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staging/lustre: Fix unsafe userspace access in many proc files
[linux-2.6/btrfs-unstable.git] / fs / affs / super.c
blob6d589f28bf9b849bae629cea4d61f7dba60eda2d
1 /*
2 * linux/fs/affs/inode.c
3 *
4 * (c) 1996 Hans-Joachim Widmaier - Rewritten
5 *
6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
7 *
8 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
9 *
10 * (C) 1991 Linus Torvalds - minix filesystem
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/statfs.h>
16 #include <linux/parser.h>
17 #include <linux/magic.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/writeback.h>
21 #include "affs.h"
22
23 extern struct timezone sys_tz;
24
25 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
26 static int affs_remount (struct super_block *sb, int *flags, char *data);
27
28 static void
29 affs_commit_super(struct super_block *sb, int wait)
30 {
31 struct affs_sb_info *sbi = AFFS_SB(sb);
32 struct buffer_head *bh = sbi->s_root_bh;
33 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
34
35 lock_buffer(bh);
36 secs_to_datestamp(get_seconds(), &tail->disk_change);
37 affs_fix_checksum(sb, bh);
38 unlock_buffer(bh);
39
40 mark_buffer_dirty(bh);
41 if (wait)
42 sync_dirty_buffer(bh);
43 }
44
45 static void
46 affs_put_super(struct super_block *sb)
47 {
48 struct affs_sb_info *sbi = AFFS_SB(sb);
49 pr_debug("AFFS: put_super()\n");
50
51 cancel_delayed_work_sync(&sbi->sb_work);
52 }
53
54 static int
55 affs_sync_fs(struct super_block *sb, int wait)
56 {
57 affs_commit_super(sb, wait);
58 return 0;
59 }
60
61 static void flush_superblock(struct work_struct *work)
62 {
63 struct affs_sb_info *sbi;
64 struct super_block *sb;
65
66 sbi = container_of(work, struct affs_sb_info, sb_work.work);
67 sb = sbi->sb;
68
69 spin_lock(&sbi->work_lock);
70 sbi->work_queued = 0;
71 spin_unlock(&sbi->work_lock);
72
73 affs_commit_super(sb, 1);
74 }
75
76 void affs_mark_sb_dirty(struct super_block *sb)
77 {
78 struct affs_sb_info *sbi = AFFS_SB(sb);
79 unsigned long delay;
80
81 if (sb->s_flags & MS_RDONLY)
82 return;
83
84 spin_lock(&sbi->work_lock);
85 if (!sbi->work_queued) {
86 delay = msecs_to_jiffies(dirty_writeback_interval * 10);
87 queue_delayed_work(system_long_wq, &sbi->sb_work, delay);
88 sbi->work_queued = 1;
89 }
90 spin_unlock(&sbi->work_lock);
91 }
92
93 static struct kmem_cache * affs_inode_cachep;
94
95 static struct inode *affs_alloc_inode(struct super_block *sb)
96 {
97 struct affs_inode_info *i;
98
99 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
100 if (!i)
101 return NULL;
102
103 i->vfs_inode.i_version = 1;
104 i->i_lc = NULL;
105 i->i_ext_bh = NULL;
106 i->i_pa_cnt = 0;
107
108 return &i->vfs_inode;
109 }
110
111 static void affs_i_callback(struct rcu_head *head)
112 {
113 struct inode *inode = container_of(head, struct inode, i_rcu);
114 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
115 }
116
117 static void affs_destroy_inode(struct inode *inode)
118 {
119 call_rcu(&inode->i_rcu, affs_i_callback);
120 }
121
122 static void init_once(void *foo)
123 {
124 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
125
126 sema_init(&ei->i_link_lock, 1);
127 sema_init(&ei->i_ext_lock, 1);
128 inode_init_once(&ei->vfs_inode);
129 }
130
131 static int __init init_inodecache(void)
132 {
133 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
134 sizeof(struct affs_inode_info),
135 0, (SLAB_RECLAIM_ACCOUNT|
136 SLAB_MEM_SPREAD),
137 init_once);
138 if (affs_inode_cachep == NULL)
139 return -ENOMEM;
140 return 0;
141 }
142
143 static void destroy_inodecache(void)
144 {
145 /*
146 * Make sure all delayed rcu free inodes are flushed before we
147 * destroy cache.
