Merge branch 'vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
[linux-3.10.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 "affs.h"
21
22 extern struct timezone sys_tz;
23
24 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
25 static int affs_remount (struct super_block *sb, int *flags, char *data);
26
27 static void
28 affs_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
42 static void
43 affs_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
58 static void
59 affs_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
70 static int
71 affs_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
80 static struct kmem_cache * affs_inode_cachep;
81
82 static 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
98 static void affs_destroy_inode(struct inode *inode)
99 {
100         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
101 }
102
103 static void init_once(void *foo)
104 {
105         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
106
107         sema_init(&ei->i_link_lock, 1);
108         sema_init(&ei->i_ext_lock, 1);
109         inode_init_once(&ei->vfs_inode);
110 }
111
112 static int init_inodecache(void)
113 {
114         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
115                                              sizeof(struct affs_inode_info),
116                                              0, (SLAB_RECLAIM_ACCOUNT|
117                                                 SLAB_MEM_SPREAD),
118                                              init_once);
119         if (affs_inode_cachep == NULL)
120                 return -ENOMEM;
121         return 0;
122 }
123
124 static void destroy_inodecache(void)
125 {
126         kmem_cache_destroy(affs_inode_cachep);
127 }
128
129 static const struct super_operations affs_sops = {
130         .alloc_inode    = affs_alloc_inode,
131         .destroy_inode  = affs_destroy_inode,
132         .write_inode    = affs_write_inode,
133         .evict_inode    = affs_evict_inode,
134         .put_super      = affs_put_super,
135         .write_super    = affs_write_super,
136         .sync_fs        = affs_sync_fs,
137         .statfs         = affs_statfs,
138         .remount_fs     = affs_remount,
139         .show_options   = generic_show_options,
140 };
141
142 enum {
143         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
144         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
145         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
146 };
147
148 static const match_table_t tokens = {
149         {Opt_bs, "bs=%u"},
150         {Opt_mode, "mode=%o"},
151         {Opt_mufs, "mufs"},
152         {Opt_prefix, "prefix=%s"},
153         {Opt_protect, "protect"},
154         {Opt_reserved, "reserved=%u"},
155         {Opt_root, "root=%u"},
156         {Opt_setgid, "setgid=%u"},
157         {Opt_setuid, "setuid=%u"},
158         {Opt_verbose, "verbose"},
159         {Opt_volume, "volume=%s"},
160         {Opt_ignore, "grpquota"},
161         {Opt_ignore, "noquota"},
162         {Opt_ignore, "quota"},
163         {Opt_ignore, "usrquota"},
164         {Opt_err, NULL},
165 };
166
167 static int
168 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
169                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
170 {
171         char *p;
172         substring_t args[MAX_OPT_ARGS];
173
174         /* Fill in defaults */
175
176         *uid        = current_uid();
177         *gid        = current_gid();
178         *reserved   = 2;
179         *root       = -1;
180         *blocksize  = -1;
181         volume[0]   = ':';
182         volume[1]   = 0;
183         *mount_opts = 0;
184         if (!options)
185                 return 1;
186
187         while ((p = strsep(&options, ",")) != NULL) {
188                 int token, n, option;
189                 if (!*p)
190                         continue;
191
192                 token = match_token(p, tokens, args);
193                 switch (token) {
194                 case Opt_bs:
195                         if (match_int(&args[0], &n))
196                                 return 0;
197                         if (n != 512 && n != 1024 && n != 2048
198                             && n != 4096) {
199                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
200                                 return 0;
201                         }
202                         *blocksize = n;
203                         break;
204                 case Opt_mode:
205                         if (match_octal(&args[0], &option))
206                                 return 0;
207                         *mode = option & 0777;
208                         *mount_opts |= SF_SETMODE;
209                         break;
210                 case Opt_mufs:
211                         *mount_opts |= SF_MUFS;
212                         break;
213                 case Opt_prefix:
214                         *prefix = match_strdup(&args[0]);
215                         if (!*prefix)
216                                 return 0;
217                         *mount_opts |= SF_PREFIX;
218                         break;
219                 case Opt_protect:
220                         *mount_opts |= SF_IMMUTABLE;
221                         break;
222                 case Opt_reserved:
223                         if (match_int(&args[0], reserved))
224                                 return 0;
225                         break;
226                 case Opt_root:
227                         if (match_int(&args[0], root))
