xref: /openbmc/linux/fs/bfs/inode.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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 void dump_imap(const char *prefix, struct super_block *s);
34 
35 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
36 {
37 	struct bfs_inode *di;
38 	struct inode *inode;
39 	struct buffer_head *bh;
40 	int block, off;
41 
42 	inode = iget_locked(sb, ino);
43 	if (IS_ERR(inode))
44 		return ERR_PTR(-ENOMEM);
45 	if (!(inode->i_state & I_NEW))
46 		return inode;
47 
48 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
49 		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
50 		goto error;
51 	}
52 
53 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
54 	bh = sb_bread(inode->i_sb, block);
55 	if (!bh) {
56 		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
57 									ino);
58 		goto error;
59 	}
60 
61 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
62 	di = (struct bfs_inode *)bh->b_data + off;
63 
64 	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
65 	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
66 		inode->i_mode |= S_IFDIR;
67 		inode->i_op = &bfs_dir_inops;
68 		inode->i_fop = &bfs_dir_operations;
69 	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
70 		inode->i_mode |= S_IFREG;
71 		inode->i_op = &bfs_file_inops;
72 		inode->i_fop = &bfs_file_operations;
73 		inode->i_mapping->a_ops = &bfs_aops;
74 	}
75 
76 	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
77 	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
78 	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
79 	inode->i_uid =  le32_to_cpu(di->i_uid);
80 	inode->i_gid =  le32_to_cpu(di->i_gid);
81 	inode->i_nlink =  le32_to_cpu(di->i_nlink);
82 	inode->i_size = BFS_FILESIZE(di);
83 	inode->i_blocks = BFS_FILEBLOCKS(di);
84 	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
85 	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
86 	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
87 	inode->i_atime.tv_nsec = 0;
88 	inode->i_mtime.tv_nsec = 0;
89 	inode->i_ctime.tv_nsec = 0;
90 
91 	brelse(bh);
92 	unlock_new_inode(inode);
93 	return inode;
94 
95 error:
96 	iget_failed(inode);
97 	return ERR_PTR(-EIO);
98 }
99 
100 static int bfs_write_inode(struct inode *inode, int unused)
101 {
102 	unsigned int ino = (u16)inode->i_ino;
103         unsigned long i_sblock;
104 	struct bfs_inode *di;
105 	struct buffer_head *bh;
106 	int block, off;
107 	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
108 
109         dprintf("ino=%08x\n", ino);
110 
111 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
112 		printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
113 		return -EIO;
114 	}
115 
116 	mutex_lock(&info->bfs_lock);
117 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
118 	bh = sb_bread(inode->i_sb, block);
119 	if (!bh) {
120 		printf("Unable to read inode %s:%08x\n",
121 				inode->i_sb->s_id, ino);
122 		mutex_unlock(&info->bfs_lock);
123 		return -EIO;
124 	}
125 
126 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
127 	di = (struct bfs_inode *)bh->b_data + off;
128 
129 	if (ino == BFS_ROOT_INO)
130 		di->i_vtype = cpu_to_le32(BFS_VDIR);
131 	else
132 		di->i_vtype = cpu_to_le32(BFS_VREG);
133 
134 	di->i_ino = cpu_to_le16(ino);
135 	di->i_mode = cpu_to_le32(inode->i_mode);
136 	di->i_uid = cpu_to_le32(inode->i_uid);
137 	di->i_gid = cpu_to_le32(inode->i_gid);
138 	di->i_nlink = cpu_to_le32(inode->i_nlink);
139 	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
140 	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
141 	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
142         i_sblock = BFS_I(inode)->i_sblock;
143 	di->i_sblock = cpu_to_le32(i_sblock);
144 	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
145 	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
146 
147 	mark_buffer_dirty(bh);
148 	brelse(bh);
149 	mutex_unlock(&info->bfs_lock);
150 	return 0;
151 }
152 
153 static void bfs_delete_inode(struct inode *inode)
154 {
155 	unsigned long ino = inode->i_ino;
156 	struct bfs_inode *di;
157 	struct buffer_head *bh;
158 	int block, off;
159 	struct super_block *s = inode->i_sb;
160 	struct bfs_sb_info *info = BFS_SB(s);
161 	struct bfs_inode_info *bi = BFS_I(inode);
162 
163 	dprintf("ino=%08lx\n", ino);
164 
165 	truncate_inode_pages(&inode->i_data, 0);
166 
167 	if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
168 		printf("invalid ino=%08lx\n", ino);
169 		return;
170 	}
171 
172 	inode->i_size = 0;
173 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
174 	mutex_lock(&info->bfs_lock);
175 	mark_inode_dirty(inode);
176 
177 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
178 	bh = sb_bread(s, block);
179 	if (!bh) {
180 		printf("Unable to read inode %s:%08lx\n",
181 					inode->i_sb->s_id, ino);
182 		mutex_unlock(&info->bfs_lock);
183 		return;
184 	}
185 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
186 	di = (struct bfs_inode *)bh->b_data + off;
187 	memset((void *)di, 0, sizeof(struct bfs_inode));
188 	mark_buffer_dirty(bh);
189 	brelse(bh);
190 
191         if (bi->i_dsk_ino) {
192 		if (bi->i_sblock)
193 			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
194 		info->si_freei++;
195 		clear_bit(ino, info->si_imap);
196 		dump_imap("delete_inode", s);
197         }
198 
199 	/*
200 	 * If this was the last file, make the previous block
201 	 * "last block of the last file" even if there is no
202 	 * real file there, saves us 1 gap.
