[PATCH] affs: implement ->drop_inode
[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 "affs.h"
19
20 extern struct timezone sys_tz;
21
22 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
23 static int affs_remount (struct super_block *sb, int *flags, char *data);
24
25 static void
26 affs_put_super(struct super_block *sb)
27 {
28         struct affs_sb_info *sbi = AFFS_SB(sb);
29         pr_debug("AFFS: put_super()\n");
30
31         if (!(sb->s_flags & MS_RDONLY)) {
32                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
33                 secs_to_datestamp(get_seconds(),
34                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
35                 affs_fix_checksum(sb, sbi->s_root_bh);
36                 mark_buffer_dirty(sbi->s_root_bh);
37         }
38
39         kfree(sbi->s_prefix);
40         affs_free_bitmap(sb);
41         affs_brelse(sbi->s_root_bh);
42         kfree(sbi);
43         sb->s_fs_info = NULL;
44         return;
45 }
46
47 static void
48 affs_write_super(struct super_block *sb)
49 {
50         int clean = 2;
51         struct affs_sb_info *sbi = AFFS_SB(sb);
52
53         if (!(sb->s_flags & MS_RDONLY)) {
54                 //      if (sbi->s_bitmap[i].bm_bh) {
55                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
56                 //                      clean = 0;
57                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
58                 secs_to_datestamp(get_seconds(),
59                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
60                 affs_fix_checksum(sb, sbi->s_root_bh);
61                 mark_buffer_dirty(sbi->s_root_bh);
62                 sb->s_dirt = !clean;    /* redo until bitmap synced */
63         } else
64                 sb->s_dirt = 0;
65
66         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
67 }
68
69 static struct kmem_cache * affs_inode_cachep;
70
71 static struct inode *affs_alloc_inode(struct super_block *sb)
72 {
73         struct affs_inode_info *ei;
74         ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
75         if (!ei)
76                 return NULL;
77         ei->vfs_inode.i_version = 1;
78         return &ei->vfs_inode;
79 }
80
81 static void affs_destroy_inode(struct inode *inode)
82 {
83         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
84 }
85
86 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
87 {
88         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
89
90         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
91             SLAB_CTOR_CONSTRUCTOR) {
92                 init_MUTEX(&ei->i_link_lock);
93                 init_MUTEX(&ei->i_ext_lock);
94                 inode_init_once(&ei->vfs_inode);
95         }
96 }
97
98 static int init_inodecache(void)
99 {
100         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
101                                              sizeof(struct affs_inode_info),
102                                              0, (SLAB_RECLAIM_ACCOUNT|
103                                                 SLAB_MEM_SPREAD),
104                                              init_once, NULL);
105         if (affs_inode_cachep == NULL)
106                 return -ENOMEM;
107         return 0;
108 }
109
110 static void destroy_inodecache(void)
111 {
112         kmem_cache_destroy(affs_inode_cachep);
113 }
114
115 static const struct super_operations affs_sops = {
116         .alloc_inode    = affs_alloc_inode,
117         .destroy_inode  = affs_destroy_inode,
118         .read_inode     = affs_read_inode,
119         .write_inode    = affs_write_inode,
120         .put_inode      = affs_put_inode,
121         .drop_inode     = affs_drop_inode,
122         .delete_inode   = affs_delete_inode,
123         .clear_inode    = affs_clear_inode,
124         .put_super      = affs_put_super,
125         .write_super    = affs_write_super,
126         .statfs         = affs_statfs,
127         .remount_fs     = affs_remount,
128 };
129
130 enum {
131         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
132         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
133         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
134 };
135
136 static match_table_t tokens = {
137         {Opt_bs, "bs=%u"},
138         {Opt_mode, "mode=%o"},
139         {Opt_mufs, "mufs"},
140         {Opt_prefix, "prefix=%s"},
141         {Opt_protect, "protect"},
142         {Opt_reserved, "reserved=%u"},
143         {Opt_root, "root=%u"},
144         {Opt_setgid, "setgid=%u"},
145         {Opt_setuid, "setuid=%u"},
146         {Opt_verbose, "verbose"},
147         {Opt_volume, "volume=%s"},
148         {Opt_ignore, "grpquota"},
149         {Opt_ignore, "noquota"},
150         {Opt_ignore, "quota"},
151         {Opt_ignore, "usrquota"},
152         {Opt_err, NULL},
153 };
154
155 static int
156 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
157                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
158 {
159         char *p;
160         substring_t args[MAX_OPT_ARGS];
161
162         /* Fill in defaults */
163
164         *uid        = current->uid;
165         *gid        = current->gid;
166         *reserved   = 2;
167         *root       = -1;
168         *blocksize  = -1;
169         volume[0]   = ':';
170         volume[1]   = 0;
171         *mount_opts = 0;
172         if (!options)
173                 return 1;
174
175         while ((p = strsep(&options, ",")) != NULL) {
