address hfs on-disk corruption robustness review comments
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / hfs / super.c
CommitLineData
1da177e4
LT
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_module() and cleanup_module(). 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
1da177e4
LT
15#include <linux/module.h>
16#include <linux/blkdev.h>
717dd80e 17#include <linux/mount.h>
1da177e4 18#include <linux/init.h>
328b9227 19#include <linux/nls.h>
1da177e4 20#include <linux/parser.h>
717dd80e 21#include <linux/seq_file.h>
1da177e4
LT
22#include <linux/vfs.h>
23
24#include "hfs_fs.h"
25#include "btree.h"
26
e18b890b 27static struct kmem_cache *hfs_inode_cachep;
1da177e4
LT
28
29MODULE_LICENSE("GPL");
30
31/*
32 * hfs_write_super()
33 *
34 * Description:
35 * This function is called by the VFS only. When the filesystem
36 * is mounted r/w it updates the MDB on disk.
37 * Input Variable(s):
38 * struct super_block *sb: Pointer to the hfs superblock
39 * Output Variable(s):
40 * NONE
41 * Returns:
42 * void
43 * Preconditions:
44 * 'sb' points to a "valid" (struct super_block).
45 * Postconditions:
46 * The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
47 * (hfs_put_super() must set this flag!). Some MDB fields are updated
48 * and the MDB buffer is written to disk by calling hfs_mdb_commit().
49 */
50static void hfs_write_super(struct super_block *sb)
51{
52 sb->s_dirt = 0;
53 if (sb->s_flags & MS_RDONLY)
54 return;
55 /* sync everything to the buffers */
56 hfs_mdb_commit(sb);
57}
58
59/*
60 * hfs_put_super()
61 *
62 * This is the put_super() entry in the super_operations structure for
63 * HFS filesystems. The purpose is to release the resources
64 * associated with the superblock sb.
65 */
66static void hfs_put_super(struct super_block *sb)
67{
68 hfs_mdb_close(sb);
69 /* release the MDB's resources */
70 hfs_mdb_put(sb);
71}
72
73/*
74 * hfs_statfs()
75 *
76 * This is the statfs() entry in the super_operations structure for
77 * HFS filesystems. The purpose is to return various data about the
78 * filesystem.
79 *
80 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
81 */
726c3342 82static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1da177e4 83{
726c3342
DH
84 struct super_block *sb = dentry->d_sb;
85
1da177e4
LT
86 buf->f_type = HFS_SUPER_MAGIC;
87 buf->f_bsize = sb->s_blocksize;
88 buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
89 buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
90 buf->f_bavail = buf->f_bfree;
91 buf->f_files = HFS_SB(sb)->fs_ablocks;
92 buf->f_ffree = HFS_SB(sb)->free_ablocks;
93 buf->f_namelen = HFS_NAMELEN;
94
95 return 0;
96}
97
98static int hfs_remount(struct super_block *sb, int *flags, char *data)
99{
100 *flags |= MS_NODIRATIME;
101 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
102 return 0;
103 if (!(*flags & MS_RDONLY)) {
104 if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
7cf3cc30 105 printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
1da177e4
LT
106 "running fsck.hfs is recommended. leaving read-only.\n");
107 sb->s_flags |= MS_RDONLY;
108 *flags |= MS_RDONLY;
109 } else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
7cf3cc30 110 printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
1da177e4
LT
111 sb->s_flags |= MS_RDONLY;
112 *flags |= MS_RDONLY;
113 }
114 }
115 return 0;
116}
117
717dd80e
RZ
118static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
119{
120 struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
121
122 if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
123 seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
124 if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
125 seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
126 seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
127 if (sbi->s_file_umask != 0133)
128 seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
129 if (sbi->s_dir_umask != 0022)
130 seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
131 if (sbi->part >= 0)
132 seq_printf(seq, ",part=%u", sbi->part);
133 if (sbi->session >= 0)
134 seq_printf(seq, ",session=%u", sbi->session);
328b9227
RZ
135 if (sbi->nls_disk)
136 seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
137 if (sbi->nls_io)
138 seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
717dd80e
RZ
139 if (sbi->s_quiet)
140 seq_printf(seq, ",quiet");
141 return 0;
142}
143
1da177e4
LT
144static struct inode *hfs_alloc_inode(struct super_block *sb)
145{
146 struct hfs_inode_info *i;
147
e94b1766 148 i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
1da177e4
LT
149 return i ? &i->vfs_inode : NULL;
150}
151
152static void hfs_destroy_inode(struct inode *inode)
153{
154 kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
155}
156
ee9b6d61 157static const struct super_operations hfs_super_operations = {
1da177e4
LT
158 .alloc_inode = hfs_alloc_inode,
159 .destroy_inode = hfs_destroy_inode,
160 .write_inode = hfs_write_inode,
161 .clear_inode = hfs_clear_inode,
162 .put_super = hfs_put_super,
163 .write_super = hfs_write_super,
164 .statfs = hfs_statfs,
165 .remount_fs = hfs_remount,
717dd80e 166 .show_options = hfs_show_options,
1da177e4
LT
167};
168
169enum {
170 opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
171 opt_part, opt_session, opt_type, opt_creator, opt_quiet,
328b9227 172 opt_codepage, opt_iocharset,
1da177e4
LT
173 opt_err
174};
175
176static match_table_t tokens = {
177 { opt_uid, "uid=%u" },
178 { opt_gid, "gid=%u" },
179 { opt_umask, "umask=%o" },
180 { opt_file_umask, "file_umask=%o" },
181 { opt_dir_umask, "dir_umask=%o" },
182 { opt_part, "part=%u" },
183 { opt_session, "session=%u" },
184 { opt_type, "type=%s" },
185 { opt_creator, "creator=%s" },
186 { opt_quiet, "quiet" },
328b9227
RZ
187 { opt_codepage, "codepage=%s" },
188 { opt_iocharset, "iocharset=%s" },
1da177e4
LT
189 { opt_err, NULL }
190};
191
192static inline int match_fourchar(substring_t *arg, u32 *result)
193{
194 if (arg->to - arg->from != 4)
195 return -EINVAL;
196 memcpy(result, arg->from, 4);
197 return 0;
198}
199
200/*
201 * parse_options()
202 *
203 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
204 * This function is called by hfs_read_super() to parse the mount options.
