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