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
28static struct kmem_cache *hfs_inode_cachep;
29
30MODULE_LICENSE("GPL");
31
32static int hfs_sync_fs(struct super_block *sb, int wait)
33{
34	hfs_mdb_commit(sb);
35	return 0;
36}
37
38/*
39 * hfs_put_super()
40 *
41 * This is the put_super() entry in the super_operations structure for
42 * HFS filesystems.  The purpose is to release the resources
43 * associated with the superblock sb.
44 */
45static void hfs_put_super(struct super_block *sb)
46{
47	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
48	hfs_mdb_close(sb);
49	/* release the MDB's resources */
50	hfs_mdb_put(sb);
51}
52
53static void flush_mdb(struct work_struct *work)
54{
55	struct hfs_sb_info *sbi;
56	struct super_block *sb;
57
58	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
59	sb = sbi->sb;
60
61	spin_lock(&sbi->work_lock);
62	sbi->work_queued = 0;
63	spin_unlock(&sbi->work_lock);
64
65	hfs_mdb_commit(sb);
66}
67
68void hfs_mark_mdb_dirty(struct super_block *sb)
69{
70	struct hfs_sb_info *sbi = HFS_SB(sb);
71	unsigned long delay;
72
73	if (sb->s_flags & MS_RDONLY)
74		return;
75
76	spin_lock(&sbi->work_lock);
77	if (!sbi->work_queued) {
78		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
79		queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
80		sbi->work_queued = 1;
81	}
82	spin_unlock(&sbi->work_lock);
83}
84
85/*
86 * hfs_statfs()
87 *
88 * This is the statfs() entry in the super_operations structure for
89 * HFS filesystems.  The purpose is to return various data about the
90 * filesystem.
91 *
92 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
93 */
94static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
95{
96	struct super_block *sb = dentry->d_sb;
97	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
98
99	buf->f_type = HFS_SUPER_MAGIC;
100	buf->f_bsize = sb->s_blocksize;
101	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
102	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
103	buf->f_bavail = buf->f_bfree;
104	buf->f_files = HFS_SB(sb)->fs_ablocks;
105	buf->f_ffree = HFS_SB(sb)->free_ablocks;
106	buf->f_fsid.val[0] = (u32)id;
107	buf->f_fsid.val[1] = (u32)(id >> 32);
108	buf->f_namelen = HFS_NAMELEN;
109
110	return 0;
111}
112
113static int hfs_remount(struct super_block *sb, int *flags, char *data)
114{
115	sync_filesystem(sb);
116	*flags |= MS_NODIRATIME;
117	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
118		return 0;
119	if (!(*flags & MS_RDONLY)) {
120		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
121			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
122			sb->s_flags |= MS_RDONLY;
123			*flags |= MS_RDONLY;
124		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
125			pr_warn("filesystem is marked locked, leaving read-only.\n");
126			sb->s_flags |= MS_RDONLY;
127			*flags |= MS_RDONLY;
128		}
129	}
130	return 0;
131}
132
133static int hfs_show_options(struct seq_file *seq, struct dentry *root)
134{
135	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
136
137	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
138		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
139	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
140		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
141	seq_printf(seq, ",uid=%u,gid=%u",
142			from_kuid_munged(&init_user_ns, sbi->s_uid),
143			from_kgid_munged(&init_user_ns, sbi->s_gid));
144	if (sbi->s_file_umask != 0133)
145		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
146	if (sbi->s_dir_umask != 0022)
147		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
148	if (sbi->part >= 0)
149		seq_printf(seq, ",part=%u", sbi->part);
150	if (sbi->session >= 0)
151		seq_printf(seq, ",session=%u", sbi->session);
152	if (sbi->nls_disk)
153		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
154	if (sbi->nls_io)
155		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
156	if (sbi->s_quiet)
157		seq_printf(seq, ",quiet");
158	return 0;
159}
160
161static struct inode *hfs_alloc_inode(struct super_block *sb)
162{
163	struct hfs_inode_info *i;
164
165	i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
166	return i ? &i->vfs_inode : NULL;
167}
168
169static void hfs_i_callback(struct rcu_head *head)
170{
171	struct inode *inode = container_of(head, struct inode, i_rcu);
172	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
173}
174
175static void hfs_destroy_inode(struct inode *inode)
176{
177	call_rcu(&inode->i_rcu, hfs_i_callback);
178}
179
180static const struct super_operations hfs_super_operations = {
181	.alloc_inode	= hfs_alloc_inode,
182	.destroy_inode	= hfs_destroy_inode,
183	.write_inode	= hfs_write_inode,
184	.evict_inode	= hfs_evict_inode,
185	.put_super	= hfs_put_super,
186	.sync_fs	= hfs_sync_fs,
187	.statfs		= hfs_statfs,
188	.remount_fs     = hfs_remount,
189	.show_options	= hfs_show_options,
190};
191
192enum {
193	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
194	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
195	opt_codepage, opt_iocharset,
196	opt_err
197};
198
199static const match_table_t tokens = {
200	{ opt_uid, "uid=%u" },
201	{ opt_gid, "gid=%u" },
202	{ opt_umask, "umask=%o" },
203	{ opt_file_umask, "file_umask=%o" },
204	{ opt_dir_umask, "dir_umask=%o" },
205	{ opt_part, "part=%u" },
206	{ opt_session, "session=%u" },
207	{ opt_type, "type=%s" },
208	{ opt_creator, "creator=%s" },
209	{ opt_quiet, "quiet" },
210	{ opt_codepage, "codepage=%s" },
211	{ opt_iocharset, "iocharset=%s" },
212	{ opt_err, NULL }
213};
214
215static inline int match_fourchar(substring_t *arg, u32 *result)
216{
217	if (arg->to - arg->from != 4)
218		return -EINVAL;
219	memcpy(result, arg->from, 4);
220	return 0;
221}
222
223/*
224 * parse_options()
225 *
226 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
227 * This function is called by hfs_read_super() to parse the mount options.
