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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 "affs.h"
21
22extern struct timezone sys_tz;
23
24static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
25static int affs_remount (struct super_block *sb, int *flags, char *data);
26
27static void
28affs_commit_super(struct super_block *sb, int wait, int clean)
29{
30 struct affs_sb_info *sbi = AFFS_SB(sb);
31 struct buffer_head *bh = sbi->s_root_bh;
32 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh);
33
34 tail->bm_flag = cpu_to_be32(clean);
35 secs_to_datestamp(get_seconds(), &tail->disk_change);
36 affs_fix_checksum(sb, bh);
37 mark_buffer_dirty(bh);
38 if (wait)
39 sync_dirty_buffer(bh);
40}
41
42static void
43affs_put_super(struct super_block *sb)
44{
45 struct affs_sb_info *sbi = AFFS_SB(sb);
46 pr_debug("AFFS: put_super()\n");
47
48 if (!(sb->s_flags & MS_RDONLY) && sb->s_dirt)
49 affs_commit_super(sb, 1, 1);
50
51 kfree(sbi->s_prefix);
52 affs_free_bitmap(sb);
53 affs_brelse(sbi->s_root_bh);
54 kfree(sbi);
55 sb->s_fs_info = NULL;
56}
57
58static void
59affs_write_super(struct super_block *sb)
60{
61 lock_super(sb);
62 if (!(sb->s_flags & MS_RDONLY))
63 affs_commit_super(sb, 1, 2);
64 sb->s_dirt = 0;
65 unlock_super(sb);
66
67 pr_debug("AFFS: write_super() at %lu, clean=2\n", get_seconds());
68}
69
70static int
71affs_sync_fs(struct super_block *sb, int wait)
72{
73 lock_super(sb);
74 affs_commit_super(sb, wait, 2);
75 sb->s_dirt = 0;
76 unlock_super(sb);
77 return 0;
78}
79
80static struct kmem_cache * affs_inode_cachep;
81
82static struct inode *affs_alloc_inode(struct super_block *sb)
83{
84 struct affs_inode_info *i;
85
86 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
87 if (!i)
88 return NULL;
89
90 i->vfs_inode.i_version = 1;
91 i->i_lc = NULL;
92 i->i_ext_bh = NULL;
93 i->i_pa_cnt = 0;
94
95 return &i->vfs_inode;
96}
97
98static void affs_i_callback(struct rcu_head *head)
99{
100 struct inode *inode = container_of(head, struct inode, i_rcu);
101 kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
102}
103
104static void affs_destroy_inode(struct inode *inode)
105{
106 call_rcu(&inode->i_rcu, affs_i_callback);
107}
108
109static void init_once(void *foo)
110{
111 struct affs_inode_info *ei = (struct affs_inode_info *) foo;
112
113 sema_init(&ei->i_link_lock, 1);
114 sema_init(&ei->i_ext_lock, 1);
115 inode_init_once(&ei->vfs_inode);
116}
117
118static int init_inodecache(void)
119{
120 affs_inode_cachep = kmem_cache_create("affs_inode_cache",
121 sizeof(struct affs_inode_info),
122 0, (SLAB_RECLAIM_ACCOUNT|
123 SLAB_MEM_SPREAD),
124 init_once);
125 if (affs_inode_cachep == NULL)
126 return -ENOMEM;
127 return 0;
128}
129
130static void destroy_inodecache(void)
131{
132 kmem_cache_destroy(affs_inode_cachep);
133}
134
135static const struct super_operations affs_sops = {
136 .alloc_inode = affs_alloc_inode,
137 .destroy_inode = affs_destroy_inode,
138 .write_inode = affs_write_inode,
139 .evict_inode = affs_evict_inode,
140 .put_super = affs_put_super,
141 .write_super = affs_write_super,
142 .sync_fs = affs_sync_fs,
143 .statfs = affs_statfs,
144 .remount_fs = affs_remount,
145 .show_options = generic_show_options,
146};
147
148enum {
149 Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
150 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
151 Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
152};
153
154static const match_table_t tokens = {
155 {Opt_bs, "bs=%u"},
156 {Opt_mode, "mode=%o"},
157 {Opt_mufs, "mufs"},
158 {Opt_prefix, "prefix=%s"},
159 {Opt_protect, "protect"},
160 {Opt_reserved, "reserved=%u"},
161 {Opt_root, "root=%u"},
162 {Opt_setgid, "setgid=%u"},
163 {Opt_setuid, "setuid=%u"},
164 {Opt_verbose, "verbose"},
165 {Opt_volume, "volume=%s"},
