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Linux-2.6.12-rc2
[linux-2.6/kvm.git] / fs / affs / super.c
blob9c3080716c924526a481c313e9176e093669068d
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 "affs.h"
18
19 extern struct timezone sys_tz;
20
21 static int affs_statfs(struct super_block *sb, struct kstatfs *buf);
22 static int affs_remount (struct super_block *sb, int *flags, char *data);
23
24 static void
25 affs_put_super(struct super_block *sb)
26 {
27 struct affs_sb_info *sbi = AFFS_SB(sb);
28 pr_debug("AFFS: put_super()\n");
29
30 if (!(sb->s_flags & MS_RDONLY)) {
31 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
32 secs_to_datestamp(get_seconds(),
33 &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
34 affs_fix_checksum(sb, sbi->s_root_bh);
35 mark_buffer_dirty(sbi->s_root_bh);
36 }
37
38 if (sbi->s_prefix)
39 kfree(sbi->s_prefix);
40 affs_free_bitmap(sb);
41 affs_brelse(sbi->s_root_bh);
42 kfree(sbi);
43 sb->s_fs_info = NULL;
44 return;
45 }
46
47 static void
48 affs_write_super(struct super_block *sb)
49 {
50 int clean = 2;
51 struct affs_sb_info *sbi = AFFS_SB(sb);
52
53 if (!(sb->s_flags & MS_RDONLY)) {
54 // if (sbi->s_bitmap[i].bm_bh) {
55 // if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
56 // clean = 0;
57 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
58 secs_to_datestamp(get_seconds(),
59 &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
60 affs_fix_checksum(sb, sbi->s_root_bh);
61 mark_buffer_dirty(sbi->s_root_bh);
62 sb->s_dirt = !clean; /* redo until bitmap synced */
63 } else
64 sb->s_dirt = 0;
65
66 pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
67 }
68
69 static kmem_cache_t * affs_inode_cachep;
70
71 static struct inode *affs_alloc_inode(struct super_block *sb)
72 {
73 struct affs_inode_info *ei;
74 ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, SLAB_KERNEL);
75 if (!ei)
76 return NULL;
77 ei->vfs_inode.i_version = 1;
78 return &ei->vfs_inode;
79 }
80
81 static void affs_destroy_inode(struct inode *inode)
82 {
83 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
84 }
85
86 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
87 {
88 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
89
90 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
91 SLAB_CTOR_CONSTRUCTOR) {
92 init_MUTEX(&ei->i_link_lock);
93 init_MUTEX(&ei->i_ext_lock);
94 inode_init_once(&ei->vfs_inode);
95 }
96 }
97
98 static int init_inodecache(void)
99 {
100 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
101 sizeof(struct affs_inode_info),
102 0, SLAB_RECLAIM_ACCOUNT,
103 init_once, NULL);
104 if (affs_inode_cachep == NULL)
105 return -ENOMEM;
106 return 0;
107 }
108
109 static void destroy_inodecache(void)
110 {
111 if (kmem_cache_destroy(affs_inode_cachep))
112 printk(KERN_INFO "affs_inode_cache: not all structures were freed\n");
113 }
114
115 static struct super_operations affs_sops = {
116 .alloc_inode = affs_alloc_inode,
117 .destroy_inode = affs_destroy_inode,
118 .read_inode = affs_read_inode,
119 .write_inode = affs_write_inode,
120 .put_inode = affs_put_inode,
121 .delete_inode = affs_delete_inode,
122 .clear_inode = affs_clear_inode,
123 .put_super = affs_put_super,
124 .write_super = affs_write_super,
125 .statfs = affs_statfs,
126 .remount_fs = affs_remount,
127 };
128
129 enum {
130 Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
131 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
132 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
133 };
134
135 static match_table_t tokens = {
136 {Opt_bs, "bs=%u"},
137 {Opt_mode, "mode=%o"},
138 {Opt_mufs, "mufs"},
139 {Opt_prefix, "prefix=%s"},
140 {Opt_protect, "protect"},
141 {Opt_reserved, "reserved=%u"},
142 {Opt_root, "root=%u"},
143 {Opt_setgid, "setgid=%u"},
144 {Opt_setuid, "setuid=%u"},