205 */
206static int parse_options(char *options, struct hfs_sb_info *hsb)
207{
208 char *p;
209 substring_t args[MAX_OPT_ARGS];
210 int tmp, token;
211
212 /* initialize the sb with defaults */
213 hsb->s_uid = current->uid;
214 hsb->s_gid = current->gid;
215 hsb->s_file_umask = 0133;
216 hsb->s_dir_umask = 0022;
217 hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
218 hsb->s_quiet = 0;
219 hsb->part = -1;
220 hsb->session = -1;
221
222 if (!options)
223 return 1;
224
225 while ((p = strsep(&options, ",")) != NULL) {
226 if (!*p)
227 continue;
228
229 token = match_token(p, tokens, args);
230 switch (token) {
231 case opt_uid:
232 if (match_int(&args[0], &tmp)) {
7cf3cc30 233 printk(KERN_ERR "hfs: uid requires an argument\n");
1da177e4
LT
234 return 0;
235 }
236 hsb->s_uid = (uid_t)tmp;
237 break;
238 case opt_gid:
239 if (match_int(&args[0], &tmp)) {
7cf3cc30 240 printk(KERN_ERR "hfs: gid requires an argument\n");
1da177e4
LT
241 return 0;
242 }
243 hsb->s_gid = (gid_t)tmp;
244 break;
245 case opt_umask:
246 if (match_octal(&args[0], &tmp)) {
7cf3cc30 247 printk(KERN_ERR "hfs: umask requires a value\n");
1da177e4
LT
248 return 0;
249 }
250 hsb->s_file_umask = (umode_t)tmp;
251 hsb->s_dir_umask = (umode_t)tmp;
252 break;
253 case opt_file_umask:
254 if (match_octal(&args[0], &tmp)) {
7cf3cc30 255 printk(KERN_ERR "hfs: file_umask requires a value\n");
1da177e4
LT
256 return 0;
257 }
258 hsb->s_file_umask = (umode_t)tmp;
259 break;
260 case opt_dir_umask:
261 if (match_octal(&args[0], &tmp)) {
7cf3cc30 262 printk(KERN_ERR "hfs: dir_umask requires a value\n");
1da177e4
LT
263 return 0;
264 }
265 hsb->s_dir_umask = (umode_t)tmp;
266 break;
267 case opt_part:
268 if (match_int(&args[0], &hsb->part)) {
7cf3cc30 269 printk(KERN_ERR "hfs: part requires an argument\n");
1da177e4
LT
270 return 0;
271 }
272 break;
273 case opt_session:
274 if (match_int(&args[0], &hsb->session)) {
7cf3cc30 275 printk(KERN_ERR "hfs: session requires an argument\n");
1da177e4
LT
276 return 0;
277 }
278 break;
279 case opt_type:
280 if (match_fourchar(&args[0], &hsb->s_type)) {
7cf3cc30 281 printk(KERN_ERR "hfs: type requires a 4 character value\n");
1da177e4
LT
282 return 0;
283 }
284 break;
285 case opt_creator:
286 if (match_fourchar(&args[0], &hsb->s_creator)) {
7cf3cc30 287 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
1da177e4
LT
288 return 0;
289 }
290 break;
291 case opt_quiet:
292 hsb->s_quiet = 1;
293 break;
328b9227
RZ
294 case opt_codepage:
295 if (hsb->nls_disk) {
7cf3cc30 296 printk(KERN_ERR "hfs: unable to change codepage\n");
328b9227
RZ
297 return 0;
298 }
299 p = match_strdup(&args[0]);
300 hsb->nls_disk = load_nls(p);
301 if (!hsb->nls_disk) {
7cf3cc30 302 printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
328b9227
RZ
303 kfree(p);
304 return 0;
305 }
306 kfree(p);
307 break;
308 case opt_iocharset:
309 if (hsb->nls_io) {
7cf3cc30 310 printk(KERN_ERR "hfs: unable to change iocharset\n");
328b9227
RZ
311 return 0;
312 }
313 p = match_strdup(&args[0]);
314 hsb->nls_io = load_nls(p);
315 if (!hsb->nls_io) {
7cf3cc30 316 printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
328b9227
RZ
317 kfree(p);
318 return 0;
319 }
320 kfree(p);
321 break;
1da177e4
LT
322 default:
323 return 0;
324 }
325 }
326
328b9227
RZ
327 if (hsb->nls_disk && !hsb->nls_io) {
328 hsb->nls_io = load_nls_default();
329 if (!hsb->nls_io) {
7cf3cc30 330 printk(KERN_ERR "hfs: unable to load default iocharset\n");
328b9227
RZ
331 return 0;
332 }
333 }
1da177e4
LT
334 hsb->s_dir_umask &= 0777;
335 hsb->s_file_umask &= 0577;
336
337 return 1;
338}
339
340/*
341 * hfs_read_super()
342 *
343 * This is the function that is responsible for mounting an HFS
344 * filesystem. It performs all the tasks necessary to get enough data
345 * from the disk to read the root inode. This includes parsing the
346 * mount options, dealing with Macintosh partitions, reading the
347 * superblock and the allocation bitmap blocks, calling
348 * hfs_btree_init() to get the necessary data about the extents and
349 * catalog B-trees and, finally, reading the root inode into memory.