166 {Opt_ignore, "grpquota"},
167 {Opt_ignore, "noquota"},
168 {Opt_ignore, "quota"},
169 {Opt_ignore, "usrquota"},
170 {Opt_err, NULL},
171};
172
173static int
174parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
175 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
176{
177 char *p;
178 substring_t args[MAX_OPT_ARGS];
179
180 /* Fill in defaults */
181
182 *uid = current_uid();
183 *gid = current_gid();
184 *reserved = 2;
185 *root = -1;
186 *blocksize = -1;
187 volume[0] = ':';
188 volume[1] = 0;
189 *mount_opts = 0;
190 if (!options)
191 return 1;
192
193 while ((p = strsep(&options, ",")) != NULL) {
194 int token, n, option;
195 if (!*p)
196 continue;
197
198 token = match_token(p, tokens, args);
199 switch (token) {
200 case Opt_bs:
201 if (match_int(&args[0], &n))
202 return 0;
203 if (n != 512 && n != 1024 && n != 2048
204 && n != 4096) {
205 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
206 return 0;
207 }
208 *blocksize = n;
209 break;
210 case Opt_mode:
211 if (match_octal(&args[0], &option))
212 return 0;
213 *mode = option & 0777;
214 *mount_opts |= SF_SETMODE;
215 break;
216 case Opt_mufs:
217 *mount_opts |= SF_MUFS;
218 break;
219 case Opt_prefix:
220 *prefix = match_strdup(&args[0]);
221 if (!*prefix)
222 return 0;
223 *mount_opts |= SF_PREFIX;
224 break;
225 case Opt_protect:
226 *mount_opts |= SF_IMMUTABLE;
227 break;
228 case Opt_reserved:
229 if (match_int(&args[0], reserved))
230 return 0;
231 break;
232 case Opt_root:
233 if (match_int(&args[0], root))
234 return 0;
235 break;
236 case Opt_setgid:
237 if (match_int(&args[0], &option))
238 return 0;
239 *gid = option;
240 *mount_opts |= SF_SETGID;
241 break;
242 case Opt_setuid:
243 if (match_int(&args[0], &option))
244 return 0;
245 *uid = option;
246 *mount_opts |= SF_SETUID;
247 break;
248 case Opt_verbose:
249 *mount_opts |= SF_VERBOSE;
250 break;
251 case Opt_volume: {
252 char *vol = match_strdup(&args[0]);
253 if (!vol)
254 return 0;
255 strlcpy(volume, vol, 32);
256 kfree(vol);
257 break;
258 }
259 case Opt_ignore:
260 /* Silently ignore the quota options */
261 break;
262 default:
263 printk("AFFS: Unrecognized mount option \"%s\" "
264 "or missing value\n", p);
265 return 0;
266 }
267 }
268 return 1;
269}
270
271/* This function definitely needs to be split up. Some fine day I'll
272 * hopefully have the guts to do so. Until then: sorry for the mess.
273 */
274
275static int affs_fill_super(struct super_block *sb, void *data, int silent)
276{
277 struct affs_sb_info *sbi;
278 struct buffer_head *root_bh = NULL;
279 struct buffer_head *boot_bh;
280 struct inode *root_inode = NULL;
281 s32 root_block;
282 int size, blocksize;
283 u32 chksum;
284 int num_bm;
285 int i, j;
286 s32 key;
287 uid_t uid;
288 gid_t gid;
289 int reserved;
290 unsigned long mount_flags;
291 int tmp_flags; /* fix remount prototype... */
292 u8 sig[4];
293 int ret = -EINVAL;
294
295 save_mount_options(sb, data);
296
297 pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
298
299 sb->s_magic = AFFS_SUPER_MAGIC;
300 sb->s_op = &affs_sops;
301 sb->s_flags |= MS_NODIRATIME;
302
303 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
304 if (!sbi)
305 return -ENOMEM;
306
307 sb->s_fs_info = sbi;
308 mutex_init(&sbi->s_bmlock);
309 spin_lock_init(&sbi->symlink_lock);
310
311 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
312 &blocksize,&sbi->s_prefix,
313 sbi->s_volume, &mount_flags)) {
314 printk(KERN_ERR "AFFS: Error parsing options\n");
315 kfree(sbi->s_prefix);
316 kfree(sbi);
317 return -EINVAL;
318 }
319 /* N.B. after this point s_prefix must be released */
320
321 sbi->s_flags = mount_flags;
322 sbi->s_mode = i;
323 sbi->s_uid = uid;
324 sbi->s_gid = gid;
325 sbi->s_reserved= reserved;
326
327 /* Get the size of the device in 512-byte blocks.
