switch open-coded instances of d_make_root() to new helper
[linux-2.6.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_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
104 static void affs_destroy_inode(struct inode *inode)
105 {
106         call_rcu(&inode->i_rcu, affs_i_callback);
107 }
108
109 static 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
118 static 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
130 static void destroy_inodecache(void)
131 {
132         kmem_cache_destroy(affs_inode_cachep);
133 }
134
135 static 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
148 enum {
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
154 static 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
173 static int
174 parse_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
275 static 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 */
389 got_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          */
496 out_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
505 static int
506 affs_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
561 static int
562 affs_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
583 static 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
589 static 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
597 static 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;
606 out:
607         destroy_inodecache();
608 out1:
609         return err;
610 }
611
612 static void __exit exit_affs_fs(void)
613 {
614         unregister_filesystem(&affs_fs_type);
615         destroy_inodecache();
616 }
617
618 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
619 MODULE_LICENSE("GPL");
620
621 module_init(init_affs_fs)
622 module_exit(exit_affs_fs)