xref: /openbmc/linux/fs/bfs/inode.c (revision b6dcefde)
1 /*
2  *	fs/bfs/inode.c
3  *	BFS superblock and inode operations.
4  *	Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5  *	From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
6  *
7  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/mm.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/fs.h>
15 #include <linux/smp_lock.h>
16 #include <linux/buffer_head.h>
17 #include <linux/vfs.h>
18 #include <asm/uaccess.h>
19 #include "bfs.h"
20 
21 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
22 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
23 MODULE_LICENSE("GPL");
24 
25 #undef DEBUG
26 
27 #ifdef DEBUG
28 #define dprintf(x...)	printf(x)
29 #else
30 #define dprintf(x...)
31 #endif
32 
33 static void bfs_write_super(struct super_block *s);
34 void dump_imap(const char *prefix, struct super_block *s);
35 
36 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
37 {
38 	struct bfs_inode *di;
39 	struct inode *inode;
40 	struct buffer_head *bh;
41 	int block, off;
42 
43 	inode = iget_locked(sb, ino);
44 	if (IS_ERR(inode))
45 		return ERR_PTR(-ENOMEM);
46 	if (!(inode->i_state & I_NEW))
47 		return inode;
48 
49 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
50 		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
51 		goto error;
52 	}
53 
54 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
55 	bh = sb_bread(inode->i_sb, block);
56 	if (!bh) {
57 		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
58 									ino);
59 		goto error;
60 	}
61 
62 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
63 	di = (struct bfs_inode *)bh->b_data + off;
64 
65 	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
66 	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
67 		inode->i_mode |= S_IFDIR;
68 		inode->i_op = &bfs_dir_inops;
69 		inode->i_fop = &bfs_dir_operations;
70 	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
71 		inode->i_mode |= S_IFREG;
72 		inode->i_op = &bfs_file_inops;
73 		inode->i_fop = &bfs_file_operations;
74 		inode->i_mapping->a_ops = &bfs_aops;
75 	}
76 
77 	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
78 	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
79 	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
80 	inode->i_uid =  le32_to_cpu(di->i_uid);
81 	inode->i_gid =  le32_to_cpu(di->i_gid);
82 	inode->i_nlink =  le32_to_cpu(di->i_nlink);
83 	inode->i_size = BFS_FILESIZE(di);
84 	inode->i_blocks = BFS_FILEBLOCKS(di);
85 	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
86 	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
87 	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
88 	inode->i_atime.tv_nsec = 0;
89 	inode->i_mtime.tv_nsec = 0;
90 	inode->i_ctime.tv_nsec = 0;
91 
92 	brelse(bh);
93 	unlock_new_inode(inode);
94 	return inode;
95 
96 error:
97 	iget_failed(inode);
98 	return ERR_PTR(-EIO);
99 }
100 
101 static int bfs_write_inode(struct inode *inode, int wait)
102 {
103 	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
104 	unsigned int ino = (u16)inode->i_ino;
105         unsigned long i_sblock;
106 	struct bfs_inode *di;
107 	struct buffer_head *bh;
108 	int block, off;
109 	int err = 0;
110 
111         dprintf("ino=%08x\n", ino);
112 
113 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
114 		printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
115 		return -EIO;
116 	}
117 
118 	mutex_lock(&info->bfs_lock);
119 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
120 	bh = sb_bread(inode->i_sb, block);
121 	if (!bh) {
122 		printf("Unable to read inode %s:%08x\n",
123 				inode->i_sb->s_id, ino);
