iget: stop AFFS from using iget() and read_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 <linux/sched.h>
19 #include "affs.h"
20
21 extern struct timezone sys_tz;
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_put_super(struct super_block *sb)
28 {
29         struct affs_sb_info *sbi = AFFS_SB(sb);
30         pr_debug("AFFS: put_super()\n");
31
32         if (!(sb->s_flags & MS_RDONLY)) {
33                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
34                 secs_to_datestamp(get_seconds(),
35                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
36                 affs_fix_checksum(sb, sbi->s_root_bh);
37                 mark_buffer_dirty(sbi->s_root_bh);
38         }
39
40         kfree(sbi->s_prefix);
41         affs_free_bitmap(sb);
42         affs_brelse(sbi->s_root_bh);
43         kfree(sbi);
44         sb->s_fs_info = NULL;
45         return;
46 }
47
48 static void
49 affs_write_super(struct super_block *sb)
50 {
51         int clean = 2;
52         struct affs_sb_info *sbi = AFFS_SB(sb);
53
54         if (!(sb->s_flags & MS_RDONLY)) {
55                 //      if (sbi->s_bitmap[i].bm_bh) {
56                 //              if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
57                 //                      clean = 0;
58                 AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
59                 secs_to_datestamp(get_seconds(),
60                                   &AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
61                 affs_fix_checksum(sb, sbi->s_root_bh);
62                 mark_buffer_dirty(sbi->s_root_bh);
63                 sb->s_dirt = !clean;    /* redo until bitmap synced */
64         } else
65                 sb->s_dirt = 0;
66
67         pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
68 }
69
70 static struct kmem_cache * affs_inode_cachep;
71
72 static struct inode *affs_alloc_inode(struct super_block *sb)
73 {
74         struct affs_inode_info *ei;
75         ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
76         if (!ei)
77                 return NULL;
78         ei->vfs_inode.i_version = 1;
79         return &ei->vfs_inode;
80 }
81
82 static void affs_destroy_inode(struct inode *inode)
83 {
84         kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
85 }
86
87 static void init_once(struct kmem_cache *cachep, void *foo)
88 {
89         struct affs_inode_info *ei = (struct affs_inode_info *) foo;
90
91         init_MUTEX(&ei->i_link_lock);
92         init_MUTEX(&ei->i_ext_lock);
93         inode_init_once(&ei->vfs_inode);
94 }
95
96 static int init_inodecache(void)
97 {
98         affs_inode_cachep = kmem_cache_create("affs_inode_cache",
99                                              sizeof(struct affs_inode_info),
100                                              0, (SLAB_RECLAIM_ACCOUNT|
101                                                 SLAB_MEM_SPREAD),
102                                              init_once);
103         if (affs_inode_cachep == NULL)
104                 return -ENOMEM;
105         return 0;
106 }
107
108 static void destroy_inodecache(void)
109 {
110         kmem_cache_destroy(affs_inode_cachep);
111 }
112
113 static const struct super_operations affs_sops = {
114         .alloc_inode    = affs_alloc_inode,
115         .destroy_inode  = affs_destroy_inode,
116         .write_inode    = affs_write_inode,
117         .put_inode      = affs_put_inode,
118         .drop_inode     = affs_drop_inode,
119         .delete_inode   = affs_delete_inode,
120         .clear_inode    = affs_clear_inode,
121         .put_super      = affs_put_super,
122         .write_super    = affs_write_super,
123         .statfs         = affs_statfs,
124         .remount_fs     = affs_remount,
125 };
126
127 enum {
128         Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
129         Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
130         Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
131 };
132
133 static match_table_t tokens = {
134         {Opt_bs, "bs=%u"},
135         {Opt_mode, "mode=%o"},
136         {Opt_mufs, "mufs"},
137         {Opt_prefix, "prefix=%s"},
138         {Opt_protect, "protect"},
139         {Opt_reserved, "reserved=%u"},
140         {Opt_root, "root=%u"},
141         {Opt_setgid, "setgid=%u"},
142         {Opt_setuid, "setuid=%u"},
143         {Opt_verbose, "verbose"},
144         {Opt_volume, "volume=%s"},
145         {Opt_ignore, "grpquota"},
146         {Opt_ignore, "noquota"},
147         {Opt_ignore, "quota"},
148         {Opt_ignore, "usrquota"},
149         {Opt_err, NULL},
150 };
151
152 static int
153 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
154                 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
155 {
156         char *p;
157         substring_t args[MAX_OPT_ARGS];
158
159         /* Fill in defaults */
160
161         *uid        = current->uid;
162         *gid        = current->gid;
163         *reserved   = 2;
164         *root       = -1;
165         *blocksize  = -1;
166         volume[0]   = ':';
167         volume[1]   = 0;
168         *mount_opts = 0;
169         if (!options)
170                 return 1;
171
172         while ((p = strsep(&options, ",")) != NULL) {
173                 int token, n, option;
174                 if (!*p)
175                         continue;
176