145 {Opt_verbose, "verbose"},
146 {Opt_volume, "volume=%s"},
147 {Opt_ignore, "grpquota"},
148 {Opt_ignore, "noquota"},
149 {Opt_ignore, "quota"},
150 {Opt_ignore, "usrquota"},
151 {Opt_err, NULL},
152 };
153
154 static int
155 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
156 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
157 {
158 char *p;
159 substring_t args[MAX_OPT_ARGS];
160
161 /* Fill in defaults */
162
163 *uid = current->uid;
164 *gid = current->gid;
165 *reserved = 2;
166 *root = -1;
167 *blocksize = -1;
168 volume[0] = ':';
169 volume[1] = 0;
170 *mount_opts = 0;
171 if (!options)
172 return 1;
173
174 while ((p = strsep(&options, ",")) != NULL) {
175 int token, n, option;
176 if (!*p)
177 continue;
178
179 token = match_token(p, tokens, args);
180 switch (token) {
181 case Opt_bs:
182 if (match_int(&args[0], &n))
183 return -EINVAL;
184 if (n != 512 && n != 1024 && n != 2048
185 && n != 4096) {
186 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
187 return 0;
188 }
189 *blocksize = n;
190 break;
191 case Opt_mode:
192 if (match_octal(&args[0], &option))
193 return 1;
194 *mode = option & 0777;
195 *mount_opts |= SF_SETMODE;
196 break;
197 case Opt_mufs:
198 *mount_opts |= SF_MUFS;
199 break;
200 case Opt_prefix:
201 if (*prefix) { /* Free any previous prefix */
202 kfree(*prefix);
203 *prefix = NULL;
204 }
205 *prefix = match_strdup(&args[0]);
206 if (!*prefix)
207 return 0;
208 *mount_opts |= SF_PREFIX;
209 break;
210 case Opt_protect:
211 *mount_opts |= SF_IMMUTABLE;
212 break;
213 case Opt_reserved:
214 if (match_int(&args[0], reserved))
215 return 1;
216 break;
217 case Opt_root:
218 if (match_int(&args[0], root))
219 return 1;
220 break;
221 case Opt_setgid:
222 if (match_int(&args[0], &option))
223 return 1;
224 *gid = option;
225 *mount_opts |= SF_SETGID;
226 break;
227 case Opt_setuid:
228 if (match_int(&args[0], &option))
229 return -EINVAL;
230 *uid = option;
231 *mount_opts |= SF_SETUID;
232 break;
233 case Opt_verbose:
234 *mount_opts |= SF_VERBOSE;
235 break;
236 case Opt_volume: {
237 char *vol = match_strdup(&args[0]);
238 strlcpy(volume, vol, 32);
239 kfree(vol);
240 break;
241 }
242 case Opt_ignore:
243 /* Silently ignore the quota options */
244 break;
245 default:
246 printk("AFFS: Unrecognized mount option \"%s\" "
247 "or missing value\n", p);
248 return 0;
249 }
250 }
251 return 1;
252 }
253
254 /* This function definitely needs to be split up. Some fine day I'll
255 * hopefully have the guts to do so. Until then: sorry for the mess.
256 */
257
258 static int affs_fill_super(struct super_block *sb, void *data, int silent)
259 {
260 struct affs_sb_info *sbi;
261 struct buffer_head *root_bh = NULL;
262 struct buffer_head *boot_bh;
263 struct inode *root_inode = NULL;
264 s32 root_block;
265 int size, blocksize;
266 u32 chksum;
267 int num_bm;
268 int i, j;
269 s32 key;
270 uid_t uid;
271 gid_t gid;
272 int reserved;
273 unsigned long mount_flags;
274 int tmp_flags; /* fix remount prototype... */
275
276 pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
277
278 sb->s_magic = AFFS_SUPER_MAGIC;
279 sb->s_op = &affs_sops;
280 sb->s_flags |= MS_NODIRATIME;
281
282 sbi = kmalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
283 if (!sbi)
284 return -ENOMEM;
285 sb->s_fs_info = sbi;
286 memset(sbi, 0, sizeof(*sbi));
287 init_MUTEX(&sbi->s_bmlock);
288
289 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
290 &blocksize,&sbi->s_prefix,
291 sbi->s_volume, &mount_flags)) {
292 printk(KERN_ERR "AFFS: Error parsing options\n");
293 return -EINVAL;
294 }
295 /* N.B. after this point s_prefix must be released */
296
297 sbi->s_flags = mount_flags;
298 sbi->s_mode = i;
299 sbi->s_uid = uid;
300 sbi->s_gid = gid;
301 sbi->s_reserved= reserved;
302
303 /* Get the size of the device in 512-byte blocks.
