
 
3110 jermar 770
void fat_mounted(ipc_callid_t rid, ipc_call_t *request)
771
{
772
	dev_handle_t dev_handle = (dev_handle_t) IPC_GET_ARG1(*request);
4572 svoboda 773
	enum cache_mode cmode;
3530 jermar 774
	fat_bs_t *bs;
3257 jermar 775
	uint16_t bps;
3119 jermar 776
	uint16_t rde;
3110 jermar 777
	int rc;
778
 
4305 jermar 779
	/* accept the mount options */
780
	ipc_callid_t callid;
781
	size_t size;
782
	if (!ipc_data_write_receive(&callid, &size)) {
783
		ipc_answer_0(callid, EINVAL);
784
		ipc_answer_0(rid, EINVAL);
785
		return;
786
	}
787
	char *opts = malloc(size + 1);
788
	if (!opts) {
789
		ipc_answer_0(callid, ENOMEM);
790
		ipc_answer_0(rid, ENOMEM);
791
		return;
792
	}
793
	ipcarg_t retval = ipc_data_write_finalize(callid, opts, size);
794
	if (retval != EOK) {
795
		ipc_answer_0(rid, retval);
796
		free(opts);
797
		return;
798
	}
799
	opts[size] = '\0';
800
 
4572 svoboda 801
	/* Check for option enabling write through. */
802
	if (str_cmp(opts, "wtcache") == 0)
803
		cmode = CACHE_MODE_WT;
804
	else
805
		cmode = CACHE_MODE_WB;
806
 
3530 jermar 807
	/* initialize libblock */
3537 jermar 808
	rc = block_init(dev_handle, BS_SIZE);
3257 jermar 809
	if (rc != EOK) {
3537 jermar 810
		ipc_answer_0(rid, rc);
3257 jermar 811
		return;
812
	}
813
 
3537 jermar 814
	/* prepare the boot block */
815
	rc = block_bb_read(dev_handle, BS_BLOCK * BS_SIZE, BS_SIZE);
816
	if (rc != EOK) {
817
		block_fini(dev_handle);
818
		ipc_answer_0(rid, rc);
819
		return;
820
	}
821
 
3530 jermar 822
	/* get the buffer with the boot sector */
823
	bs = block_bb_get(dev_handle);
824
 
3119 jermar 825
	/* Read the number of root directory entries. */
3530 jermar 826
	bps = uint16_t_le2host(bs->bps);
827
	rde = uint16_t_le2host(bs->root_ent_max);
3119 jermar 828
 
3257 jermar 829
	if (bps != BS_SIZE) {
3530 jermar 830
		block_fini(dev_handle);
3257 jermar 831
		ipc_answer_0(rid, ENOTSUP);
832
		return;
833
	}
834
 
3539 jermar 835
	/* Initialize the block cache */
4572 svoboda 836
	rc = block_cache_init(dev_handle, bps, 0 /* XXX */, cmode);
3539 jermar 837
	if (rc != EOK) {
838
		block_fini(dev_handle);
839
		ipc_answer_0(rid, rc);
840
		return;
841
	}
842
 
3110 jermar 843
	rc = fat_idx_init_by_dev_handle(dev_handle);
844
	if (rc != EOK) {
3530 jermar 845
		block_fini(dev_handle);
3110 jermar 846
		ipc_answer_0(rid, rc);
847
		return;
848
	}
849
 
3119 jermar 850
	/* Initialize the root node. */
4357 jermar 851
	fs_node_t *rfn = (fs_node_t *)malloc(sizeof(fs_node_t));
852
	if (!rfn) {
853
		block_fini(dev_handle);
854
		fat_idx_fini_by_dev_handle(dev_handle);
855
		ipc_answer_0(rid, ENOMEM);
856
		return;
857
	}
4409 jermar 858
	fs_node_initialize(rfn);
3119 jermar 859
	fat_node_t *rootp = (fat_node_t *)malloc(sizeof(fat_node_t));
860
	if (!rootp) {
4357 jermar 861
		free(rfn);
3530 jermar 862
		block_fini(dev_handle);
3119 jermar 863
		fat_idx_fini_by_dev_handle(dev_handle);
864
		ipc_answer_0(rid, ENOMEM);
865
		return;
866
	}
867
	fat_node_initialize(rootp);
868
 
