summaryrefslogtreecommitdiff
path: root/fs/omfs/inode.c
blob: 14a22863291a6dedb60336d571c2d1b2dc069561 (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
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
/*
 * Optimized MPEG FS - inode and super operations.
 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
 * Released under GPL v2.
 */
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/vfs.h>
#include <linux/parser.h>
#include <linux/buffer_head.h>
#include <linux/vmalloc.h>
#include <linux/writeback.h>
#include <linux/crc-itu-t.h>
#include "omfs.h"

MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
MODULE_LICENSE("GPL");

struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
{
	struct omfs_sb_info *sbi = OMFS_SB(sb);
	if (block >= sbi->s_num_blocks)
		return NULL;

	return sb_bread(sb, clus_to_blk(sbi, block));
}

struct inode *omfs_new_inode(struct inode *dir, int mode)
{
	struct inode *inode;
	u64 new_block;
	int err;
	int len;
	struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);

	inode = new_inode(dir->i_sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

	err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
			&new_block, &len);
	if (err)
		goto fail;

	inode->i_ino = new_block;
	inode_init_owner(inode, NULL, mode);
	inode->i_mapping->a_ops = &omfs_aops;

	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	switch (mode & S_IFMT) {
	case S_IFDIR:
		inode->i_op = &omfs_dir_inops;
		inode->i_fop = &omfs_dir_operations;
		inode->i_size = sbi->s_sys_blocksize;
		inc_nlink(inode);
		break;
	case S_IFREG:
		inode->i_op = &omfs_file_inops;
		inode->i_fop = &omfs_file_operations;
		inode->i_size = 0;
		break;
	}

	insert_inode_hash(inode);
	mark_inode_dirty(inode);
	return inode;
fail:
	make_bad_inode(inode);
	iput(inode);
	return ERR_PTR(err);
}

/*
 * Update the header checksums for a dirty inode based on its contents.
 * Caller is expected to hold the buffer head underlying oi and mark it
 * dirty.
 */
static void omfs_update_checksums(struct omfs_inode *oi)
{
	int xor, i, ofs = 0, count;
	u16 crc = 0;
	unsigned char *ptr = (unsigned char *) oi;

	count = be32_to_cpu(oi->i_head.h_body_size);
	ofs = sizeof(struct omfs_header);

	crc = crc_itu_t(crc, ptr + ofs, count);
	oi->i_head.h_crc = cpu_to_be16(crc);

	xor = ptr[0];
	for (i = 1; i < OMFS_XOR_COUNT; i++)
		xor ^= ptr[i];

	oi->i_head.h_check_xor = xor;
}

static int __omfs_write_inode(struct inode *inode, int wait)
{
	struct omfs_inode *oi;
	struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
	struct buffer_head *bh, *bh2;
	u64 ctime;
	int i;
	int ret = -EIO;
	int sync_failed = 0;

	/* get current inode since we may have written sibling ptrs etc. */
	bh = omfs_bread(inode->i_sb, inode->i_ino);
	if (!bh)
		goto out;

	oi = (struct omfs_inode *) bh->b_data;

	oi->i_head.h_self = cpu_to_be64(inode->i_ino);
	if (S_ISDIR(inode->i_mode))
		oi->i_type = OMFS_DIR;
	else if (S_ISREG(inode->i_mode))
		oi->i_type = OMFS_FILE;
	else {
		printk(KERN_WARNING "omfs: unknown file type: %d\n",
			inode->i_mode);
		goto out_brelse;
	}

	oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
		sizeof(struct omfs_header));
	oi->i_head.h_version = 1;
	oi->i_head.h_type = OMFS_INODE_NORMAL;
	oi->i_head.h_magic = OMFS_IMAGIC;
	oi->i_size = cpu_to_be64(inode->i_size);

	ctime = inode->i_ctime.tv_sec * 1000LL +
		((inode->i_ctime.tv_nsec + 999)/1000);
	oi->i_ctime = cpu_to_be64(ctime);

	omfs_update_checksums(oi);

	mark_buffer_dirty(bh);
	if (wait) {
		sync_dirty_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
			sync_failed = 1;
	}

	/* if mirroring writes, copy to next fsblock */
	for (i = 1; i < sbi->s_mirrors; i++) {
		bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
		if (!bh2)
			goto out_brelse;

		memcpy(bh2->b_data, bh->b_data, bh->b_size);
		mark_buffer_dirty(bh2);
		if (wait) {
			sync_dirty_buffer(bh2);
			if (buffer_req(bh2) && !buffer_uptodate(bh2))
				sync_failed = 1;
		}
		brelse(bh2);
	}
	ret = (sync_failed) ? -EIO : 0;
out_brelse:
	brelse(bh);
out:
	return ret;
}

static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
}

int omfs_sync_inode(struct inode *inode)
{
	return __omfs_write_inode(inode, 1);
}