177                 token = match_token(p, tokens, args);
178                 switch (token) {
179                 case Opt_bs:
180                         if (match_int(&args[0], &n))
181                                 return -EINVAL;
182                         if (n != 512 && n != 1024 && n != 2048
183                             && n != 4096) {
184                                 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
185                                 return 0;
186                         }
187                         *blocksize = n;
188                         break;
189                 case Opt_mode:
190                         if (match_octal(&args[0], &option))
191                                 return 1;
192                         *mode = option & 0777;
193                         *mount_opts |= SF_SETMODE;
194                         break;
195                 case Opt_mufs:
196                         *mount_opts |= SF_MUFS;
197                         break;
198                 case Opt_prefix:
199                         /* Free any previous prefix */
200                         kfree(*prefix);
201                         *prefix = NULL;
202                         *prefix = match_strdup(&args[0]);
203                         if (!*prefix)
204                                 return 0;
205                         *mount_opts |= SF_PREFIX;
206                         break;
207                 case Opt_protect:
208                         *mount_opts |= SF_IMMUTABLE;
209                         break;
210                 case Opt_reserved:
211                         if (match_int(&args[0], reserved))
212                                 return 1;
213                         break;
214                 case Opt_root:
215                         if (match_int(&args[0], root))
216                                 return 1;
217                         break;
218                 case Opt_setgid:
219                         if (match_int(&args[0], &option))
220                                 return 1;
221                         *gid = option;
222                         *mount_opts |= SF_SETGID;
223                         break;
224                 case Opt_setuid:
225                         if (match_int(&args[0], &option))
226                                 return -EINVAL;
227                         *uid = option;
228                         *mount_opts |= SF_SETUID;
229                         break;
230                 case Opt_verbose:
231                         *mount_opts |= SF_VERBOSE;
232                         break;
233                 case Opt_volume: {
234                         char *vol = match_strdup(&args[0]);
235                         strlcpy(volume, vol, 32);
236                         kfree(vol);
237                         break;
238                 }
239                 case Opt_ignore:
240                         /* Silently ignore the quota options */
241                         break;
242                 default:
243                         printk("AFFS: Unrecognized mount option \"%s\" "
244                                         "or missing value\n", p);
245                         return 0;
246                 }
247         }
248         return 1;
249 }
250
251 /* This function definitely needs to be split up. Some fine day I'll
252  * hopefully have the guts to do so. Until then: sorry for the mess.
253  */
254
255 static int affs_fill_super(struct super_block *sb, void *data, int silent)
256 {
257         struct affs_sb_info     *sbi;
258         struct buffer_head      *root_bh = NULL;
259         struct buffer_head      *boot_bh;
260         struct inode            *root_inode = NULL;
261         s32                      root_block;
262         int                      size, blocksize;
263         u32                      chksum;
264         int                      num_bm;
265         int                      i, j;
266         s32                      key;
267         uid_t                    uid;
268         gid_t                    gid;
269         int                      reserved;
270         unsigned long            mount_flags;
271         int                      tmp_flags;     /* fix remount prototype... */
272         u8                       sig[4];
273         int                      ret = -EINVAL;
274
275         pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
276
277         sb->s_magic             = AFFS_SUPER_MAGIC;
278         sb->s_op                = &affs_sops;
279         sb->s_flags |= MS_NODIRATIME;
280
281         sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
282         if (!sbi)
283                 return -ENOMEM;
284         sb->s_fs_info = sbi;
285         init_MUTEX(&sbi->s_bmlock);
286
287         if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
288                                 &blocksize,&sbi->s_prefix,
289                                 sbi->s_volume, &mount_flags)) {
290                 printk(KERN_ERR "AFFS: Error parsing options\n");
291                 return -EINVAL;
292         }
293         /* N.B. after this point s_prefix must be released */
294
295         sbi->s_flags   = mount_flags;
296         sbi->s_mode    = i;
297         sbi->s_uid     = uid;
298         sbi->s_gid     = gid;
299         sbi->s_reserved= reserved;
300
301         /* Get the size of the device in 512-byte blocks.
