xref: /openbmc/linux/fs/hfs/super.c (revision c4c3c32d) 
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 
29 static struct kmem_cache *hfs_inode_cachep;
30 
31 MODULE_LICENSE("GPL");
32 
33 static 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  */
46 static 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 
54 static 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 
69 void 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  */
95 static 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 
113 static 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 
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_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 
161 static 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 
169 static void hfs_free_inode(struct inode *inode)
170 {
171 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
172 }
173 
174 static 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 
186 enum {
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 
193 static 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 
209 static 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  */
223 static 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  */
378 static 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 
444 bail_hfs_find:
445 	hfs_find_exit(&fd);
446 bail_no_root:
447 	pr_err("get root inode failed\n");
448 bail:
449 	hfs_mdb_put(sb);
450 	return res;
451 }
452 
453 static 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 
459 static 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 };
466 MODULE_ALIAS_FS("hfs");
467 
468 static void hfs_init_once(void *p)
469 {
470 	struct hfs_inode_info *i = p;
471 
472 	inode_init_once(&i->vfs_inode);
473 }
474 
475 static 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 
490 static 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 
502 module_init(init_hfs_fs)
503 module_exit(exit_hfs_fs)
504