fs: icache RCU free inodes
[linux-2.6.git] / fs / hfs / super.c
1 /*
2  *  linux/fs/hfs/super.c
3  *
4  * Copyright (C) 1995-1997  Paul H. Hargrove
5  * (C) 2003 Ardis Technologies <roman@ardistech.com>
6  * This file may be distributed under the terms of the GNU General Public License.
7  *
8  * This file contains hfs_read_super(), some of the super_ops and
9  * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
10  * inode.c since they deal with inodes.
11  *
12  * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
13  */
14
15 #include <linux/module.h>
16 #include <linux/blkdev.h>
17 #include <linux/mount.h>
18 #include <linux/init.h>
19 #include <linux/nls.h>
20 #include <linux/parser.h>
21 #include <linux/seq_file.h>
22 #include <linux/slab.h>
23 #include <linux/vfs.h>
24
25 #include "hfs_fs.h"
26 #include "btree.h"
27
28 static struct kmem_cache *hfs_inode_cachep;
29
30 MODULE_LICENSE("GPL");
31
32 /*
33  * hfs_write_super()
34  *
35  * Description:
36  *   This function is called by the VFS only. When the filesystem
37  *   is mounted r/w it updates the MDB on disk.
38  * Input Variable(s):
39  *   struct super_block *sb: Pointer to the hfs superblock
40  * Output Variable(s):
41  *   NONE
42  * Returns:
43  *   void
44  * Preconditions:
45  *   'sb' points to a "valid" (struct super_block).
46  * Postconditions:
47  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
48  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
49  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
50  */
51 static void hfs_write_super(struct super_block *sb)
52 {
53         lock_super(sb);
54         sb->s_dirt = 0;
55
56         /* sync everything to the buffers */
57         if (!(sb->s_flags & MS_RDONLY))
58                 hfs_mdb_commit(sb);
59         unlock_super(sb);
60 }
61
62 static int hfs_sync_fs(struct super_block *sb, int wait)
63 {
64         lock_super(sb);
65         hfs_mdb_commit(sb);
66         sb->s_dirt = 0;
67         unlock_super(sb);
68
69         return 0;
70 }
71
72 /*
73  * hfs_put_super()
74  *
75  * This is the put_super() entry in the super_operations structure for
76  * HFS filesystems.  The purpose is to release the resources
77  * associated with the superblock sb.
78  */
79 static void hfs_put_super(struct super_block *sb)
80 {
81         if (sb->s_dirt)
82                 hfs_write_super(sb);
83         hfs_mdb_close(sb);
84         /* release the MDB's resources */
85         hfs_mdb_put(sb);
86 }
87
88 /*
89  * hfs_statfs()
90  *
91  * This is the statfs() entry in the super_operations structure for
92  * HFS filesystems.  The purpose is to return various data about the
93  * filesystem.
94  *
95  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
96  */
97 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
98 {
99         struct super_block *sb = dentry->d_sb;
100         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
101
102         buf->f_type = HFS_SUPER_MAGIC;
103         buf->f_bsize = sb->s_blocksize;
104         buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
105         buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
106         buf->f_bavail = buf->f_bfree;
107         buf->f_files = HFS_SB(sb)->fs_ablocks;
108         buf->f_ffree = HFS_SB(sb)->free_ablocks;
109         buf->f_fsid.val[0] = (u32)id;
110         buf->f_fsid.val[1] = (u32)(id >> 32);
111         buf->f_namelen = HFS_NAMELEN;
112
113         return 0;
114 }
115
116 static int hfs_remount(struct super_block *sb, int *flags, char *data)
117 {
118         *flags |= MS_NODIRATIME;
119         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
120                 return 0;
121         if (!(*flags & MS_RDONLY)) {
122                 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
123                         printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
124                                "running fsck.hfs is recommended.  leaving read-only.\n");
125                         sb->s_flags |= MS_RDONLY;
126                         *flags |= MS_RDONLY;
127                 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
128                         printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
129                         sb->s_flags |= MS_RDONLY;
130                         *flags |= MS_RDONLY;
131                 }
132         }
133         return 0;
134 }
135
136 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
137 {
138         struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
139
140         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
141                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
142         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
143                 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
144         seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
145         if (sbi->s_file_umask != 0133)
146                 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
147         if (sbi->s_dir_umask != 0022)
148                 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
149         if (sbi->part >= 0)
150                 seq_printf(seq, ",part=%u", sbi->part);
151         if (sbi->session >= 0)
152                 seq_printf(seq, ",session=%u", sbi->session);
153         if (sbi->nls_disk)
154                 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
155         if (sbi->nls_io)
156                 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
157         if (sbi->s_quiet)
158                 seq_printf(seq, ",quiet");
159         return 0;
160 }
161
162 static struct inode *hfs_alloc_inode(struct super_block *sb)
163 {
164         struct hfs_inode_info *i;
165
166         i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
167         return i ? &i->vfs_inode : NULL;
168 }
169
170 static void hfs_i_callback(struct rcu_head *head)
171 {
172         struct inode *inode = container_of(head, struct inode, i_rcu);
173         INIT_LIST_HEAD(&inode->i_dentry);
