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
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/vfs.h>
23
24#include "hfs_fs.h"
25#include "btree.h"
26
27static struct kmem_cache *hfs_inode_cachep;
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 */
82static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
83{
84	struct super_block *sb = dentry->d_sb;
85
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))) {
105			printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "
106			       "running fsck.hfs is recommended.  leaving read-only.\n");
107        /* Foxconn removed start pling 05/31/2010 */
108        /* Ignore this flag to force writeable */
109#if 0
110			sb->s_flags |= MS_RDONLY;
111			*flags |= MS_RDONLY;
112#endif
113        /* Foxconn removed end pling 05/31/2010 */
114		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
115			printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.\n");
116			sb->s_flags |= MS_RDONLY;
117			*flags |= MS_RDONLY;
118		}
119	}
120	return 0;
121}
122
123static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
124{
125	struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
126
127	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
128		seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
129	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
130		seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
131	seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
132	if (sbi->s_file_umask != 0133)
133		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
134	if (sbi->s_dir_umask != 0022)
135		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
136	if (sbi->part >= 0)
137		seq_printf(seq, ",part=%u", sbi->part);
138	if (sbi->session >= 0)
139		seq_printf(seq, ",session=%u", sbi->session);
140	if (sbi->nls_disk)
141		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
142	if (sbi->nls_io)
143		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
144	if (sbi->s_quiet)
145		seq_printf(seq, ",quiet");
146	return 0;
147}
148
149static struct inode *hfs_alloc_inode(struct super_block *sb)
150{
151	struct hfs_inode_info *i;
152
153	i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
154	return i ? &i->vfs_inode : NULL;
155}
156
157static void hfs_destroy_inode(struct inode *inode)
158{
159	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
160}
161
162static const struct super_operations hfs_super_operations = {
163	.alloc_inode	= hfs_alloc_inode,
164	.destroy_inode	= hfs_destroy_inode,
165	.write_inode	= hfs_write_inode,
166	.clear_inode	= hfs_clear_inode,
167	.put_super	= hfs_put_super,
168	.write_super	= hfs_write_super,
169	.statfs		= hfs_statfs,
170	.remount_fs     = hfs_remount,
171	.show_options	= hfs_show_options,
172};
173
174enum {
175	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
176	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
177	opt_codepage, opt_iocharset,
178	opt_err
179};
180
181static match_table_t tokens = {
182	{ opt_uid, "uid=%u" },
183	{ opt_gid, "gid=%u" },
184	{ opt_umask, "umask=%o" },
185	{ opt_file_umask, "file_umask=%o" },
186	{ opt_dir_umask, "dir_umask=%o" },
187	{ opt_part, "part=%u" },
188	{ opt_session, "session=%u" },
189	{ opt_type, "type=%s" },
190	{ opt_creator, "creator=%s" },
191	{ opt_quiet, "quiet" },
192	{ opt_codepage, "codepage=%s" },
193	{ opt_iocharset, "iocharset=%s" },
194	{ opt_err, NULL }
195};
196
197static inline int match_fourchar(substring_t *arg, u32 *result)
198{
199	if (arg->to - arg->from != 4)
200		return -EINVAL;
201	memcpy(result, arg->from, 4);
202	return 0;
203}
204
205/*
206 * parse_options()
207 *
208 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
209 * This function is called by hfs_read_super() to parse the mount options.
210 */
211static int parse_options(char *options, struct hfs_sb_info *hsb)
212{
213	char *p;
214	substring_t args[MAX_OPT_ARGS];
215	int tmp, token;
216
217	/* initialize the sb with defaults */
218	hsb->s_uid = current->uid;
219	hsb->s_gid = current->gid;
220	hsb->s_file_umask = 0133;
221	hsb->s_dir_umask = 0022;
222	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
223	hsb->s_quiet = 0;
224	hsb->part = -1;
225	hsb->session = -1;
226
227	if (!options)
228		return 1;
229
230	while ((p = strsep(&options, ",")) != NULL) {
231		if (!*p)
232			continue;
233
234		token = match_token(p, tokens, args);
235		switch (token) {
236		case opt_uid:
237			if (match_int(&args[0], &tmp)) {
238				printk(KERN_ERR "hfs: uid requires an argument\n");
239				return 0;
240			}
241			hsb->s_uid = (uid_t)tmp;
242			break;
243		case opt_gid:
244			if (match_int(&args[0], &tmp)) {
245				printk(KERN_ERR "hfs: gid requires an argument\n");
246				return 0;
247			}
248			hsb->s_gid = (gid_t)tmp;
249			break;
250		case opt_umask:
251			if (match_octal(&args[0], &tmp)) {
252				printk(KERN_ERR "hfs: umask requires a value\n");
253				return 0;
254			}
255			hsb->s_file_umask = (umode_t)tmp;
256			hsb->s_dir_umask = (umode_t)tmp;
257			break;
258		case opt_file_umask:
259			if (match_octal(&args[0], &tmp)) {
260				printk(KERN_ERR "hfs: file_umask requires a value\n");
261				return 0;
262			}
263			hsb->s_file_umask = (umode_t)tmp;
264			break;
265		case opt_dir_umask:
266			if (match_octal(&args[0], &tmp)) {