124 		mutex_unlock(&info->bfs_lock);
125 		return -EIO;
126 	}
127 
128 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
129 	di = (struct bfs_inode *)bh->b_data + off;
130 
131 	if (ino == BFS_ROOT_INO)
132 		di->i_vtype = cpu_to_le32(BFS_VDIR);
133 	else
134 		di->i_vtype = cpu_to_le32(BFS_VREG);
135 
136 	di->i_ino = cpu_to_le16(ino);
137 	di->i_mode = cpu_to_le32(inode->i_mode);
138 	di->i_uid = cpu_to_le32(inode->i_uid);
139 	di->i_gid = cpu_to_le32(inode->i_gid);
140 	di->i_nlink = cpu_to_le32(inode->i_nlink);
141 	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
142 	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
143 	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
144         i_sblock = BFS_I(inode)->i_sblock;
145 	di->i_sblock = cpu_to_le32(i_sblock);
146 	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
147 	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
148 
149 	mark_buffer_dirty(bh);
150 	if (wait) {
151 		sync_dirty_buffer(bh);
152 		if (buffer_req(bh) && !buffer_uptodate(bh))
153 			err = -EIO;
154 	}
155 	brelse(bh);
156 	mutex_unlock(&info->bfs_lock);
157 	return err;
158 }
159 
160 static void bfs_delete_inode(struct inode *inode)
161 {
162 	unsigned long ino = inode->i_ino;
163 	struct bfs_inode *di;
164 	struct buffer_head *bh;
165 	int block, off;
166 	struct super_block *s = inode->i_sb;
167 	struct bfs_sb_info *info = BFS_SB(s);
168 	struct bfs_inode_info *bi = BFS_I(inode);
169 
170 	dprintf("ino=%08lx\n", ino);
171 
172 	truncate_inode_pages(&inode->i_data, 0);
173 
174 	if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
175 		printf("invalid ino=%08lx\n", ino);
176 		return;
177 	}
178 
179 	inode->i_size = 0;
180 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
181 	mutex_lock(&info->bfs_lock);
182 	mark_inode_dirty(inode);
183 
184 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
185 	bh = sb_bread(s, block);
186 	if (!bh) {
187 		printf("Unable to read inode %s:%08lx\n",
188 					inode->i_sb->s_id, ino);
189 		mutex_unlock(&info->bfs_lock);
190 		return;
191 	}
192 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
193 	di = (struct bfs_inode *)bh->b_data + off;
194 	memset((void *)di, 0, sizeof(struct bfs_inode));
195 	mark_buffer_dirty(bh);
196 	brelse(bh);
197 
198         if (bi->i_dsk_ino) {
199 		if (bi->i_sblock)
200 			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
201 		info->si_freei++;
202 		clear_bit(ino, info->si_imap);
203 		dump_imap("delete_inode", s);
204         }
205 
206 	/*
207 	 * If this was the last file, make the previous block
208 	 * "last block of the last file" even if there is no
209 	 * real file there, saves us 1 gap.
210 	 */
211 	if (info->si_lf_eblk == bi->i_eblock) {
212 		info->si_lf_eblk = bi->i_sblock - 1;
213 		mark_buffer_dirty(info->si_sbh);
214 	}
215 	mutex_unlock(&info->bfs_lock);
216 	clear_inode(inode);
217 }
218 
219 static int bfs_sync_fs(struct super_block *sb, int wait)
220 {
221 	struct bfs_sb_info *info = BFS_SB(sb);
222 
223 	mutex_lock(&info->bfs_lock);
224 	mark_buffer_dirty(info->si_sbh);
225 	sb->s_dirt = 0;
226 	mutex_unlock(&info->bfs_lock);
227 
228 	return 0;
229 }
230 
231 static void bfs_write_super(struct super_block *sb)
232 {
233 	if (!(sb->s_flags & MS_RDONLY))
234 		bfs_sync_fs(sb, 1);
235 	else
236 		sb->s_dirt = 0;
237 }
238 
239 static void bfs_put_super(struct super_block *s)
240 {
241 	struct bfs_sb_info *info = BFS_SB(s);
242 
243 	if (!info)
244 		return;
245 
246 	lock_kernel();
247 
248 	if (s->s_dirt)
249 		bfs_write_super(s);
250 
251 	brelse(info->si_sbh);
252 	mutex_destroy(&info->bfs_lock);
253 	kfree(info->si_imap);
254 	kfree(info);