176                 int token, n, option;
177                 if (!*p)
178                         continue;
179
180                 token = match_token(p, tokens, args);
181                 switch (token) {
182                 case Opt_bs:
183                         if (match_int(&args[0], &n))
184                                 return -EINVAL;
185                         if (n != 512 && n != 1024 && n != 2048
186                             && n != 4096) {
187                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
188                                 return 0;
189                         }
190                         *blocksize = n;
191                         break;
192                 case Opt_mode:
193                         if (match_octal(&args[0], &option))
194                                 return 1;
195                         *mode = option & 0777;
196                         *mount_opts |= SF_SETMODE;
197                         break;
198                 case Opt_mufs:
199                         *mount_opts |= SF_MUFS;
200                         break;
201                 case Opt_prefix:
202                         /* Free any previous prefix */
203                         kfree(*prefix);
204                         *prefix = NULL;
205                         *prefix = match_strdup(&args[0]);
206                         if (!*prefix)
207                                 return 0;
208                         *mount_opts |= SF_PREFIX;
209                         break;
210                 case Opt_protect:
211                         *mount_opts |= SF_IMMUTABLE;
212                         break;
213                 case Opt_reserved:
214                         if (match_int(&args[0], reserved))
215                                 return 1;
216                         break;
217                 case Opt_root:
218                         if (match_int(&args[0], root))
219                                 return 1;
220                         break;
221                 case Opt_setgid:
222                         if (match_int(&args[0], &option))
223                                 return 1;
224                         *gid = option;
225                         *mount_opts |= SF_SETGID;
226                         break;
227                 case Opt_setuid:
228                         if (match_int(&args[0], &option))
229                                 return -EINVAL;
230                         *uid = option;
231                         *mount_opts |= SF_SETUID;
232                         break;
233                 case Opt_verbose:
234                         *mount_opts |= SF_VERBOSE;
235                         break;
236                 case Opt_volume: {
237                         char *vol = match_strdup(&args[0]);
238                         strlcpy(volume, vol, 32);
239                         kfree(vol);
240                         break;
241                 }
242                 case Opt_ignore:
243                         /* Silently ignore the quota options */
244                         break;
245                 default:
246                         printk("AFFS: Unrecognized mount option \"%s\" "
247                                         "or missing value\n", p);
248                         return 0;
249                 }
250         }
251         return 1;
252 }
253
254 /* This function definitely needs to be split up. Some fine day I'll
255  * hopefully have the guts to do so. Until then: sorry for the mess.
256  */
257
258 static int affs_fill_super(struct super_block *sb, void *data, int silent)
259 {
260         struct affs_sb_info     *sbi;
261         struct buffer_head      *root_bh = NULL;
262         struct buffer_head      *boot_bh;
263         struct inode            *root_inode = NULL;
264         s32                      root_block;
265         int                      size, blocksize;
266         u32                      chksum;
267         int                      num_bm;
268         int                      i, j;
269         s32                      key;
270         uid_t                    uid;
271         gid_t                    gid;
272         int                      reserved;
273         unsigned long            mount_flags;
274         int                      tmp_flags;     /* fix remount prototype... */
275         u8                       sig[4];
276
277         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
278
279         sb->s_magic             = AFFS_SUPER_MAGIC;
280         sb->s_op                = &affs_sops;
281         sb->s_flags |= MS_NODIRATIME;
282
283         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
284         if (!sbi)
285                 return -ENOMEM;
286         sb->s_fs_info = sbi;
287         init_MUTEX(&sbi->s_bmlock);
288
289         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
290                                 &blocksize,&sbi->s_prefix,
291                                 sbi->s_volume, &mount_flags)) {
292                 printk(KERN_ERR "AFFS: Error parsing options\n");
293                 return -EINVAL;
294         }
295         /* N.B. after this point s_prefix must be released */
296
297         sbi->s_flags   = mount_flags;
298         sbi->s_mode    = i;
299         sbi->s_uid     = uid;
300         sbi->s_gid     = gid;
301         sbi->s_reserved= reserved;
302
303         /* Get the size of the device in 512-byte blocks.
