summaryrefslogtreecommitdiff
path: root/fs/hfs/super.c
blob: 1e2c193134cc81732cb10f116d647f370b0901ef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
 *  linux/fs/hfs/super.c
 *
 * Copyright (C) 1995-1997  Paul H. Hargrove
 * (C) 2003 Ardis Technologies <roman@ardistech.com>
 * This file may be distributed under the terms of the GNU General Public License.
 *
 * This file contains hfs_read_super(), some of the super_ops and
 * init_module() and cleanup_module().	The remaining super_ops are in
 * inode.c since they deal with inodes.
 *
 * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/parser.h>
#include <linux/vfs.h>

#include "hfs_fs.h"
#include "btree.h"

static kmem_cache_t *hfs_inode_cachep;

MODULE_LICENSE("GPL");

/*
 * hfs_write_super()
 *
 * Description:
 *   This function is called by the VFS only. When the filesystem
 *   is mounted r/w it updates the MDB on disk.
 * Input Variable(s):
 *   struct super_block *sb: Pointer to the hfs superblock
 * Output Variable(s):
 *   NONE
 * Returns:
 *   void
 * Preconditions:
 *   'sb' points to a "valid" (struct super_block).
 * Postconditions:
 *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
 *   (hfs_put_super() must set this flag!). Some MDB fields are updated
 *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
 */
static void hfs_write_super(struct super_block *sb)
{
	sb->s_dirt = 0;
	if (sb->s_flags & MS_RDONLY)
		return;
	/* sync everything to the buffers */
	hfs_mdb_commit(sb);
}

/*
 * hfs_put_super()
 *
 * This is the put_super() entry in the super_operations structure for
 * HFS filesystems.  The purpose is to release the resources
 * associated with the superblock sb.
 */
static void hfs_put_super(struct super_block *sb)
{
	hfs_mdb_close(sb);
	/* release the MDB's resources */
	hfs_mdb_put(sb);
}

/*
 * hfs_statfs()
 *
 * This is the statfs() entry in the super_operations structure for
 * HFS filesystems.  The purpose is to return various data about the
 * filesystem.
 *
 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
 */
static int hfs_statfs(struct super_block *sb, struct kstatfs *buf)
{
	buf->f_type = HFS_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
	buf->f_bavail = buf->f_bfree;
	buf->f_files = HFS_SB(sb)->fs_ablocks;
	buf->f_ffree = HFS_SB(sb)->free_ablocks;
	buf->f_namelen = HFS_NAMELEN;

	return 0;
}

static int hfs_remount(struct super_block *sb, int *flags, char *data)
{
	*flags |= MS_NODIRATIME;
	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
		return 0;
	if (!(*flags & MS_RDONLY)) {
		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
			printk("HFS-fs warning: Filesystem was not cleanly unmounted, "
			       "running fsck.hfs is recommended.  leaving read-only.\n");
			sb->s_flags |= MS_RDONLY;
			*flags |= MS_RDONLY;
		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
			printk("HFS-fs: Filesystem is marked locked, leaving read-only.\n");
			sb->s_flags |= MS_RDONLY;
			*flags |= MS_RDONLY;
		}
	}
	return 0;
}

static struct inode *hfs_alloc_inode(struct super_block *sb)
{
	struct hfs_inode_info *i;

	i = kmem_cache_alloc(hfs_inode_cachep, SLAB_KERNEL);
	return i ? &i->vfs_inode : NULL;
}

static void hfs_destroy_inode(struct inode *inode)
{
	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
}

static struct super_operations hfs_super_operations = {
	.alloc_inode	= hfs_alloc_inode,
	.destroy_inode	= hfs_destroy_inode,
	.write_inode	= hfs_write_inode,
	.clear_inode	= hfs_clear_inode,
	.put_super	= hfs_put_super,
	.write_super	= hfs_write_super,
	.statfs		= hfs_statfs,
	.remount_fs     = hfs_remount,
};

enum {
	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
	opt_err
};

static match_table_t tokens = {
	{ opt_uid, "uid=%u" },
	{ opt_gid, "gid=%u" },
	{ opt_umask, "umask=%o" },
	{ opt_file_umask, "file_umask=%o" },
	{ opt_dir_umask, "dir_umask=%o" },
	{ opt_part, "part=%u" },
	{ opt_session, "session=%u" },
	{ opt_type, "type=%s" },
	{ opt_creator, "creator=%s" },
	{ opt_quiet, "quiet" },
	{ opt_err, NULL }
};

static inline int match_fourchar(substring_t *arg, u32 *result)
{
	if (arg->to - arg->from != 4)
		return -EINVAL;
	memcpy(result, arg->from, 4);
	return 0;
}

/*
 * parse_options()
 *
 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
 * This function is called by hfs_read_super() to parse the mount options.
 */
static int parse_options(char *options, struct hfs_sb_info *hsb)
{
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int tmp, token;

