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[S390] Fix comments in lowcore structure
[zen-stable.git] / fs / affs / super.c
bloba19d64b582aac0e2882610b3a5839d88e0bd329d
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 "affs.h"
20
21 extern struct timezone sys_tz;
22
23 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
24 static int affs_remount (struct super_block *sb, int *flags, char *data);
25
26 static void
27 affs_put_super(struct super_block *sb)
28 {
29 struct affs_sb_info *sbi = AFFS_SB(sb);
30 pr_debug("AFFS: put_super()\n");
31
32 if (!(sb->s_flags & MS_RDONLY)) {
33 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
34 secs_to_datestamp(get_seconds(),
35 &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
36 affs_fix_checksum(sb, sbi->s_root_bh);
37 mark_buffer_dirty(sbi->s_root_bh);
38 }
39
40 kfree(sbi->s_prefix);
41 affs_free_bitmap(sb);
42 affs_brelse(sbi->s_root_bh);
43 kfree(sbi);
44 sb->s_fs_info = NULL;
45 return;
46 }
47
48 static void
49 affs_write_super(struct super_block *sb)
50 {
51 int clean = 2;
52 struct affs_sb_info *sbi = AFFS_SB(sb);
53
54 if (!(sb->s_flags & MS_RDONLY)) {
55 // if (sbi->s_bitmap[i].bm_bh) {
56 // if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
57 // clean = 0;
58 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
59 secs_to_datestamp(get_seconds(),
60 &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
61 affs_fix_checksum(sb, sbi->s_root_bh);
62 mark_buffer_dirty(sbi->s_root_bh);
63 sb->s_dirt = !clean; /* redo until bitmap synced */
64 } else
65 sb->s_dirt = 0;
66
67 pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
68 }
69
70 static struct kmem_cache * affs_inode_cachep;
71
72 static struct inode *affs_alloc_inode(struct super_block *sb)
73 {
74 struct affs_inode_info *i;
75
76 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
77 if (!i)
78 return NULL;
79
80 i->vfs_inode.i_version = 1;
81 i->i_lc = NULL;
82 i->i_ext_bh = NULL;
83 i->i_pa_cnt = 0;
84
85 return &i->vfs_inode;
86 }
87
88 static void affs_destroy_inode(struct inode *inode)
89 {
90 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
91 }
92
93 static void init_once(void *foo)
94 {
95 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
96
97 init_MUTEX(&ei->i_link_lock);
98 init_MUTEX(&ei->i_ext_lock);
99 inode_init_once(&ei->vfs_inode);
100 }
101
102 static int init_inodecache(void)
103 {
104 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
105 sizeof(struct affs_inode_info),
106 0, (SLAB_RECLAIM_ACCOUNT|
107 SLAB_MEM_SPREAD),
108 init_once);
109 if (affs_inode_cachep == NULL)
110 return -ENOMEM;
111 return 0;
112 }
113
114 static void destroy_inodecache(void)
115 {
116 kmem_cache_destroy(affs_inode_cachep);
117 }
118
119 static const struct super_operations affs_sops = {
120 .alloc_inode = affs_alloc_inode,
121 .destroy_inode = affs_destroy_inode,
122 .write_inode = affs_write_inode,
123 .delete_inode = affs_delete_inode,
124 .clear_inode = affs_clear_inode,
125 .put_super = affs_put_super,
126 .write_super = affs_write_super,
127 .statfs = affs_statfs,
128 .remount_fs = affs_remount,
129 .show_options = generic_show_options,
130 };
131
132 enum {
133 Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
134 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
135 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
136 };
137
138 static const match_table_t tokens = {
139 {Opt_bs, "bs=%u"},
140 {Opt_mode, "mode=%o"},
141 {Opt_mufs, "mufs"},
142 {Opt_prefix, "prefix=%s"},
143 {Opt_protect, "protect"},
144 {Opt_reserved, "reserved=%u"},
145 {Opt_root, "root=%u"},
146 {Opt_setgid, "setgid=%u"},
147 {Opt_setuid, "setuid=%u"},
148 {Opt_verbose, "verbose"},
149 {Opt_volume, "volume=%s"},
150 {Opt_ignore, "grpquota"},