228                                 return 0;
229                         break;
230                 case Opt_setgid:
231                         if (match_int(&args[0], &option))
232                                 return 0;
233                         *gid = option;
234                         *mount_opts |= SF_SETGID;
235                         break;
236                 case Opt_setuid:
237                         if (match_int(&args[0], &option))
238                                 return 0;
239                         *uid = option;
240                         *mount_opts |= SF_SETUID;
241                         break;
242                 case Opt_verbose:
243                         *mount_opts |= SF_VERBOSE;
244                         break;
245                 case Opt_volume: {
246                         char *vol = match_strdup(&args[0]);
247                         if (!vol)
248                                 return 0;
249                         strlcpy(volume, vol, 32);
250                         kfree(vol);
251                         break;
252                 }
253                 case Opt_ignore:
254                         /* Silently ignore the quota options */
255                         break;
256                 default:
257                         printk("AFFS: Unrecognized mount option \"%s\" "
258                                         "or missing value\n", p);
259                         return 0;
260                 }
261         }
262         return 1;
263 }
264
265 /* This function definitely needs to be split up. Some fine day I'll
266  * hopefully have the guts to do so. Until then: sorry for the mess.
267  */
268
269 static int affs_fill_super(struct super_block *sb, void *data, int silent)
270 {
271         struct affs_sb_info     *sbi;
272         struct buffer_head      *root_bh = NULL;
273         struct buffer_head      *boot_bh;
274         struct inode            *root_inode = NULL;
275         s32                      root_block;
276         int                      size, blocksize;
277         u32                      chksum;
278         int                      num_bm;
279         int                      i, j;
280         s32                      key;
281         uid_t                    uid;
282         gid_t                    gid;
283         int                      reserved;
284         unsigned long            mount_flags;
285         int                      tmp_flags;     /* fix remount prototype... */
286         u8                       sig[4];
287         int                      ret = -EINVAL;
288
289         save_mount_options(sb, data);
290
291         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
292
293         sb->s_magic             = AFFS_SUPER_MAGIC;
294         sb->s_op                = &affs_sops;
295         sb->s_flags |= MS_NODIRATIME;
296
297         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
298         if (!sbi)
299                 return -ENOMEM;
300
301         sb->s_fs_info = sbi;
302         mutex_init(&sbi->s_bmlock);
303         spin_lock_init(&sbi->symlink_lock);
304
305         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
306                                 &blocksize,&sbi->s_prefix,
307                                 sbi->s_volume, &mount_flags)) {
308                 printk(KERN_ERR "AFFS: Error parsing options\n");
309                 kfree(sbi->s_prefix);
310                 kfree(sbi);
311                 return -EINVAL;
312         }
313         /* N.B. after this point s_prefix must be released */
314
315         sbi->s_flags   = mount_flags;
316         sbi->s_mode    = i;
317         sbi->s_uid     = uid;
318         sbi->s_gid     = gid;
319         sbi->s_reserved= reserved;
320
321         /* Get the size of the device in 512-byte blocks.
322          * If we later see that the partition uses bigger
323          * blocks, we will have to change it.
324          */
325
326         size = sb->s_bdev->bd_inode->i_size >> 9;
327         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
328
329         affs_set_blocksize(sb, PAGE_SIZE);
330         /* Try to find root block. Its location depends on the block size. */
331
332         i = 512;
333         j = 4096;
334         if (blocksize > 0) {
335                 i = j = blocksize;
336                 size = size / (blocksize / 512);
337         }
338         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
339                 sbi->s_root_block = root_block;
340                 if (root_block < 0)
341                         sbi->s_root_block = (reserved + size - 1) / 2;
342                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
343                 affs_set_blocksize(sb, blocksize);
344                 sbi->s_partition_size = size;
345
346                 /* The root block location that was calculated above is not
347                  * correct if the partition size is an odd number of 512-
348                  * byte blocks, which will be rounded down to a number of
349                  * 1024-byte blocks, and if there were an even number of
350                  * reserved blocks. Ideally, all partition checkers should
351                  * report the real number of blocks of the real blocksize,
352                  * but since this just cannot be done, we have to try to
353                  * find the root block anyways. In the above case, it is one
354                  * block behind the calculated one. So we check this one, too.