304 * If we later see that the partition uses bigger
305 * blocks, we will have to change it.
306 */
307
308 size = sb->s_bdev->bd_inode->i_size >> 9;
309 pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
310
311 affs_set_blocksize(sb, PAGE_SIZE);
312 /* Try to find root block. Its location depends on the block size. */
313
314 i = 512;
315 j = 4096;
316 if (blocksize > 0) {
317 i = j = blocksize;
318 size = size / (blocksize / 512);
319 }
320 for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
321 sbi->s_root_block = root_block;
322 if (root_block < 0)
323 sbi->s_root_block = (reserved + size - 1) / 2;
324 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
325 affs_set_blocksize(sb, blocksize);
326 sbi->s_partition_size = size;
327
328 /* The root block location that was calculated above is not
329 * correct if the partition size is an odd number of 512-
330 * byte blocks, which will be rounded down to a number of
331 * 1024-byte blocks, and if there were an even number of
332 * reserved blocks. Ideally, all partition checkers should
333 * report the real number of blocks of the real blocksize,
334 * but since this just cannot be done, we have to try to
335 * find the root block anyways. In the above case, it is one
336 * block behind the calculated one. So we check this one, too.
337 */
338 for (num_bm = 0; num_bm < 2; num_bm++) {
339 pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
340 "size=%d, reserved=%d\n",
341 sb->s_id,
342 sbi->s_root_block + num_bm,
343 blocksize, size, reserved);
344 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
345 if (!root_bh)
346 continue;
347 if (!affs_checksum_block(sb, root_bh) &&
348 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
349 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
350 sbi->s_hashsize = blocksize / 4 - 56;
351 sbi->s_root_block += num_bm;
352 key = 1;
353 goto got_root;
354 }
355 affs_brelse(root_bh);
356 root_bh = NULL;
357 }
358 }
359 if (!silent)
360 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
361 sb->s_id);
362 goto out_error;
363
364 /* N.B. after this point bh must be released */
365 got_root:
366 root_block = sbi->s_root_block;
367
368 /* Find out which kind of FS we have */
369 boot_bh = sb_bread(sb, 0);
370 if (!boot_bh) {
371 printk(KERN_ERR "AFFS: Cannot read boot block\n");
372 goto out_error;
373 }
374 chksum = be32_to_cpu(*(__be32 *)boot_bh->b_data);
375 brelse(boot_bh);
376
377 /* Dircache filesystems are compatible with non-dircache ones
378 * when reading. As long as they aren't supported, writing is
379 * not recommended.
