aboutsummaryrefslogtreecommitdiffstats
path: root/fs/hfsplus/extents.c
blob: 9d8c087ef4f4486bdd0443dedf860d189ec668a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
/*
 *  linux/fs/hfsplus/extents.c
 *
 * Copyright (C) 2001
 * Brad Boyer (flar@allandria.com)
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 *
 * Handling of Extents both in catalog and extents overflow trees
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/pagemap.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

/* Compare two extents keys, returns 0 on same, pos/neg for difference */
int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
			const hfsplus_btree_key *k2)
{
	__be32 k1id, k2id;
	__be32 k1s, k2s;

	k1id = k1->ext.cnid;
	k2id = k2->ext.cnid;
	if (k1id != k2id)
		return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1;

	if (k1->ext.fork_type != k2->ext.fork_type)
		return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1;

	k1s = k1->ext.start_block;
	k2s = k2->ext.start_block;
	if (k1s == k2s)
		return 0;
	return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1;
}

static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid,
				  u32 block, u8 type)
{
	key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2);
	key->ext.cnid = cpu_to_be32(cnid);
	key->ext.start_block = cpu_to_be32(block);
	key->ext.fork_type = type;
	key->ext.pad = 0;
}

static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off)
{
	int i;
	u32 count;

	for (i = 0; i < 8; ext++, i++) {
		count = be32_to_cpu(ext->block_count);
		if (off < count)
			return be32_to_cpu(ext->start_block) + off;
		off -= count;
	}
	/* panic? */
	return 0;
}

static int hfsplus_ext_block_count(struct hfsplus_extent *ext)
{
	int i;
	u32 count = 0;

	for (i = 0; i < 8; ext++, i++)
		count += be32_to_cpu(ext->block_count);
	return count;
}

static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext)
{
	int i;

	ext += 7;
	for (i = 0; i < 7; ext--, i++)
		if (ext->block_count)
			break;
	return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count);
}

static void __hfsplus_ext_write_extent(struct inode *inode,
		struct hfs_find_data *fd)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,
			      HFSPLUS_IS_RSRC(inode) ?
				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);

	res = hfs_brec_find(fd);
	if (hip->extent_state & HFSPLUS_EXT_NEW) {
		if (res != -ENOENT)
			return;
		hfs_brec_insert(fd, hip->cached_extents,
				sizeof(hfsplus_extent_rec));
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	} else {
		if (res)
			return;
		hfs_bnode_write(fd->bnode, hip->cached_extents,
				fd->entryoffset, fd->entrylength);
		hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
	}

	/*
	 * We can't just use hfsplus_mark_inode_dirty here, because we
	 * also get called from hfsplus_write_inode, which should not
	 * redirty the inode.  Instead the callers have to be careful
	 * to explicily mark the inode dirty, too.
	 */
	set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
}

static void hfsplus_ext_write_extent_locked(struct inode *inode)
{
	if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) {
		struct hfs_find_data fd;

		hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
		__hfsplus_ext_write_extent(inode, &fd);
		hfs_find_exit(&fd);
	}
}

void hfsplus_ext_write_extent(struct inode *inode)
{
	mutex_lock(&HFSPLUS_I(inode)->extents_lock);
	hfsplus_ext_write_extent_locked(inode);
	mutex_unlock(&HFSPLUS_I(inode)->extents_lock);
}

static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,
					    struct hfsplus_extent *extent,
					    u32 cnid, u32 block, u8 type)
{
	int res;

	hfsplus_ext_build_key(fd->search_key, cnid, block, type);
	fd->key->ext.cnid = 0;
	res = hfs_brec_find(fd);
	if (res && res != -ENOENT)
		return res;
	if (fd->key->ext.cnid != fd->search_key->ext.cnid ||
	    fd->key->ext.fork_type != fd->search_key->ext.fork_type)
		return -ENOENT;
	if (fd->entrylength != sizeof(hfsplus_extent_rec))
		return -EIO;
	hfs_bnode_read(fd->bnode, extent, fd->entryoffset,
		sizeof(hfsplus_extent_rec));
	return 0;
}

static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd,
		struct inode *inode, u32 block)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res;