355                  */
356                 for (num_bm = 0; num_bm < 2; num_bm++) {
357                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
358                                 "size=%d, reserved=%d\n",
359                                 sb->s_id,
360                                 sbi->s_root_block + num_bm,
361                                 blocksize, size, reserved);
362                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
363                         if (!root_bh)
364                                 continue;
365                         if (!affs_checksum_block(sb, root_bh) &&
366                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
367                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
368                                 sbi->s_hashsize    = blocksize / 4 - 56;
369                                 sbi->s_root_block += num_bm;
370                                 key                        = 1;
371                                 goto got_root;
372                         }
373                         affs_brelse(root_bh);
374                         root_bh = NULL;
375                 }
376         }
377         if (!silent)
378                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
379                         sb->s_id);
380         goto out_error;
381
382         /* N.B. after this point bh must be released */
383 got_root:
384         root_block = sbi->s_root_block;
385
386         /* Find out which kind of FS we have */
387         boot_bh = sb_bread(sb, 0);
388         if (!boot_bh) {
389                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
390                 goto out_error;
391         }
392         memcpy(sig, boot_bh->b_data, 4);
393         brelse(boot_bh);
394         chksum = be32_to_cpu(*(__be32 *)sig);
395
396         /* Dircache filesystems are compatible with non-dircache ones
397          * when reading. As long as they aren't supported, writing is
398          * not recommended.
399          */
400         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
401              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
402                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
403                         sb->s_id);
404                 sb->s_flags |= MS_RDONLY;
405         }
406         switch (chksum) {
407                 case MUFS_FS:
408                 case MUFS_INTLFFS:
409                 case MUFS_DCFFS:
410                         sbi->s_flags |= SF_MUFS;
411                         /* fall thru */
412                 case FS_INTLFFS:
413                 case FS_DCFFS:
414                         sbi->s_flags |= SF_INTL;
415                         break;
416                 case MUFS_FFS:
417                         sbi->s_flags |= SF_MUFS;
418                         break;
419                 case FS_FFS:
420                         break;
421                 case MUFS_OFS:
422                         sbi->s_flags |= SF_MUFS;
423                         /* fall thru */
424                 case FS_OFS:
425                         sbi->s_flags |= SF_OFS;
426                         sb->s_flags |= MS_NOEXEC;
427                         break;
428                 case MUFS_DCOFS:
429                 case MUFS_INTLOFS:
430                         sbi->s_flags |= SF_MUFS;
431                 case FS_DCOFS:
432                 case FS_INTLOFS:
433                         sbi->s_flags |= SF_INTL | SF_OFS;
434                         sb->s_flags |= MS_NOEXEC;
435                         break;
436                 default:
437                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
438                                 sb->s_id, chksum);
439                         goto out_error;
440         }
441
442         if (mount_flags & SF_VERBOSE) {
443                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
444                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
445                         len > 31 ? 31 : len,
446                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
447                         sig, sig[3] + '0', blocksize);
448         }
449
450         sb->s_flags |= MS_NODEV | MS_NOSUID;
451
452         sbi->s_data_blksize = sb->s_blocksize;
453         if (sbi->s_flags & SF_OFS)
454                 sbi->s_data_blksize -= 24;
455
456         /* Keep super block in cache */
457         sbi->s_root_bh = root_bh;
458         /* N.B. after this point s_root_bh must be released */
459
460         tmp_flags = sb->s_flags;
461         if (affs_init_bitmap(sb, &tmp_flags))
462                 goto out_error;
463         sb->s_flags = tmp_flags;
464
465         /* set up enough so that it can read an inode */
466
467         root_inode = affs_iget(sb, root_block);
468         if (IS_ERR(root_inode)) {
469                 ret = PTR_ERR(root_inode);
470                 goto out_error_noinode;
471         }
472
473         sb->s_root = d_alloc_root(root_inode);
474         if (!sb->s_root) {
475                 printk(KERN_ERR "AFFS: Get root inode failed\n");
476                 goto out_error;
477         }
478         sb->s_root->d_op = &affs_dentry_operations;
479
480         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
481         return 0;
482
483         /*
484          * Begin the cascaded cleanup ...