	/* initialize the sb with defaults */
	hsb->s_uid = current->uid;
	hsb->s_gid = current->gid;
	hsb->s_file_umask = 0133;
	hsb->s_dir_umask = 0022;
	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
	hsb->s_quiet = 0;
	hsb->part = -1;
	hsb->session = -1;

	if (!options)
		return 1;

	while ((p = strsep(&options, ",")) != NULL) {
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case opt_uid:
			if (match_int(&args[0], &tmp)) {
				printk("HFS: uid requires an argument\n");
				return 0;
			}
			hsb->s_uid = (uid_t)tmp;
			break;
		case opt_gid:
			if (match_int(&args[0], &tmp)) {
				printk("HFS: gid requires an argument\n");
				return 0;
			}
			hsb->s_gid = (gid_t)tmp;
			break;
		case opt_umask:
			if (match_octal(&args[0], &tmp)) {
				printk("HFS: umask requires a value\n");
				return 0;
			}
			hsb->s_file_umask = (umode_t)tmp;
			hsb->s_dir_umask = (umode_t)tmp;
			break;
		case opt_file_umask:
			if (match_octal(&args[0], &tmp)) {
				printk("HFS: file_umask requires a value\n");
				return 0;
			}
			hsb->s_file_umask = (umode_t)tmp;
			break;
		case opt_dir_umask:
			if (match_octal(&args[0], &tmp)) {
				printk("HFS: dir_umask requires a value\n");
				return 0;
			}
			hsb->s_dir_umask = (umode_t)tmp;
			break;
		case opt_part:
			if (match_int(&args[0], &hsb->part)) {
				printk("HFS: part requires an argument\n");
				return 0;
			}
			break;
		case opt_session:
			if (match_int(&args[0], &hsb->session)) {
				printk("HFS: session requires an argument\n");
				return 0;
			}
			break;
		case opt_type:
			if (match_fourchar(&args[0], &hsb->s_type)) {
				printk("HFS+-fs: type requires a 4 character value\n");
				return 0;
			}
			break;
		case opt_creator:
			if (match_fourchar(&args[0], &hsb->s_creator)) {
				printk("HFS+-fs: creator requires a 4 character value\n");
				return 0;
			}
			break;
		case opt_quiet:
			hsb->s_quiet = 1;
			break;
		default:
			return 0;
		}
	}

	hsb->s_dir_umask &= 0777;
	hsb->s_file_umask &= 0577;

	return 1;
}

/*
 * hfs_read_super()
 *
 * This is the function that is responsible for mounting an HFS
 * filesystem.	It performs all the tasks necessary to get enough data
 * from the disk to read the root inode.  This includes parsing the
 * mount options, dealing with Macintosh partitions, reading the
 * superblock and the allocation bitmap blocks, calling
 * hfs_btree_init() to get the necessary data about the extents and
 * catalog B-trees and, finally, reading the root inode into memory.
 */
static int hfs_fill_super(struct super_block *sb, void *data, int silent)
{
	struct hfs_sb_info *sbi;
	struct hfs_find_data fd;
	hfs_cat_rec rec;
	struct inode *root_inode;
	int res;

	sbi = kmalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;
	sb->s_fs_info = sbi;
	memset(sbi, 0, sizeof(struct hfs_sb_info));
	INIT_HLIST_HEAD(&sbi->rsrc_inodes);

	res = -EINVAL;
	if (!parse_options((char *)data, sbi)) {
		hfs_warn("hfs_fs: unable to parse mount options.\n");
		goto bail3;
	}

	sb->s_op = &hfs_super_operations;
	sb->s_flags |= MS_NODIRATIME;
	init_MUTEX(&sbi->bitmap_lock);

	res = hfs_mdb_get(sb);
	if (res) {
		if (!silent)
			hfs_warn("VFS: Can't find a HFS filesystem on dev %s.\n",
				hfs_mdb_name(sb));
		res = -EINVAL;
		goto bail2;
	}

	/* try to get the root inode */
	hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
	if (!res)
		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
	if (res) {
		hfs_find_exit(&fd);
		goto bail_no_root;
	}
	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
	hfs_find_exit(&fd);
	if (!root_inode)
		goto bail_no_root;

	sb->s_root = d_alloc_root(root_inode);
	if (!sb->s_root)
		goto bail_iput;

	sb->s_root->d_op = &hfs_dentry_operations;

	/* everything's okay */
	return 0;

bail_iput:
	iput(root_inode);
bail_no_root:
	hfs_warn("hfs_fs: get root inode failed.\n");
	hfs_mdb_put(sb);
bail2:
bail3:
	kfree(sbi);
	return res;
}

static struct super_block *hfs_get_sb(struct file_system_type *fs_type,
				      int flags, const char *dev_name, void *data)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
}

static struct file_system_type hfs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "hfs",
	.get_sb		= hfs_get_sb,
	.kill_sb	= kill_block_super,
	.fs_flags	= FS_REQUIRES_DEV,
};

static void hfs_init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
{
	struct hfs_inode_info *i = p;

	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
		inode_init_once(&i->vfs_inode);
}

static int __init init_hfs_fs(void)
{
	int err;

	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
		sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
		hfs_init_once, NULL);
	if (!hfs_inode_cachep)
		return -ENOMEM;
	err = register_filesystem(&hfs_fs_type);
	if (err)
		kmem_cache_destroy(hfs_inode_cachep);
	return err;
}

static void __exit exit_hfs_fs(void)
{
	unregister_filesystem(&hfs_fs_type);
	if (kmem_cache_destroy(hfs_inode_cachep))
		printk(KERN_INFO "hfs_inode_cache: not all structures were freed\n");
}

module_init(init_hfs_fs)
module_exit(exit_hfs_fs)