148 */
149 rcu_barrier();
150 kmem_cache_destroy(affs_inode_cachep);
151 }
152
153 static const struct super_operations affs_sops = {
154 .alloc_inode = affs_alloc_inode,
155 .destroy_inode = affs_destroy_inode,
156 .write_inode = affs_write_inode,
157 .evict_inode = affs_evict_inode,
158 .put_super = affs_put_super,
159 .sync_fs = affs_sync_fs,
160 .statfs = affs_statfs,
161 .remount_fs = affs_remount,
162 .show_options = generic_show_options,
163 };
164
165 enum {
166 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect,
167 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
168 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
169 };
170
171 static const match_table_t tokens = {
172 {Opt_bs, "bs=%u"},
173 {Opt_mode, "mode=%o"},
174 {Opt_mufs, "mufs"},
175 {Opt_notruncate, "nofilenametruncate"},
176 {Opt_prefix, "prefix=%s"},
177 {Opt_protect, "protect"},
178 {Opt_reserved, "reserved=%u"},
179 {Opt_root, "root=%u"},
180 {Opt_setgid, "setgid=%u"},
181 {Opt_setuid, "setuid=%u"},
182 {Opt_verbose, "verbose"},
183 {Opt_volume, "volume=%s"},
184 {Opt_ignore, "grpquota"},
185 {Opt_ignore, "noquota"},
186 {Opt_ignore, "quota"},
187 {Opt_ignore, "usrquota"},
188 {Opt_err, NULL},
189 };
190
191 static int
192 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root,
193 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
194 {
195 char *p;
196 substring_t args[MAX_OPT_ARGS];
197
198 /* Fill in defaults */
199
200 *uid = current_uid();
201 *gid = current_gid();
202 *reserved = 2;
203 *root = -1;
204 *blocksize = -1;
205 volume[0] = ':';
206 volume[1] = 0;
207 *mount_opts = 0;
208 if (!options)
209 return 1;
210
211 while ((p = strsep(&options, ",")) != NULL) {
212 int token, n, option;
213 if (!*p)
214 continue;
215
216 token = match_token(p, tokens, args);
217 switch (token) {
218 case Opt_bs:
219 if (match_int(&args[0], &n))
220 return 0;
221 if (n != 512 && n != 1024 && n != 2048
222 && n != 4096) {
223 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
224 return 0;
225 }
226 *blocksize = n;
227 break;
228 case Opt_mode:
229 if (match_octal(&args[0], &option))
230 return 0;
231 *mode = option & 0777;
232 *mount_opts |= SF_SETMODE;
233 break;
234 case Opt_mufs:
235 *mount_opts |= SF_MUFS;
236 break;
237 case Opt_notruncate:
238 *mount_opts |= SF_NO_TRUNCATE;
239 break;
240 case Opt_prefix:
241 *prefix = match_strdup(&args[0]);
242 if (!*prefix)
243 return 0;
244 *mount_opts |= SF_PREFIX;
245 break;
246 case Opt_protect:
247 *mount_opts |= SF_IMMUTABLE;
248 break;
249 case Opt_reserved:
250 if (match_int(&args[0], reserved))
251 return 0;
252 break;
253 case Opt_root:
254 if (match_int(&args[0], root))
255 return 0;
256 break;
257 case Opt_setgid:
258 if (match_int(&args[0], &option))
259 return 0;
260 *gid = make_kgid(current_user_ns(), option);
261 if (!gid_valid(*gid))
262 return 0;
263 *mount_opts |= SF_SETGID;
264 break;
265 case Opt_setuid:
266 if (match_int(&args[0], &option))
267 return 0;
268 *uid = make_kuid(current_user_ns(), option);
269 if (!uid_valid(*uid))
270 return 0;
271 *mount_opts |= SF_SETUID;
272 break;
273 case Opt_verbose:
274 *mount_opts |= SF_VERBOSE;
275 break;
276 case Opt_volume: {
277 char *vol = match_strdup(&args[0]);
278 if (!vol)
279 return 0;
280 strlcpy(volume, vol, 32);
281 kfree(vol);
282 break;
283 }
284 case Opt_ignore:
285 /* Silently ignore the quota options */
286 break;
287 default:
288 printk("AFFS: Unrecognized mount option \"%s\" "
289 "or missing value\n", p);
290 return 0;
291 }
292 }
293 return 1;
294 }
295
296 /* This function definitely needs to be split up. Some fine day I'll
297 * hopefully have the guts to do so. Until then: sorry for the mess.