869
	fat_idx_t *ridxp = fat_idx_get_by_pos(dev_handle, FAT_CLST_ROOTPAR, 0);
870
	if (!ridxp) {
4357 jermar 871
		free(rfn);
872
		free(rootp);
3530 jermar 873
		block_fini(dev_handle);
3119 jermar 874
		fat_idx_fini_by_dev_handle(dev_handle);
875
		ipc_answer_0(rid, ENOMEM);
876
		return;
877
	}
878
	assert(ridxp->index == 0);
879
	/* ridxp->lock held */
880
 
881
	rootp->type = FAT_DIRECTORY;
882
	rootp->firstc = FAT_CLST_ROOT;
883
	rootp->refcnt = 1;
3352 jermar 884
	rootp->lnkcnt = 0;	/* FS root is not linked */
3119 jermar 885
	rootp->size = rde * sizeof(fat_dentry_t);
886
	rootp->idx = ridxp;
887
	ridxp->nodep = rootp;
4357 jermar 888
	rootp->bp = rfn;
889
	rfn->data = rootp;
3119 jermar 890
 
4552 jermar 891
	fibril_mutex_unlock(&ridxp->lock);
3119 jermar 892
 
3352 jermar 893
	ipc_answer_3(rid, EOK, ridxp->index, rootp->size, rootp->lnkcnt);
3110 jermar 894
}
895
 
896
void fat_mount(ipc_callid_t rid, ipc_call_t *request)
897
{
4429 jermar 898
	libfs_mount(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
3110 jermar 899
}
900
 
2627 jermar 901
void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
902
{
2793 jermar 903
	libfs_lookup(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
2627 jermar 904
}
905
 
3307 jermar 906
void fat_read(ipc_callid_t rid, ipc_call_t *request)
907
{
908
	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
909
	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
910
	off_t pos = (off_t)IPC_GET_ARG3(*request);
4357 jermar 911
	fs_node_t *fn = fat_node_get(dev_handle, index);
912
	fat_node_t *nodep;
3530 jermar 913
	fat_bs_t *bs;
3516 jermar 914
	uint16_t bps;
3308 jermar 915
	size_t bytes;
3530 jermar 916
	block_t *b;
3308 jermar 917
 
4357 jermar 918
	if (!fn) {
3307 jermar 919
		ipc_answer_0(rid, ENOENT);
920
		return;
921
	}
4357 jermar 922
	nodep = FAT_NODE(fn);
3307 jermar 923
 
924
	ipc_callid_t callid;
925
	size_t len;
3314 jermar 926
	if (!ipc_data_read_receive(&callid, &len)) {
4357 jermar 927
		fat_node_put(fn);
3307 jermar 928
		ipc_answer_0(callid, EINVAL);
929
		ipc_answer_0(rid, EINVAL);
930
		return;
931
	}
932
 
3530 jermar 933
	bs = block_bb_get(dev_handle);
934
	bps = uint16_t_le2host(bs->bps);
3516 jermar 935
 
3307 jermar 936
	if (nodep->type == FAT_FILE) {
3335 jermar 937
		/*
938
		 * Our strategy for regular file reads is to read one block at
939
		 * most and make use of the possibility to return less data than
940
		 * requested. This keeps the code very simple.
941
		 */
3532 jermar 942
		if (pos >= nodep->size) {
3533 jermar 943
			/* reading beyond the EOF */
944
			bytes = 0;
3532 jermar 945
			(void) ipc_data_read_finalize(callid, NULL, 0);
946
		} else {
947
			bytes = min(len, bps - pos % bps);
948
			bytes = min(bytes, nodep->size - pos);
3595 jermar 949
			b = fat_block_get(bs, nodep, pos / bps,
950
			    BLOCK_FLAGS_NONE);
3532 jermar 951
			(void) ipc_data_read_finalize(callid, b->data + pos % bps,
952
			    bytes);
953
			block_put(b);
954
		}
3307 jermar 955
	} else {
3335 jermar 956
		unsigned bnum;
957
		off_t spos = pos;
958
		char name[FAT_NAME_LEN + 1 + FAT_EXT_LEN + 1];
959
		fat_dentry_t *d;
960
 