151 {Opt_ignore, "noquota"},
152 {Opt_ignore, "quota"},
153 {Opt_ignore, "usrquota"},
154 {Opt_err, NULL},
155 };
156
157 static int
158 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
159 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
160 {
161 char *p;
162 substring_t args[MAX_OPT_ARGS];
163
164 /* Fill in defaults */
165
166 *uid = current_uid();
167 *gid = current_gid();
168 *reserved = 2;
169 *root = -1;
170 *blocksize = -1;
171 volume[0] = ':';
172 volume[1] = 0;
173 *mount_opts = 0;
174 if (!options)
175 return 1;
176
177 while ((p = strsep(&options, ",")) != NULL) {
178 int token, n, option;
179 if (!*p)
180 continue;
181
182 token = match_token(p, tokens, args);
183 switch (token) {
184 case Opt_bs:
185 if (match_int(&args[0], &n))
186 return -EINVAL;
187 if (n != 512 && n != 1024 && n != 2048
188 && n != 4096) {
189 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
190 return 0;
191 }
192 *blocksize = n;
193 break;
194 case Opt_mode:
195 if (match_octal(&args[0], &option))
196 return 1;
197 *mode = option & 0777;
198 *mount_opts |= SF_SETMODE;
199 break;
200 case Opt_mufs:
201 *mount_opts |= SF_MUFS;
202 break;
203 case Opt_prefix:
204 /* Free any previous prefix */
205 kfree(*prefix);
206 *prefix = match_strdup(&args[0]);
207 if (!*prefix)
208 return 0;
209 *mount_opts |= SF_PREFIX;
210 break;
211 case Opt_protect:
212 *mount_opts |= SF_IMMUTABLE;
213 break;
214 case Opt_reserved:
215 if (match_int(&args[0], reserved))
216 return 1;
217 break;
218 case Opt_root:
219 if (match_int(&args[0], root))
220 return 1;
221 break;
222 case Opt_setgid:
223 if (match_int(&args[0], &option))
224 return 1;
225 *gid = option;
226 *mount_opts |= SF_SETGID;
227 break;
228 case Opt_setuid:
229 if (match_int(&args[0], &option))
230 return -EINVAL;
231 *uid = option;
232 *mount_opts |= SF_SETUID;
233 break;
234 case Opt_verbose:
235 *mount_opts |= SF_VERBOSE;
236 break;
237 case Opt_volume: {
238 char *vol = match_strdup(&args[0]);
239 if (!vol)
240 return 0;
241 strlcpy(volume, vol, 32);
242 kfree(vol);
243 break;
244 }
245 case Opt_ignore:
246 /* Silently ignore the quota options */
247 break;
248 default:
249 printk("AFFS: Unrecognized mount option \"%s\" "
250 "or missing value\n", p);
251 return 0;
252 }
253 }
254 return 1;
255 }
256
257 /* This function definitely needs to be split up. Some fine day I'll
258 * hopefully have the guts to do so. Until then: sorry for the mess.
259 */
260
261 static int affs_fill_super(struct super_block *sb, void *data, int silent)
262 {
263 struct affs_sb_info *sbi;
264 struct buffer_head *root_bh = NULL;
265 struct buffer_head *boot_bh;
266 struct inode *root_inode = NULL;
267 s32 root_block;
268 int size, blocksize;
269 u32 chksum;
270 int num_bm;
271 int i, j;
272 s32 key;
273 uid_t uid;
274 gid_t gid;
275 int reserved;
276 unsigned long mount_flags;
277 int tmp_flags; /* fix remount prototype... */
278 u8 sig[4];
279 int ret = -EINVAL;
280
281 save_mount_options(sb, data);
282
283 pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
284
285 sb->s_magic = AFFS_SUPER_MAGIC;
286 sb->s_op = &affs_sops;
287 sb->s_flags |= MS_NODIRATIME;
288
289 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
290 if (!sbi)
291 return -ENOMEM;
292 sb->s_fs_info = sbi;
293 mutex_init(&sbi->s_bmlock);
294
295 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
296 &blocksize,&sbi->s_prefix,
297 sbi->s_volume, &mount_flags)) {
298 printk(KERN_ERR "AFFS: Error parsing options\n");
299 return -EINVAL;
300 }
301 /* N.B. after this point s_prefix must be released */
302
303 sbi->s_flags = mount_flags;
304 sbi->s_mode = i;
305 sbi->s_uid = uid;
306 sbi->s_gid = gid;
307 sbi->s_reserved= reserved;
308
309 /* Get the size of the device in 512-byte blocks.
