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BFS: clean up the superblock usage
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / bfs / inode.c
blobc4daf0f5fc021e9b98fa2521b96ee28ea67c9b4c
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 <linux/writeback.h>
19 #include <asm/uaccess.h>
20 #include "bfs.h"
21
22 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
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 void dump_imap(const char *prefix, struct super_block *s);
35
36 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
37 {
38 struct bfs_inode *di;
39 struct inode *inode;
40 struct buffer_head *bh;
41 int block, off;
42
43 inode = iget_locked(sb, ino);
44 if (IS_ERR(inode))
45 return ERR_PTR(-ENOMEM);
46 if (!(inode->i_state & I_NEW))
47 return inode;
48
49 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
50 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
51 goto error;
52 }
53
54 block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
55 bh = sb_bread(inode->i_sb, block);
56 if (!bh) {
57 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
58 ino);
59 goto error;
60 }
61
62 off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
63 di = (struct bfs_inode *)bh->b_data + off;
64
65 inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
66 if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
67 inode->i_mode |= S_IFDIR;
68 inode->i_op = &bfs_dir_inops;
69 inode->i_fop = &bfs_dir_operations;
70 } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
71 inode->i_mode |= S_IFREG;
72 inode->i_op = &bfs_file_inops;
73 inode->i_fop = &bfs_file_operations;
74 inode->i_mapping->a_ops = &bfs_aops;
75 }
76
77 BFS_I(inode)->i_sblock = le32_to_cpu(di->i_sblock);
78 BFS_I(inode)->i_eblock = le32_to_cpu(di->i_eblock);
79 BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
80 inode->i_uid = le32_to_cpu(di->i_uid);
81 inode->i_gid = le32_to_cpu(di->i_gid);
82 inode->i_nlink = le32_to_cpu(di->i_nlink);
83 inode->i_size = BFS_FILESIZE(di);
84 inode->i_blocks = BFS_FILEBLOCKS(di);
85 inode->i_atime.tv_sec = le32_to_cpu(di->i_atime);
86 inode->i_mtime.tv_sec = le32_to_cpu(di->i_mtime);
87 inode->i_ctime.tv_sec = le32_to_cpu(di->i_ctime);
88 inode->i_atime.tv_nsec = 0;
89 inode->i_mtime.tv_nsec = 0;
90 inode->i_ctime.tv_nsec = 0;
91
92 brelse(bh);
93 unlock_new_inode(inode);
94 return inode;
95
96 error:
97 iget_failed(inode);
98 return ERR_PTR(-EIO);
99 }
100
101 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
102 {
103 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
104 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
105 return ERR_PTR(-EIO);
106 }
107
108 ino -= BFS_ROOT_INO;
109
110 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
111 if (!*p) {
112 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
113 return ERR_PTR(-EIO);
114 }
115
116 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
117 }
118
119 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
120 {
121 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
122 unsigned int ino = (u16)inode->i_ino;
123 unsigned long i_sblock;
124 struct bfs_inode *di;
125 struct buffer_head *bh;
126 int err = 0;
127
128 dprintf("ino=%08x\n", ino);
129
130 di = find_inode(inode->i_sb, ino, &bh);
131 if (IS_ERR(di))
132 return PTR_ERR(di);
133
134 mutex_lock(&info->bfs_lock);
135
136 if (ino == BFS_ROOT_INO)
137 di->i_vtype = cpu_to_le32(BFS_VDIR);
138 else
139 di->i_vtype = cpu_to_le32(BFS_VREG);
140
141 di->i_ino = cpu_to_le16(ino);
142 di->i_mode = cpu_to_le32(inode->i_mode);
143 di->i_uid = cpu_to_le32(inode->i_uid);
144 di->i_gid = cpu_to_le32(inode->i_gid);
145 di->i_nlink = cpu_to_le32(inode->i_nlink);
146 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
147 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
148 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
149 i_sblock = BFS_I(inode)->i_sblock;
