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Avoid beyond bounds copy while caching ACL
[zen-stable.git] / fs / bfs / inode.c
blobb0391bc402b14a22912c01457da5021c373704af
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 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 set_nlink(inode, 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 struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
101 {
102 if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
103 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
104 return ERR_PTR(-EIO);
105 }
106
107 ino -= BFS_ROOT_INO;
108
109 *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
110 if (!*p) {
111 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
112 return ERR_PTR(-EIO);
113 }
114
115 return (struct bfs_inode *)(*p)->b_data + ino % BFS_INODES_PER_BLOCK;
116 }
117
118 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
119 {
120 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
121 unsigned int ino = (u16)inode->i_ino;
122 unsigned long i_sblock;
123 struct bfs_inode *di;
124 struct buffer_head *bh;
125 int err = 0;
126
127 dprintf("ino=%08x\n", ino);
128
129 di = find_inode(inode->i_sb, ino, &bh);
130 if (IS_ERR(di))
131 return PTR_ERR(di);
132
133 mutex_lock(&info->bfs_lock);
134
135 if (ino == BFS_ROOT_INO)
136 di->i_vtype = cpu_to_le32(BFS_VDIR);
137 else
138 di->i_vtype = cpu_to_le32(BFS_VREG);
139
140 di->i_ino = cpu_to_le16(ino);
141 di->i_mode = cpu_to_le32(inode->i_mode);
142 di->i_uid = cpu_to_le32(inode->i_uid);
143 di->i_gid = cpu_to_le32(inode->i_gid);
144 di->i_nlink = cpu_to_le32(inode->i_nlink);
145 di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
146 di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
147 di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
148 i_sblock = BFS_I(inode)->i_sblock;
149 di->i_sblock = cpu_to_le32(i_sblock);
150 di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
151 di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
152
153 mark_buffer_dirty(bh);
154 if (wbc->sync_mode == WB_SYNC_ALL) {
155 sync_dirty_buffer(bh);
156 if (buffer_req(bh) && !buffer_uptodate(bh))
157 err = -EIO;
158 }
159 brelse(bh);
160 mutex_unlock(&info->bfs_lock);
161 return err;
162 }
163
164 static void bfs_evict_inode(struct inode *inode)
165 {
166 unsigned long ino = inode->i_ino;
167 struct bfs_inode *di;
168 struct buffer_head *bh;
169 struct super_block *s = inode->i_sb;
170 struct bfs_sb_info *info = BFS_SB(s);
171 struct bfs_inode_info *bi = BFS_I(inode);
172
173 dprintf("ino=%08lx\n", ino);
174
175 truncate_inode_pages(&inode->i_data, 0);
176 invalidate_inode_buffers(inode);
177 end_writeback(inode);
178
179 if (inode->i_nlink)
180 return;
181
182 di = find_inode(s, inode->i_ino, &bh);
183 if (IS_ERR(di))
184 return;
185
186 mutex_lock(&info->bfs_lock);
187 /* clear on-disk inode */
188 memset(di, 0, sizeof(struct bfs_inode));
189 mark_buffer_dirty(bh);
190 brelse(bh);
191
192 if (bi->i_dsk_ino) {
193 if (bi->i_sblock)
194 info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
195 info->si_freei++;
196 clear_bit(ino, info->si_imap);
197 dump_imap("delete_inode", s);
198 }
199
200 /*
201 * If this was the last file, make the previous block
202 * "last block of the last file" even if there is no
203 * real file there, saves us 1 gap.
204 */
205 if (info->si_lf_eblk == bi->i_eblock)
206 info->si_lf_eblk = bi->i_sblock - 1;
207 mutex_unlock(&info->bfs_lock);
208 }
209
210 static void bfs_put_super(struct super_block *s)
211 {
212 struct bfs_sb_info *info = BFS_SB(s);
213
214 if (!info)
215 return;
216
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 struct kmem_cache *bfs_inode_cachep;
241
242 static struct inode *bfs_alloc_inode(struct super_block *sb)
243 {
244 struct bfs_inode_info *bi;
245 bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
246 if (!bi)
247 return NULL;
248 return &bi->vfs_inode;
249 }
250
251 static void bfs_i_callback(struct rcu_head *head)
252 {
253 struct inode *inode = container_of(head, struct inode, i_rcu);
254 kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
255 }
256
257 static void bfs_destroy_inode(struct inode *inode)
258 {
259 call_rcu(&inode->i_rcu, bfs_i_callback);
260 }
261
262 static void init_once(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 .evict_inode = bfs_evict_inode,
291 .put_super = bfs_put_super,
292 .statfs = bfs_statfs,
293 };
294
295 void dump_imap(const char *prefix, struct super_block *s)
296 {
297 #ifdef DEBUG
298 int i;
299 char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
300
301 if (!tmpbuf)
302 return;
303 for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