	WARN_ON(!mutex_is_locked(&hip->extents_lock));

	if (hip->extent_state & HFSPLUS_EXT_DIRTY)
		__hfsplus_ext_write_extent(inode, fd);

	res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino,
					block, HFSPLUS_IS_RSRC(inode) ?
						HFSPLUS_TYPE_RSRC :
						HFSPLUS_TYPE_DATA);
	if (!res) {
		hip->cached_start = be32_to_cpu(fd->key->ext.start_block);
		hip->cached_blocks =
			hfsplus_ext_block_count(hip->cached_extents);
	} else {
		hip->cached_start = hip->cached_blocks = 0;
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
	}
	return res;
}

static int hfsplus_ext_read_extent(struct inode *inode, u32 block)
{
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	struct hfs_find_data fd;
	int res;

	if (block >= hip->cached_start &&
	    block < hip->cached_start + hip->cached_blocks)
		return 0;

	hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd);
	res = __hfsplus_ext_cache_extent(&fd, inode, block);
	hfs_find_exit(&fd);
	return res;
}

/* Get a block at iblock for inode, possibly allocating if create */
int hfsplus_get_block(struct inode *inode, sector_t iblock,
		      struct buffer_head *bh_result, int create)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	int res = -EIO;
	u32 ablock, dblock, mask;
	int was_dirty = 0;
	int shift;

	/* Convert inode block to disk allocation block */
	shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
	ablock = iblock >> sbi->fs_shift;

	if (iblock >= hip->fs_blocks) {
		if (iblock > hip->fs_blocks || !create)
			return -EIO;
		if (ablock >= hip->alloc_blocks) {
			res = hfsplus_file_extend(inode);
			if (res)
				return res;
		}
	} else
		create = 0;

	if (ablock < hip->first_blocks) {
		dblock = hfsplus_ext_find_block(hip->first_extents, ablock);
		goto done;
	}

	if (inode->i_ino == HFSPLUS_EXT_CNID)
		return -EIO;

	mutex_lock(&hip->extents_lock);

	/*
	 * hfsplus_ext_read_extent will write out a cached extent into
	 * the extents btree.  In that case we may have to mark the inode
	 * dirty even for a pure read of an extent here.
	 */
	was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
	res = hfsplus_ext_read_extent(inode, ablock);
	if (res) {
		mutex_unlock(&hip->extents_lock);
		return -EIO;
	}
	dblock = hfsplus_ext_find_block(hip->cached_extents,
					ablock - hip->cached_start);
	mutex_unlock(&hip->extents_lock);

done:
	dprint(DBG_EXTENT, "get_block(%lu): %llu - %u\n",
		inode->i_ino, (long long)iblock, dblock);
	mask = (1 << sbi->fs_shift) - 1;
	map_bh(bh_result, sb,
		(dblock << sbi->fs_shift) + sbi->blockoffset +
			(iblock & mask));
	if (create) {
		set_buffer_new(bh_result);
		hip->phys_size += sb->s_blocksize;
		hip->fs_blocks++;
		inode_add_bytes(inode, sb->s_blocksize);
	}
	if (create || was_dirty)
		mark_inode_dirty(inode);
	return 0;
}

static void hfsplus_dump_extent(struct hfsplus_extent *extent)
{
	int i;

	dprint(DBG_EXTENT, "   ");
	for (i = 0; i < 8; i++)
		dprint(DBG_EXTENT, " %u:%u", be32_to_cpu(extent[i].start_block),
				 be32_to_cpu(extent[i].block_count));
	dprint(DBG_EXTENT, "\n");
}

static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset,
			      u32 alloc_block, u32 block_count)
{
	u32 count, start;
	int i;