298 */
299
300 static int affs_fill_super(struct super_block *sb, void *data, int silent)
301 {
302 struct affs_sb_info *sbi;
303 struct buffer_head *root_bh = NULL;
304 struct buffer_head *boot_bh;
305 struct inode *root_inode = NULL;
306 s32 root_block;
307 int size, blocksize;
308 u32 chksum;
309 int num_bm;
310 int i, j;
311 s32 key;
312 kuid_t uid;
313 kgid_t gid;
314 int reserved;
315 unsigned long mount_flags;
316 int tmp_flags; /* fix remount prototype... */
317 u8 sig[4];
318 int ret;
319
320 save_mount_options(sb, data);
321
322 pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
323
324 sb->s_magic = AFFS_SUPER_MAGIC;
325 sb->s_op = &affs_sops;
326 sb->s_flags |= MS_NODIRATIME;
327
328 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
329 if (!sbi)
330 return -ENOMEM;
331
332 sb->s_fs_info = sbi;
333 sbi->sb = sb;
334 mutex_init(&sbi->s_bmlock);
335 spin_lock_init(&sbi->symlink_lock);
336 spin_lock_init(&sbi->work_lock);
337 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);
338
339 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
340 &blocksize,&sbi->s_prefix,
341 sbi->s_volume, &mount_flags)) {
342 printk(KERN_ERR "AFFS: Error parsing options\n");
343 kfree(sbi->s_prefix);
344 kfree(sbi);
345 return -EINVAL;
346 }
347 /* N.B. after this point s_prefix must be released */
348
349 sbi->s_flags = mount_flags;
350 sbi->s_mode = i;
351 sbi->s_uid = uid;
352 sbi->s_gid = gid;
353 sbi->s_reserved= reserved;
354
355 /* Get the size of the device in 512-byte blocks.
356 * If we later see that the partition uses bigger
357 * blocks, we will have to change it.
358 */
359
360 size = sb->s_bdev->bd_inode->i_size >> 9;
361 pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
362
363 affs_set_blocksize(sb, PAGE_SIZE);
364 /* Try to find root block. Its location depends on the block size. */
365
366 i = 512;
367 j = 4096;
368 if (blocksize > 0) {
369 i = j = blocksize;
370 size = size / (blocksize / 512);
371 }
372 for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
373 sbi->s_root_block = root_block;
374 if (root_block < 0)
375 sbi->s_root_block = (reserved + size - 1) / 2;
376 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
377 affs_set_blocksize(sb, blocksize);
378 sbi->s_partition_size = size;
379
380 /* The root block location that was calculated above is not
381 * correct if the partition size is an odd number of 512-
382 * byte blocks, which will be rounded down to a number of
383 * 1024-byte blocks, and if there were an even number of
384 * reserved blocks. Ideally, all partition checkers should
385 * report the real number of blocks of the real blocksize,
386 * but since this just cannot be done, we have to try to
387 * find the root block anyways. In the above case, it is one
388 * block behind the calculated one. So we check this one, too.