255 	s->s_fs_info = NULL;
256 
257 	unlock_kernel();
258 }
259 
260 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
261 {
262 	struct super_block *s = dentry->d_sb;
263 	struct bfs_sb_info *info = BFS_SB(s);
264 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
265 	buf->f_type = BFS_MAGIC;
266 	buf->f_bsize = s->s_blocksize;
267 	buf->f_blocks = info->si_blocks;
268 	buf->f_bfree = buf->f_bavail = info->si_freeb;
269 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
270 	buf->f_ffree = info->si_freei;
271 	buf->f_fsid.val[0] = (u32)id;
272 	buf->f_fsid.val[1] = (u32)(id >> 32);
273 	buf->f_namelen = BFS_NAMELEN;
274 	return 0;
275 }
276 
277 static struct kmem_cache *bfs_inode_cachep;
278 
279 static struct inode *bfs_alloc_inode(struct super_block *sb)
280 {
281 	struct bfs_inode_info *bi;
282 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
283 	if (!bi)
284 		return NULL;
285 	return &bi->vfs_inode;
286 }
287 
288 static void bfs_destroy_inode(struct inode *inode)
289 {
290 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
291 }
292 
293 static void init_once(void *foo)
294 {
295 	struct bfs_inode_info *bi = foo;
296 
297 	inode_init_once(&bi->vfs_inode);
298 }
299 
300 static int init_inodecache(void)
301 {
302 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
303 					     sizeof(struct bfs_inode_info),
304 					     0, (SLAB_RECLAIM_ACCOUNT|
305 						SLAB_MEM_SPREAD),
306 					     init_once);
307 	if (bfs_inode_cachep == NULL)
308 		return -ENOMEM;
309 	return 0;
310 }
311 
312 static void destroy_inodecache(void)
313 {
314 	kmem_cache_destroy(bfs_inode_cachep);
315 }
316 
317 static const struct super_operations bfs_sops = {
318 	.alloc_inode	= bfs_alloc_inode,
319 	.destroy_inode	= bfs_destroy_inode,
320 	.write_inode	= bfs_write_inode,
321 	.delete_inode	= bfs_delete_inode,
322 	.put_super	= bfs_put_super,
323 	.write_super	= bfs_write_super,
324 	.sync_fs	= bfs_sync_fs,
325 	.statfs		= bfs_statfs,
326 };
327 
328 void dump_imap(const char *prefix, struct super_block *s)
329 {
330 #ifdef DEBUG
331 	int i;
332 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
333 
334 	if (!tmpbuf)
335 		return;
336 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
337 		if (i > PAGE_SIZE - 100) break;
338 		if (test_bit(i, BFS_SB(s)->si_imap))
339 			strcat(tmpbuf, "1");
340 		else
341 			strcat(tmpbuf, "0");
342 	}
343 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
344 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
345 	free_page((unsigned long)tmpbuf);
346 #endif
347 }
348 
349 static int bfs_fill_super(struct super_block *s, void *data, int silent)
350 {
351 	struct buffer_head *bh;
352 	struct bfs_super_block *bfs_sb;
353 	struct inode *inode;
354 	unsigned i, imap_len;
355 	struct bfs_sb_info *info;
356 	int ret = -EINVAL;
357 	unsigned long i_sblock, i_eblock, i_eoff, s_size;
358 
359 	info = kzalloc(sizeof(*info), GFP_KERNEL);
360 	if (!info)
361 		return -ENOMEM;
362 	mutex_init(&info->bfs_lock);
363 	s->s_fs_info = info;
364 
365 	sb_set_blocksize(s, BFS_BSIZE);
366 
367 	info->si_sbh = sb_bread(s, 0);
368 	if (!info->si_sbh)
369 		goto out;
370 	bfs_sb = (struct bfs_super_block *)info->si_sbh->b_data;
371 	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
372 		if (!silent)
373 			printf("No BFS filesystem on %s (magic=%08x)\n",
374 				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
375 		goto out1;
376 	}
377 	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
378 		printf("%s is unclean, continuing\n", s->s_id);
379 
380 	s->s_magic = BFS_MAGIC;
381 
382 	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
