summaryrefslogtreecommitdiff
path: root/fs/bfs/inode.c
blob: db81570c963751c68a3b5c1fe6fdf978b1838148 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 *	fs/bfs/inode.c
 *	BFS superblock and inode operations.
 *	Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
 *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
 *	Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <linux/writeback.h>
#include <linux/uio.h>
#include <linux/uaccess.h>
#include "bfs.h"

MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
MODULE_LICENSE("GPL");

#undef DEBUG

#ifdef DEBUG
#define dprintf(x...)	printf(x)
#else
#define dprintf(x...)
#endif

struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
{
	struct bfs_inode *di;
	struct inode *inode;
	struct buffer_head *bh;
	int block, off;

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

	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
		goto error;
	}

	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
	bh = sb_bread(inode->i_sb, block);
	if (!bh) {
		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
									ino);
		goto error;
	}

	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
	di = (struct bfs_inode *)bh->b_data + off;

	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
		inode->i_mode |= S_IFDIR;
		inode->i_op = &bfs_dir_inops;
		inode->i_fop = &bfs_dir_operations;
	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
		inode->i_mode |= S_IFREG;
		inode->i_op = &bfs_file_inops;
		inode->i_fop = &bfs_file_operations;
		inode->i_mapping->a_ops = &bfs_aops;
	}

	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
	i_uid_write(inode, le32_to_cpu(di->i_uid));
	i_gid_write(inode,  le32_to_cpu(di->i_gid));
	set_nlink(inode, le32_to_cpu(di->i_nlink));
	inode->i_size = BFS_FILESIZE(di);
	inode->i_blocks = BFS_FILEBLOCKS(di);
	inode_set_atime(inode, le32_to_cpu(di->i_atime), 0);
	inode_set_mtime(inode, le32_to_cpu(di->i_mtime), 0);
	inode_set_ctime(inode, le32_to_cpu(di->i_ctime), 0);

	brelse(bh);
	unlock_new_inode(inode);
	return inode;

error:
	iget_failed(inode);
	return ERR_PTR(-EIO);
}

static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
{
	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
		return ERR_PTR(-EIO);
	}

	ino -= BFS_ROOT_INO;

	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
	if (!*p) {
		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
		return ERR_PTR(-EIO);
	}

	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
}

static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
	unsigned int ino = (u16)inode->i_ino;
	unsigned long i_sblock;
	struct bfs_inode *di;
	struct buffer_head *bh;
	int err = 0;

	dprintf("ino=%08x\n", ino);

	di = find_inode(inode->i_sb, ino, &bh);
	if (IS_ERR(di))
		return PTR_ERR(di);

	mutex_lock(&info->bfs_lock);

	if (ino == BFS_ROOT_INO)
		di->i_vtype = cpu_to_le32(BFS_VDIR);
	else
		di->i_vtype = cpu_to_le32(BFS_VREG);

	di->i_ino = cpu_to_le16(ino);
	di->i_mode = cpu_to_le32(inode->i_mode);
	di->i_uid = cpu_to_le32(i_uid_read(inode));
	di->i_gid = cpu_to_le32(i_gid_read(inode));
	di->i_nlink = cpu_to_le32(inode->i_nlink);
	di->i_atime = cpu_to_le32(inode_get_atime_sec(inode));
	di->i_mtime = cpu_to_le32(inode_get_mtime_sec(inode));
	di->i_ctime = cpu_to_le32(inode_get_ctime_sec(inode));
	i_sblock = BFS_I(inode)->i_sblock;
	di->i_sblock = cpu_to_le32(i_sblock);
	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);

	mark_buffer_dirty(bh);
	if (wbc->sync_mode == WB_SYNC_ALL) {
		sync_dirty_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
			err = -EIO;
	}
	brelse(bh);
	mutex_unlock(&info->bfs_lock);
	return err;
}

static void bfs_evict_inode(struct inode *inode)
{
	unsigned long ino = inode->i_ino;
	struct bfs_inode *di;
	struct buffer_head *bh;
	struct super_block *s = inode->i_sb;
	struct bfs_sb_info *info = BFS_SB(s);
	struct bfs_inode_info *bi = BFS_I(inode);

	dprintf("ino=%08lx\n", ino);