	hfsplus_dump_extent(extent);
	for (i = 0; i < 8; extent++, i++) {
		count = be32_to_cpu(extent->block_count);
		if (offset == count) {
			start = be32_to_cpu(extent->start_block);
			if (alloc_block != start + count) {
				if (++i >= 8)
					return -ENOSPC;
				extent++;
				extent->start_block = cpu_to_be32(alloc_block);
			} else
				block_count += count;
			extent->block_count = cpu_to_be32(block_count);
			return 0;
		} else if (offset < count)
			break;
		offset -= count;
	}
	/* panic? */
	return -EIO;
}

static int hfsplus_free_extents(struct super_block *sb,
				struct hfsplus_extent *extent,
				u32 offset, u32 block_nr)
{
	u32 count, start;
	int i;

	hfsplus_dump_extent(extent);
	for (i = 0; i < 8; extent++, i++) {
		count = be32_to_cpu(extent->block_count);
		if (offset == count)
			goto found;
		else if (offset < count)
			break;
		offset -= count;
	}
	/* panic? */
	return -EIO;
found:
	for (;;) {
		start = be32_to_cpu(extent->start_block);
		if (count <= block_nr) {
			hfsplus_block_free(sb, start, count);
			extent->block_count = 0;
			extent->start_block = 0;
			block_nr -= count;
		} else {
			count -= block_nr;
			hfsplus_block_free(sb, start + count, block_nr);
			extent->block_count = cpu_to_be32(count);
			block_nr = 0;
		}
		if (!block_nr || !i)
			return 0;
		i--;
		extent--;
		count = be32_to_cpu(extent->block_count);
	}
}

int hfsplus_free_fork(struct super_block *sb, u32 cnid,
		struct hfsplus_fork_raw *fork, int type)
{
	struct hfs_find_data fd;
	hfsplus_extent_rec ext_entry;
	u32 total_blocks, blocks, start;
	int res, i;

	total_blocks = be32_to_cpu(fork->total_blocks);
	if (!total_blocks)
		return 0;

	blocks = 0;
	for (i = 0; i < 8; i++)
		blocks += be32_to_cpu(fork->extents[i].block_count);

	res = hfsplus_free_extents(sb, fork->extents, blocks, blocks);
	if (res)
		return res;
	if (total_blocks == blocks)
		return 0;

	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	do {
		res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid,
						total_blocks, type);
		if (res)
			break;
		start = be32_to_cpu(fd.key->ext.start_block);
		hfsplus_free_extents(sb, ext_entry,
				     total_blocks - start,
				     total_blocks);
		hfs_brec_remove(&fd);
		total_blocks = start;
	} while (total_blocks > blocks);
	hfs_find_exit(&fd);

	return res;
}

int hfsplus_file_extend(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	u32 start, len, goal;
	int res;

	if (sbi->alloc_file->i_size * 8 <
	    sbi->total_blocks - sbi->free_blocks + 8) {
		/* extend alloc file */
		printk(KERN_ERR "hfs: extend alloc file! "
				"(%llu,%u,%u)\n",
			sbi->alloc_file->i_size * 8,
			sbi->total_blocks, sbi->free_blocks);
		return -ENOSPC;
	}

	mutex_lock(&hip->extents_lock);
	if (hip->alloc_blocks == hip->first_blocks)
		goal = hfsplus_ext_lastblock(hip->first_extents);
	else {
		res = hfsplus_ext_read_extent(inode, hip->alloc_blocks);
		if (res)
			goto out;
		goal = hfsplus_ext_lastblock(hip->cached_extents);
	}

	len = hip->clump_blocks;
	start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len);
	if (start >= sbi->total_blocks) {
		start = hfsplus_block_allocate(sb, goal, 0, &len);
		if (start >= goal) {
			res = -ENOSPC;
			goto out;
		}
	}

	dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);

