xref: /linux/fs/bfs/inode.c (revision 2d6ffcca623a9a16df6cdfbe8250b7a5904a5f5e)
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 
108         dprintf("ino=%08x\n", ino);
109 
110 	if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
111 		printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
112 		return -EIO;
113 	}
114 
115 	lock_kernel();
116 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
117 	bh = sb_bread(inode->i_sb, block);
118 	if (!bh) {
119 		printf("Unable to read inode %s:%08x\n",
120 				inode->i_sb->s_id, ino);
121 		unlock_kernel();
122 		return -EIO;
123 	}
124 
125 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
126 	di = (struct bfs_inode *)bh->b_data + off;
127 
128 	if (ino == BFS_ROOT_INO)
129 		di->i_vtype = cpu_to_le32(BFS_VDIR);
130 	else
131 		di->i_vtype = cpu_to_le32(BFS_VREG);
132 
133 	di->i_ino = cpu_to_le16(ino);
134 	di->i_mode = cpu_to_le32(inode->i_mode);
135 	di->i_uid = cpu_to_le32(inode->i_uid);
136 	di->i_gid = cpu_to_le32(inode->i_gid);
137 	di->i_nlink = cpu_to_le32(inode->i_nlink);
138 	di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
139 	di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
140 	di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
141         i_sblock = BFS_I(inode)->i_sblock;
142 	di->i_sblock = cpu_to_le32(i_sblock);
143 	di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
144 	di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
145 
146 	mark_buffer_dirty(bh);
147 	brelse(bh);
148 	unlock_kernel();
149 	return 0;
150 }
151 
152 static void bfs_delete_inode(struct inode *inode)
153 {
154 	unsigned long ino = inode->i_ino;
155 	struct bfs_inode *di;
156 	struct buffer_head *bh;
157 	int block, off;
158 	struct super_block *s = inode->i_sb;
159 	struct bfs_sb_info *info = BFS_SB(s);
160 	struct bfs_inode_info *bi = BFS_I(inode);
161 
162 	dprintf("ino=%08lx\n", ino);
163 
164 	truncate_inode_pages(&inode->i_data, 0);
165 
166 	if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
167 		printf("invalid ino=%08lx\n", ino);
168 		return;
169 	}
170 
171 	inode->i_size = 0;
172 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
173 	lock_kernel();
174 	mark_inode_dirty(inode);
175 
176 	block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
177 	bh = sb_bread(s, block);
178 	if (!bh) {
179 		printf("Unable to read inode %s:%08lx\n",
180 					inode->i_sb->s_id, ino);
181 		unlock_kernel();
182 		return;
183 	}
184 	off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
185 	di = (struct bfs_inode *)bh->b_data + off;
186 	memset((void *)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 		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 		mark_buffer_dirty(info->si_sbh);
206 	}
207 	unlock_kernel();
208 	clear_inode(inode);
209 }
210 
211 static void bfs_put_super(struct super_block *s)
212 {
213 	struct bfs_sb_info *info = BFS_SB(s);
214 	brelse(info->si_sbh);
215 	kfree(info->si_imap);
216 	kfree(info);
217 	s->s_fs_info = NULL;
218 }
219 
220 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
221 {
222 	struct super_block *s = dentry->d_sb;
223 	struct bfs_sb_info *info = BFS_SB(s);
224 	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
225 	buf->f_type = BFS_MAGIC;
226 	buf->f_bsize = s->s_blocksize;
227 	buf->f_blocks = info->si_blocks;
228 	buf->f_bfree = buf->f_bavail = info->si_freeb;
229 	buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
230 	buf->f_ffree = info->si_freei;
231 	buf->f_fsid.val[0] = (u32)id;
232 	buf->f_fsid.val[1] = (u32)(id >> 32);
233 	buf->f_namelen = BFS_NAMELEN;
234 	return 0;
235 }
236 
237 static void bfs_write_super(struct super_block *s)
238 {
239 	lock_kernel();
240 	if (!(s->s_flags & MS_RDONLY))
241 		mark_buffer_dirty(BFS_SB(s)->si_sbh);
242 	s->s_dirt = 0;
243 	unlock_kernel();
244 }
245 
246 static struct kmem_cache *bfs_inode_cachep;
247 
248 static struct inode *bfs_alloc_inode(struct super_block *sb)
249 {
250 	struct bfs_inode_info *bi;
251 	bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
252 	if (!bi)
253 		return NULL;
254 	return &bi->vfs_inode;
255 }
256 
257 static void bfs_destroy_inode(struct inode *inode)
258 {
259 	kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
260 }
261 
262 static void init_once(struct kmem_cache *cachep, void *foo)
263 {
264 	struct bfs_inode_info *bi = foo;
265 
266 	inode_init_once(&bi->vfs_inode);
267 }
268 
269 static int init_inodecache(void)
270 {
271 	bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
272 					     sizeof(struct bfs_inode_info),
273 					     0, (SLAB_RECLAIM_ACCOUNT|
274 						SLAB_MEM_SPREAD),
275 					     init_once);
276 	if (bfs_inode_cachep == NULL)
277 		return -ENOMEM;
278 	return 0;