304          * If we later see that the partition uses bigger
305          * blocks, we will have to change it.
306          */
307
308         size = sb->s_bdev->bd_inode->i_size >> 9;
309         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
310
311         affs_set_blocksize(sb, PAGE_SIZE);
312         /* Try to find root block. Its location depends on the block size. */
313
314         i = 512;
315         j = 4096;
316         if (blocksize > 0) {
317                 i = j = blocksize;
318                 size = size / (blocksize / 512);
319         }
320         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
321                 sbi->s_root_block = root_block;
322                 if (root_block < 0)
323                         sbi->s_root_block = (reserved + size - 1) / 2;
324                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
325                 affs_set_blocksize(sb, blocksize);
326                 sbi->s_partition_size = size;
327
328                 /* The root block location that was calculated above is not
329                  * correct if the partition size is an odd number of 512-
330                  * byte blocks, which will be rounded down to a number of
331                  * 1024-byte blocks, and if there were an even number of
332                  * reserved blocks. Ideally, all partition checkers should
333                  * report the real number of blocks of the real blocksize,
334                  * but since this just cannot be done, we have to try to
335                  * find the root block anyways. In the above case, it is one
336                  * block behind the calculated one. So we check this one, too.
337                  */
338                 for (num_bm = 0; num_bm < 2; num_bm++) {
339                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
340                                 "size=%d, reserved=%d\n",
341                                 sb->s_id,
342                                 sbi->s_root_block + num_bm,
343                                 blocksize, size, reserved);
344                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
345                         if (!root_bh)
346                                 continue;
347                         if (!affs_checksum_block(sb, root_bh) &&
348                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
349                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
350                                 sbi->s_hashsize    = blocksize / 4 - 56;
351                                 sbi->s_root_block += num_bm;
352                                 key                        = 1;
353                                 goto got_root;
354                         }
355                         affs_brelse(root_bh);
356                         root_bh = NULL;
357                 }
358         }
359         if (!silent)
360                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
361                         sb->s_id);
362         goto out_error;
363
364         /* N.B. after this point bh must be released */
365 got_root:
366         root_block = sbi->s_root_block;
367
368         /* Find out which kind of FS we have */
369         boot_bh = sb_bread(sb, 0);
370         if (!boot_bh) {
371                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
372                 goto out_error;
373         }
374         memcpy(sig, boot_bh->b_data, 4);
375         brelse(boot_bh);
376         chksum = be32_to_cpu(*(__be32 *)sig);
377
378         /* Dircache filesystems are compatible with non-dircache ones
379          * when reading. As long as they aren't supported, writing is
380          * not recommended.