150 di->i_sblock = cpu_to_le32(i_sblock);
151 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
152 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
153
154 mark_buffer_dirty(bh);
155 if (wbc->sync_mode == WB_SYNC_ALL) {
156 sync_dirty_buffer(bh);
157 if (buffer_req(bh) && !buffer_uptodate(bh))
158 err = -EIO;
159 }
160 brelse(bh);
161 mutex_unlock(&info->bfs_lock);
162 return err;
163 }
164
165 static void bfs_evict_inode(struct inode *inode)
166 {
167 unsigned long ino = inode->i_ino;
168 struct bfs_inode *di;
169 struct buffer_head *bh;
170 struct super_block *s = inode->i_sb;
171 struct bfs_sb_info *info = BFS_SB(s);
172 struct bfs_inode_info *bi = BFS_I(inode);
173
174 dprintf("ino=%08lx\n", ino);
175
176 truncate_inode_pages(&inode->i_data, 0);
177 invalidate_inode_buffers(inode);
178 end_writeback(inode);
179
180 if (inode->i_nlink)
181 return;
182
183 di = find_inode(s, inode->i_ino, &bh);
184 if (IS_ERR(di))
185 return;
186
187 mutex_lock(&info->bfs_lock);
188 /* clear on-disk inode */
189 memset(di, 0, sizeof(struct bfs_inode));
190 mark_buffer_dirty(bh);
191 brelse(bh);
192
193 if (bi->i_dsk_ino) {
194 if (bi->i_sblock)
195 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
196 info->si_freei++;
197 clear_bit(ino, info->si_imap);
198 dump_imap("delete_inode", s);
199 }
200
201 /*
202 * If this was the last file, make the previous block
203 * "last block of the last file" even if there is no
204 * real file there, saves us 1 gap.
205 */
206 if (info->si_lf_eblk == bi->i_eblock)
207 info->si_lf_eblk = bi->i_sblock - 1;
208 mutex_unlock(&info->bfs_lock);
209 }
210
211 static void bfs_put_super(struct super_block *s)
212 {
213 struct bfs_sb_info *info = BFS_SB(s);
214
215 if (!info)
216 return;
217
218 lock_kernel();
219
220 mutex_destroy(&info->bfs_lock);
221 kfree(info->si_imap);
222 kfree(info);
223 s->s_fs_info = NULL;
224
225 unlock_kernel();
226 }
227
228 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
229 {
230 struct super_block *s = dentry->d_sb;
231 struct bfs_sb_info *info = BFS_SB(s);
232 u64 id = huge_encode_dev(s->s_bdev->bd_dev);
233 buf->f_type = BFS_MAGIC;
234 buf->f_bsize = s->s_blocksize;
235 buf->f_blocks = info->si_blocks;
236 buf->f_bfree = buf->f_bavail = info->si_freeb;
237 buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
238 buf->f_ffree = info->si_freei;
239 buf->f_fsid.val[0] = (u32)id;
240 buf->f_fsid.val[1] = (u32)(id >> 32);
241 buf->f_namelen = BFS_NAMELEN;
242 return 0;
243 }
244
245 static struct kmem_cache *bfs_inode_cachep;
246
247 static struct inode *bfs_alloc_inode(struct super_block *sb)
248 {
249 struct bfs_inode_info *bi;
250 bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
251 if (!bi)
252 return NULL;
253 return &bi->vfs_inode;
254 }
255
256 static void bfs_destroy_inode(struct inode *inode)
257 {
258 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
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_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),
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 kmem_cache_destroy(bfs_inode_cachep);
283 }
284
285 static const struct super_operations bfs_sops = {
286 .alloc_inode = bfs_alloc_inode,
287 .destroy_inode = bfs_destroy_inode,
288 .write_inode = bfs_write_inode,
289 .evict_inode = bfs_evict_inode,
290 .put_super = bfs_put_super,
291 .statfs = bfs_statfs,
292 };
293
294 void dump_imap(const char *prefix, struct super_block *s)
295 {
296 #ifdef DEBUG
297 int i;
298 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
299
300 if (!tmpbuf)
301 return;
302 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
303 if (i > PAGE_SIZE - 100) break;
304 if (test_bit(i, BFS_SB(s)->si_imap))
305 strcat(tmpbuf, "1");
306 else
307 strcat(tmpbuf, "0");
308 }
309 printf("BFS-fs: %s: lasti=%08lx <%s>\n",
310 prefix, BFS_SB(s)->si_lasti, tmpbuf);
311 free_page((unsigned long)tmpbuf);
312 #endif