	truncate_inode_pages_final(&inode->i_data);
	invalidate_inode_buffers(inode);
	clear_inode(inode);

	if (inode->i_nlink)
		return;

	di = find_inode(s, inode->i_ino, &bh);
	if (IS_ERR(di))
		return;

	mutex_lock(&info->bfs_lock);
	/* clear on-disk inode */
	memset(di, 0, sizeof(struct bfs_inode));
	mark_buffer_dirty(bh);
	brelse(bh);

	if (bi->i_dsk_ino) {
		if (bi->i_sblock)
			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
		info->si_freei++;
		clear_bit(ino, info->si_imap);
		bfs_dump_imap("evict_inode", s);
	}

	/*
	 * If this was the last file, make the previous block
	 * "last block of the last file" even if there is no
	 * real file there, saves us 1 gap.
	 */
	if (info->si_lf_eblk == bi->i_eblock)
		info->si_lf_eblk = bi->i_sblock - 1;
	mutex_unlock(&info->bfs_lock);
}

static void bfs_put_super(struct super_block *s)
{
	struct bfs_sb_info *info = BFS_SB(s);

	if (!info)
		return;

	mutex_destroy(&info->bfs_lock);
	kfree(info);
	s->s_fs_info = NULL;
}

static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *s = dentry->d_sb;
	struct bfs_sb_info *info = BFS_SB(s);
	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
	buf->f_type = BFS_MAGIC;
	buf->f_bsize = s->s_blocksize;
	buf->f_blocks = info->si_blocks;
	buf->f_bfree = buf->f_bavail = info->si_freeb;
	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
	buf->f_ffree = info->si_freei;
	buf->f_fsid = u64_to_fsid(id);
	buf->f_namelen = BFS_NAMELEN;
	return 0;
}

static struct kmem_cache *bfs_inode_cachep;

static struct inode *bfs_alloc_inode(struct super_block *sb)
{
	struct bfs_inode_info *bi;
	bi = alloc_inode_sb(sb, bfs_inode_cachep, GFP_KERNEL);
	if (!bi)
		return NULL;
	return &bi->vfs_inode;
}

static void bfs_free_inode(struct inode *inode)
{
	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
}

static void init_once(void *foo)
{
	struct bfs_inode_info *bi = foo;

	inode_init_once(&bi->vfs_inode);
}

static int __init init_inodecache(void)
{
	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
					     sizeof(struct bfs_inode_info),
					     0, (SLAB_RECLAIM_ACCOUNT|
						SLAB_ACCOUNT),
					     init_once);
	if (bfs_inode_cachep == NULL)
		return -ENOMEM;
	return 0;
}

static void destroy_inodecache(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(bfs_inode_cachep);
}

static const struct super_operations bfs_sops = {
	.alloc_inode	= bfs_alloc_inode,
	.free_inode	= bfs_free_inode,
	.write_inode	= bfs_write_inode,
	.evict_inode	= bfs_evict_inode,
	.put_super	= bfs_put_super,
	.statfs		= bfs_statfs,
};

void bfs_dump_imap(const char *prefix, struct super_block *s)
{
#ifdef DEBUG
	int i;
	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);

	if (!tmpbuf)
		return;
	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
		if (i > PAGE_SIZE - 100) break;
		if (test_bit(i, BFS_SB(s)->si_imap))
			strcat(tmpbuf, "1");
		else
			strcat(tmpbuf, "0");
	}
	printf("%s: lasti=%08lx <%s>\n", prefix, BFS_SB(s)->si_lasti, tmpbuf);
	free_page((unsigned long)tmpbuf);
#endif
}

static int bfs_fill_super(struct super_block *s, void *data, int silent)
{
	struct buffer_head *bh, *sbh;
	struct bfs_super_block *bfs_sb;
	struct inode *inode;
	unsigned i;
	struct bfs_sb_info *info;
	int ret = -EINVAL;
	unsigned long i_sblock, i_eblock, i_eoff, s_size;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	mutex_init(&info->bfs_lock);
	s->s_fs_info = info;
	s->s_time_min = 0;
	s->s_time_max = U32_MAX;

	sb_set_blocksize(s, BFS_BSIZE);

	sbh = sb_bread(s, 0);
	if (!sbh)
		goto out;
	bfs_sb = (struct bfs_super_block *)sbh->b_data;
	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
		if (!silent)
			printf("No BFS filesystem on %s (magic=%08x)\n", s->s_id,  le32_to_cpu(bfs_sb->s_magic));
		goto out1;
	}
	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
		printf("%s is unclean, continuing\n", s->s_id);

	s->s_magic = BFS_MAGIC;