389 */
390 for (num_bm = 0; num_bm < 2; num_bm++) {
391 pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
392 "size=%d, reserved=%d\n",
393 sb->s_id,
394 sbi->s_root_block + num_bm,
395 blocksize, size, reserved);
396 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
397 if (!root_bh)
398 continue;
399 if (!affs_checksum_block(sb, root_bh) &&
400 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
401 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
402 sbi->s_hashsize = blocksize / 4 - 56;
403 sbi->s_root_block += num_bm;
404 key = 1;
405 goto got_root;
406 }
407 affs_brelse(root_bh);
408 root_bh = NULL;
409 }
410 }
411 if (!silent)
412 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
413 sb->s_id);
414 return -EINVAL;
415
416 /* N.B. after this point bh must be released */
417 got_root:
418 /* Keep super block in cache */
419 sbi->s_root_bh = root_bh;
420 root_block = sbi->s_root_block;
421
422 /* Find out which kind of FS we have */
423 boot_bh = sb_bread(sb, 0);
424 if (!boot_bh) {
425 printk(KERN_ERR "AFFS: Cannot read boot block\n");
426 return -EINVAL;
427 }
428 memcpy(sig, boot_bh->b_data, 4);
429 brelse(boot_bh);
430 chksum = be32_to_cpu(*(__be32 *)sig);
431
432 /* Dircache filesystems are compatible with non-dircache ones
433 * when reading. As long as they aren't supported, writing is
434 * not recommended.
435 */
436 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
437 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
438 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
439 sb->s_id);
440 sb->s_flags |= MS_RDONLY;
441 }
442 switch (chksum) {
443 case MUFS_FS:
444 case MUFS_INTLFFS:
445 case MUFS_DCFFS:
446 sbi->s_flags |= SF_MUFS;
447 /* fall thru */
448 case FS_INTLFFS:
449 case FS_DCFFS:
450 sbi->s_flags |= SF_INTL;
451 break;
452 case MUFS_FFS:
453 sbi->s_flags |= SF_MUFS;
454 break;
455 case FS_FFS:
456 break;
457 case MUFS_OFS:
458 sbi->s_flags |= SF_MUFS;
459 /* fall thru */
460 case FS_OFS:
461 sbi->s_flags |= SF_OFS;
462 sb->s_flags |= MS_NOEXEC;
463 break;
464 case MUFS_DCOFS:
465 case MUFS_INTLOFS:
466 sbi->s_flags |= SF_MUFS;
467 case FS_DCOFS:
468 case FS_INTLOFS:
469 sbi->s_flags |= SF_INTL | SF_OFS;
470 sb->s_flags |= MS_NOEXEC;
471 break;
472 default:
473 printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
474 sb->s_id, chksum);
475 return -EINVAL;
476 }
477
478 if (mount_flags & SF_VERBOSE) {
479 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
480 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
481 len > 31 ? 31 : len,
482 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
483 sig, sig[3] + '0', blocksize);
484 }
485
486 sb->s_flags |= MS_NODEV | MS_NOSUID;
487
488 sbi->s_data_blksize = sb->s_blocksize;
489 if (sbi->s_flags & SF_OFS)
490 sbi->s_data_blksize -= 24;
491
492 tmp_flags = sb->s_flags;
493 ret = affs_init_bitmap(sb, &tmp_flags);
494 if (ret)
495 return ret;
496 sb->s_flags = tmp_flags;
497
498 /* set up enough so that it can read an inode */
499
500 root_inode = affs_iget(sb, root_block);
501 if (IS_ERR(root_inode))
502 return PTR_ERR(root_inode);
503
504 if (AFFS_SB(sb)->s_flags & SF_INTL)
505 sb->s_d_op = &affs_intl_dentry_operations;
506 else
507 sb->s_d_op = &affs_dentry_operations;
508
509 sb->s_root = d_make_root(root_inode);
510 if (!sb->s_root) {
511 printk(KERN_ERR "AFFS: Get root inode failed\n");