380 */
381 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
382 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
383 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
384 sb->s_id);
385 sb->s_flags |= MS_RDONLY;
386 }
387 switch (chksum) {
388 case MUFS_FS:
389 case MUFS_INTLFFS:
390 case MUFS_DCFFS:
391 sbi->s_flags |= SF_MUFS;
392 /* fall thru */
393 case FS_INTLFFS:
394 case FS_DCFFS:
395 sbi->s_flags |= SF_INTL;
396 break;
397 case MUFS_FFS:
398 sbi->s_flags |= SF_MUFS;
399 break;
400 case FS_FFS:
401 break;
402 case MUFS_OFS:
403 sbi->s_flags |= SF_MUFS;
404 /* fall thru */
405 case FS_OFS:
406 sbi->s_flags |= SF_OFS;
407 sb->s_flags |= MS_NOEXEC;
408 break;
409 case MUFS_DCOFS:
410 case MUFS_INTLOFS:
411 sbi->s_flags |= SF_MUFS;
412 case FS_DCOFS:
413 case FS_INTLOFS:
414 sbi->s_flags |= SF_INTL | SF_OFS;
415 sb->s_flags |= MS_NOEXEC;
416 break;
417 default:
418 printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
419 sb->s_id, chksum);
420 goto out_error;
421 }
422
423 if (mount_flags & SF_VERBOSE) {
424 chksum = cpu_to_be32(chksum);
425 printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
426 AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0],
427 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
428 (char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
429 }
430
431 sb->s_flags |= MS_NODEV | MS_NOSUID;
432
433 sbi->s_data_blksize = sb->s_blocksize;
434 if (sbi->s_flags & SF_OFS)
435 sbi->s_data_blksize -= 24;
436
437 /* Keep super block in cache */
438 sbi->s_root_bh = root_bh;
439 /* N.B. after this point s_root_bh must be released */
440
441 tmp_flags = sb->s_flags;
442 if (affs_init_bitmap(sb, &tmp_flags))
443 goto out_error;
444 sb->s_flags = tmp_flags;
445
446 /* set up enough so that it can read an inode */
447
448 root_inode = iget(sb, root_block);
449 sb->s_root = d_alloc_root(root_inode);
450 if (!sb->s_root) {
451 printk(KERN_ERR "AFFS: Get root inode failed\n");
452 goto out_error;
453 }
454 sb->s_root->d_op = &affs_dentry_operations;
455
456 pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
457 return 0;
458
459 /*
460 * Begin the cascaded cleanup ...
461 */
462 out_error:
463 if (root_inode)
464 iput(root_inode);
465 if (sbi->s_bitmap)
466 kfree(sbi->s_bitmap);
467 affs_brelse(root_bh);
468 if (sbi->s_prefix)
469 kfree(sbi->s_prefix);
470 kfree(sbi);
471 sb->s_fs_info = NULL;
472 return -EINVAL;
473 }
474
475 static int
476 affs_remount(struct super_block *sb, int *flags, char *data)
477 {
478 struct affs_sb_info *sbi = AFFS_SB(sb);
479 int blocksize;
480 uid_t uid;
481 gid_t gid;
482 int mode;
483 int reserved;
484 int root_block;
485 unsigned long mount_flags;
486 int res = 0;
487
488 pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
489
490 *flags |= MS_NODIRATIME;
491
492 if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
493 &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
494 return -EINVAL;
495 sbi->s_flags = mount_flags;
496 sbi->s_mode = mode;
497 sbi->s_uid = uid;
498 sbi->s_gid = gid;
499
500 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
501 return 0;
502 if (*flags & MS_RDONLY) {
503 sb->s_dirt = 1;
504 while (sb->s_dirt)
505 affs_write_super(sb);
506 affs_free_bitmap(sb);
507 } else
508 res = affs_init_bitmap(sb, flags);
509
510 return res;
511 }
512
513 static int
514 affs_statfs(struct super_block *sb, struct kstatfs *buf)
515 {
516 int free;
517
518 pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
519 AFFS_SB(sb)->s_reserved);
520
521 free = affs_count_free_blocks(sb);
522 buf->f_type = AFFS_SUPER_MAGIC;
523 buf->f_bsize = sb->s_blocksize;
524 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
525 buf->f_bfree = free;
526 buf->f_bavail = free;
527 return 0;
528 }
529
530 static struct super_block *affs_get_sb(struct file_system_type *fs_type,
531 int flags, const char *dev_name, void *data)
532 {
533 return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super);
534 }
535
536 static struct file_system_type affs_fs_type = {
537 .owner = THIS_MODULE,
538 .name = "affs",
539 .get_sb = affs_get_sb,
540 .kill_sb = kill_block_super,
541 .fs_flags = FS_REQUIRES_DEV,
542 };
543
544 static int __init init_affs_fs(void)
545 {
546 int err = init_inodecache();
547 if (err)
548 goto out1;
549 err = register_filesystem(&affs_fs_type);
550 if (err)
551 goto out;
552 return 0;
553 out:
554 destroy_inodecache();
555 out1:
556 return err;
557 }
558
559 static void __exit exit_affs_fs(void)
560 {
561 unregister_filesystem(&affs_fs_type);
562 destroy_inodecache();
563 }
564
565 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
566 MODULE_LICENSE("GPL");
567
568 module_init(init_affs_fs)
569 module_exit(exit_affs_fs)
kernel-based virtual machine