381          */
382         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
383              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
384                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
385                         sb->s_id);
386                 sb->s_flags |= MS_RDONLY;
387         }
388         switch (chksum) {
389                 case MUFS_FS:
390                 case MUFS_INTLFFS:
391                 case MUFS_DCFFS:
392                         sbi->s_flags |= SF_MUFS;
393                         /* fall thru */
394                 case FS_INTLFFS:
395                 case FS_DCFFS:
396                         sbi->s_flags |= SF_INTL;
397                         break;
398                 case MUFS_FFS:
399                         sbi->s_flags |= SF_MUFS;
400                         break;
401                 case FS_FFS:
402                         break;
403                 case MUFS_OFS:
404                         sbi->s_flags |= SF_MUFS;
405                         /* fall thru */
406                 case FS_OFS:
407                         sbi->s_flags |= SF_OFS;
408                         sb->s_flags |= MS_NOEXEC;
409                         break;
410                 case MUFS_DCOFS:
411                 case MUFS_INTLOFS:
412                         sbi->s_flags |= SF_MUFS;
413                 case FS_DCOFS:
414                 case FS_INTLOFS:
415                         sbi->s_flags |= SF_INTL | SF_OFS;
416                         sb->s_flags |= MS_NOEXEC;
417                         break;
418                 default:
419                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
420                                 sb->s_id, chksum);
421                         goto out_error;
422         }
423
424         if (mount_flags & SF_VERBOSE) {
425                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
426                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
427                         len > 31 ? 31 : len,
428                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
429                         sig, sig[3] + '0', blocksize);
430         }
431
432         sb->s_flags |= MS_NODEV | MS_NOSUID;
433
434         sbi->s_data_blksize = sb->s_blocksize;
435         if (sbi->s_flags & SF_OFS)
436                 sbi->s_data_blksize -= 24;
437
438         /* Keep super block in cache */
439         sbi->s_root_bh = root_bh;
440         /* N.B. after this point s_root_bh must be released */
441
442         tmp_flags = sb->s_flags;
443         if (affs_init_bitmap(sb, &tmp_flags))
444                 goto out_error;
445         sb->s_flags = tmp_flags;
446
447         /* set up enough so that it can read an inode */
448
449         root_inode = iget(sb, root_block);
450         sb->s_root = d_alloc_root(root_inode);
451         if (!sb->s_root) {
452                 printk(KERN_ERR "AFFS: Get root inode failed\n");
453                 goto out_error;
454         }
455         sb->s_root->d_op = &affs_dentry_operations;
456
457         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
458         return 0;
459
460         /*
461          * Begin the cascaded cleanup ...
462          */
463 out_error:
464         if (root_inode)
465                 iput(root_inode);
466         kfree(sbi->s_bitmap);
467         affs_brelse(root_bh);
468         kfree(sbi->s_prefix);
469         kfree(sbi);
470         sb->s_fs_info = NULL;
471         return -EINVAL;
472 }
473
474 static int
475 affs_remount(struct super_block *sb, int *flags, char *data)
476 {
477         struct affs_sb_info     *sbi = AFFS_SB(sb);
478         int                      blocksize;
479         uid_t                    uid;
480         gid_t                    gid;
481         int                      mode;
482         int                      reserved;
483         int                      root_block;
484         unsigned long            mount_flags;
485         int                      res = 0;
486
487         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
488
489         *flags |= MS_NODIRATIME;
490
491         if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
492             &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
493                 return -EINVAL;
494         sbi->s_flags = mount_flags;
495         sbi->s_mode  = mode;
496         sbi->s_uid   = uid;
497         sbi->s_gid   = gid;
498
499         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
500                 return 0;
501         if (*flags & MS_RDONLY) {
502                 sb->s_dirt = 1;
503                 while (sb->s_dirt)
504                         affs_write_super(sb);
505                 affs_free_bitmap(sb);
506         } else
507                 res = affs_init_bitmap(sb, flags);
508
509         return res;
510 }
511
512 static int
513 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
514 {
515         struct super_block *sb = dentry->d_sb;
516         int              free;
517
518         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
519              AFFS_SB(sb)->s_reserved);
520
521         free          = affs_count_free_blocks(sb);
522         buf->f_type    = AFFS_SUPER_MAGIC;
523         buf->f_bsize   = sb->s_blocksize;
524         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
525         buf->f_bfree   = free;
526         buf->f_bavail  = free;
527         return 0;
528 }
529
530 static int affs_get_sb(struct file_system_type *fs_type,
531         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
532 {
533         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
534                            mnt);
535 }
536
537 static struct file_system_type affs_fs_type = {
538         .owner          = THIS_MODULE,
539         .name           = "affs",
540         .get_sb         = affs_get_sb,
541         .kill_sb        = kill_block_super,
542         .fs_flags       = FS_REQUIRES_DEV,
543 };
544
545 static int __init init_affs_fs(void)
546 {
547         int err = init_inodecache();
548         if (err)
549                 goto out1;
550         err = register_filesystem(&affs_fs_type);
551         if (err)
552                 goto out;
553         return 0;
554 out:
555         destroy_inodecache();
556 out1:
557         return err;
558 }
559
560 static void __exit exit_affs_fs(void)
561 {
562         unregister_filesystem(&affs_fs_type);
563         destroy_inodecache();
564 }
565
566 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
567 MODULE_LICENSE("GPL");
568
569 module_init(init_affs_fs)
570 module_exit(exit_affs_fs)