485          */
486 out_error:
487         if (root_inode)
488                 iput(root_inode);
489 out_error_noinode:
490         kfree(sbi->s_bitmap);
491         affs_brelse(root_bh);
492         kfree(sbi->s_prefix);
493         kfree(sbi);
494         sb->s_fs_info = NULL;
495         return ret;
496 }
497
498 static int
499 affs_remount(struct super_block *sb, int *flags, char *data)
500 {
501         struct affs_sb_info     *sbi = AFFS_SB(sb);
502         int                      blocksize;
503         uid_t                    uid;
504         gid_t                    gid;
505         int                      mode;
506         int                      reserved;
507         int                      root_block;
508         unsigned long            mount_flags;
509         int                      res = 0;
510         char                    *new_opts = kstrdup(data, GFP_KERNEL);
511         char                     volume[32];
512         char                    *prefix = NULL;
513
514         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
515
516         *flags |= MS_NODIRATIME;
517
518         memcpy(volume, sbi->s_volume, 32);
519         if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block,
520                            &blocksize, &prefix, volume,
521                            &mount_flags)) {
522                 kfree(prefix);
523                 kfree(new_opts);
524                 return -EINVAL;
525         }
526
527         replace_mount_options(sb, new_opts);
528
529         sbi->s_flags = mount_flags;
530         sbi->s_mode  = mode;
531         sbi->s_uid   = uid;
532         sbi->s_gid   = gid;
533         /* protect against readers */
534         spin_lock(&sbi->symlink_lock);
535         if (prefix) {
536                 kfree(sbi->s_prefix);
537                 sbi->s_prefix = prefix;
538         }
539         memcpy(sbi->s_volume, volume, 32);
540         spin_unlock(&sbi->symlink_lock);
541
542         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
543                 return 0;
544
545         if (*flags & MS_RDONLY) {
546                 affs_write_super(sb);
547                 affs_free_bitmap(sb);
548         } else
549                 res = affs_init_bitmap(sb, flags);
550
551         return res;
552 }
553
554 static int
555 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
556 {
557         struct super_block *sb = dentry->d_sb;
558         int              free;
559         u64              id = huge_encode_dev(sb->s_bdev->bd_dev);
560
561         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
562              AFFS_SB(sb)->s_reserved);
563
564         free          = affs_count_free_blocks(sb);
565         buf->f_type    = AFFS_SUPER_MAGIC;
566         buf->f_bsize   = sb->s_blocksize;
567         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
568         buf->f_bfree   = free;
569         buf->f_bavail  = free;
570         buf->f_fsid.val[0] = (u32)id;
571         buf->f_fsid.val[1] = (u32)(id >> 32);
572         buf->f_namelen = 30;
573         return 0;
574 }
575
576 static int affs_get_sb(struct file_system_type *fs_type,
577         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
578 {
579         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
580                            mnt);
581 }
582
583 static struct file_system_type affs_fs_type = {
584         .owner          = THIS_MODULE,
585         .name           = "affs",
586         .get_sb         = affs_get_sb,
587         .kill_sb        = kill_block_super,
588         .fs_flags       = FS_REQUIRES_DEV,
589 };
590
591 static int __init init_affs_fs(void)
592 {
593         int err = init_inodecache();
594         if (err)
595                 goto out1;
596         err = register_filesystem(&affs_fs_type);
597         if (err)
598                 goto out;
599         return 0;
600 out:
601         destroy_inodecache();
602 out1:
603         return err;
604 }
605
606 static void __exit exit_affs_fs(void)
607 {
608         unregister_filesystem(&affs_fs_type);
609         destroy_inodecache();
610 }
611
612 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
613 MODULE_LICENSE("GPL");
614
615 module_init(init_affs_fs)
616 module_exit(exit_affs_fs)