3307 jermar 961
		assert(nodep->type == FAT_DIRECTORY);
3335 jermar 962
		assert(nodep->size % bps == 0);
963
		assert(bps % sizeof(fat_dentry_t) == 0);
964
 
965
		/*
966
		 * Our strategy for readdir() is to use the position pointer as
967
		 * an index into the array of all dentries. On entry, it points
968
		 * to the first unread dentry. If we skip any dentries, we bump
969
		 * the position pointer accordingly.
970
		 */
971
		bnum = (pos * sizeof(fat_dentry_t)) / bps;
972
		while (bnum < nodep->size / bps) {
973
			off_t o;
974
 
3595 jermar 975
			b = fat_block_get(bs, nodep, bnum, BLOCK_FLAGS_NONE);
3335 jermar 976
			for (o = pos % (bps / sizeof(fat_dentry_t));
977
			    o < bps / sizeof(fat_dentry_t);
978
			    o++, pos++) {
979
				d = ((fat_dentry_t *)b->data) + o;
980
				switch (fat_classify_dentry(d)) {
981
				case FAT_DENTRY_SKIP:
3628 jermar 982
				case FAT_DENTRY_FREE:
3335 jermar 983
					continue;
984
				case FAT_DENTRY_LAST:
985
					block_put(b);
986
					goto miss;
987
				default:
988
				case FAT_DENTRY_VALID:
3628 jermar 989
					fat_dentry_name_get(d, name);
3335 jermar 990
					block_put(b);
991
					goto hit;
992
				}
993
			}
994
			block_put(b);
995
			bnum++;
996
		}
997
miss:
4357 jermar 998
		fat_node_put(fn);
3335 jermar 999
		ipc_answer_0(callid, ENOENT);
1000
		ipc_answer_1(rid, ENOENT, 0);
3307 jermar 1001
		return;
3335 jermar 1002
hit:
4264 svoboda 1003
		(void) ipc_data_read_finalize(callid, name, str_size(name) + 1);
3335 jermar 1004
		bytes = (pos - spos) + 1;
3307 jermar 1005
	}
1006
 
4357 jermar 1007
	fat_node_put(fn);
3308 jermar 1008
	ipc_answer_1(rid, EOK, (ipcarg_t)bytes);
3307 jermar 1009
}
1010
 
3497 jermar 1011
void fat_write(ipc_callid_t rid, ipc_call_t *request)
1012
{
3499 jermar 1013
	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
1014
	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
1015
	off_t pos = (off_t)IPC_GET_ARG3(*request);
4357 jermar 1016
	fs_node_t *fn = fat_node_get(dev_handle, index);
1017
	fat_node_t *nodep;
3530 jermar 1018
	fat_bs_t *bs;
3499 jermar 1019
	size_t bytes;
3530 jermar 1020
	block_t *b;
3499 jermar 1021
	uint16_t bps;
1022
	unsigned spc;
3572 jermar 1023
	unsigned bpc;		/* bytes per cluster */
3501 jermar 1024
	off_t boundary;
3595 jermar 1025
	int flags = BLOCK_FLAGS_NONE;
3499 jermar 1026
 
4357 jermar 1027
	if (!fn) {
3499 jermar 1028
		ipc_answer_0(rid, ENOENT);
1029
		return;
1030
	}
4357 jermar 1031
	nodep = FAT_NODE(fn);
3499 jermar 1032
 
1033
	ipc_callid_t callid;
1034
	size_t len;
1035
	if (!ipc_data_write_receive(&callid, &len)) {
4357 jermar 1036
		fat_node_put(fn);
3499 jermar 1037
		ipc_answer_0(callid, EINVAL);
1038
		ipc_answer_0(rid, EINVAL);
1039
		return;
1040
	}
1041
 
3572 jermar 1042
	bs = block_bb_get(dev_handle);
1043
	bps = uint16_t_le2host(bs->bps);
1044
	spc = bs->spc;
1045
	bpc = bps * spc;
1046
 