	if (hip->alloc_blocks <= hip->first_blocks) {
		if (!hip->first_blocks) {
			dprint(DBG_EXTENT, "first extents\n");
			/* no extents yet */
			hip->first_extents[0].start_block = cpu_to_be32(start);
			hip->first_extents[0].block_count = cpu_to_be32(len);
			res = 0;
		} else {
			/* try to append to extents in inode */
			res = hfsplus_add_extent(hip->first_extents,
						 hip->alloc_blocks,
						 start, len);
			if (res == -ENOSPC)
				goto insert_extent;
		}
		if (!res) {
			hfsplus_dump_extent(hip->first_extents);
			hip->first_blocks += len;
		}
	} else {
		res = hfsplus_add_extent(hip->cached_extents,
					 hip->alloc_blocks - hip->cached_start,
					 start, len);
		if (!res) {
			hfsplus_dump_extent(hip->cached_extents);
			hip->extent_state |= HFSPLUS_EXT_DIRTY;
			hip->cached_blocks += len;
		} else if (res == -ENOSPC)
			goto insert_extent;
	}
out:
	mutex_unlock(&hip->extents_lock);
	if (!res) {
		hip->alloc_blocks += len;
		hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
	}
	return res;

insert_extent:
	dprint(DBG_EXTENT, "insert new extent\n");
	hfsplus_ext_write_extent_locked(inode);

	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));
	hip->cached_extents[0].start_block = cpu_to_be32(start);
	hip->cached_extents[0].block_count = cpu_to_be32(len);
	hfsplus_dump_extent(hip->cached_extents);
	hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW;
	hip->cached_start = hip->alloc_blocks;
	hip->cached_blocks = len;

	res = 0;
	goto out;
}

void hfsplus_file_truncate(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
	struct hfs_find_data fd;
	u32 alloc_cnt, blk_cnt, start;
	int res;

	dprint(DBG_INODE, "truncate: %lu, %llu -> %llu\n",
		inode->i_ino, (long long)hip->phys_size,
		inode->i_size);

	if (inode->i_size > hip->phys_size) {
		struct address_space *mapping = inode->i_mapping;
		struct page *page;
		void *fsdata;
		loff_t size = inode->i_size;
		int res;

		res = pagecache_write_begin(NULL, mapping, size, 0,
						AOP_FLAG_UNINTERRUPTIBLE,
						&page, &fsdata);
		if (res)
			return;
		res = pagecache_write_end(NULL, mapping, size,
			0, 0, page, fsdata);
		if (res < 0)
			return;
		mark_inode_dirty(inode);
		return;
	} else if (inode->i_size == hip->phys_size)
		return;

	blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >>
			HFSPLUS_SB(sb)->alloc_blksz_shift;
	alloc_cnt = hip->alloc_blocks;
	if (blk_cnt == alloc_cnt)
		goto out;

	mutex_lock(&hip->extents_lock);
	hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd);
	while (1) {
		if (alloc_cnt == hip->first_blocks) {
			hfsplus_free_extents(sb, hip->first_extents,
					     alloc_cnt, alloc_cnt - blk_cnt);
			hfsplus_dump_extent(hip->first_extents);
			hip->first_blocks = blk_cnt;
			break;
		}
		res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt);
		if (res)
			break;
		start = hip->cached_start;
		hfsplus_free_extents(sb, hip->cached_extents,
				     alloc_cnt - start, alloc_cnt - blk_cnt);
		hfsplus_dump_extent(hip->cached_extents);
		if (blk_cnt > start) {
			hip->extent_state |= HFSPLUS_EXT_DIRTY;
			break;
		}
		alloc_cnt = start;
		hip->cached_start = hip->cached_blocks = 0;
		hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW);
		hfs_brec_remove(&fd);
	}
	hfs_find_exit(&fd);
	mutex_unlock(&hip->extents_lock);

	hip->alloc_blocks = blk_cnt;
out:
	hip->phys_size = inode->i_size;
	hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
		sb->s_blocksize_bits;
	inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
	hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}