310 * If we later see that the partition uses bigger
311 * blocks, we will have to change it.
312 */
313
314 size = sb->s_bdev->bd_inode->i_size >> 9;
315 pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
316
317 affs_set_blocksize(sb, PAGE_SIZE);
318 /* Try to find root block. Its location depends on the block size. */
319
320 i = 512;
321 j = 4096;
322 if (blocksize > 0) {
323 i = j = blocksize;
324 size = size / (blocksize / 512);
325 }
326 for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
327 sbi->s_root_block = root_block;
328 if (root_block < 0)
329 sbi->s_root_block = (reserved + size - 1) / 2;
330 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
331 affs_set_blocksize(sb, blocksize);
332 sbi->s_partition_size = size;
333
334 /* The root block location that was calculated above is not
335 * correct if the partition size is an odd number of 512-
336 * byte blocks, which will be rounded down to a number of
337 * 1024-byte blocks, and if there were an even number of
338 * reserved blocks. Ideally, all partition checkers should
339 * report the real number of blocks of the real blocksize,
340 * but since this just cannot be done, we have to try to
341 * find the root block anyways. In the above case, it is one
342 * block behind the calculated one. So we check this one, too.
343 */
344 for (num_bm = 0; num_bm < 2; num_bm++) {
345 pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
346 "size=%d, reserved=%d\n",
347 sb->s_id,
348 sbi->s_root_block + num_bm,
349 blocksize, size, reserved);
350 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
351 if (!root_bh)
352 continue;
353 if (!affs_checksum_block(sb, root_bh) &&
354 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
355 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
356 sbi->s_hashsize = blocksize / 4 - 56;
357 sbi->s_root_block += num_bm;
358 key = 1;
359 goto got_root;
360 }
361 affs_brelse(root_bh);
362 root_bh = NULL;
363 }
364 }
365 if (!silent)
366 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
367 sb->s_id);
368 goto out_error;
369
370 /* N.B. after this point bh must be released */
371 got_root:
372 root_block = sbi->s_root_block;
373
374 /* Find out which kind of FS we have */
375 boot_bh = sb_bread(sb, 0);
376 if (!boot_bh) {
377 printk(KERN_ERR "AFFS: Cannot read boot block\n");
378 goto out_error;
379 }
380 memcpy(sig, boot_bh->b_data, 4);
381 brelse(boot_bh);
382 chksum = be32_to_cpu(*(__be32 *)sig);
383
384 /* Dircache filesystems are compatible with non-dircache ones
385 * when reading. As long as they aren't supported, writing is
386 * not recommended.
387 */
388 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
389 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
390 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
391 sb->s_id);
392 sb->s_flags |= MS_RDONLY;
393 }
394 switch (chksum) {
395 case MUFS_FS:
396 case MUFS_INTLFFS:
397 case MUFS_DCFFS:
398 sbi->s_flags |= SF_MUFS;
399 /* fall thru */
400 case FS_INTLFFS:
401 case FS_DCFFS:
402 sbi->s_flags |= SF_INTL;
403 break;
404 case MUFS_FFS:
405 sbi->s_flags |= SF_MUFS;
406 break;
407 case FS_FFS:
408 break;
409 case MUFS_OFS:
410 sbi->s_flags |= SF_MUFS;
411 /* fall thru */
412 case FS_OFS:
413 sbi->s_flags |= SF_OFS;
414 sb->s_flags |= MS_NOEXEC;
415 break;
416 case MUFS_DCOFS:
417 case MUFS_INTLOFS:
418 sbi->s_flags |= SF_MUFS;
419 case FS_DCOFS:
420 case FS_INTLOFS:
421 sbi->s_flags |= SF_INTL | SF_OFS;
422 sb->s_flags |= MS_NOEXEC;
423 break;
424 default:
425 printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
426 sb->s_id, chksum);
427 goto out_error;
428 }
429
430 if (mount_flags & SF_VERBOSE) {
431 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
432 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
433 len > 31 ? 31 : len,
434 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
435 sig, sig[3] + '0', blocksize);
436 }
437
438 sb->s_flags |= MS_NODEV | MS_NOSUID;
439
440 sbi->s_data_blksize = sb->s_blocksize;
441 if (sbi->s_flags & SF_OFS)
442 sbi->s_data_blksize -= 24;
443
444 /* Keep super block in cache */
445 sbi->s_root_bh = root_bh;
446 /* N.B. after this point s_root_bh must be released */
447
448 tmp_flags = sb->s_flags;
449 if (affs_init_bitmap(sb, &tmp_flags))
450 goto out_error;
451 sb->s_flags = tmp_flags;
452
453 /* set up enough so that it can read an inode */
454
455 root_inode = affs_iget(sb, root_block);
456 if (IS_ERR(root_inode)) {
457 ret = PTR_ERR(root_inode);
458 goto out_error_noinode;
459 }
460
461 sb->s_root = d_alloc_root(root_inode);
462 if (!sb->s_root) {
463 printk(KERN_ERR "AFFS: Get root inode failed\n");
464 goto out_error;
465 }
466 sb->s_root->d_op = &affs_dentry_operations;
467
468 pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
469 return 0;
470
471 /*
472 * Begin the cascaded cleanup ...