174         kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
175 }
176
177 static void hfs_destroy_inode(struct inode *inode)
178 {
179         call_rcu(&inode->i_rcu, hfs_i_callback);
180 }
181
182 static const struct super_operations hfs_super_operations = {
183         .alloc_inode    = hfs_alloc_inode,
184         .destroy_inode  = hfs_destroy_inode,
185         .write_inode    = hfs_write_inode,
186         .evict_inode    = hfs_evict_inode,
187         .put_super      = hfs_put_super,
188         .write_super    = hfs_write_super,
189         .sync_fs        = hfs_sync_fs,
190         .statfs         = hfs_statfs,
191         .remount_fs     = hfs_remount,
192         .show_options   = hfs_show_options,
193 };
194
195 enum {
196         opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
197         opt_part, opt_session, opt_type, opt_creator, opt_quiet,
198         opt_codepage, opt_iocharset,
199         opt_err
200 };
201
202 static const match_table_t tokens = {
203         { opt_uid, "uid=%u" },
204         { opt_gid, "gid=%u" },
205         { opt_umask, "umask=%o" },
206         { opt_file_umask, "file_umask=%o" },
207         { opt_dir_umask, "dir_umask=%o" },
208         { opt_part, "part=%u" },
209         { opt_session, "session=%u" },
210         { opt_type, "type=%s" },
211         { opt_creator, "creator=%s" },
212         { opt_quiet, "quiet" },
213         { opt_codepage, "codepage=%s" },
214         { opt_iocharset, "iocharset=%s" },
215         { opt_err, NULL }
216 };
217
218 static inline int match_fourchar(substring_t *arg, u32 *result)
219 {
220         if (arg->to - arg->from != 4)
221                 return -EINVAL;
222         memcpy(result, arg->from, 4);
223         return 0;
224 }
225
226 /*
227  * parse_options()
228  *
229  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
230  * This function is called by hfs_read_super() to parse the mount options.
231  */
232 static int parse_options(char *options, struct hfs_sb_info *hsb)
233 {
234         char *p;
235         substring_t args[MAX_OPT_ARGS];
236         int tmp, token;
237
238         /* initialize the sb with defaults */
239         hsb->s_uid = current_uid();
240         hsb->s_gid = current_gid();
241         hsb->s_file_umask = 0133;
242         hsb->s_dir_umask = 0022;
243         hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
244         hsb->s_quiet = 0;
245         hsb->part = -1;
246         hsb->session = -1;
247
248         if (!options)
249                 return 1;
250
251         while ((p = strsep(&options, ",")) != NULL) {
252                 if (!*p)
253                         continue;
254
255                 token = match_token(p, tokens, args);
256                 switch (token) {
257                 case opt_uid:
258                         if (match_int(&args[0], &tmp)) {
259                                 printk(KERN_ERR "hfs: uid requires an argument\n");
260                                 return 0;
261                         }
262                         hsb->s_uid = (uid_t)tmp;
263                         break;
264                 case opt_gid:
265                         if (match_int(&args[0], &tmp)) {
266                                 printk(KERN_ERR "hfs: gid requires an argument\n");
267                                 return 0;
268                         }
269                         hsb->s_gid = (gid_t)tmp;
270                         break;
271                 case opt_umask:
272                         if (match_octal(&args[0], &tmp)) {
273                                 printk(KERN_ERR "hfs: umask requires a value\n");
274                                 return 0;
275                         }
276                         hsb->s_file_umask = (umode_t)tmp;
277                         hsb->s_dir_umask = (umode_t)tmp;
278                         break;
279                 case opt_file_umask:
280                         if (match_octal(&args[0], &tmp)) {
281                                 printk(KERN_ERR "hfs: file_umask requires a value\n");
282                                 return 0;
283                         }
284                         hsb->s_file_umask = (umode_t)tmp;
285                         break;
286                 case opt_dir_umask:
287                         if (match_octal(&args[0], &tmp)) {
288                                 printk(KERN_ERR "hfs: dir_umask requires a value\n");
289                                 return 0;
290                         }
291                         hsb->s_dir_umask = (umode_t)tmp;
292                         break;
293                 case opt_part:
294                         if (match_int(&args[0], &hsb->part)) {
295                                 printk(KERN_ERR "hfs: part requires an argument\n");
296                                 return 0;
297                         }
298                         break;
299                 case opt_session:
300                         if (match_int(&args[0], &hsb->session)) {
301                                 printk(KERN_ERR "hfs: session requires an argument\n");
302                                 return 0;
303                         }
304                         break;
305                 case opt_type:
306                         if (match_fourchar(&args[0], &hsb->s_type)) {
307                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
308                                 return 0;
309                         }
310                         break;
311                 case opt_creator:
312                         if (match_fourchar(&args[0], &hsb->s_creator)) {
313                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
314                                 return 0;
315                         }
316                         break;
317                 case opt_quiet:
318                         hsb->s_quiet = 1;
319                         break;
320                 case opt_codepage:
321                         if (hsb->nls_disk) {
322                                 printk(KERN_ERR "hfs: unable to change codepage\n");