383 		printf("Superblock is corrupted\n");
384 		goto out1;
385 	}
386 
387 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
388 					sizeof(struct bfs_inode)
389 					+ BFS_ROOT_INO - 1;
390 	imap_len = (info->si_lasti / 8) + 1;
391 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
392 	if (!info->si_imap)
393 		goto out1;
394 	for (i = 0; i < BFS_ROOT_INO; i++)
395 		set_bit(i, info->si_imap);
396 
397 	s->s_op = &bfs_sops;
398 	inode = bfs_iget(s, BFS_ROOT_INO);
399 	if (IS_ERR(inode)) {
400 		ret = PTR_ERR(inode);
401 		goto out2;
402 	}
403 	s->s_root = d_alloc_root(inode);
404 	if (!s->s_root) {
405 		iput(inode);
406 		ret = -ENOMEM;
407 		goto out2;
408 	}
409 
410 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
411 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
412 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
413 	info->si_freei = 0;
414 	info->si_lf_eblk = 0;
415 
416 	/* can we read the last block? */
417 	bh = sb_bread(s, info->si_blocks - 1);
418 	if (!bh) {
419 		printf("Last block not available: %lu\n", info->si_blocks - 1);
420 		ret = -EIO;
421 		goto out3;
422 	}
423 	brelse(bh);
424 
425 	bh = NULL;
426 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
427 		struct bfs_inode *di;
428 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
429 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
430 		unsigned long eblock;
431 
432 		if (!off) {
433 			brelse(bh);
434 			bh = sb_bread(s, block);
435 		}
436 
437 		if (!bh)
438 			continue;
439 
440 		di = (struct bfs_inode *)bh->b_data + off;
441 
442 		/* test if filesystem is not corrupted */
443 
444 		i_eoff = le32_to_cpu(di->i_eoffset);
445 		i_sblock = le32_to_cpu(di->i_sblock);
446 		i_eblock = le32_to_cpu(di->i_eblock);
447 		s_size = le32_to_cpu(bfs_sb->s_end);
448 
449 		if (i_sblock > info->si_blocks ||
450 			i_eblock > info->si_blocks ||
451 			i_sblock > i_eblock ||
452 			i_eoff > s_size ||
453 			i_sblock * BFS_BSIZE > i_eoff) {
454 
455 			printf("Inode 0x%08x corrupted\n", i);
456 
457 			brelse(bh);
458 			ret = -EIO;
459 			goto out3;
460 		}
461 
462 		if (!di->i_ino) {
463 			info->si_freei++;
464 			continue;
465 		}
466 		set_bit(i, info->si_imap);
467 		info->si_freeb -= BFS_FILEBLOCKS(di);
468 
469 		eblock =  le32_to_cpu(di->i_eblock);
470 		if (eblock > info->si_lf_eblk)
471 			info->si_lf_eblk = eblock;
472 	}
473 	brelse(bh);
474 	if (!(s->s_flags & MS_RDONLY)) {
475 		mark_buffer_dirty(info->si_sbh);
476 		s->s_dirt = 1;
477 	}
478 	dump_imap("read_super", s);
479 	return 0;
480 
481 out3:
482 	dput(s->s_root);
483 	s->s_root = NULL;
484 out2:
485 	kfree(info->si_imap);
486 out1:
487 	brelse(info->si_sbh);
488 out:
489 	mutex_destroy(&info->bfs_lock);
490 	kfree(info);
491 	s->s_fs_info = NULL;
492 	return ret;
493 }
494 
495 static int bfs_get_sb(struct file_system_type *fs_type,
496 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
497 {
498 	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
499 }
500 
501 static struct file_system_type bfs_fs_type = {
502 	.owner		= THIS_MODULE,
503 	.name		= "bfs",
504 	.get_sb		= bfs_get_sb,
505 	.kill_sb	= kill_block_super,
506 	.fs_flags	= FS_REQUIRES_DEV,
507 };
508 
509 static int __init init_bfs_fs(void)
510 {
511 	int err = init_inodecache();
512 	if (err)
513 		goto out1;
514         err = register_filesystem(&bfs_fs_type);
515 	if (err)
516 		goto out;
517 	return 0;
518 out:
519 	destroy_inodecache();
520 out1:
521 	return err;
522 }
523 
524 static void __exit exit_bfs_fs(void)
525 {
526 	unregister_filesystem(&bfs_fs_type);
527 	destroy_inodecache();
528 }
529 
530 module_init(init_bfs_fs)
531 module_exit(exit_bfs_fs)
532