xref: /openbmc/linux/fs/bfs/inode.c (revision 6b5fc336) 
1 /*
2  *	fs/bfs/inode.c
3  *	BFS superblock and inode operations.
4  *	Copyright (C) 1999-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
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 <linux/uio.h>
19 #include <linux/uaccess.h>
20 #include "bfs.h"
21 
22 MODULE_AUTHOR("Tigran Aivazian <aivazian.tigran@gmail.com>");
23 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
24 MODULE_LICENSE("GPL");
25 
26 #undef DEBUG
27 
28 #ifdef DEBUG
29 #define dprintf(x...)	printf(x)
30 #else
31 #define dprintf(x...)
32 #endif
33 
34 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
35 {
36 	struct bfs_inode *di;
37 	struct inode *inode;
38 	struct buffer_head *bh;
39 	int block, off;
40 
41 	inode = iget_locked(sb, ino);
42 	if (!inode)
43 		return ERR_PTR(-ENOMEM);
44 	if (!(inode->i_state & I_NEW))
45 		return inode;
46 
47 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
48 		printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
49 		goto error;
50 	}
51 
52 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
53 	bh = sb_bread(inode->i_sb, block);
54 	if (!bh) {
55 		printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
56 									ino);
57 		goto error;
58 	}
59 
60 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
61 	di = (struct bfs_inode *)bh->b_data + off;
62 
63 	inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
64 	if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
65 		inode->i_mode |= S_IFDIR;
66 		inode->i_op = &bfs_dir_inops;
67 		inode->i_fop = &bfs_dir_operations;
68 	} else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
69 		inode->i_mode |= S_IFREG;
70 		inode->i_op = &bfs_file_inops;
71 		inode->i_fop = &bfs_file_operations;
72 		inode->i_mapping->a_ops = &bfs_aops;
73 	}
74 
75 	BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
76 	BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
77 	BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
78 	i_uid_write(inode, le32_to_cpu(di->i_uid));
79 	i_gid_write(inode,  le32_to_cpu(di->i_gid));
80 	set_nlink(inode, le32_to_cpu(di->i_nlink));
81 	inode->i_size = BFS_FILESIZE(di);
82 	inode->i_blocks = BFS_FILEBLOCKS(di);
83 	inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
84 	inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
85 	inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
86 	inode->i_atime.tv_nsec = 0;
87 	inode->i_mtime.tv_nsec = 0;
88 	inode->i_ctime.tv_nsec = 0;
89 
90 	brelse(bh);
91 	unlock_new_inode(inode);
92 	return inode;
93 
94 error:
95 	iget_failed(inode);
96 	return ERR_PTR(-EIO);
97 }
98 
99 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
100 {
101 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
102 		printf("Bad inode number %s:%08x\n", sb->s_id, ino);
103 		return ERR_PTR(-EIO);
104 	}
105 
106 	ino -= BFS_ROOT_INO;
107 
108 	*p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
109 	if (!*p) {
110 		printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
111 		return ERR_PTR(-EIO);
112 	}
113 
114 	return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
115 }
116 
117 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
118 {
119 	struct bfs_sb_info *info = BFS_SB(inode->i_sb);
120 	unsigned int ino = (u16)inode->i_ino;
121         unsigned long i_sblock;
122 	struct bfs_inode *di;
123 	struct buffer_head *bh;
124 	int err = 0;
125 
126         dprintf("ino=%08x\n", ino);
127 
128 	di = find_inode(inode->i_sb, ino, &bh);
129 	if (IS_ERR(di))
130 		return PTR_ERR(di);
131 
132 	mutex_lock(&info->bfs_lock);
133 
134 	if (ino == BFS_ROOT_INO)
135 		di->i_vtype = cpu_to_le32(BFS_VDIR);
136 	else
137 		di->i_vtype = cpu_to_le32(BFS_VREG);
138 
139 	di->i_ino = cpu_to_le16(ino);
140 	di->i_mode = cpu_to_le32(inode->i_mode);
141 	di->i_uid = cpu_to_le32(i_uid_read(inode));
142 	di->i_gid = cpu_to_le32(i_gid_read(inode));
143 	di->i_nlink = cpu_to_le32(inode->i_nlink);
144 	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
145 	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
146 	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
147         i_sblock = BFS_I(inode)->i_sblock;
148 	di->i_sblock = cpu_to_le32(i_sblock);
149 	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
150 	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
151 
152 	mark_buffer_dirty(bh);
