xref: /linux/fs/bfs/inode.c (revision 384740dc49ea651ba350704d13ff6be9976e37fe)
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 	brelse(info->si_sbh);
217 	mutex_destroy(&info->bfs_lock);
218 	kfree(info->si_imap);
219 	kfree(info);
220 	s->s_fs_info = NULL;
221 }
222 
223 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
224 {
225 	struct super_block *s = dentry->d_sb;
226 	struct bfs_sb_info *info = BFS_SB(s);
227 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
228 	buf->f_type = BFS_MAGIC;
229 	buf->f_bsize = s->s_blocksize;
230 	buf->f_blocks = info->si_blocks;
231 	buf->f_bfree = buf->f_bavail = info->si_freeb;
232 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
233 	buf->f_ffree = info->si_freei;
234 	buf->f_fsid.val[0] = (u32)id;
235 	buf->f_fsid.val[1] = (u32)(id >> 32);
236 	buf->f_namelen = BFS_NAMELEN;
237 	return 0;
238 }
239 
240 static void bfs_write_super(struct super_block *s)
241 {
242 	struct bfs_sb_info *info = BFS_SB(s);
243 
244 	mutex_lock(&info->bfs_lock);
245 	if (!(s->s_flags & MS_RDONLY))
246 		mark_buffer_dirty(info->si_sbh);
247 	s->s_dirt = 0;
248 	mutex_unlock(&info->bfs_lock);
249 }
250 
251 static struct kmem_cache *bfs_inode_cachep;
252 
253 static struct inode *bfs_alloc_inode(struct super_block *sb)
254 {
255 	struct bfs_inode_info *bi;
256 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
257 	if (!bi)
258 		return NULL;
259 	return &bi->vfs_inode;
260 }
261 
262 static void bfs_destroy_inode(struct inode *inode)
263 {
264 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
265 }
266 
267 static void init_once(void *foo)
268 {
269 	struct bfs_inode_info *bi = foo;
270 
271 	inode_init_once(&bi->vfs_inode);
272 }
273 
274 static int init_inodecache(void)
275 {
276 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
277 					     sizeof(struct bfs_inode_info),
278 					     0, (SLAB_RECLAIM_ACCOUNT|
279 						SLAB_MEM_SPREAD),
280 					     init_once);
281 	if (bfs_inode_cachep == NULL)
282 		return -ENOMEM;
283 	return 0;
284 }
285 
286 static void destroy_inodecache(void)
287 {
288 	kmem_cache_destroy(bfs_inode_cachep);
289 }
290 
291 static const struct super_operations bfs_sops = {
292 	.alloc_inode	= bfs_alloc_inode,
293 	.destroy_inode	= bfs_destroy_inode,
294 	.write_inode	= bfs_write_inode,
295 	.delete_inode	= bfs_delete_inode,
296 	.put_super	= bfs_put_super,
297 	.write_super	= bfs_write_super,
298 	.statfs		= bfs_statfs,
299 };
300 
301 void dump_imap(const char *prefix, struct super_block *s)
302 {
303 #ifdef DEBUG
304 	int i;
305 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
306 
307 	if (!tmpbuf)
308 		return;
309 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
310 		if (i > PAGE_SIZE - 100) break;
311 		if (test_bit(i, BFS_SB(s)->si_imap))
312 			strcat(tmpbuf, "1");
313 		else
314 			strcat(tmpbuf, "0");
315 	}
316 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
317 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
318 	free_page((unsigned long)tmpbuf);
319 #endif
320 }
321 
322 static int bfs_fill_super(struct super_block *s, void *data, int silent)
323 {
324 	struct buffer_head *bh;
325 	struct bfs_super_block *bfs_sb;
326 	struct inode *inode;
327 	unsigned i, imap_len;
328 	struct bfs_sb_info *info;
329 	long ret = -EINVAL;
330 
331 	info = kzalloc(sizeof(*info), GFP_KERNEL);
332 	if (!info)
333 		return -ENOMEM;
334 	s->s_fs_info = info;
335 
336 	sb_set_blocksize(s, BFS_BSIZE);
337 
338 	bh = sb_bread(s, 0);
339 	if(!bh)
340 		goto out;
341 	bfs_sb = (struct bfs_super_block *)bh->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 out;
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 	info->si_sbh = bh;
353 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
354 					sizeof(struct bfs_inode)
355 					+ BFS_ROOT_INO - 1;
356 	imap_len = (info->si_lasti / 8) + 1;
357 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
358 	if (!info->si_imap)
359 		goto out;
360 	for (i = 0; i < BFS_ROOT_INO; i++)
361 		set_bit(i, info->si_imap);
362 
363 	s->s_op = &bfs_sops;
364 	inode = bfs_iget(s, BFS_ROOT_INO);
365 	if (IS_ERR(inode)) {
366 		ret = PTR_ERR(inode);
367 		kfree(info->si_imap);
368 		goto out;
369 	}
370 	s->s_root = d_alloc_root(inode);
371 	if (!s->s_root) {
372 		iput(inode);
373 		ret = -ENOMEM;
374 		kfree(info->si_imap);
375 		goto out;
376 	}
377 
378 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
379 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
380 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
381 	info->si_freei = 0;
382 	info->si_lf_eblk = 0;
383 	bh = NULL;
384 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
385 		struct bfs_inode *di;
386 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
387 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
388 		unsigned long eblock;
389 
390 		if (!off) {
391 			brelse(bh);
392 			bh = sb_bread(s, block);
393 		}
394 
395 		if (!bh)
396 			continue;
397 
398 		di = (struct bfs_inode *)bh->b_data + off;
399 
400 		if (!di->i_ino) {
401 			info->si_freei++;
402 			continue;
403 		}
404 		set_bit(i, info->si_imap);
405 		info->si_freeb -= BFS_FILEBLOCKS(di);
406 
407 		eblock =  le32_to_cpu(di->i_eblock);
408 		if (eblock > info->si_lf_eblk)
409 			info->si_lf_eblk = eblock;
410 	}
411 	brelse(bh);
412 	if (!(s->s_flags & MS_RDONLY)) {
413 		mark_buffer_dirty(info->si_sbh);
414 		s->s_dirt = 1;
415 	}
416 	dump_imap("read_super", s);
417 	mutex_init(&info->bfs_lock);
418 	return 0;
419 
420 out:
421 	brelse(bh);
422 	kfree(info);
423 	s->s_fs_info = NULL;
424 	return ret;
425 }
426 
427 static int bfs_get_sb(struct file_system_type *fs_type,
428 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
429 {
430 	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
431 }
432 
433 static struct file_system_type bfs_fs_type = {
434 	.owner		= THIS_MODULE,
435 	.name		= "bfs",
436 	.get_sb		= bfs_get_sb,
437 	.kill_sb	= kill_block_super,
438 	.fs_flags	= FS_REQUIRES_DEV,
439 };
440 
441 static int __init init_bfs_fs(void)
442 {
443 	int err = init_inodecache();
444 	if (err)
445 		goto out1;
446         err = register_filesystem(&bfs_fs_type);
447 	if (err)
448 		goto out;
449 	return 0;
450 out:
451 	destroy_inodecache();
452 out1:
453 	return err;
454 }
455 
456 static void __exit exit_bfs_fs(void)
457 {
458 	unregister_filesystem(&bfs_fs_type);
459 	destroy_inodecache();
460 }
461 
462 module_init(init_bfs_fs)
463 module_exit(exit_bfs_fs)
464