313 }
314
315 static int bfs_fill_super(struct super_block *s, void *data, int silent)
316 {
317 struct buffer_head *bh, *sbh;
318 struct bfs_super_block *bfs_sb;
319 struct inode *inode;
320 unsigned i, imap_len;
321 struct bfs_sb_info *info;
322 int ret = -EINVAL;
323 unsigned long i_sblock, i_eblock, i_eoff, s_size;
324
325 info = kzalloc(sizeof(*info), GFP_KERNEL);
326 if (!info)
327 return -ENOMEM;
328 mutex_init(&info->bfs_lock);
329 s->s_fs_info = info;
330
331 sb_set_blocksize(s, BFS_BSIZE);
332
333 sbh = sb_bread(s, 0);
334 if (!sbh)
335 goto out;
336 bfs_sb = (struct bfs_super_block *)sbh->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 out1;
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
348 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
349 printf("Superblock is corrupted\n");
350 goto out1;
351 }
352
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 out1;
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 goto out2;
368 }
369 s->s_root = d_alloc_root(inode);
370 if (!s->s_root) {
371 iput(inode);
372 ret = -ENOMEM;
373 goto out2;
374 }
375
376 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
377 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
378 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
379 info->si_freei = 0;
380 info->si_lf_eblk = 0;
381
382 /* can we read the last block? */
383 bh = sb_bread(s, info->si_blocks - 1);
384 if (!bh) {
385 printf("Last block not available: %lu\n", info->si_blocks - 1);
386 ret = -EIO;
387 goto out3;
388 }
389 brelse(bh);
390
391 bh = NULL;
392 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
393 struct bfs_inode *di;
394 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
395 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
396 unsigned long eblock;
397
398 if (!off) {
399 brelse(bh);
400 bh = sb_bread(s, block);
401 }
402
403 if (!bh)
404 continue;
405
406 di = (struct bfs_inode *)bh->b_data + off;
407
408 /* test if filesystem is not corrupted */
409
410 i_eoff = le32_to_cpu(di->i_eoffset);
411 i_sblock = le32_to_cpu(di->i_sblock);
412 i_eblock = le32_to_cpu(di->i_eblock);
413 s_size = le32_to_cpu(bfs_sb->s_end);
414
415 if (i_sblock > info->si_blocks ||
416 i_eblock > info->si_blocks ||
417 i_sblock > i_eblock ||
418 i_eoff > s_size ||
419 i_sblock * BFS_BSIZE > i_eoff) {
420
421 printf("Inode 0x%08x corrupted\n", i);
422
423 brelse(bh);
424 ret = -EIO;
425 goto out3;
426 }
427
428 if (!di->i_ino) {
429 info->si_freei++;
430 continue;
431 }
432 set_bit(i, info->si_imap);
433 info->si_freeb -= BFS_FILEBLOCKS(di);
434
435 eblock = le32_to_cpu(di->i_eblock);
436 if (eblock > info->si_lf_eblk)
437 info->si_lf_eblk = eblock;
438 }
439 brelse(bh);
440 brelse(sbh);
441 dump_imap("read_super", s);
442 return 0;
443
444 out3:
445 dput(s->s_root);
446 s->s_root = NULL;
447 out2:
448 kfree(info->si_imap);
449 out1:
450 brelse(sbh);
451 out:
452 mutex_destroy(&info->bfs_lock);
453 kfree(info);
454 s->s_fs_info = NULL;
455 return ret;
456 }
457
458 static int bfs_get_sb(struct file_system_type *fs_type,
459 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
460 {
461 return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
462 }
463
464 static struct file_system_type bfs_fs_type = {
465 .owner = THIS_MODULE,
466 .name = "bfs",
467 .get_sb = bfs_get_sb,
468 .kill_sb = kill_block_super,
469 .fs_flags = FS_REQUIRES_DEV,
470 };
471
472 static int __init init_bfs_fs(void)
473 {
474 int err = init_inodecache();
475 if (err)
476 goto out1;
477 err = register_filesystem(&bfs_fs_type);
478 if (err)
479 goto out;
480 return 0;
481 out:
482 destroy_inodecache();
483 out1:
484 return err;
485 }
486
487 static void __exit exit_bfs_fs(void)
488 {
489 unregister_filesystem(&bfs_fs_type);
490 destroy_inodecache();
491 }
492
493 module_init(init_bfs_fs)
494 module_exit(exit_bfs_fs)
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