279 }
280 
281 static void destroy_inodecache(void)
282 {
283 	kmem_cache_destroy(bfs_inode_cachep);
284 }
285 
286 static const struct super_operations bfs_sops = {
287 	.alloc_inode	= bfs_alloc_inode,
288 	.destroy_inode	= bfs_destroy_inode,
289 	.write_inode	= bfs_write_inode,
290 	.delete_inode	= bfs_delete_inode,
291 	.put_super	= bfs_put_super,
292 	.write_super	= bfs_write_super,
293 	.statfs		= bfs_statfs,
294 };
295 
296 void dump_imap(const char *prefix, struct super_block *s)
297 {
298 #ifdef DEBUG
299 	int i;
300 	char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
301 
302 	if (!tmpbuf)
303 		return;
304 	for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
305 		if (i > PAGE_SIZE - 100) break;
306 		if (test_bit(i, BFS_SB(s)->si_imap))
307 			strcat(tmpbuf, "1");
308 		else
309 			strcat(tmpbuf, "0");
310 	}
311 	printf("BFS-fs: %s: lasti=%08lx <%s>\n",
312 				prefix, BFS_SB(s)->si_lasti, tmpbuf);
313 	free_page((unsigned long)tmpbuf);
314 #endif
315 }
316 
317 static int bfs_fill_super(struct super_block *s, void *data, int silent)
318 {
319 	struct buffer_head *bh;
320 	struct bfs_super_block *bfs_sb;
321 	struct inode *inode;
322 	unsigned i, imap_len;
323 	struct bfs_sb_info *info;
324 	long ret = -EINVAL;
325 
326 	info = kzalloc(sizeof(*info), GFP_KERNEL);
327 	if (!info)
328 		return -ENOMEM;
329 	s->s_fs_info = info;
330 
331 	sb_set_blocksize(s, BFS_BSIZE);
332 
333 	bh = sb_bread(s, 0);
334 	if(!bh)
335 		goto out;
336 	bfs_sb = (struct bfs_super_block *)bh->b_data;
337 	if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
338 		if (!silent)
339 			printf("No BFS filesystem on %s (magic=%08x)\n",
340 				s->s_id,  le32_to_cpu(bfs_sb->s_magic));
341 		goto out;
342 	}
343 	if (BFS_UNCLEAN(bfs_sb, s) && !silent)
344 		printf("%s is unclean, continuing\n", s->s_id);
345 
346 	s->s_magic = BFS_MAGIC;
347 	info->si_sbh = bh;
348 	info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
349 					sizeof(struct bfs_inode)
350 					+ BFS_ROOT_INO - 1;
351 	imap_len = (info->si_lasti / 8) + 1;
352 	info->si_imap = kzalloc(imap_len, GFP_KERNEL);
353 	if (!info->si_imap)
354 		goto out;
355 	for (i = 0; i < BFS_ROOT_INO; i++)
356 		set_bit(i, info->si_imap);
357 
358 	s->s_op = &bfs_sops;
359 	inode = bfs_iget(s, BFS_ROOT_INO);
360 	if (IS_ERR(inode)) {
361 		ret = PTR_ERR(inode);
362 		kfree(info->si_imap);
363 		goto out;
364 	}
365 	s->s_root = d_alloc_root(inode);
366 	if (!s->s_root) {
367 		iput(inode);
368 		ret = -ENOMEM;
369 		kfree(info->si_imap);
370 		goto out;
371 	}
372 
373 	info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
374 	info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
375 			- le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
376 	info->si_freei = 0;
377 	info->si_lf_eblk = 0;
378 	bh = NULL;
379 	for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
380 		struct bfs_inode *di;
381 		int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
382 		int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
383 		unsigned long sblock, eblock;
384 
385 		if (!off) {
386 			brelse(bh);
387 			bh = sb_bread(s, block);
388 		}
389 
390 		if (!bh)
391 			continue;
392 
393 		di = (struct bfs_inode *)bh->b_data + off;
394 
395 		if (!di->i_ino) {
396 			info->si_freei++;
397 			continue;
398 		}
399 		set_bit(i, info->si_imap);
400 		info->si_freeb -= BFS_FILEBLOCKS(di);
401 
402 		sblock =  le32_to_cpu(di->i_sblock);
403 		eblock =  le32_to_cpu(di->i_eblock);
404 		if (eblock > info->si_lf_eblk)
405 			info->si_lf_eblk = eblock;
406 	}
407 	brelse(bh);
408 	if (!(s->s_flags & MS_RDONLY)) {
409 		mark_buffer_dirty(info->si_sbh);
410 		s->s_dirt = 1;
411 	}
412 	dump_imap("read_super", s);
413 	return 0;
414 
415 out:
416 	brelse(bh);
417 	kfree(info);
418 	s->s_fs_info = NULL;
419 	return ret;
420 }
421 
422 static int bfs_get_sb(struct file_system_type *fs_type,
423 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
424 {
425 	return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
426 }
427 
428 static struct file_system_type bfs_fs_type = {
429 	.owner		= THIS_MODULE,
430 	.name		= "bfs",
431 	.get_sb		= bfs_get_sb,
432 	.kill_sb	= kill_block_super,
433 	.fs_flags	= FS_REQUIRES_DEV,
434 };
435 
436 static int __init init_bfs_fs(void)
437 {
438 	int err = init_inodecache();
439 	if (err)
440 		goto out1;
441         err = register_filesystem(&bfs_fs_type);
442 	if (err)
443 		goto out;
444 	return 0;
445 out:
446 	destroy_inodecache();
447 out1:
448 	return err;
449 }
450 
451 static void __exit exit_bfs_fs(void)
452 {
453 	unregister_filesystem(&bfs_fs_type);
454 	destroy_inodecache();
455 }
456 
457 module_init(init_bfs_fs)
458 module_exit(exit_bfs_fs)
459