473 */
474 out_error:
475 if (root_inode)
476 iput(root_inode);
477 out_error_noinode:
478 kfree(sbi->s_bitmap);
479 affs_brelse(root_bh);
480 kfree(sbi->s_prefix);
481 kfree(sbi);
482 sb->s_fs_info = NULL;
483 return ret;
484 }
485
486 static int
487 affs_remount(struct super_block *sb, int *flags, char *data)
488 {
489 struct affs_sb_info *sbi = AFFS_SB(sb);
490 int blocksize;
491 uid_t uid;
492 gid_t gid;
493 int mode;
494 int reserved;
495 int root_block;
496 unsigned long mount_flags;
497 int res = 0;
498 char *new_opts = kstrdup(data, GFP_KERNEL);
499
500 pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
501
502 *flags |= MS_NODIRATIME;
503
504 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
505 &blocksize, &sbi->s_prefix, sbi->s_volume,
506 &mount_flags)) {
507 kfree(new_opts);
508 return -EINVAL;
509 }
510 kfree(sb->s_options);
511 sb->s_options = new_opts;
512
513 sbi->s_flags = mount_flags;
514 sbi->s_mode = mode;
515 sbi->s_uid = uid;
516 sbi->s_gid = gid;
517
518 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
519 return 0;
520 if (*flags & MS_RDONLY) {
521 sb->s_dirt = 1;
522 while (sb->s_dirt)
523 affs_write_super(sb);
524 affs_free_bitmap(sb);
525 } else
526 res = affs_init_bitmap(sb, flags);
527
528 return res;
529 }
530
531 static int
532 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
533 {
534 struct super_block *sb = dentry->d_sb;
535 int free;
536
537 pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
538 AFFS_SB(sb)->s_reserved);
539
540 free = affs_count_free_blocks(sb);
541 buf->f_type = AFFS_SUPER_MAGIC;
542 buf->f_bsize = sb->s_blocksize;
543 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
544 buf->f_bfree = free;
545 buf->f_bavail = free;
546 return 0;
547 }
548
549 static int affs_get_sb(struct file_system_type *fs_type,
550 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
551 {
552 return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
553 mnt);
554 }
555
556 static struct file_system_type affs_fs_type = {
557 .owner = THIS_MODULE,
558 .name = "affs",
559 .get_sb = affs_get_sb,
560 .kill_sb = kill_block_super,
561 .fs_flags = FS_REQUIRES_DEV,
562 };
563
564 static int __init init_affs_fs(void)
565 {
566 int err = init_inodecache();
567 if (err)
568 goto out1;
569 err = register_filesystem(&affs_fs_type);
570 if (err)
571 goto out;
572 return 0;
573 out:
574 destroy_inodecache();
575 out1:
576 return err;
577 }
578
579 static void __exit exit_affs_fs(void)
580 {
581 unregister_filesystem(&affs_fs_type);
582 destroy_inodecache();
583 }
584
585 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
586 MODULE_LICENSE("GPL");
587
588 module_init(init_affs_fs)
589 module_exit(exit_affs_fs)