xref: /openbmc/linux/fs/bfs/inode.c (revision 93d90ad7) 
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/buffer_head.h>
16 #include <linux/vfs.h>
17 #include <linux/writeback.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 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
34 {
35 	struct bfs_inode *di;
36 	struct inode *inode;
37 	struct buffer_head *bh;
38 	int block, off;
39 
40 	inode = iget_locked(sb, ino);
41 	if (!inode)
42 		return ERR_PTR(-ENOMEM);
43 	if (!(inode->i_state & I_NEW))
44 		return inode;
45 
46 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
47 		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
48 		goto error;
49 	}
50 
51 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
52 	bh = sb_bread(inode->i_sb, block);
53 	if (!bh) {
54 		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
55 									ino);
56 		goto error;
57 	}
58 
59 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
60 	di = (struct bfs_inode *)bh->b_data + off;
61 
62 	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
63 	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
64 		inode->i_mode |= S_IFDIR;
65 		inode->i_op = &bfs_dir_inops;
66 		inode->i_fop = &bfs_dir_operations;
67 	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
68 		inode->i_mode |= S_IFREG;
69 		inode->i_op = &bfs_file_inops;
70 		inode->i_fop = &bfs_file_operations;
71 		inode->i_mapping->a_ops = &bfs_aops;
72 	}
73 
74 	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
75 	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
76 	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
77 	i_uid_write(inode, le32_to_cpu(di->i_uid));
78 	i_gid_write(inode,  le32_to_cpu(di->i_gid));
79 	set_nlink(inode, le32_to_cpu(di->i_nlink));
80 	inode->i_size = BFS_FILESIZE(di);
81 	inode->i_blocks = BFS_FILEBLOCKS(di);
82 	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
83 	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
84 	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
85 	inode->i_atime.tv_nsec = 0;
86 	inode->i_mtime.tv_nsec = 0;
87 	inode->i_ctime.tv_nsec = 0;
88 
89 	brelse(bh);
90 	unlock_new_inode(inode);
91 	return inode;
92 
93 error:
94 	iget_failed(inode);
95 	return ERR_PTR(-EIO);
96 }
97 
98 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
99 {
100 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
101 		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
102 		return ERR_PTR(-EIO);
103 	}
104 
105 	ino -= BFS_ROOT_INO;
106 
107 	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
108 	if (!*p) {
109 		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
110 		return ERR_PTR(-EIO);
111 	}
112 
113 	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
114 }
115 
116 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
117 {
118 	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
119 	unsigned int ino = (u16)inode->i_ino;
120         unsigned long i_sblock;
121 	struct bfs_inode *di;
122 	struct buffer_head *bh;
123 	int err = 0;
124 
125         dprintf("ino=%08x\n", ino);
126 
127 	di = find_inode(inode->i_sb, ino, &bh);
128 	if (IS_ERR(di))
129 		return PTR_ERR(di);
130 
131 	mutex_lock(&info->bfs_lock);
132 
133 	if (ino == BFS_ROOT_INO)
134 		di->i_vtype = cpu_to_le32(BFS_VDIR);
135 	else
136 		di->i_vtype = cpu_to_le32(BFS_VREG);
137 
138 	di->i_ino = cpu_to_le16(ino);
139 	di->i_mode = cpu_to_le32(inode->i_mode);
140 	di->i_uid = cpu_to_le32(i_uid_read(inode));
141 	di->i_gid = cpu_to_le32(i_gid_read(inode));
142 	di->i_nlink = cpu_to_le32(inode->i_nlink);
143 	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
144 	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
145 	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
146         i_sblock = BFS_I(inode)->i_sblock;
147 	di->i_sblock = cpu_to_le32(i_sblock);
148 	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
149 	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
150 
151 	mark_buffer_dirty(bh);
152 	if (wbc->sync_mode == WB_SYNC_ALL) {
153 		sync_dirty_buffer(bh);
154 		if (buffer_req(bh) && !buffer_uptodate(bh))
155 			err = -EIO;
156 	}
157 	brelse(bh);
158 	mutex_unlock(&info->bfs_lock);
159 	return err;
160 }
161 
162 static void bfs_evict_inode(struct inode *inode)
163 {
164 	unsigned long ino = inode->i_ino;
165 	struct bfs_inode *di;
166 	struct buffer_head *bh;
167 	struct super_block *s = inode->i_sb;
168 	struct bfs_sb_info *info = BFS_SB(s);
169 	struct bfs_inode_info *bi = BFS_I(inode);
170 
171 	dprintf("ino=%08lx\n", ino);
172 
173 	truncate_inode_pages_final(&inode->i_data);
174 	invalidate_inode_buffers(inode);
175 	clear_inode(inode);
176 
177 	if (inode->i_nlink)
178 		return;
179 
180 	di = find_inode(s, inode->i_ino, &bh);
181 	if (IS_ERR(di))
182 		return;
183 
184 	mutex_lock(&info->bfs_lock);
185 	/* clear on-disk inode */
186 	memset(di, 0, sizeof(struct bfs_inode));
187 	mark_buffer_dirty(bh);
188 	brelse(bh);
189 
190         if (bi->i_dsk_ino) {
191 		if (bi->i_sblock)
192 			info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
193 		info->si_freei++;
194 		clear_bit(ino, info->si_imap);
195 		bfs_dump_imap("delete_inode", s);
196         }
197 
198 	/*
199 	 * If this was the last file, make the previous block
200 	 * "last block of the last file" even if there is no
201 	 * real file there, saves us 1 gap.