350 */
351static int hfs_fill_super(struct super_block *sb, void *data, int silent)
352{
353 struct hfs_sb_info *sbi;
354 struct hfs_find_data fd;
355 hfs_cat_rec rec;
356 struct inode *root_inode;
357 int res;
358
f8314dc6 359 sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
1da177e4
LT
360 if (!sbi)
361 return -ENOMEM;
362 sb->s_fs_info = sbi;
1da177e4
LT
363 INIT_HLIST_HEAD(&sbi->rsrc_inodes);
364
365 res = -EINVAL;
366 if (!parse_options((char *)data, sbi)) {
7cf3cc30 367 printk(KERN_ERR "hfs: unable to parse mount options.\n");
945b0920 368 goto bail;
1da177e4
LT
369 }
370
371 sb->s_op = &hfs_super_operations;
372 sb->s_flags |= MS_NODIRATIME;
373 init_MUTEX(&sbi->bitmap_lock);
374
375 res = hfs_mdb_get(sb);
376 if (res) {
377 if (!silent)
7cf3cc30 378 printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
1da177e4
LT
379 hfs_mdb_name(sb));
380 res = -EINVAL;
945b0920 381 goto bail;
1da177e4
LT
382 }
383
384 /* try to get the root inode */
385 hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
386 res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
387 if (!res)
388 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
389 if (res) {
390 hfs_find_exit(&fd);
391 goto bail_no_root;
392 }
d6ddf554 393 res = -EINVAL;
1da177e4
LT
394 root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
395 hfs_find_exit(&fd);
396 if (!root_inode)
397 goto bail_no_root;
398
d6ddf554 399 res = -ENOMEM;
1da177e4
LT
400 sb->s_root = d_alloc_root(root_inode);
401 if (!sb->s_root)
402 goto bail_iput;
403
404 sb->s_root->d_op = &hfs_dentry_operations;
405
406 /* everything's okay */
407 return 0;
408
409bail_iput:
410 iput(root_inode);
411bail_no_root:
7cf3cc30 412 printk(KERN_ERR "hfs: get root inode failed.\n");
945b0920 413bail:
1da177e4 414 hfs_mdb_put(sb);
1da177e4
LT
415 return res;
416}
417
454e2398
DH
418static int hfs_get_sb(struct file_system_type *fs_type,
419 int flags, const char *dev_name, void *data,
420 struct vfsmount *mnt)
1da177e4 421{
454e2398 422 return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
1da177e4
LT
423}
424
425static struct file_system_type hfs_fs_type = {
426 .owner = THIS_MODULE,
427 .name = "hfs",
428 .get_sb = hfs_get_sb,
429 .kill_sb = kill_block_super,
430 .fs_flags = FS_REQUIRES_DEV,
431};
432
4ba9b9d0 433static void hfs_init_once(struct kmem_cache *cachep, void *p)
1da177e4
LT
434{
435 struct hfs_inode_info *i = p;
436
a35afb83 437 inode_init_once(&i->vfs_inode);
1da177e4
LT
438}
439
440static int __init init_hfs_fs(void)
441{
442 int err;
443
444 hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
445 sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
20c2df83 446 hfs_init_once);
1da177e4
LT
447 if (!hfs_inode_cachep)
448 return -ENOMEM;
449 err = register_filesystem(&hfs_fs_type);
450 if (err)
451 kmem_cache_destroy(hfs_inode_cachep);
452 return err;
453}
454
455static void __exit exit_hfs_fs(void)
456{
457 unregister_filesystem(&hfs_fs_type);
1a1d92c1 458 kmem_cache_destroy(hfs_inode_cachep);
1da177e4
LT
459}
460
461module_init(init_hfs_fs)
462module_exit(exit_hfs_fs)