228 */
229static int parse_options(char *options, struct hfs_sb_info *hsb)
230{
231	char *p;
232	substring_t args[MAX_OPT_ARGS];
233	int tmp, token;
234
235	/* initialize the sb with defaults */
236	hsb->s_uid = current_uid();
237	hsb->s_gid = current_gid();
238	hsb->s_file_umask = 0133;
239	hsb->s_dir_umask = 0022;
240	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
241	hsb->s_quiet = 0;
242	hsb->part = -1;
243	hsb->session = -1;
244
245	if (!options)
246		return 1;
247
248	while ((p = strsep(&options, ",")) != NULL) {
249		if (!*p)
250			continue;
251
252		token = match_token(p, tokens, args);
253		switch (token) {
254		case opt_uid:
255			if (match_int(&args[0], &tmp)) {
256				pr_err("uid requires an argument\n");
257				return 0;
258			}
259			hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
260			if (!uid_valid(hsb->s_uid)) {
261				pr_err("invalid uid %d\n", tmp);
262				return 0;
263			}
264			break;
265		case opt_gid:
266			if (match_int(&args[0], &tmp)) {
267				pr_err("gid requires an argument\n");
268				return 0;
269			}
270			hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
271			if (!gid_valid(hsb->s_gid)) {
272				pr_err("invalid gid %d\n", tmp);
273				return 0;
274			}
275			break;
276		case opt_umask:
277			if (match_octal(&args[0], &tmp)) {
278				pr_err("umask requires a value\n");
279				return 0;
280			}
281			hsb->s_file_umask = (umode_t)tmp;
282			hsb->s_dir_umask = (umode_t)tmp;
283			break;
284		case opt_file_umask:
285			if (match_octal(&args[0], &tmp)) {
286				pr_err("file_umask requires a value\n");
287				return 0;
288			}
289			hsb->s_file_umask = (umode_t)tmp;
290			break;
291		case opt_dir_umask:
292			if (match_octal(&args[0], &tmp)) {
293				pr_err("dir_umask requires a value\n");
294				return 0;
295			}
296			hsb->s_dir_umask = (umode_t)tmp;
297			break;
298		case opt_part:
299			if (match_int(&args[0], &hsb->part)) {
300				pr_err("part requires an argument\n");
301				return 0;
302			}
303			break;
304		case opt_session:
305			if (match_int(&args[0], &hsb->session)) {
306				pr_err("session requires an argument\n");
307				return 0;
308			}
309			break;
310		case opt_type:
311			if (match_fourchar(&args[0], &hsb->s_type)) {
312				pr_err("type requires a 4 character value\n");
313				return 0;
314			}
315			break;
316		case opt_creator:
317			if (match_fourchar(&args[0], &hsb->s_creator)) {
318				pr_err("creator requires a 4 character value\n");
319				return 0;
320			}
321			break;
322		case opt_quiet:
323			hsb->s_quiet = 1;
324			break;
325		case opt_codepage:
326			if (hsb->nls_disk) {
327				pr_err("unable to change codepage\n");
328				return 0;
329			}
330			p = match_strdup(&args[0]);
331			if (p)
332				hsb->nls_disk = load_nls(p);
333			if (!hsb->nls_disk) {
334				pr_err("unable to load codepage \"%s\"\n", p);
335				kfree(p);
336				return 0;
337			}
338			kfree(p);
339			break;
340		case opt_iocharset:
341			if (hsb->nls_io) {
342				pr_err("unable to change iocharset\n");
343				return 0;
344			}
345			p = match_strdup(&args[0]);
346			if (p)
347				hsb->nls_io = load_nls(p);
348			if (!hsb->nls_io) {
349				pr_err("unable to load iocharset \"%s\"\n", p);
350				kfree(p);
351				return 0;
352			}
353			kfree(p);
354			break;
355		default:
356			return 0;
357		}
358	}
359
360	if (hsb->nls_disk && !hsb->nls_io) {
361		hsb->nls_io = load_nls_default();
362		if (!hsb->nls_io) {
363			pr_err("unable to load default iocharset\n");
364			return 0;
365		}
366	}
367	hsb->s_dir_umask &= 0777;
368	hsb->s_file_umask &= 0577;
369
370	return 1;
371}
372
373/*
374 * hfs_read_super()
375 *
376 * This is the function that is responsible for mounting an HFS
377 * filesystem.	It performs all the tasks necessary to get enough data
378 * from the disk to read the root inode.  This includes parsing the
379 * mount options, dealing with Macintosh partitions, reading the
380 * superblock and the allocation bitmap blocks, calling
381 * hfs_btree_init() to get the necessary data about the extents and
382 * catalog B-trees and, finally, reading the root inode into memory.