202 	 */
203 	if (info->si_lf_eblk == bi->i_eblock)
204 		info->si_lf_eblk = bi->i_sblock - 1;
205 	mutex_unlock(&info->bfs_lock);
206 }
207 
208 static void bfs_put_super(struct super_block *s)
209 {
210 	struct bfs_sb_info *info = BFS_SB(s);
211 
212 	if (!info)
213 		return;
214 
215 	mutex_destroy(&info->bfs_lock);
216 	kfree(info->si_imap);
217 	kfree(info);
218 	s->s_fs_info = NULL;
219 }
220 
221 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
222 {
223 	struct super_block *s = dentry->d_sb;
224 	struct bfs_sb_info *info = BFS_SB(s);
225 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
226 	buf->f_type = BFS_MAGIC;
227 	buf->f_bsize = s->s_blocksize;
228 	buf->f_blocks = info->si_blocks;
229 	buf->f_bfree = buf->f_bavail = info->si_freeb;
230 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
231 	buf->f_ffree = info->si_freei;
232 	buf->f_fsid.val[0] = (u32)id;
233 	buf->f_fsid.val[1] = (u32)(id >> 32);
234 	buf->f_namelen = BFS_NAMELEN;
235 	return 0;
236 }
237 
238 static struct kmem_cache *bfs_inode_cachep;
239 
240 static struct inode *bfs_alloc_inode(struct super_block *sb)
241 {
242 	struct bfs_inode_info *bi;
243 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
244 	if (!bi)
245 		return NULL;
246 	return &bi->vfs_inode;
247 }
248 
249 static void bfs_i_callback(struct rcu_head *head)
250 {
251 	struct inode *inode = container_of(head, struct inode, i_rcu);
252 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
253 }
254 
255 static void bfs_destroy_inode(struct inode *inode)
256 {
257 	call_rcu(&inode->i_rcu, bfs_i_callback);
258 }
259 
260 static void init_once(void *foo)
261 {
262 	struct bfs_inode_info *bi = foo;
263 
264 	inode_init_once(&bi->vfs_inode);
265 }
266 
267 static int __init init_inodecache(void)
268 {
269 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
270 					     sizeof(struct bfs_inode_info),
271 					     0, (SLAB_RECLAIM_ACCOUNT|
272 						SLAB_MEM_SPREAD),
273 					     init_once);
274 	if (bfs_inode_cachep == NULL)
275 		return -ENOMEM;
276 	return 0;
277 }
278 
279 static void destroy_inodecache(void)
280 {
281 	/*
282 	 * Make sure all delayed rcu free inodes are flushed before we
283 	 * destroy cache.
284 	 */
285 	rcu_barrier();
286 	kmem_cache_destroy(bfs_inode_cachep);
287 }
288 
289 static const struct super_operations bfs_sops = {
290 	.alloc_inode	= bfs_alloc_inode,
291 	.destroy_inode	= bfs_destroy_inode,
292 	.write_inode	= bfs_write_inode,
293 	.evict_inode	= bfs_evict_inode,
294 	.put_super	= bfs_put_super,
295 	.statfs		= bfs_statfs,
296 };
297 
298 void bfs_dump_imap(const char *prefix, struct super_block *s)
299 {
300 #ifdef DEBUG
301 	int i;
302 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
303 
304 	if (!tmpbuf)
305 		return;
306 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
307 		if (i > PAGE_SIZE - 100) break;
308 		if (test_bit(i, BFS_SB(s)->si_imap))
309 			strcat(tmpbuf, "1");
310 		else
311 			strcat(tmpbuf, "0");
312 	}
313 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
314 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
315 	free_page((unsigned long)tmpbuf);
316 #endif
317 }
318 
319 static int bfs_fill_super(struct super_block *s, void *data, int silent)
320 {
321 	struct buffer_head *bh, *sbh;
322 	struct bfs_super_block *bfs_sb;
323 	struct inode *inode;
324 	unsigned i, imap_len;
325 	struct bfs_sb_info *info;
326 	int ret = -EINVAL;
327 	unsigned long i_sblock, i_eblock, i_eoff, s_size;
328 
329 	info = kzalloc(sizeof(*info), GFP_KERNEL);
330 	if (!info)
331 		return -ENOMEM;
332 	mutex_init(&info->bfs_lock);
333 	s->s_fs_info = info;
334 
335 	sb_set_blocksize(s, BFS_BSIZE);
336 
337 	sbh = sb_bread(s, 0);
338 	if (!sbh)
339 		goto out;
340 	bfs_sb = (struct bfs_super_block *)sbh->b_data;
341 	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
342 		if (!silent)
343 			printf("No BFS filesystem on %s (magic=%08x)\n",