153 	if (wbc->sync_mode == WB_SYNC_ALL) {
154 		sync_dirty_buffer(bh);
155 		if (buffer_req(bh) && !buffer_uptodate(bh))
156 			err = -EIO;
157 	}
158 	brelse(bh);
159 	mutex_unlock(&info->bfs_lock);
160 	return err;
161 }
162 
163 static void bfs_evict_inode(struct inode *inode)
164 {
165 	unsigned long ino = inode->i_ino;
166 	struct bfs_inode *di;
167 	struct buffer_head *bh;
168 	struct super_block *s = inode->i_sb;
169 	struct bfs_sb_info *info = BFS_SB(s);
170 	struct bfs_inode_info *bi = BFS_I(inode);
171 
172 	dprintf("ino=%08lx\n", ino);
173 
174 	truncate_inode_pages_final(&inode->i_data);
175 	invalidate_inode_buffers(inode);
176 	clear_inode(inode);
177 
178 	if (inode->i_nlink)
179 		return;
180 
181 	di = find_inode(s, inode->i_ino, &bh);
182 	if (IS_ERR(di))
183 		return;
184 
185 	mutex_lock(&info->bfs_lock);
186 	/* clear on-disk inode */
187 	memset(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 		bfs_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 	mutex_unlock(&info->bfs_lock);
207 }
208 
209 static void bfs_put_super(struct super_block *s)
210 {
211 	struct bfs_sb_info *info = BFS_SB(s);
212 
213 	if (!info)
214 		return;
215 
216 	mutex_destroy(&info->bfs_lock);
217 	kfree(info->si_imap);
218 	kfree(info);
219 	s->s_fs_info = NULL;
220 }
221 
222 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
223 {
224 	struct super_block *s = dentry->d_sb;
225 	struct bfs_sb_info *info = BFS_SB(s);
226 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
227 	buf->f_type = BFS_MAGIC;
228 	buf->f_bsize = s->s_blocksize;
229 	buf->f_blocks = info->si_blocks;
230 	buf->f_bfree = buf->f_bavail = info->si_freeb;
231 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
232 	buf->f_ffree = info->si_freei;
233 	buf->f_fsid.val[0] = (u32)id;
234 	buf->f_fsid.val[1] = (u32)(id >> 32);
235 	buf->f_namelen = BFS_NAMELEN;
236 	return 0;
237 }
238 
239 static struct kmem_cache *bfs_inode_cachep;
240 
241 static struct inode *bfs_alloc_inode(struct super_block *sb)
242 {
243 	struct bfs_inode_info *bi;
244 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
245 	if (!bi)
246 		return NULL;
247 	return &bi->vfs_inode;
248 }
249 
250 static void bfs_i_callback(struct rcu_head *head)
251 {
252 	struct inode *inode = container_of(head, struct inode, i_rcu);
253 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
254 }
255 
256 static void bfs_destroy_inode(struct inode *inode)
257 {
258 	call_rcu(&inode->i_rcu, bfs_i_callback);
259 }
260 
261 static void init_once(void *foo)
262 {
263 	struct bfs_inode_info *bi = foo;
264 
265 	inode_init_once(&bi->vfs_inode);
266 }
267 
268 static int __init init_inodecache(void)
269 {
270 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
271 					     sizeof(struct bfs_inode_info),
272 					     0, (SLAB_RECLAIM_ACCOUNT|
273 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
274 					     init_once);
275 	if (bfs_inode_cachep == NULL)
276 		return -ENOMEM;
277 	return 0;
278 }
279 
280 static void destroy_inodecache(void)
281 {
282 	/*
283 	 * Make sure all delayed rcu free inodes are flushed before we
284 	 * destroy cache.
285 	 */
286 	rcu_barrier();
287 	kmem_cache_destroy(bfs_inode_cachep);
288 }
289 
290 static const struct super_operations bfs_sops = {
291 	.alloc_inode	= bfs_alloc_inode,
292 	.destroy_inode	= bfs_destroy_inode,
293 	.write_inode	= bfs_write_inode,
294 	.evict_inode	= bfs_evict_inode,
295 	.put_super	= bfs_put_super,
296 	.statfs		= bfs_statfs,
297 };
298 
299 void bfs_dump_imap(const char *prefix, struct super_block *s)
300 {
301 #ifdef DEBUG
302 	int i;
303 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
304 
305 	if (!tmpbuf)
306 		return;
307 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
308 		if (i > PAGE_SIZE - 100) break;
309 		if (test_bit(i, BFS_SB(s)->si_imap))
310 			strcat(tmpbuf, "1");
311 		else
312 			strcat(tmpbuf, "0");
313 	}
314 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
315 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
316 	free_page((unsigned long)tmpbuf);
317 #endif
318 }
319 
320 static int bfs_fill_super(struct super_block *s, void *data, int silent)
321 {
322 	struct buffer_head *bh, *sbh;
323 	struct bfs_super_block *bfs_sb;
324 	struct inode *inode;
325 	unsigned i, imap_len;
326 	struct bfs_sb_info *info;
327 	int ret = -EINVAL;
328 	unsigned long i_sblock, i_eblock, i_eoff, s_size;