267				printk(KERN_ERR "hfs: dir_umask requires a value\n");
268				return 0;
269			}
270			hsb->s_dir_umask = (umode_t)tmp;
271			break;
272		case opt_part:
273			if (match_int(&args[0], &hsb->part)) {
274				printk(KERN_ERR "hfs: part requires an argument\n");
275				return 0;
276			}
277			break;
278		case opt_session:
279			if (match_int(&args[0], &hsb->session)) {
280				printk(KERN_ERR "hfs: session requires an argument\n");
281				return 0;
282			}
283			break;
284		case opt_type:
285			if (match_fourchar(&args[0], &hsb->s_type)) {
286				printk(KERN_ERR "hfs: type requires a 4 character value\n");
287				return 0;
288			}
289			break;
290		case opt_creator:
291			if (match_fourchar(&args[0], &hsb->s_creator)) {
292				printk(KERN_ERR "hfs: creator requires a 4 character value\n");
293				return 0;
294			}
295			break;
296		case opt_quiet:
297			hsb->s_quiet = 1;
298			break;
299		case opt_codepage:
300			if (hsb->nls_disk) {
301				printk(KERN_ERR "hfs: unable to change codepage\n");
302				return 0;
303			}
304			p = match_strdup(&args[0]);
305			hsb->nls_disk = load_nls(p);
306			if (!hsb->nls_disk) {
307				printk(KERN_ERR "hfs: unable to load codepage \"%s\"\n", p);
308				kfree(p);
309				return 0;
310			}
311			kfree(p);
312			break;
313		case opt_iocharset:
314			if (hsb->nls_io) {
315				printk(KERN_ERR "hfs: unable to change iocharset\n");
316				return 0;
317			}
318			p = match_strdup(&args[0]);
319			hsb->nls_io = load_nls(p);
320			if (!hsb->nls_io) {
321				printk(KERN_ERR "hfs: unable to load iocharset \"%s\"\n", p);
322				kfree(p);
323				return 0;
324			}
325			kfree(p);
326			break;
327		default:
328			return 0;
329		}
330	}
331
332	if (hsb->nls_disk && !hsb->nls_io) {
333		hsb->nls_io = load_nls_default();
334		if (!hsb->nls_io) {
335			printk(KERN_ERR "hfs: unable to load default iocharset\n");
336			return 0;
337		}
338	}
339	hsb->s_dir_umask &= 0777;
340	hsb->s_file_umask &= 0577;
341
342	return 1;
343}
344
345/*
346 * hfs_read_super()
347 *
348 * This is the function that is responsible for mounting an HFS
349 * filesystem.	It performs all the tasks necessary to get enough data
350 * from the disk to read the root inode.  This includes parsing the
351 * mount options, dealing with Macintosh partitions, reading the
352 * superblock and the allocation bitmap blocks, calling
353 * hfs_btree_init() to get the necessary data about the extents and
354 * catalog B-trees and, finally, reading the root inode into memory.
355 */
356static int hfs_fill_super(struct super_block *sb, void *data, int silent)
357{
358	struct hfs_sb_info *sbi;
359	struct hfs_find_data fd;
360	hfs_cat_rec rec;
361	struct inode *root_inode;
362	int res;
363
364	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
365	if (!sbi)
366		return -ENOMEM;
367	sb->s_fs_info = sbi;
368	INIT_HLIST_HEAD(&sbi->rsrc_inodes);
369
370	res = -EINVAL;
371	if (!parse_options((char *)data, sbi)) {
372		printk(KERN_ERR "hfs: unable to parse mount options.\n");
373		goto bail;
374	}
375
376	sb->s_op = &hfs_super_operations;
377	sb->s_flags |= MS_NODIRATIME;
378	init_MUTEX(&sbi->bitmap_lock);
379
380	res = hfs_mdb_get(sb);
381	if (res) {
382		if (!silent)
383			printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.\n",
384				hfs_mdb_name(sb));
385		res = -EINVAL;
386		goto bail;
387	}
388
389	/* try to get the root inode */
390	hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
391	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
392	if (!res)
393		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
394	if (res) {
395		hfs_find_exit(&fd);
396		goto bail_no_root;
397	}
398	res = -EINVAL;
399	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
400	hfs_find_exit(&fd);
401	if (!root_inode)
402		goto bail_no_root;
403
404	res = -ENOMEM;
405	sb->s_root = d_alloc_root(root_inode);
406	if (!sb->s_root)
407		goto bail_iput;
408
409	sb->s_root->d_op = &hfs_dentry_operations;
410
411	/* everything's okay */
412	return 0;
413
414bail_iput:
415	iput(root_inode);
416bail_no_root:
417	printk(KERN_ERR "hfs: get root inode failed.\n");
418bail:
419	hfs_mdb_put(sb);
420	return res;
421}
422
423static int hfs_get_sb(struct file_system_type *fs_type,
424		      int flags, const char *dev_name, void *data,
425		      struct vfsmount *mnt)
426{
427	return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super, mnt);
428}
429
430static struct file_system_type hfs_fs_type = {
431	.owner		= THIS_MODULE,
432	.name		= "hfs",
433	.get_sb		= hfs_get_sb,
434	.kill_sb	= kill_block_super,
435	.fs_flags	= FS_REQUIRES_DEV,
436};
437
438static void hfs_init_once(void *p, struct kmem_cache *cachep, unsigned long flags)
439{
440	struct hfs_inode_info *i = p;
441
442	inode_init_once(&i->vfs_inode);
443}
444
445static int __init init_hfs_fs(void)
446{
447	int err;
448
449	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
450		sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
451		hfs_init_once, NULL);
452	if (!hfs_inode_cachep)
453		return -ENOMEM;
454	err = register_filesystem(&hfs_fs_type);
455	if (err)
456		kmem_cache_destroy(hfs_inode_cachep);
457	return err;
458}
459
460static void __exit exit_hfs_fs(void)
461{
462	unregister_filesystem(&hfs_fs_type);
463	kmem_cache_destroy(hfs_inode_cachep);
464}
465
466module_init(init_hfs_fs)
467module_exit(exit_hfs_fs)
468