383 */
384static int hfs_fill_super(struct super_block *sb, void *data, int silent)
385{
386	struct hfs_sb_info *sbi;
387	struct hfs_find_data fd;
388	hfs_cat_rec rec;
389	struct inode *root_inode;
390	int res;
391
392	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
393	if (!sbi)
394		return -ENOMEM;
395
396	sbi->sb = sb;
397	sb->s_fs_info = sbi;
398	spin_lock_init(&sbi->work_lock);
399	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
400
401	res = -EINVAL;
402	if (!parse_options((char *)data, sbi)) {
403		pr_err("unable to parse mount options\n");
404		goto bail;
405	}
406
407	sb->s_op = &hfs_super_operations;
408	sb->s_flags |= MS_NODIRATIME;
409	mutex_init(&sbi->bitmap_lock);
410
411	res = hfs_mdb_get(sb);
412	if (res) {
413		if (!silent)
414			pr_warn("can't find a HFS filesystem on dev %s\n",
415				hfs_mdb_name(sb));
416		res = -EINVAL;
417		goto bail;
418	}
419
420	/* try to get the root inode */
421	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
422	if (res)
423		goto bail_no_root;
424	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
425	if (!res) {
426		if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
427			res =  -EIO;
428			goto bail;
429		}
430		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
431	}
432	if (res) {
433		hfs_find_exit(&fd);
434		goto bail_no_root;
435	}
436	res = -EINVAL;
437	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
438	hfs_find_exit(&fd);
439	if (!root_inode)
440		goto bail_no_root;
441
442	sb->s_d_op = &hfs_dentry_operations;
443	res = -ENOMEM;
444	sb->s_root = d_make_root(root_inode);
445	if (!sb->s_root)
446		goto bail_no_root;
447
448	/* everything's okay */
449	return 0;
450
451bail_no_root:
452	pr_err("get root inode failed\n");
453bail:
454	hfs_mdb_put(sb);
455	return res;
456}
457
458static struct dentry *hfs_mount(struct file_system_type *fs_type,
459		      int flags, const char *dev_name, void *data)
460{
461	return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
462}
463
464static struct file_system_type hfs_fs_type = {
465	.owner		= THIS_MODULE,
466	.name		= "hfs",
467	.mount		= hfs_mount,
468	.kill_sb	= kill_block_super,
469	.fs_flags	= FS_REQUIRES_DEV,
470};
471MODULE_ALIAS_FS("hfs");
472
473static void hfs_init_once(void *p)
474{
475	struct hfs_inode_info *i = p;
476
477	inode_init_once(&i->vfs_inode);
478}
479
480static int __init init_hfs_fs(void)
481{
482	int err;
483
484	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
485		sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
486		hfs_init_once);
487	if (!hfs_inode_cachep)
488		return -ENOMEM;
489	err = register_filesystem(&hfs_fs_type);
490	if (err)
491		kmem_cache_destroy(hfs_inode_cachep);
492	return err;
493}
494
495static void __exit exit_hfs_fs(void)
496{
497	unregister_filesystem(&hfs_fs_type);
498
499	/*
500	 * Make sure all delayed rcu free inodes are flushed before we
501	 * destroy cache.
502	 */
503	rcu_barrier();
504	kmem_cache_destroy(hfs_inode_cachep);
505}
506
507module_init(init_hfs_fs)
508module_exit(exit_hfs_fs)
509