323                                 return 0;
324                         }
325                         p = match_strdup(&args[0]);
326                         if (p)
327                                 hsb->nls_disk = load_nls(p);
328                         if (!hsb->nls_disk) {
329                                 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
330                                 kfree(p);
331                                 return 0;
332                         }
333                         kfree(p);
334                         break;
335                 case opt_iocharset:
336                         if (hsb->nls_io) {
337                                 printk(KERN_ERR "hfs: unable to change iocharset\n");
338                                 return 0;
339                         }
340                         p = match_strdup(&args[0]);
341                         if (p)
342                                 hsb->nls_io = load_nls(p);
343                         if (!hsb->nls_io) {
344                                 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
345                                 kfree(p);
346                                 return 0;
347                         }
348                         kfree(p);
349                         break;
350                 default:
351                         return 0;
352                 }
353         }
354
355         if (hsb->nls_disk && !hsb->nls_io) {
356                 hsb->nls_io = load_nls_default();
357                 if (!hsb->nls_io) {
358                         printk(KERN_ERR "hfs: unable to load default iocharset\n");
359                         return 0;
360                 }
361         }
362         hsb->s_dir_umask &= 0777;
363         hsb->s_file_umask &= 0577;
364
365         return 1;
366 }
367
368 /*
369  * hfs_read_super()
370  *
371  * This is the function that is responsible for mounting an HFS
372  * filesystem.  It performs all the tasks necessary to get enough data
373  * from the disk to read the root inode.  This includes parsing the
374  * mount options, dealing with Macintosh partitions, reading the
375  * superblock and the allocation bitmap blocks, calling
376  * hfs_btree_init() to get the necessary data about the extents and
377  * catalog B-trees and, finally, reading the root inode into memory.
378  */
379 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
380 {
381         struct hfs_sb_info *sbi;
382         struct hfs_find_data fd;
383         hfs_cat_rec rec;
384         struct inode *root_inode;
385         int res;
386
387         sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
388         if (!sbi)
389                 return -ENOMEM;
390
391         sb->s_fs_info = sbi;
392
393         res = -EINVAL;
394         if (!parse_options((char *)data, sbi)) {
395                 printk(KERN_ERR "hfs: unable to parse mount options.\n");
396                 goto bail;
397         }
398
399         sb->s_op = &hfs_super_operations;
400         sb->s_flags |= MS_NODIRATIME;
401         mutex_init(&sbi->bitmap_lock);
402
403         res = hfs_mdb_get(sb);
404         if (res) {
405                 if (!silent)
406                         printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
407                                 hfs_mdb_name(sb));
408                 res = -EINVAL;
409                 goto bail;
410         }
411
412         /* try to get the root inode */
413         hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
414         res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
415         if (!res) {
416                 if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
417                         res =  -EIO;
418                         goto bail;
419                 }
420                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
421         }
422         if (res) {
423                 hfs_find_exit(&fd);
424                 goto bail_no_root;
425         }
426         res = -EINVAL;
427         root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
428         hfs_find_exit(&fd);
429         if (!root_inode)
430                 goto bail_no_root;
431
432         res = -ENOMEM;
433         sb->s_root = d_alloc_root(root_inode);
434         if (!sb->s_root)
435                 goto bail_iput;
436
437         sb->s_root->d_op = &hfs_dentry_operations;
438
439         /* everything's okay */
440         return 0;
441
442 bail_iput:
443         iput(root_inode);
444 bail_no_root:
445         printk(KERN_ERR "hfs: get root inode failed.\n");
446 bail:
447         hfs_mdb_put(sb);
448         return res;
449 }
450
451 static struct dentry *hfs_mount(struct file_system_type *fs_type,
452                       int flags, const char *dev_name, void *data)
453 {
454         return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
455 }
456
457 static struct file_system_type hfs_fs_type = {
458         .owner          = THIS_MODULE,
459         .name           = "hfs",
460         .mount          = hfs_mount,
461         .kill_sb        = kill_block_super,
462         .fs_flags       = FS_REQUIRES_DEV,
463 };
464
465 static void hfs_init_once(void *p)
466 {
467         struct hfs_inode_info *i = p;
468
469         inode_init_once(&i->vfs_inode);
470 }
471
472 static int __init init_hfs_fs(void)
473 {
474         int err;
475
476         hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
477                 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
478                 hfs_init_once);
479         if (!hfs_inode_cachep)
480                 return -ENOMEM;
481         err = register_filesystem(&hfs_fs_type);
482         if (err)
483                 kmem_cache_destroy(hfs_inode_cachep);
484         return err;
485 }
486
487 static void __exit exit_hfs_fs(void)
488 {
489         unregister_filesystem(&hfs_fs_type);
490         kmem_cache_destroy(hfs_inode_cachep);
491 }
492
493 module_init(init_hfs_fs)
494 module_exit(exit_hfs_fs)