302          * If we later see that the partition uses bigger
303          * blocks, we will have to change it.
304          */
305
306         size = sb->s_bdev->bd_inode->i_size >> 9;
307         pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
308
309         affs_set_blocksize(sb, PAGE_SIZE);
310         /* Try to find root block. Its location depends on the block size. */
311
312         i = 512;
313         j = 4096;
314         if (blocksize > 0) {
315                 i = j = blocksize;
316                 size = size / (blocksize / 512);
317         }
318         for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
319                 sbi->s_root_block = root_block;
320                 if (root_block < 0)
321                         sbi->s_root_block = (reserved + size - 1) / 2;
322                 pr_debug("AFFS: setting blocksize to %d\n", blocksize);
323                 affs_set_blocksize(sb, blocksize);
324                 sbi->s_partition_size = size;
325
326                 /* The root block location that was calculated above is not
327                  * correct if the partition size is an odd number of 512-
328                  * byte blocks, which will be rounded down to a number of
329                  * 1024-byte blocks, and if there were an even number of
330                  * reserved blocks. Ideally, all partition checkers should
331                  * report the real number of blocks of the real blocksize,
332                  * but since this just cannot be done, we have to try to
333                  * find the root block anyways. In the above case, it is one
334                  * block behind the calculated one. So we check this one, too.
335                  */
336                 for (num_bm = 0; num_bm < 2; num_bm++) {
337                         pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
338                                 "size=%d, reserved=%d\n",
339                                 sb->s_id,
340                                 sbi->s_root_block + num_bm,
341                                 blocksize, size, reserved);
342                         root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
343                         if (!root_bh)
344                                 continue;
345                         if (!affs_checksum_block(sb, root_bh) &&
346                             be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
347                             be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
348                                 sbi->s_hashsize    = blocksize / 4 - 56;
349                                 sbi->s_root_block += num_bm;
350                                 key                        = 1;
351                                 goto got_root;
352                         }
353                         affs_brelse(root_bh);
354                         root_bh = NULL;
355                 }
356         }
357         if (!silent)
358                 printk(KERN_ERR "AFFS: No valid root block on device %s\n",
359                         sb->s_id);
360         goto out_error;
361
362         /* N.B. after this point bh must be released */
363 got_root:
364         root_block = sbi->s_root_block;
365
366         /* Find out which kind of FS we have */
367         boot_bh = sb_bread(sb, 0);
368         if (!boot_bh) {
369                 printk(KERN_ERR "AFFS: Cannot read boot block\n");
370                 goto out_error;
371         }
372         memcpy(sig, boot_bh->b_data, 4);
373         brelse(boot_bh);
374         chksum = be32_to_cpu(*(__be32 *)sig);
375
376         /* Dircache filesystems are compatible with non-dircache ones
377          * when reading. As long as they aren't supported, writing is
378          * not recommended.
379          */
380         if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
381              || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
382                 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
383                         sb->s_id);
384                 sb->s_flags |= MS_RDONLY;
385         }
386         switch (chksum) {
387                 case MUFS_FS:
388                 case MUFS_INTLFFS:
389                 case MUFS_DCFFS:
390                         sbi->s_flags |= SF_MUFS;
391                         /* fall thru */
392                 case FS_INTLFFS:
393                 case FS_DCFFS:
394                         sbi->s_flags |= SF_INTL;
395                         break;
396                 case MUFS_FFS:
397                         sbi->s_flags |= SF_MUFS;
398                         break;
399                 case FS_FFS:
400                         break;
401                 case MUFS_OFS:
402                         sbi->s_flags |= SF_MUFS;
403                         /* fall thru */
404                 case FS_OFS:
405                         sbi->s_flags |= SF_OFS;
406                         sb->s_flags |= MS_NOEXEC;
407                         break;
408                 case MUFS_DCOFS:
409                 case MUFS_INTLOFS:
410                         sbi->s_flags |= SF_MUFS;
411                 case FS_DCOFS:
412                 case FS_INTLOFS:
413                         sbi->s_flags |= SF_INTL | SF_OFS;
414                         sb->s_flags |= MS_NOEXEC;
