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/backing-dev.h>
18#include <linux/mount.h>
19#include <linux/init.h>
20#include <linux/nls.h>
21#include <linux/parser.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/vfs.h>
25
26#include "hfs_fs.h"
27#include "btree.h"
28
29static struct kmem_cache *hfs_inode_cachep;
30
31MODULE_LICENSE("GPL");
32
33static int hfs_sync_fs(struct super_block *sb, int wait)
34{
35	hfs_mdb_commit(sb);
36	return 0;
37}
38
39/*
40 * hfs_put_super()
41 *
42 * This is the put_super() entry in the super_operations structure for
43 * HFS filesystems.  The purpose is to release the resources
44 * associated with the superblock sb.
45 */
46static void hfs_put_super(struct super_block *sb)
47{
48	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
49	hfs_mdb_close(sb);
50	/* release the MDB's resources */
51	hfs_mdb_put(sb);
52}
53
54static void flush_mdb(struct work_struct *work)
55{
56	struct hfs_sb_info *sbi;
57	struct super_block *sb;
58
59	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
60	sb = sbi->sb;
61
62	spin_lock(&sbi->work_lock);
63	sbi->work_queued = 0;
64	spin_unlock(&sbi->work_lock);
65
66	hfs_mdb_commit(sb);
67}
68
69void hfs_mark_mdb_dirty(struct super_block *sb)
70{
71	struct hfs_sb_info *sbi = HFS_SB(sb);
72	unsigned long delay;
73
74	if (sb_rdonly(sb))
75		return;
76
77	spin_lock(&sbi->work_lock);
78	if (!sbi->work_queued) {
79		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
80		queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
81		sbi->work_queued = 1;
82	}
83	spin_unlock(&sbi->work_lock);
84}
85
86/*
87 * hfs_statfs()
88 *
89 * This is the statfs() entry in the super_operations structure for
90 * HFS filesystems.  The purpose is to return various data about the
91 * filesystem.
92 *
93 * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
94 */
95static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
96{
97	struct super_block *sb = dentry->d_sb;
98	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
99
100	buf->f_type = HFS_SUPER_MAGIC;
101	buf->f_bsize = sb->s_blocksize;
102	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
103	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
104	buf->f_bavail = buf->f_bfree;
105	buf->f_files = HFS_SB(sb)->fs_ablocks;
106	buf->f_ffree = HFS_SB(sb)->free_ablocks;
107	buf->f_fsid = u64_to_fsid(id);
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 |= SB_NODIRATIME;
117	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
118		return 0;
119	if (!(*flags & SB_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 |= SB_RDONLY;
123			*flags |= SB_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 |= SB_RDONLY;
127			*flags |= SB_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 = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
166	return i ? &i->vfs_inode : NULL;
167}
168
169static void hfs_free_inode(struct inode *inode)
170{
171	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
172}
173
174static const struct super_operations hfs_super_operations = {
175	.alloc_inode	= hfs_alloc_inode,
176	.free_inode	= hfs_free_inode,
177	.write_inode	= hfs_write_inode,
178	.evict_inode	= hfs_evict_inode,
179	.put_super	= hfs_put_super,
180	.sync_fs	= hfs_sync_fs,
181	.statfs		= hfs_statfs,
182	.remount_fs     = hfs_remount,
183	.show_options	= hfs_show_options,
184};
185
186enum {
187	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
188	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
189	opt_codepage, opt_iocharset,
190	opt_err
191};
192
193static const match_table_t tokens = {
194	{ opt_uid, "uid=%u" },
195	{ opt_gid, "gid=%u" },
196	{ opt_umask, "umask=%o" },
197	{ opt_file_umask, "file_umask=%o" },
198	{ opt_dir_umask, "dir_umask=%o" },
199	{ opt_part, "part=%u" },
200	{ opt_session, "session=%u" },
201	{ opt_type, "type=%s" },
202	{ opt_creator, "creator=%s" },
203	{ opt_quiet, "quiet" },
204	{ opt_codepage, "codepage=%s" },
205	{ opt_iocharset, "iocharset=%s" },
206	{ opt_err, NULL }
207};
208
209static inline int match_fourchar(substring_t *arg, u32 *result)
210{
211	if (arg->to - arg->from != 4)
212		return -EINVAL;
213	memcpy(result, arg->from, 4);
214	return 0;
215}
216
217/*
218 * parse_options()
219 *
220 * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
221 * This function is called by hfs_read_super() to parse the mount options.