329 
330 	info = kzalloc(sizeof(*info), GFP_KERNEL);
331 	if (!info)
332 		return -ENOMEM;
333 	mutex_init(&info->bfs_lock);
334 	s->s_fs_info = info;
335 
336 	sb_set_blocksize(s, BFS_BSIZE);
337 
338 	sbh = sb_bread(s, 0);
339 	if (!sbh)
340 		goto out;
341 	bfs_sb = (struct bfs_super_block *)sbh->b_data;
342 	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
343 		if (!silent)
344 			printf("No BFS filesystem on %s (magic=%08x)\n",
345 				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
346 		goto out1;
347 	}
348 	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
349 		printf("%s is unclean, continuing\n", s->s_id);
350 
351 	s->s_magic = BFS_MAGIC;
352 
353 	if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
354 		printf("Superblock is corrupted\n");
355 		goto out1;
356 	}
357 
358 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
359 					sizeof(struct bfs_inode)
360 					+ BFS_ROOT_INO - 1;
361 	imap_len = (info->si_lasti / 8) + 1;
362 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
363 	if (!info->si_imap)
364 		goto out1;
365 	for (i = 0; i < BFS_ROOT_INO; i++)
366 		set_bit(i, info->si_imap);
367 
368 	s->s_op = &bfs_sops;
369 	inode = bfs_iget(s, BFS_ROOT_INO);
370 	if (IS_ERR(inode)) {
371 		ret = PTR_ERR(inode);
372 		goto out2;
373 	}
374 	s->s_root = d_make_root(inode);
375 	if (!s->s_root) {
376 		ret = -ENOMEM;
377 		goto out2;
378 	}
379 
380 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
381 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
382 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
383 	info->si_freei = 0;
384 	info->si_lf_eblk = 0;
385 
386 	/* can we read the last block? */
387 	bh = sb_bread(s, info->si_blocks - 1);
388 	if (!bh) {
389 		printf("Last block not available: %lu\n", info->si_blocks - 1);
390 		ret = -EIO;
391 		goto out3;
392 	}
393 	brelse(bh);
394 
395 	bh = NULL;
396 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
397 		struct bfs_inode *di;
398 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
399 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
400 		unsigned long eblock;
401 
402 		if (!off) {
403 			brelse(bh);
404 			bh = sb_bread(s, block);
405 		}
406 
407 		if (!bh)
408 			continue;
409 
410 		di = (struct bfs_inode *)bh->b_data + off;
411 
412 		/* test if filesystem is not corrupted */
413 
414 		i_eoff = le32_to_cpu(di->i_eoffset);
415 		i_sblock = le32_to_cpu(di->i_sblock);
416 		i_eblock = le32_to_cpu(di->i_eblock);
417 		s_size = le32_to_cpu(bfs_sb->s_end);
418 
419 		if (i_sblock > info->si_blocks ||
420 			i_eblock > info->si_blocks ||
421 			i_sblock > i_eblock ||
422 			(i_eoff != le32_to_cpu(-1) && i_eoff > s_size) ||
423 			i_sblock * BFS_BSIZE > i_eoff) {
424 
425 			printf("Inode 0x%08x corrupted\n", i);
426 
427 			brelse(bh);
428 			ret = -EIO;
429 			goto out3;
430 		}
431 
432 		if (!di->i_ino) {
433 			info->si_freei++;
434 			continue;
435 		}
436 		set_bit(i, info->si_imap);
437 		info->si_freeb -= BFS_FILEBLOCKS(di);
438 
439 		eblock =  le32_to_cpu(di->i_eblock);
440 		if (eblock > info->si_lf_eblk)
441 			info->si_lf_eblk = eblock;
442 	}
443 	brelse(bh);
444 	brelse(sbh);
445 	bfs_dump_imap("read_super", s);
446 	return 0;
447 
448 out3:
449 	dput(s->s_root);
450 	s->s_root = NULL;
451 out2:
452 	kfree(info->si_imap);
453 out1:
454 	brelse(sbh);
455 out:
456 	mutex_destroy(&info->bfs_lock);
457 	kfree(info);
458 	s->s_fs_info = NULL;
459 	return ret;
460 }
461 
462 static struct dentry *bfs_mount(struct file_system_type *fs_type,
463 	int flags, const char *dev_name, void *data)
464 {
465 	return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
466 }
467 
468 static struct file_system_type bfs_fs_type = {
469 	.owner		= THIS_MODULE,
470 	.name		= "bfs",
471 	.mount		= bfs_mount,
472 	.kill_sb	= kill_block_super,
473 	.fs_flags	= FS_REQUIRES_DEV,
474 };
475 MODULE_ALIAS_FS("bfs");
476 
477 static int __init init_bfs_fs(void)
478 {
479 	int err = init_inodecache();
480 	if (err)
481 		goto out1;
482         err = register_filesystem(&bfs_fs_type);
483 	if (err)
484 		goto out;
485 	return 0;
486 out:
487 	destroy_inodecache();
488 out1:
489 	return err;
490 }
491 
492 static void __exit exit_bfs_fs(void)
493 {
494 	unregister_filesystem(&bfs_fs_type);
495 	destroy_inodecache();
496 }
497 
498 module_init(init_bfs_fs)
499 module_exit(exit_bfs_fs)
500