/*
 * called when an entry is deleted, need to clear the bits in the
 * bitmaps.
 */
static void omfs_evict_inode(struct inode *inode)
{
	truncate_inode_pages(&inode->i_data, 0);
	end_writeback(inode);

	if (inode->i_nlink)
		return;

	if (S_ISREG(inode->i_mode)) {
		inode->i_size = 0;
		omfs_shrink_inode(inode);
	}

	omfs_clear_range(inode->i_sb, inode->i_ino, 2);
}

struct inode *omfs_iget(struct super_block *sb, ino_t ino)
{
	struct omfs_sb_info *sbi = OMFS_SB(sb);
	struct omfs_inode *oi;
	struct buffer_head *bh;
	u64 ctime;
	unsigned long nsecs;
	struct inode *inode;

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	bh = omfs_bread(inode->i_sb, ino);
	if (!bh)
		goto iget_failed;

	oi = (struct omfs_inode *)bh->b_data;

	/* check self */
	if (ino != be64_to_cpu(oi->i_head.h_self))
		goto fail_bh;

	inode->i_uid = sbi->s_uid;
	inode->i_gid = sbi->s_gid;

	ctime = be64_to_cpu(oi->i_ctime);
	nsecs = do_div(ctime, 1000) * 1000L;

	inode->i_atime.tv_sec = ctime;
	inode->i_mtime.tv_sec = ctime;
	inode->i_ctime.tv_sec = ctime;
	inode->i_atime.tv_nsec = nsecs;
	inode->i_mtime.tv_nsec = nsecs;
	inode->i_ctime.tv_nsec = nsecs;

	inode->i_mapping->a_ops = &omfs_aops;

	switch (oi->i_type) {
	case OMFS_DIR:
		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
		inode->i_op = &omfs_dir_inops;
		inode->i_fop = &omfs_dir_operations;
		inode->i_size = sbi->s_sys_blocksize;
		inc_nlink(inode);
		break;
	case OMFS_FILE:
		inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
		inode->i_fop = &omfs_file_operations;
		inode->i_size = be64_to_cpu(oi->i_size);
		break;
	}
	brelse(bh);
	unlock_new_inode(inode);
	return inode;
fail_bh:
	brelse(bh);
iget_failed:
	iget_failed(inode);
	return ERR_PTR(-EIO);
}

static void omfs_put_super(struct super_block *sb)
{
	struct omfs_sb_info *sbi = OMFS_SB(sb);
	kfree(sbi->s_imap);
	kfree(sbi);
	sb->s_fs_info = NULL;
}

static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *s = dentry->d_sb;
	struct omfs_sb_info *sbi = OMFS_SB(s);
	u64 id = huge_encode_dev(s->s_bdev->bd_dev);

	buf->f_type = OMFS_MAGIC;
	buf->f_bsize = sbi->s_blocksize;
	buf->f_blocks = sbi->s_num_blocks;
	buf->f_files = sbi->s_num_blocks;
	buf->f_namelen = OMFS_NAMELEN;
	buf->f_fsid.val[0] = (u32)id;
	buf->f_fsid.val[1] = (u32)(id >> 32);

	buf->f_bfree = buf->f_bavail = buf->f_ffree =
		omfs_count_free(s);

	return 0;
}

static const struct super_operations omfs_sops = {
	.write_inode	= omfs_write_inode,
	.evict_inode	= omfs_evict_inode,
	.put_super	= omfs_put_super,
	.statfs		= omfs_statfs,
	.show_options	= generic_show_options,
};

/*
 * For Rio Karma, there is an on-disk free bitmap whose location is
 * stored in the root block.  For ReplayTV, there is no such free bitmap
 * so we have to walk the tree.  Both inodes and file data are allocated
 * from the same map.  This array can be big (300k) so we allocate
 * in units of the blocksize.
 */
static int omfs_get_imap(struct super_block *sb)
{
	int bitmap_size;
	int array_size;
	int count;
	struct omfs_sb_info *sbi = OMFS_SB(sb);
	struct buffer_head *bh;
	unsigned long **ptr;
	sector_t block;

	bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
	array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);

	if (sbi->s_bitmap_ino == ~0ULL)
		goto out;

	sbi->s_imap_size = array_size;
	sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
	if (!sbi->s_imap)
		goto nomem;

	block = clus_to_blk(sbi, sbi->s_bitmap_ino);
	if (block >= sbi->s_num_blocks)
		goto nomem;

	ptr = sbi->s_imap;
	for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
		bh = sb_bread(sb, block++);
		if (!bh)
			goto nomem_free;
		*ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
		if (!*ptr) {
			brelse(bh);
			goto nomem_free;
		}
		memcpy(*ptr, bh->b_data, sb->s_blocksize);
		if (count < sb->s_blocksize)
			memset((void *)*ptr + count, 0xff,
				sb->s_blocksize - count);
		brelse(bh);
		ptr++;
	}
out:
	return 0;

nomem_free:
	for (count = 0; count < array_size; count++)
		kfree(sbi->s_imap[count]);

	kfree(sbi->s_imap);
nomem:
	sbi->s_imap = NULL;
	sbi->s_imap_size = 0;
	return -ENOMEM;
}

enum {
	Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
};

static const match_table_t tokens = {
	{Opt_uid, "uid=%u"},
	{Opt_gid, "gid=%u"},
	{Opt_umask, "umask=%o"},
	{Opt_dmask, "dmask=%o"},
	{Opt_fmask, "fmask=%o"},
};

static int parse_options(char *options, struct omfs_sb_info *sbi)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;