512 return -ENOMEM;
513 }
514
515 pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
516 return 0;
517 }
518
519 static int
520 affs_remount(struct super_block *sb, int *flags, char *data)
521 {
522 struct affs_sb_info *sbi = AFFS_SB(sb);
523 int blocksize;
524 kuid_t uid;
525 kgid_t gid;
526 int mode;
527 int reserved;
528 int root_block;
529 unsigned long mount_flags;
530 int res = 0;
531 char *new_opts = kstrdup(data, GFP_KERNEL);
532 char volume[32];
533 char *prefix = NULL;
534
535 pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
536
537 sync_filesystem(sb);
538 *flags |= MS_NODIRATIME;
539
540 memcpy(volume, sbi->s_volume, 32);
541 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
542 &blocksize, &prefix, volume,
543 &mount_flags)) {
544 kfree(prefix);
545 kfree(new_opts);
546 return -EINVAL;
547 }
548
549 flush_delayed_work(&sbi->sb_work);
550 replace_mount_options(sb, new_opts);
551
552 sbi->s_flags = mount_flags;
553 sbi->s_mode = mode;
554 sbi->s_uid = uid;
555 sbi->s_gid = gid;
556 /* protect against readers */
557 spin_lock(&sbi->symlink_lock);
558 if (prefix) {
559 kfree(sbi->s_prefix);
560 sbi->s_prefix = prefix;
561 }
562 memcpy(sbi->s_volume, volume, 32);
563 spin_unlock(&sbi->symlink_lock);
564
565 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
566 return 0;
567
568 if (*flags & MS_RDONLY)
569 affs_free_bitmap(sb);
570 else
571 res = affs_init_bitmap(sb, flags);
572
573 return res;
574 }
575
576 static int
577 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
578 {
579 struct super_block *sb = dentry->d_sb;
580 int free;
581 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
582
583 pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
584 AFFS_SB(sb)->s_reserved);
585
586 free = affs_count_free_blocks(sb);
587 buf->f_type = AFFS_SUPER_MAGIC;
588 buf->f_bsize = sb->s_blocksize;
589 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
590 buf->f_bfree = free;
591 buf->f_bavail = free;
592 buf->f_fsid.val[0] = (u32)id;
593 buf->f_fsid.val[1] = (u32)(id >> 32);
594 buf->f_namelen = 30;
595 return 0;
596 }
597
598 static struct dentry *affs_mount(struct file_system_type *fs_type,
599 int flags, const char *dev_name, void *data)
600 {
601 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
602 }
603
604 static void affs_kill_sb(struct super_block *sb)
605 {
606 struct affs_sb_info *sbi = AFFS_SB(sb);
607 kill_block_super(sb);
608 if (sbi) {
609 affs_free_bitmap(sb);
610 affs_brelse(sbi->s_root_bh);
611 kfree(sbi->s_prefix);
612 kfree(sbi);
613 }
614 }
615
616 static struct file_system_type affs_fs_type = {
617 .owner = THIS_MODULE,
618 .name = "affs",
619 .mount = affs_mount,
620 .kill_sb = affs_kill_sb,
621 .fs_flags = FS_REQUIRES_DEV,
622 };
623 MODULE_ALIAS_FS("affs");
624
625 static int __init init_affs_fs(void)
626 {
627 int err = init_inodecache();
628 if (err)
629 goto out1;
630 err = register_filesystem(&affs_fs_type);
631 if (err)
632 goto out;
633 return 0;
634 out:
635 destroy_inodecache();
636 out1:
637 return err;
638 }
639
640 static void __exit exit_affs_fs(void)
641 {
642 unregister_filesystem(&affs_fs_type);
643 destroy_inodecache();
644 }
645
646 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
647 MODULE_LICENSE("GPL");
648
649 module_init(init_affs_fs)
650 module_exit(exit_affs_fs)
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