203 	 */
204 	if (info->si_lf_eblk == bi->i_eblock) {
205 		info->si_lf_eblk = bi->i_sblock - 1;
206 		mark_buffer_dirty(info->si_sbh);
207 	}
208 	mutex_unlock(&info->bfs_lock);
209 	clear_inode(inode);
210 }
211 
212 static void bfs_put_super(struct super_block *s)
213 {
214 	struct bfs_sb_info *info = BFS_SB(s);
215 
216 	if (!info)
217 		return;
218 
219 	brelse(info->si_sbh);
220 	mutex_destroy(&info->bfs_lock);
221 	kfree(info->si_imap);
222 	kfree(info);
223 	s->s_fs_info = NULL;
224 }
225 
226 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
227 {
228 	struct super_block *s = dentry->d_sb;
229 	struct bfs_sb_info *info = BFS_SB(s);
230 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
231 	buf->f_type = BFS_MAGIC;
232 	buf->f_bsize = s->s_blocksize;
233 	buf->f_blocks = info->si_blocks;
234 	buf->f_bfree = buf->f_bavail = info->si_freeb;
235 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
236 	buf->f_ffree = info->si_freei;
237 	buf->f_fsid.val[0] = (u32)id;
238 	buf->f_fsid.val[1] = (u32)(id >> 32);
239 	buf->f_namelen = BFS_NAMELEN;
240 	return 0;
241 }
242 
243 static void bfs_write_super(struct super_block *s)
244 {
245 	struct bfs_sb_info *info = BFS_SB(s);
246 
247 	mutex_lock(&info->bfs_lock);
248 	if (!(s->s_flags & MS_RDONLY))
249 		mark_buffer_dirty(info->si_sbh);
250 	s->s_dirt = 0;
251 	mutex_unlock(&info->bfs_lock);
252 }
253 
254 static struct kmem_cache *bfs_inode_cachep;
255 
256 static struct inode *bfs_alloc_inode(struct super_block *sb)
257 {
258 	struct bfs_inode_info *bi;
259 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
260 	if (!bi)
261 		return NULL;
262 	return &bi->vfs_inode;
263 }
264 
265 static void bfs_destroy_inode(struct inode *inode)
266 {
267 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
268 }
269 
270 static void init_once(void *foo)
271 {
272 	struct bfs_inode_info *bi = foo;
273 
274 	inode_init_once(&bi->vfs_inode);
275 }
276 
277 static int init_inodecache(void)
278 {
279 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
280 					     sizeof(struct bfs_inode_info),
281 					     0, (SLAB_RECLAIM_ACCOUNT|
282 						SLAB_MEM_SPREAD),
283 					     init_once);
284 	if (bfs_inode_cachep == NULL)
285 		return -ENOMEM;
286 	return 0;
287 }
288 
289 static void destroy_inodecache(void)
290 {
291 	kmem_cache_destroy(bfs_inode_cachep);
292 }
293 
294 static const struct super_operations bfs_sops = {
295 	.alloc_inode	= bfs_alloc_inode,
296 	.destroy_inode	= bfs_destroy_inode,
297 	.write_inode	= bfs_write_inode,
298 	.delete_inode	= bfs_delete_inode,
299 	.put_super	= bfs_put_super,
300 	.write_super	= bfs_write_super,
301 	.statfs		= bfs_statfs,
302 };
303 
304 void dump_imap(const char *prefix, struct super_block *s)
305 {
306 #ifdef DEBUG
307 	int i;
308 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
309 
310 	if (!tmpbuf)
311 		return;
312 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
313 		if (i > PAGE_SIZE - 100) break;
314 		if (test_bit(i, BFS_SB(s)->si_imap))
315 			strcat(tmpbuf, "1");
316 		else
317 			strcat(tmpbuf, "0");
318 	}
319 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
320 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
321 	free_page((unsigned long)tmpbuf);
322 #endif
323 }
324 
325 static int bfs_fill_super(struct super_block *s, void *data, int silent)
326 {
327 	struct buffer_head *bh;
328 	struct bfs_super_block *bfs_sb;
329 	struct inode *inode;
330 	unsigned i, imap_len;
331 	struct bfs_sb_info *info;
332 	long ret = -EINVAL;
333 	unsigned long i_sblock, i_eblock, i_eoff, s_size;
334 
335 	info = kzalloc(sizeof(*info), GFP_KERNEL);
336 	if (!info)
337 		return -ENOMEM;
338 	s->s_fs_info = info;
339 
340 	sb_set_blocksize(s, BFS_BSIZE);
341 
342 	bh = sb_bread(s, 0);
343 	if(!bh)
344 		goto out;
345 	bfs_sb = (struct bfs_super_block *)bh->b_data;
346 	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
347 		if (!silent)
348 			printf("No BFS filesystem on %s (magic=%08x)\n",
349 				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