3499 jermar 1047
	/*
1048
	 * In all scenarios, we will attempt to write out only one block worth
1049
	 * of data at maximum. There might be some more efficient approaches,
1050
	 * but this one greatly simplifies fat_write(). Note that we can afford
1051
	 * to do this because the client must be ready to handle the return
1052
	 * value signalizing a smaller number of bytes written. 
1053
	 */ 
1054
	bytes = min(len, bps - pos % bps);
3595 jermar 1055
	if (bytes == bps)
1056
		flags |= BLOCK_FLAGS_NOREAD;
3499 jermar 1057
 
3572 jermar 1058
	boundary = ROUND_UP(nodep->size, bpc);
3501 jermar 1059
	if (pos < boundary) {
3499 jermar 1060
		/*
1061
		 * This is the easier case - we are either overwriting already
1062
		 * existing contents or writing behind the EOF, but still within
1063
		 * the limits of the last cluster. The node size may grow to the
1064
		 * next block size boundary.
1065
		 */
3530 jermar 1066
		fat_fill_gap(bs, nodep, FAT_CLST_RES0, pos);
3595 jermar 1067
		b = fat_block_get(bs, nodep, pos / bps, flags);
3499 jermar 1068
		(void) ipc_data_write_finalize(callid, b->data + pos % bps,
1069
		    bytes);
1070
		b->dirty = true;		/* need to sync block */
3500 jermar 1071
		block_put(b);
3499 jermar 1072
		if (pos + bytes > nodep->size) {
1073
			nodep->size = pos + bytes;
1074
			nodep->dirty = true;	/* need to sync node */
1075
		}
3573 jermar 1076
		ipc_answer_2(rid, EOK, bytes, nodep->size);	
4357 jermar 1077
		fat_node_put(fn);
3499 jermar 1078
		return;
1079
	} else {
1080
		/*
1081
		 * This is the more difficult case. We must allocate new
1082
		 * clusters for the node and zero them out.
1083
		 */
3500 jermar 1084
		int status;
3499 jermar 1085
		unsigned nclsts;
3548 jermar 1086
		fat_cluster_t mcl, lcl; 
1087
 
3572 jermar 1088
		nclsts = (ROUND_UP(pos + bytes, bpc) - boundary) / bpc;
3500 jermar 1089
		/* create an independent chain of nclsts clusters in all FATs */
3572 jermar 1090
		status = fat_alloc_clusters(bs, dev_handle, nclsts, &mcl, &lcl);
3500 jermar 1091
		if (status != EOK) {
1092
			/* could not allocate a chain of nclsts clusters */
4357 jermar 1093
			fat_node_put(fn);
3500 jermar 1094
			ipc_answer_0(callid, status);
1095
			ipc_answer_0(rid, status);
1096
			return;
1097
		}
1098
		/* zero fill any gaps */
3530 jermar 1099
		fat_fill_gap(bs, nodep, mcl, pos);
3595 jermar 1100
		b = _fat_block_get(bs, dev_handle, lcl, (pos / bps) % spc,
1101
		    flags);
3500 jermar 1102
		(void) ipc_data_write_finalize(callid, b->data + pos % bps,
1103
		    bytes);
3501 jermar 1104
		b->dirty = true;		/* need to sync block */
3500 jermar 1105
		block_put(b);
1106
		/*
1107
		 * Append the cluster chain starting in mcl to the end of the
1108
		 * node's cluster chain.
1109
		 */
3530 jermar 1110
		fat_append_clusters(bs, nodep, mcl);
3500 jermar 1111
		nodep->size = pos + bytes;
3501 jermar 1112
		nodep->dirty = true;		/* need to sync node */
3573 jermar 1113
		ipc_answer_2(rid, EOK, bytes, nodep->size);
4357 jermar 1114
		fat_node_put(fn);
3500 jermar 1115
		return;
3499 jermar 1116
	}
3497 jermar 1117
}
1118
 