328 * If we later see that the partition uses bigger
329 * blocks, we will have to change it.
330 */
331
332 size = sb->s_bdev->bd_inode->i_size >> 9;
333 pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
334
335 affs_set_blocksize(sb, PAGE_SIZE);
336 /* Try to find root block. Its location depends on the block size. */
337
338 i = 512;
339 j = 4096;
340 if (blocksize > 0) {
341 i = j = blocksize;
342 size = size / (blocksize / 512);
343 }
344 for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
345 sbi->s_root_block = root_block;
346 if (root_block < 0)
347 sbi->s_root_block = (reserved + size - 1) / 2;
348 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
349 affs_set_blocksize(sb, blocksize);
350 sbi->s_partition_size = size;
351
352 /* The root block location that was calculated above is not
353 * correct if the partition size is an odd number of 512-
354 * byte blocks, which will be rounded down to a number of
355 * 1024-byte blocks, and if there were an even number of
356 * reserved blocks. Ideally, all partition checkers should
357 * report the real number of blocks of the real blocksize,
358 * but since this just cannot be done, we have to try to
359 * find the root block anyways. In the above case, it is one
360 * block behind the calculated one. So we check this one, too.
361 */
362 for (num_bm = 0; num_bm < 2; num_bm++) {
363 pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
364 "size=%d, reserved=%d\n",
365 sb->s_id,
366 sbi->s_root_block + num_bm,
367 blocksize, size, reserved);
368 root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
369 if (!root_bh)
370 continue;
371 if (!affs_checksum_block(sb, root_bh) &&
372 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
373 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
374 sbi->s_hashsize = blocksize / 4 - 56;
375 sbi->s_root_block += num_bm;
376 key = 1;
377 goto got_root;
378 }
379 affs_brelse(root_bh);
380 root_bh = NULL;
381 }
382 }
383 if (!silent)
384 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
385 sb->s_id);
386 goto out_error;
387
388 /* N.B. after this point bh must be released */
389got_root:
390 root_block = sbi->s_root_block;
391
392 /* Find out which kind of FS we have */
393 boot_bh = sb_bread(sb, 0);
394 if (!boot_bh) {
395 printk(KERN_ERR "AFFS: Cannot read boot block\n");
396 goto out_error;
397 }
398 memcpy(sig, boot_bh->b_data, 4);
399 brelse(boot_bh);
400 chksum = be32_to_cpu(*(__be32 *)sig);
401
402 /* Dircache filesystems are compatible with non-dircache ones
403 * when reading. As long as they aren't supported, writing is
404 * not recommended.
405 */
406 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
407 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
408 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
409 sb->s_id);
410 sb->s_flags |= MS_RDONLY;
411 }
412 switch (chksum) {
413 case MUFS_FS:
414 case MUFS_INTLFFS:
415 case MUFS_DCFFS:
416 sbi->s_flags |= SF_MUFS;
417 /* fall thru */
418 case FS_INTLFFS:
419 case FS_DCFFS:
420 sbi->s_flags |= SF_INTL;
421 break;
422 case MUFS_FFS:
423 sbi->s_flags |= SF_MUFS;
424 break;
425 case FS_FFS:
426 break;
427 case MUFS_OFS:
428 sbi->s_flags |= SF_MUFS;
429 /* fall thru */
430 case FS_OFS:
431 sbi->s_flags |= SF_OFS;
432 sb->s_flags |= MS_NOEXEC;
433 break;
434 case MUFS_DCOFS:
435 case MUFS_INTLOFS:
436 sbi->s_flags |= SF_MUFS;
437 case FS_DCOFS:
438 case FS_INTLOFS:
439 sbi->s_flags |= SF_INTL | SF_OFS;
440 sb->s_flags |= MS_NOEXEC;
441 break;
442 default:
443 printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
444 sb->s_id, chksum);
445 goto out_error;
446 }
447
448 if (mount_flags & SF_VERBOSE) {
449 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
450 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
451 len > 31 ? 31 : len,
452 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
453 sig, sig[3] + '0', blocksize);
454 }
455
456 sb->s_flags |= MS_NODEV | MS_NOSUID;
457
458 sbi->s_data_blksize = sb->s_blocksize;
459 if (sbi->s_flags & SF_OFS)
460 sbi->s_data_blksize -= 24;
461
462 /* Keep super block in cache */
463 sbi->s_root_bh = root_bh;
464 /* N.B. after this point s_root_bh must be released */
465
466 tmp_flags = sb->s_flags;
467 if (affs_init_bitmap(sb, &tmp_flags))
468 goto out_error;
469 sb->s_flags = tmp_flags;
470
471 /* set up enough so that it can read an inode */
472
473 root_inode = affs_iget(sb, root_block);
474 if (IS_ERR(root_inode)) {
475 ret = PTR_ERR(root_inode);
476 goto out_error;
477 }
478
479 if (AFFS_SB(sb)->s_flags & SF_INTL)
480 sb->s_d_op = &affs_intl_dentry_operations;
481 else
482 sb->s_d_op = &affs_dentry_operations;
483
484 sb->s_root = d_make_root(root_inode);
485 if (!sb->s_root) {
486 printk(KERN_ERR "AFFS: Get root inode failed\n");
487 goto out_error;
488 }
489
490 pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
491 return 0;
492
493 /*
494 * Begin the cascaded cleanup ...