	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
	    le32_to_cpu(bfs_sb->s_start) < sizeof(struct bfs_super_block) + sizeof(struct bfs_dirent)) {
		printf("Superblock is corrupted on %s\n", s->s_id);
		goto out1;
	}

	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) / sizeof(struct bfs_inode) + BFS_ROOT_INO - 1;
	if (info->si_lasti == BFS_MAX_LASTI)
		printf("NOTE: filesystem %s was created with 512 inodes, the real maximum is 511, mounting anyway\n", s->s_id);
	else if (info->si_lasti > BFS_MAX_LASTI) {
		printf("Impossible last inode number %lu > %d on %s\n", info->si_lasti, BFS_MAX_LASTI, s->s_id);
		goto out1;
	}
	for (i = 0; i < BFS_ROOT_INO; i++)
		set_bit(i, info->si_imap);

	s->s_op = &bfs_sops;
	inode = bfs_iget(s, BFS_ROOT_INO);
	if (IS_ERR(inode)) {
		ret = PTR_ERR(inode);
		goto out1;
	}
	s->s_root = d_make_root(inode);
	if (!s->s_root) {
		ret = -ENOMEM;
		goto out1;
	}

	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
	info->si_freei = 0;
	info->si_lf_eblk = 0;

	/* can we read the last block? */
	bh = sb_bread(s, info->si_blocks - 1);
	if (!bh) {
		printf("Last block not available on %s: %lu\n", s->s_id, info->si_blocks - 1);
		ret = -EIO;
		goto out2;
	}
	brelse(bh);

	bh = NULL;
	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
		struct bfs_inode *di;
		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
		unsigned long eblock;

		if (!off) {
			brelse(bh);
			bh = sb_bread(s, block);
		}

		if (!bh)
			continue;

		di = (struct bfs_inode *)bh->b_data + off;

		/* test if filesystem is not corrupted */

		i_eoff = le32_to_cpu(di->i_eoffset);
		i_sblock = le32_to_cpu(di->i_sblock);
		i_eblock = le32_to_cpu(di->i_eblock);
		s_size = le32_to_cpu(bfs_sb->s_end);

		if (i_sblock > info->si_blocks ||
			i_eblock > info->si_blocks ||
			i_sblock > i_eblock ||
			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
			i_sblock * BFS_BSIZE > i_eoff) {

			printf("Inode 0x%08x corrupted on %s\n", i, s->s_id);

			brelse(bh);
			ret = -EIO;
			goto out2;
		}

		if (!di->i_ino) {
			info->si_freei++;
			continue;
		}
		set_bit(i, info->si_imap);
		info->si_freeb -= BFS_FILEBLOCKS(di);

		eblock =  le32_to_cpu(di->i_eblock);
		if (eblock > info->si_lf_eblk)
			info->si_lf_eblk = eblock;
	}
	brelse(bh);
	brelse(sbh);
	bfs_dump_imap("fill_super", s);
	return 0;

out2:
	dput(s->s_root);
	s->s_root = NULL;
out1:
	brelse(sbh);
out:
	mutex_destroy(&info->bfs_lock);
	kfree(info);
	s->s_fs_info = NULL;
	return ret;
}

static struct dentry *bfs_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
{
	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
}

static struct file_system_type bfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "bfs",
	.mount		= bfs_mount,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("bfs");

static int __init init_bfs_fs(void)
{
	int err = init_inodecache();
	if (err)
		goto out1;
	err = register_filesystem(&bfs_fs_type);
	if (err)
		goto out;
	return 0;
out:
	destroy_inodecache();
out1:
	return err;
}

static void __exit exit_bfs_fs(void)
{
	unregister_filesystem(&bfs_fs_type);
	destroy_inodecache();
}

module_init(init_bfs_fs)
module_exit(exit_bfs_fs)