350 		goto out;
351 	}
352 	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
353 		printf("%s is unclean, continuing\n", s->s_id);
354 
355 	s->s_magic = BFS_MAGIC;
356 	info->si_sbh = bh;
357 
358 	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
359 		printf("Superblock is corrupted\n");
360 		goto out;
361 	}
362 
363 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
364 					sizeof(struct bfs_inode)
365 					+ BFS_ROOT_INO - 1;
366 	imap_len = (info->si_lasti / 8) + 1;
367 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
368 	if (!info->si_imap)
369 		goto out;
370 	for (i = 0; i < BFS_ROOT_INO; i++)
371 		set_bit(i, info->si_imap);
372 
373 	s->s_op = &bfs_sops;
374 	inode = bfs_iget(s, BFS_ROOT_INO);
375 	if (IS_ERR(inode)) {
376 		ret = PTR_ERR(inode);
377 		kfree(info->si_imap);
378 		goto out;
379 	}
380 	s->s_root = d_alloc_root(inode);
381 	if (!s->s_root) {
382 		iput(inode);
383 		ret = -ENOMEM;
384 		kfree(info->si_imap);
385 		goto out;
386 	}
387 
388 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
389 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
390 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
391 	info->si_freei = 0;
392 	info->si_lf_eblk = 0;
393 
394 	/* can we read the last block? */
395 	bh = sb_bread(s, info->si_blocks - 1);
396 	if (!bh) {
397 		printf("Last block not available: %lu\n", info->si_blocks - 1);
398 		iput(inode);
399 		ret = -EIO;
400 		kfree(info->si_imap);
401 		goto out;
402 	}
403 	brelse(bh);
404 
405 	bh = NULL;
406 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
407 		struct bfs_inode *di;
408 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
409 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
410 		unsigned long eblock;
411 
412 		if (!off) {
413 			brelse(bh);
414 			bh = sb_bread(s, block);
415 		}
416 
417 		if (!bh)
418 			continue;
419 
420 		di = (struct bfs_inode *)bh->b_data + off;
421 
422 		/* test if filesystem is not corrupted */
423 
424 		i_eoff = le32_to_cpu(di->i_eoffset);
425 		i_sblock = le32_to_cpu(di->i_sblock);
426 		i_eblock = le32_to_cpu(di->i_eblock);
427 		s_size = le32_to_cpu(bfs_sb->s_end);
428 
429 		if (i_sblock > info->si_blocks ||
430 			i_eblock > info->si_blocks ||
431 			i_sblock > i_eblock ||
432 			i_eoff > s_size ||
433 			i_sblock * BFS_BSIZE > i_eoff) {
434 
435 			printf("Inode 0x%08x corrupted\n", i);
436 
437 			brelse(bh);
438 			s->s_root = NULL;
439 			kfree(info->si_imap);
440 			kfree(info);
441 			s->s_fs_info = NULL;
442 			return -EIO;
443 		}
444 
445 		if (!di->i_ino) {
446 			info->si_freei++;
447 			continue;
448 		}
449 		set_bit(i, info->si_imap);
450 		info->si_freeb -= BFS_FILEBLOCKS(di);
451 
452 		eblock =  le32_to_cpu(di->i_eblock);
453 		if (eblock > info->si_lf_eblk)
454 			info->si_lf_eblk = eblock;
455 	}
456 	brelse(bh);
457 	if (!(s->s_flags & MS_RDONLY)) {
458 		mark_buffer_dirty(info->si_sbh);
459 		s->s_dirt = 1;
460 	}
461 	dump_imap("read_super", s);
462 	mutex_init(&info->bfs_lock);
463 	return 0;
464 
465 out:
466 	brelse(bh);
467 	kfree(info);
468 	s->s_fs_info = NULL;
469 	return ret;
470 }
471 
472 static int bfs_get_sb(struct file_system_type *fs_type,
473 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
474 {
475 	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
476 }
477 
478 static struct file_system_type bfs_fs_type = {
479 	.owner		= THIS_MODULE,
480 	.name		= "bfs",
481 	.get_sb		= bfs_get_sb,
482 	.kill_sb	= kill_block_super,
483 	.fs_flags	= FS_REQUIRES_DEV,
484 };
485 
486 static int __init init_bfs_fs(void)
487 {
488 	int err = init_inodecache();
489 	if (err)
490 		goto out1;
491         err = register_filesystem(&bfs_fs_type);
492 	if (err)
493 		goto out;
494 	return 0;
495 out:
496 	destroy_inodecache();
497 out1:
498 	return err;
499 }
500 
501 static void __exit exit_bfs_fs(void)
502 {
503 	unregister_filesystem(&bfs_fs_type);
504 	destroy_inodecache();
505 }
506 
507 module_init(init_bfs_fs)
508 module_exit(exit_bfs_fs)
509