495 */
496out_error:
497 kfree(sbi->s_bitmap);
498 affs_brelse(root_bh);
499 kfree(sbi->s_prefix);
500 kfree(sbi);
501 sb->s_fs_info = NULL;
502 return ret;
503}
504
505static int
506affs_remount(struct super_block *sb, int *flags, char *data)
507{
508 struct affs_sb_info *sbi = AFFS_SB(sb);
509 int blocksize;
510 uid_t uid;
511 gid_t gid;
512 int mode;
513 int reserved;
514 int root_block;
515 unsigned long mount_flags;
516 int res = 0;
517 char *new_opts = kstrdup(data, GFP_KERNEL);
518 char volume[32];
519 char *prefix = NULL;
520
521 pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
522
523 *flags |= MS_NODIRATIME;
524
525 memcpy(volume, sbi->s_volume, 32);
526 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
527 &blocksize, &prefix, volume,
528 &mount_flags)) {
529 kfree(prefix);
530 kfree(new_opts);
531 return -EINVAL;
532 }
533
534 replace_mount_options(sb, new_opts);
535
536 sbi->s_flags = mount_flags;
537 sbi->s_mode = mode;
538 sbi->s_uid = uid;
539 sbi->s_gid = gid;
540 /* protect against readers */
541 spin_lock(&sbi->symlink_lock);
542 if (prefix) {
543 kfree(sbi->s_prefix);
544 sbi->s_prefix = prefix;
545 }
546 memcpy(sbi->s_volume, volume, 32);
547 spin_unlock(&sbi->symlink_lock);
548
549 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
550 return 0;
551
552 if (*flags & MS_RDONLY) {
553 affs_write_super(sb);
554 affs_free_bitmap(sb);
555 } else
556 res = affs_init_bitmap(sb, flags);
557
558 return res;
559}
560
561static int
562affs_statfs(struct dentry *dentry, struct kstatfs *buf)
563{
564 struct super_block *sb = dentry->d_sb;
565 int free;
566 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
567
568 pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
569 AFFS_SB(sb)->s_reserved);
570
571 free = affs_count_free_blocks(sb);
572 buf->f_type = AFFS_SUPER_MAGIC;
573 buf->f_bsize = sb->s_blocksize;
574 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
575 buf->f_bfree = free;
576 buf->f_bavail = free;
577 buf->f_fsid.val[0] = (u32)id;
578 buf->f_fsid.val[1] = (u32)(id >> 32);
579 buf->f_namelen = 30;
580 return 0;
581}
582
583static struct dentry *affs_mount(struct file_system_type *fs_type,
584 int flags, const char *dev_name, void *data)
585{
586 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super);
587}
588
589static struct file_system_type affs_fs_type = {
590 .owner = THIS_MODULE,
591 .name = "affs",
592 .mount = affs_mount,
593 .kill_sb = kill_block_super,
594 .fs_flags = FS_REQUIRES_DEV,
595};
596
597static int __init init_affs_fs(void)
598{
599 int err = init_inodecache();
600 if (err)
601 goto out1;
602 err = register_filesystem(&affs_fs_type);
603 if (err)
604 goto out;
605 return 0;
606out:
607 destroy_inodecache();
608out1:
609 return err;
610}
611
612static void __exit exit_affs_fs(void)
613{
614 unregister_filesystem(&affs_fs_type);
615 destroy_inodecache();
616}
617
618MODULE_DESCRIPTION("Amiga filesystem support for Linux");
619MODULE_LICENSE("GPL");
620
621module_init(init_affs_fs)
622module_exit(exit_affs_fs)