304 if (i > PAGE_SIZE - 100) break;
305 if (test_bit(i, BFS_SB(s)->si_imap))
306 strcat(tmpbuf, "1");
307 else
308 strcat(tmpbuf, "0");
309 }
310 printf("BFS-fs: %s: lasti=%08lx <%s>\n",
311 prefix, BFS_SB(s)->si_lasti, tmpbuf);
312 free_page((unsigned long)tmpbuf);
313 #endif
314 }
315
316 static int bfs_fill_super(struct super_block *s, void *data, int silent)
317 {
318 struct buffer_head *bh, *sbh;
319 struct bfs_super_block *bfs_sb;
320 struct inode *inode;
321 unsigned i, imap_len;
322 struct bfs_sb_info *info;
323 int ret = -EINVAL;
324 unsigned long i_sblock, i_eblock, i_eoff, s_size;
325
326 info = kzalloc(sizeof(*info), GFP_KERNEL);
327 if (!info)
328 return -ENOMEM;
329 mutex_init(&info->bfs_lock);
330 s->s_fs_info = info;
331
332 sb_set_blocksize(s, BFS_BSIZE);
333
334 sbh = sb_bread(s, 0);
335 if (!sbh)
336 goto out;
337 bfs_sb = (struct bfs_super_block *)sbh->b_data;
338 if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
339 if (!silent)
340 printf("No BFS filesystem on %s (magic=%08x)\n",
341 s->s_id, le32_to_cpu(bfs_sb->s_magic));
342 goto out1;
343 }
344 if (BFS_UNCLEAN(bfs_sb, s) && !silent)
345 printf("%s is unclean, continuing\n", s->s_id);
346
347 s->s_magic = BFS_MAGIC;
348
349 if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
350 printf("Superblock is corrupted\n");
351 goto out1;
352 }
353
354 info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
355 sizeof(struct bfs_inode)
356 + BFS_ROOT_INO - 1;
357 imap_len = (info->si_lasti / 8) + 1;
358 info->si_imap = kzalloc(imap_len, GFP_KERNEL);
359 if (!info->si_imap)
360 goto out1;
361 for (i = 0; i < BFS_ROOT_INO; i++)
362 set_bit(i, info->si_imap);
363
364 s->s_op = &bfs_sops;
365 inode = bfs_iget(s, BFS_ROOT_INO);
366 if (IS_ERR(inode)) {
367 ret = PTR_ERR(inode);
368 goto out2;
369 }
370 s->s_root = d_alloc_root(inode);
371 if (!s->s_root) {
372 iput(inode);
373 ret = -ENOMEM;
374 goto out2;
375 }
376
377 info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
378 info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
379 - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
380 info->si_freei = 0;
381 info->si_lf_eblk = 0;
382
383 /* can we read the last block? */
384 bh = sb_bread(s, info->si_blocks - 1);
385 if (!bh) {
386 printf("Last block not available: %lu\n", info->si_blocks - 1);
387 ret = -EIO;
388 goto out3;
389 }
390 brelse(bh);
391
392 bh = NULL;
393 for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
394 struct bfs_inode *di;
395 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
396 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
397 unsigned long eblock;
398
399 if (!off) {
400 brelse(bh);
401 bh = sb_bread(s, block);
402 }
403
404 if (!bh)
405 continue;
406
407 di = (struct bfs_inode *)bh->b_data + off;
408
409 /* test if filesystem is not corrupted */
410
411 i_eoff = le32_to_cpu(di->i_eoffset);
412 i_sblock = le32_to_cpu(di->i_sblock);
413 i_eblock = le32_to_cpu(di->i_eblock);
414 s_size = le32_to_cpu(bfs_sb->s_end);
415
416 if (i_sblock > info->si_blocks ||
417 i_eblock > info->si_blocks ||
418 i_sblock > i_eblock ||
419 i_eoff > s_size ||
420 i_sblock * BFS_BSIZE > i_eoff) {
421
422 printf("Inode 0x%08x corrupted\n", i);
423
424 brelse(bh);
425 ret = -EIO;
426 goto out3;
427 }
428
429 if (!di->i_ino) {
430 info->si_freei++;
431 continue;
432 }
433 set_bit(i, info->si_imap);
434 info->si_freeb -= BFS_FILEBLOCKS(di);
435
436 eblock = le32_to_cpu(di->i_eblock);
437 if (eblock > info->si_lf_eblk)
438 info->si_lf_eblk = eblock;
439 }
440 brelse(bh);
441 brelse(sbh);
442 dump_imap("read_super", s);
443 return 0;
444
445 out3:
446 dput(s->s_root);
447 s->s_root = NULL;
448 out2:
449 kfree(info->si_imap);
450 out1:
451 brelse(sbh);
452 out:
453 mutex_destroy(&info->bfs_lock);
454 kfree(info);
455 s->s_fs_info = NULL;
456 return ret;
457 }
458
459 static struct dentry *bfs_mount(struct file_system_type *fs_type,
460 int flags, const char *dev_name, void *data)
461 {
462 return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
463 }
464
465 static struct file_system_type bfs_fs_type = {
466 .owner = THIS_MODULE,
467 .name = "bfs",
468 .mount = bfs_mount,
469 .kill_sb = kill_block_super,
470 .fs_flags = FS_REQUIRES_DEV,
471 };
472
473 static int __init init_bfs_fs(void)
474 {
475 int err = init_inodecache();
476 if (err)
477 goto out1;
478 err = register_filesystem(&bfs_fs_type);
479 if (err)
480 goto out;
481 return 0;
482 out:
483 destroy_inodecache();
484 out1:
485 return err;
486 }
487
488 static void __exit exit_bfs_fs(void)
489 {
490 unregister_filesystem(&bfs_fs_type);
491 destroy_inodecache();
492 }
493
494 module_init(init_bfs_fs)
495 module_exit(exit_bfs_fs)