	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_uid:
			if (match_int(&args[0], &option))
				return 0;
			sbi->s_uid = option;
			break;
		case Opt_gid:
			if (match_int(&args[0], &option))
				return 0;
			sbi->s_gid = option;
			break;
		case Opt_umask:
			if (match_octal(&args[0], &option))
				return 0;
			sbi->s_fmask = sbi->s_dmask = option;
			break;
		case Opt_dmask:
			if (match_octal(&args[0], &option))
				return 0;
			sbi->s_dmask = option;
			break;
		case Opt_fmask:
			if (match_octal(&args[0], &option))
				return 0;
			sbi->s_fmask = option;
			break;
		default:
			return 0;
		}
	}
	return 1;
}

static int omfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct buffer_head *bh, *bh2;
	struct omfs_super_block *omfs_sb;
	struct omfs_root_block *omfs_rb;
	struct omfs_sb_info *sbi;
	struct inode *root;
	int ret = -EINVAL;

	save_mount_options(sb, (char *) data);

	sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;

	sb->s_fs_info = sbi;

	sbi->s_uid = current_uid();
	sbi->s_gid = current_gid();
	sbi->s_dmask = sbi->s_fmask = current_umask();

	if (!parse_options((char *) data, sbi))
		goto end;

	sb->s_maxbytes = 0xffffffff;

	sb_set_blocksize(sb, 0x200);

	bh = sb_bread(sb, 0);
	if (!bh)
		goto end;

	omfs_sb = (struct omfs_super_block *)bh->b_data;

	if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
		if (!silent)
			printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
				   omfs_sb->s_magic);
		goto out_brelse_bh;
	}
	sb->s_magic = OMFS_MAGIC;

	sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
	sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
	sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
	sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
	sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
	mutex_init(&sbi->s_bitmap_lock);

	if (sbi->s_sys_blocksize > PAGE_SIZE) {
		printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
			sbi->s_sys_blocksize);
		goto out_brelse_bh;
	}

	if (sbi->s_blocksize < sbi->s_sys_blocksize ||
	    sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
		printk(KERN_ERR "omfs: block size (%d) is out of range\n",
			sbi->s_blocksize);
		goto out_brelse_bh;
	}

	/*
	 * Use sys_blocksize as the fs block since it is smaller than a
	 * page while the fs blocksize can be larger.
	 */
	sb_set_blocksize(sb, sbi->s_sys_blocksize);

	/*
	 * ...and the difference goes into a shift.  sys_blocksize is always
	 * a power of two factor of blocksize.
	 */
	sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
		get_bitmask_order(sbi->s_sys_blocksize);

	bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
	if (!bh2)
		goto out_brelse_bh;

	omfs_rb = (struct omfs_root_block *)bh2->b_data;

	sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
	sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);

	if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
		printk(KERN_ERR "omfs: block count discrepancy between "
			"super and root blocks (%llx, %llx)\n",
			(unsigned long long)sbi->s_num_blocks,
			(unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
		goto out_brelse_bh2;
	}

	if (sbi->s_bitmap_ino != ~0ULL &&
	    sbi->s_bitmap_ino > sbi->s_num_blocks) {
		printk(KERN_ERR "omfs: free space bitmap location is corrupt "
			"(%llx, total blocks %llx)\n",
			(unsigned long long) sbi->s_bitmap_ino,
			(unsigned long long) sbi->s_num_blocks);
		goto out_brelse_bh2;
	}
	if (sbi->s_clustersize < 1 ||
	    sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
		printk(KERN_ERR "omfs: cluster size out of range (%d)",
			sbi->s_clustersize);
		goto out_brelse_bh2;
	}

	ret = omfs_get_imap(sb);
	if (ret)
		goto out_brelse_bh2;

	sb->s_op = &omfs_sops;

	root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
		goto out_brelse_bh2;
	}

	sb->s_root = d_alloc_root(root);
	if (!sb->s_root) {
		iput(root);
		goto out_brelse_bh2;
	}
	printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);

	ret = 0;
out_brelse_bh2:
	brelse(bh2);
out_brelse_bh:
	brelse(bh);
end:
	if (ret)
		kfree(sbi);
	return ret;
}

static int omfs_get_sb(struct file_system_type *fs_type,
			int flags, const char *dev_name,
			void *data, struct vfsmount *m)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, omfs_fill_super, m);
}

static struct file_system_type omfs_fs_type = {
	.owner = THIS_MODULE,
	.name = "omfs",
	.get_sb = omfs_get_sb,
	.kill_sb = kill_block_super,
	.fs_flags = FS_REQUIRES_DEV,
};

static int __init init_omfs_fs(void)
{
	return register_filesystem(&omfs_fs_type);
}

static void __exit exit_omfs_fs(void)
{
	unregister_filesystem(&omfs_fs_type);
}

module_init(init_omfs_fs);
module_exit(exit_omfs_fs);