222 */
223static int parse_options(char *options, struct hfs_sb_info *hsb)
224{
225	char *p;
226	substring_t args[MAX_OPT_ARGS];
227	int tmp, token;
228
229	/* initialize the sb with defaults */
230	hsb->s_uid = current_uid();
231	hsb->s_gid = current_gid();
232	hsb->s_file_umask = 0133;
233	hsb->s_dir_umask = 0022;
234	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
235	hsb->s_quiet = 0;
236	hsb->part = -1;
237	hsb->session = -1;
238
239	if (!options)
240		return 1;
241
242	while ((p = strsep(&options, ",")) != NULL) {
243		if (!*p)
244			continue;
245
246		token = match_token(p, tokens, args);
247		switch (token) {
248		case opt_uid:
249			if (match_int(&args[0], &tmp)) {
250				pr_err("uid requires an argument\n");
251				return 0;
252			}
253			hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
254			if (!uid_valid(hsb->s_uid)) {
255				pr_err("invalid uid %d\n", tmp);
256				return 0;
257			}
258			break;
259		case opt_gid:
260			if (match_int(&args[0], &tmp)) {
261				pr_err("gid requires an argument\n");
262				return 0;
263			}
264			hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
265			if (!gid_valid(hsb->s_gid)) {
266				pr_err("invalid gid %d\n", tmp);
267				return 0;
268			}
269			break;
270		case opt_umask:
271			if (match_octal(&args[0], &tmp)) {
272				pr_err("umask requires a value\n");
273				return 0;
274			}
275			hsb->s_file_umask = (umode_t)tmp;
276			hsb->s_dir_umask = (umode_t)tmp;
277			break;
278		case opt_file_umask:
279			if (match_octal(&args[0], &tmp)) {
280				pr_err("file_umask requires a value\n");
281				return 0;
282			}
283			hsb->s_file_umask = (umode_t)tmp;
284			break;
285		case opt_dir_umask:
286			if (match_octal(&args[0], &tmp)) {
287				pr_err("dir_umask requires a value\n");
288				return 0;
289			}
290			hsb->s_dir_umask = (umode_t)tmp;
291			break;
292		case opt_part:
293			if (match_int(&args[0], &hsb->part)) {
294				pr_err("part requires an argument\n");
295				return 0;
296			}
297			break;
298		case opt_session:
299			if (match_int(&args[0], &hsb->session)) {
300				pr_err("session requires an argument\n");
301				return 0;
302			}
303			break;
304		case opt_type:
305			if (match_fourchar(&args[0], &hsb->s_type)) {
306				pr_err("type requires a 4 character value\n");
307				return 0;
308			}
309			break;
310		case opt_creator:
311			if (match_fourchar(&args[0], &hsb->s_creator)) {
312				pr_err("creator requires a 4 character value\n");
313				return 0;
314			}
315			break;
316		case opt_quiet:
317			hsb->s_quiet = 1;
318			break;
319		case opt_codepage:
320			if (hsb->nls_disk) {
321				pr_err("unable to change codepage\n");
322				return 0;
323			}
324			p = match_strdup(&args[0]);
325			if (p)
326				hsb->nls_disk = load_nls(p);
327			if (!hsb->nls_disk) {
328				pr_err("unable to load codepage \"%s\"\n", p);
329				kfree(p);
330				return 0;
331			}
332			kfree(p);
333			break;
334		case opt_iocharset:
335			if (hsb->nls_io) {
336				pr_err("unable to change iocharset\n");
337				return 0;
338			}
339			p = match_strdup(&args[0]);
340			if (p)
341				hsb->nls_io = load_nls(p);
342			if (!hsb->nls_io) {
343				pr_err("unable to load iocharset \"%s\"\n", p);
344				kfree(p);
345				return 0;
346			}
347			kfree(p);
348			break;
349		default:
350			return 0;
351		}
352	}
353
354	if (hsb->nls_disk && !hsb->nls_io) {
355		hsb->nls_io = load_nls_default();
356		if (!hsb->nls_io) {
357			pr_err("unable to load default iocharset\n");
358			return 0;
359		}
360	}
361	hsb->s_dir_umask &= 0777;
362	hsb->s_file_umask &= 0577;
363
364	return 1;
365}
366
367/*
368 * hfs_read_super()
369 *
370 * This is the function that is responsible for mounting an HFS
371 * filesystem.	It performs all the tasks necessary to get enough data
372 * from the disk to read the root inode.  This includes parsing the
373 * mount options, dealing with Macintosh partitions, reading the
374 * superblock and the allocation bitmap blocks, calling
375 * hfs_btree_init() to get the necessary data about the extents and
376 * catalog B-trees and, finally, reading the root inode into memory.
