xref: /openbmc/linux/fs/hfs/super.c (revision 3c6a73cc) 
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 
28 static struct kmem_cache *hfs_inode_cachep;
29 
30 MODULE_LICENSE("GPL");
31 
32 static 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  */
45 static 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 
53 static 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 
68 void 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  */
94 static 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 
113 static 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 
133 static 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_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
139 	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
140 		seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
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 
161 static 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 
169 static 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 
175 static void hfs_destroy_inode(struct inode *inode)
176 {
177 	call_rcu(&inode->i_rcu, hfs_i_callback);
178 }
179 
180 static 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 
192 enum {
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 
199 static 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 
215 static 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  */
229 static 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  */
384 static 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 
451 bail_no_root:
452 	pr_err("get root inode failed\n");
453 bail:
454 	hfs_mdb_put(sb);
455 	return res;
456 }
457 
458 static 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 
464 static 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 };
471 MODULE_ALIAS_FS("hfs");
472 
473 static void hfs_init_once(void *p)
474 {
475 	struct hfs_inode_info *i = p;
476 
477 	inode_init_once(&i->vfs_inode);
478 }
479 
480 static 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 
495 static 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 
507 module_init(init_hfs_fs)
508 module_exit(exit_hfs_fs)
509