415                         break;
416                 default:
417                         printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
418                                 sb->s_id, chksum);
419                         goto out_error;
420         }
421
422         if (mount_flags & SF_VERBOSE) {
423                 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
424                 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
425                         len > 31 ? 31 : len,
426                         AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
427                         sig, sig[3] + '0', blocksize);
428         }
429
430         sb->s_flags |= MS_NODEV | MS_NOSUID;
431
432         sbi->s_data_blksize = sb->s_blocksize;
433         if (sbi->s_flags & SF_OFS)
434                 sbi->s_data_blksize -= 24;
435
436         /* Keep super block in cache */
437         sbi->s_root_bh = root_bh;
438         /* N.B. after this point s_root_bh must be released */
439
440         tmp_flags = sb->s_flags;
441         if (affs_init_bitmap(sb, &tmp_flags))
442                 goto out_error;
443         sb->s_flags = tmp_flags;
444
445         /* set up enough so that it can read an inode */
446
447         root_inode = affs_iget(sb, root_block);
448         if (IS_ERR(root_inode)) {
449                 ret = PTR_ERR(root_inode);
450                 goto out_error_noinode;
451         }
452
453         sb->s_root = d_alloc_root(root_inode);
454         if (!sb->s_root) {
455                 printk(KERN_ERR "AFFS: Get root inode failed\n");
456                 goto out_error;
457         }
458         sb->s_root->d_op = &affs_dentry_operations;
459
460         pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
461         return 0;
462
463         /*
464          * Begin the cascaded cleanup ...
465          */
466 out_error:
467         if (root_inode)
468                 iput(root_inode);
469 out_error_noinode:
470         kfree(sbi->s_bitmap);
471         affs_brelse(root_bh);
472         kfree(sbi->s_prefix);
473         kfree(sbi);
474         sb->s_fs_info = NULL;
475         return ret;
476 }
477
478 static int
479 affs_remount(struct super_block *sb, int *flags, char *data)
480 {
481         struct affs_sb_info     *sbi = AFFS_SB(sb);
482         int                      blocksize;
483         uid_t                    uid;
484         gid_t                    gid;
485         int                      mode;
486         int                      reserved;
487         int                      root_block;
488         unsigned long            mount_flags;
489         int                      res = 0;
490
491         pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
492
493         *flags |= MS_NODIRATIME;
494
495         if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
496             &blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
497                 return -EINVAL;
498         sbi->s_flags = mount_flags;
499         sbi->s_mode  = mode;
500         sbi->s_uid   = uid;
501         sbi->s_gid   = gid;
502
503         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
504                 return 0;
505         if (*flags & MS_RDONLY) {
506                 sb->s_dirt = 1;
507                 while (sb->s_dirt)
508                         affs_write_super(sb);
509                 affs_free_bitmap(sb);
510         } else
511                 res = affs_init_bitmap(sb, flags);
512
513         return res;
514 }
515
516 static int
517 affs_statfs(struct dentry *dentry, struct kstatfs *buf)
518 {
519         struct super_block *sb = dentry->d_sb;
520         int              free;
521
522         pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
523              AFFS_SB(sb)->s_reserved);
524
525         free          = affs_count_free_blocks(sb);
526         buf->f_type    = AFFS_SUPER_MAGIC;
527         buf->f_bsize   = sb->s_blocksize;
528         buf->f_blocks  = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
529         buf->f_bfree   = free;
530         buf->f_bavail  = free;
531         return 0;
532 }
533
534 static int affs_get_sb(struct file_system_type *fs_type,
535         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
536 {
537         return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
538                            mnt);
539 }
540
541 static struct file_system_type affs_fs_type = {
542         .owner          = THIS_MODULE,
543         .name           = "affs",
544         .get_sb         = affs_get_sb,
545         .kill_sb        = kill_block_super,
546         .fs_flags       = FS_REQUIRES_DEV,
547 };
548
549 static int __init init_affs_fs(void)
550 {
551         int err = init_inodecache();
552         if (err)
553                 goto out1;
554         err = register_filesystem(&affs_fs_type);
555         if (err)
556                 goto out;
557         return 0;
558 out:
559         destroy_inodecache();
560 out1:
561         return err;
562 }
563
564 static void __exit exit_affs_fs(void)
565 {
566         unregister_filesystem(&affs_fs_type);
567         destroy_inodecache();
568 }
569
570 MODULE_DESCRIPTION("Amiga filesystem support for Linux");
571 MODULE_LICENSE("GPL");
572
573 module_init(init_affs_fs)
574 module_exit(exit_affs_fs)