377 */
378static int hfs_fill_super(struct super_block *sb, void *data, int silent)
379{
380	struct hfs_sb_info *sbi;
381	struct hfs_find_data fd;
382	hfs_cat_rec rec;
383	struct inode *root_inode;
384	int res;
385
386	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
387	if (!sbi)
388		return -ENOMEM;
389
390	sbi->sb = sb;
391	sb->s_fs_info = sbi;
392	spin_lock_init(&sbi->work_lock);
393	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
394
395	res = -EINVAL;
396	if (!parse_options((char *)data, sbi)) {
397		pr_err("unable to parse mount options\n");
398		goto bail;
399	}
400
401	sb->s_op = &hfs_super_operations;
402	sb->s_xattr = hfs_xattr_handlers;
403	sb->s_flags |= SB_NODIRATIME;
404	mutex_init(&sbi->bitmap_lock);
405
406	res = hfs_mdb_get(sb);
407	if (res) {
408		if (!silent)
409			pr_warn("can't find a HFS filesystem on dev %s\n",
410				hfs_mdb_name(sb));
411		res = -EINVAL;
412		goto bail;
413	}
414
415	/* try to get the root inode */
416	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
417	if (res)
418		goto bail_no_root;
419	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
420	if (!res) {
421		if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
422			res =  -EIO;
423			goto bail_hfs_find;
424		}
425		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
426	}
427	if (res)
428		goto bail_hfs_find;
429	res = -EINVAL;
430	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
431	hfs_find_exit(&fd);
432	if (!root_inode)
433		goto bail_no_root;
434
435	sb->s_d_op = &hfs_dentry_operations;
436	res = -ENOMEM;
437	sb->s_root = d_make_root(root_inode);
438	if (!sb->s_root)
439		goto bail_no_root;
440
441	/* everything's okay */
442	return 0;
443
444bail_hfs_find:
445	hfs_find_exit(&fd);
446bail_no_root:
447	pr_err("get root inode failed\n");
448bail:
449	hfs_mdb_put(sb);
450	return res;
451}
452
453static struct dentry *hfs_mount(struct file_system_type *fs_type,
454		      int flags, const char *dev_name, void *data)
455{
456	return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
457}
458
459static struct file_system_type hfs_fs_type = {
460	.owner		= THIS_MODULE,
461	.name		= "hfs",
462	.mount		= hfs_mount,
463	.kill_sb	= kill_block_super,
464	.fs_flags	= FS_REQUIRES_DEV,
465};
466MODULE_ALIAS_FS("hfs");
467
468static void hfs_init_once(void *p)
469{
470	struct hfs_inode_info *i = p;
471
472	inode_init_once(&i->vfs_inode);
473}
474
475static int __init init_hfs_fs(void)
476{
477	int err;
478
479	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
480		sizeof(struct hfs_inode_info), 0,
481		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
482	if (!hfs_inode_cachep)
483		return -ENOMEM;
484	err = register_filesystem(&hfs_fs_type);
485	if (err)
486		kmem_cache_destroy(hfs_inode_cachep);
487	return err;
488}
489
490static void __exit exit_hfs_fs(void)
491{
492	unregister_filesystem(&hfs_fs_type);
493
494	/*
495	 * Make sure all delayed rcu free inodes are flushed before we
496	 * destroy cache.
497	 */
498	rcu_barrier();
499	kmem_cache_destroy(hfs_inode_cachep);
500}
501
502module_init(init_hfs_fs)
503module_exit(exit_hfs_fs)
504