344 				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
345 		goto out1;
346 	}
347 	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
348 		printf("%s is unclean, continuing\n", s->s_id);
349 
350 	s->s_magic = BFS_MAGIC;
351 
352 	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
353 		printf("Superblock is corrupted\n");
354 		goto out1;
355 	}
356 
357 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
358 					sizeof(struct bfs_inode)
359 					+ BFS_ROOT_INO - 1;
360 	imap_len = (info->si_lasti / 8) + 1;
361 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
362 	if (!info->si_imap)
363 		goto out1;
364 	for (i = 0; i < BFS_ROOT_INO; i++)
365 		set_bit(i, info->si_imap);
366 
367 	s->s_op = &bfs_sops;
368 	inode = bfs_iget(s, BFS_ROOT_INO);
369 	if (IS_ERR(inode)) {
370 		ret = PTR_ERR(inode);
371 		goto out2;
372 	}
373 	s->s_root = d_make_root(inode);
374 	if (!s->s_root) {
375 		ret = -ENOMEM;
376 		goto out2;
377 	}
378 
379 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
380 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
381 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
382 	info->si_freei = 0;
383 	info->si_lf_eblk = 0;
384 
385 	/* can we read the last block? */
386 	bh = sb_bread(s, info->si_blocks - 1);
387 	if (!bh) {
388 		printf("Last block not available: %lu\n", info->si_blocks - 1);
389 		ret = -EIO;
390 		goto out3;
391 	}
392 	brelse(bh);
393 
394 	bh = NULL;
395 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
396 		struct bfs_inode *di;
397 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
398 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
399 		unsigned long eblock;
400 
401 		if (!off) {
402 			brelse(bh);
403 			bh = sb_bread(s, block);
404 		}
405 
406 		if (!bh)
407 			continue;
408 
409 		di = (struct bfs_inode *)bh->b_data + off;
410 
411 		/* test if filesystem is not corrupted */
412 
413 		i_eoff = le32_to_cpu(di->i_eoffset);
414 		i_sblock = le32_to_cpu(di->i_sblock);
415 		i_eblock = le32_to_cpu(di->i_eblock);
416 		s_size = le32_to_cpu(bfs_sb->s_end);
417 
418 		if (i_sblock > info->si_blocks ||
419 			i_eblock > info->si_blocks ||
420 			i_sblock > i_eblock ||
421 			i_eoff > s_size ||
422 			i_sblock * BFS_BSIZE > i_eoff) {
423 
424 			printf("Inode 0x%08x corrupted\n", i);
425 
426 			brelse(bh);
427 			ret = -EIO;
428 			goto out3;
429 		}
430 
431 		if (!di->i_ino) {
432 			info->si_freei++;
433 			continue;
434 		}
435 		set_bit(i, info->si_imap);
436 		info->si_freeb -= BFS_FILEBLOCKS(di);
437 
438 		eblock =  le32_to_cpu(di->i_eblock);
439 		if (eblock > info->si_lf_eblk)
440 			info->si_lf_eblk = eblock;
441 	}
442 	brelse(bh);
443 	brelse(sbh);
444 	bfs_dump_imap("read_super", s);
445 	return 0;
446 
447 out3:
448 	dput(s->s_root);
449 	s->s_root = NULL;
450 out2:
451 	kfree(info->si_imap);
452 out1:
453 	brelse(sbh);
454 out:
455 	mutex_destroy(&info->bfs_lock);
456 	kfree(info);
457 	s->s_fs_info = NULL;
458 	return ret;
459 }
460 
461 static struct dentry *bfs_mount(struct file_system_type *fs_type,
462 	int flags, const char *dev_name, void *data)
463 {
464 	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
465 }
466 
467 static struct file_system_type bfs_fs_type = {
468 	.owner		= THIS_MODULE,
469 	.name		= "bfs",
470 	.mount		= bfs_mount,
471 	.kill_sb	= kill_block_super,
472 	.fs_flags	= FS_REQUIRES_DEV,
473 };
474 MODULE_ALIAS_FS("bfs");
475 
476 static int __init init_bfs_fs(void)
477 {
478 	int err = init_inodecache();
479 	if (err)
480 		goto out1;
481         err = register_filesystem(&bfs_fs_type);
482 	if (err)
483 		goto out;
484 	return 0;
485 out:
486 	destroy_inodecache();
487 out1:
488 	return err;
489 }
490 
491 static void __exit exit_bfs_fs(void)
492 {
493 	unregister_filesystem(&bfs_fs_type);
494 	destroy_inodecache();
495 }
496 
497 module_init(init_bfs_fs)
498 module_exit(exit_bfs_fs)
499