3546 jermar 1119
void fat_truncate(ipc_callid_t rid, ipc_call_t *request)
1120
{
3548 jermar 1121
	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
1122
	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
1123
	size_t size = (off_t)IPC_GET_ARG3(*request);
4357 jermar 1124
	fs_node_t *fn = fat_node_get(dev_handle, index);
1125
	fat_node_t *nodep;
3572 jermar 1126
	fat_bs_t *bs;
1127
	uint16_t bps;
1128
	uint8_t spc;
1129
	unsigned bpc;	/* bytes per cluster */
3548 jermar 1130
	int rc;
1131
 
4357 jermar 1132
	if (!fn) {
3548 jermar 1133
		ipc_answer_0(rid, ENOENT);
1134
		return;
1135
	}
4357 jermar 1136
	nodep = FAT_NODE(fn);
3548 jermar 1137
 
3572 jermar 1138
	bs = block_bb_get(dev_handle);
1139
	bps = uint16_t_le2host(bs->bps);
1140
	spc = bs->spc;
1141
	bpc = bps * spc;
1142
 
3548 jermar 1143
	if (nodep->size == size) {
1144
		rc = EOK;
1145
	} else if (nodep->size < size) {
1146
		/*
3572 jermar 1147
		 * The standard says we have the freedom to grow the node.
3548 jermar 1148
		 * For now, we simply return an error.
1149
		 */
1150
		rc = EINVAL;
3572 jermar 1151
	} else if (ROUND_UP(nodep->size, bpc) == ROUND_UP(size, bpc)) {
1152
		/*
1153
		 * The node will be shrunk, but no clusters will be deallocated.
1154
		 */
1155
		nodep->size = size;
1156
		nodep->dirty = true;		/* need to sync node */
1157
		rc = EOK;	
3548 jermar 1158
	} else {
1159
		/*
3572 jermar 1160
		 * The node will be shrunk, clusters will be deallocated.
3548 jermar 1161
		 */
3572 jermar 1162
		if (size == 0) {
1163
			fat_chop_clusters(bs, nodep, FAT_CLST_RES0);
1164
		} else {
1165
			fat_cluster_t lastc;
1166
			(void) fat_cluster_walk(bs, dev_handle, nodep->firstc,
1167
			    &lastc, (size - 1) / bpc);
1168
			fat_chop_clusters(bs, nodep, lastc);
1169
		}
1170
		nodep->size = size;
1171
		nodep->dirty = true;		/* need to sync node */
1172
		rc = EOK;	
3548 jermar 1173
	}
4357 jermar 1174
	fat_node_put(fn);
3548 jermar 1175
	ipc_answer_0(rid, rc);
1176
	return;
3546 jermar 1177
}
1178
 
4465 decky 1179
void fat_close(ipc_callid_t rid, ipc_call_t *request)
1180
{
1181
	ipc_answer_0(rid, EOK);
1182
}
1183
 
3621 jermar 1184
void fat_destroy(ipc_callid_t rid, ipc_call_t *request)
1185
{
1186
	dev_handle_t dev_handle = (dev_handle_t)IPC_GET_ARG1(*request);
1187
	fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
1188
	int rc;
1189
 
4357 jermar 1190
	fs_node_t *fn = fat_node_get(dev_handle, index);
1191
	if (!fn) {
3621 jermar 1192
		ipc_answer_0(rid, ENOENT);
1193
		return;
1194
	}
1195
 
4357 jermar 1196
	rc = fat_destroy_node(fn);
3621 jermar 1197
	ipc_answer_0(rid, rc);
1198
}
1199
 
4465 decky 1200
void fat_open_node(ipc_callid_t rid, ipc_call_t *request)
1201
{
1202
	libfs_open_node(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
1203
}
1204
 
4585 jermar 1205
void fat_stat(ipc_callid_t rid, ipc_call_t *request)
4465 decky 1206
{
4586 jermar 1207
	libfs_stat(&fat_libfs_ops, fat_reg.fs_handle, rid, request);
4465 decky 1208
}
1209
 
1210
void fat_sync(ipc_callid_t rid, ipc_call_t *request)
1211
{
1212
	/* Dummy implementation */
1213
	ipc_answer_0(rid, EOK);
1214
}
1215
 
2627 jermar 1216
/**
1217
 * @}
4465 decky 1218
 */