xref: /openbmc/linux/fs/hfs/super.c (revision b830f94f) 
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.val[0] = (u32)id;
108 	buf->f_fsid.val[1] = (u32)(id >> 32);
109 	buf->f_namelen = HFS_NAMELEN;
110 
111 	return 0;
112 }
113 
114 static int hfs_remount(struct super_block *sb, int *flags, char *data)
115 {
116 	sync_filesystem(sb);
117 	*flags |= SB_NODIRATIME;
118 	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
119 		return 0;
120 	if (!(*flags & SB_RDONLY)) {
121 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
122 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
123 			sb->s_flags |= SB_RDONLY;
124 			*flags |= SB_RDONLY;
125 		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
126 			pr_warn("filesystem is marked locked, leaving read-only.\n");
127 			sb->s_flags |= SB_RDONLY;
128 			*flags |= SB_RDONLY;
129 		}
130 	}
131 	return 0;
132 }
133 
134 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
135 {
136 	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
137 
138 	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
139 		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
140 	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
141 		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
142 	seq_printf(seq, ",uid=%u,gid=%u",
143 			from_kuid_munged(&init_user_ns, sbi->s_uid),
144 			from_kgid_munged(&init_user_ns, sbi->s_gid));
145 	if (sbi->s_file_umask != 0133)
146 		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
147 	if (sbi->s_dir_umask != 0022)
148 		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
149 	if (sbi->part >= 0)
150 		seq_printf(seq, ",part=%u", sbi->part);
151 	if (sbi->session >= 0)
152 		seq_printf(seq, ",session=%u", sbi->session);
153 	if (sbi->nls_disk)
154 		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
155 	if (sbi->nls_io)
156 		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
157 	if (sbi->s_quiet)
158 		seq_printf(seq, ",quiet");
159 	return 0;
160 }
161 
162 static struct inode *hfs_alloc_inode(struct super_block *sb)
163 {
164 	struct hfs_inode_info *i;
165 
166 	i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);
167 	return i ? &i->vfs_inode : NULL;
168 }
169 
170 static void hfs_free_inode(struct inode *inode)
171 {
172 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
173 }
174 
175 static const struct super_operations hfs_super_operations = {
176 	.alloc_inode	= hfs_alloc_inode,
177 	.free_inode	= hfs_free_inode,
178 	.write_inode	= hfs_write_inode,
179 	.evict_inode	= hfs_evict_inode,
180 	.put_super	= hfs_put_super,
181 	.sync_fs	= hfs_sync_fs,
182 	.statfs		= hfs_statfs,
183 	.remount_fs     = hfs_remount,
184 	.show_options	= hfs_show_options,
185 };
186 
187 enum {
188 	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
189 	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
190 	opt_codepage, opt_iocharset,
191 	opt_err
192 };
193 
194 static const match_table_t tokens = {
195 	{ opt_uid, "uid=%u" },
196 	{ opt_gid, "gid=%u" },
197 	{ opt_umask, "umask=%o" },
198 	{ opt_file_umask, "file_umask=%o" },
199 	{ opt_dir_umask, "dir_umask=%o" },
200 	{ opt_part, "part=%u" },
201 	{ opt_session, "session=%u" },
202 	{ opt_type, "type=%s" },
203 	{ opt_creator, "creator=%s" },
204 	{ opt_quiet, "quiet" },
205 	{ opt_codepage, "codepage=%s" },
206 	{ opt_iocharset, "iocharset=%s" },
207 	{ opt_err, NULL }
208 };
209 
210 static inline int match_fourchar(substring_t *arg, u32 *result)
211 {
212 	if (arg->to - arg->from != 4)
213 		return -EINVAL;
214 	memcpy(result, arg->from, 4);
215 	return 0;
216 }
217 
218 /*
219  * parse_options()
220  *
221  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
222  * This function is called by hfs_read_super() to parse the mount options.
223  */
224 static int parse_options(char *options, struct hfs_sb_info *hsb)
225 {
226 	char *p;
227 	substring_t args[MAX_OPT_ARGS];
228 	int tmp, token;
229 
230 	/* initialize the sb with defaults */
231 	hsb->s_uid = current_uid();
232 	hsb->s_gid = current_gid();
233 	hsb->s_file_umask = 0133;
234 	hsb->s_dir_umask = 0022;
235 	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
236 	hsb->s_quiet = 0;
237 	hsb->part = -1;
238 	hsb->session = -1;
239 
240 	if (!options)
241 		return 1;
242 
243 	while ((p = strsep(&options, ",")) != NULL) {
244 		if (!*p)
245 			continue;
246 
247 		token = match_token(p, tokens, args);
248 		switch (token) {
249 		case opt_uid:
250 			if (match_int(&args[0], &tmp)) {
251 				pr_err("uid requires an argument\n");
252 				return 0;
253 			}
254 			hsb->s_uid = make_kuid(current_user_ns(), (uid_t)tmp);
255 			if (!uid_valid(hsb->s_uid)) {
256 				pr_err("invalid uid %d\n", tmp);
257 				return 0;
258 			}
259 			break;
260 		case opt_gid:
261 			if (match_int(&args[0], &tmp)) {
262 				pr_err("gid requires an argument\n");
263 				return 0;
264 			}
265 			hsb->s_gid = make_kgid(current_user_ns(), (gid_t)tmp);
266 			if (!gid_valid(hsb->s_gid)) {
267 				pr_err("invalid gid %d\n", tmp);
268 				return 0;
269 			}
270 			break;
271 		case opt_umask:
272 			if (match_octal(&args[0], &tmp)) {
273 				pr_err("umask requires a value\n");
274 				return 0;
275 			}
276 			hsb->s_file_umask = (umode_t)tmp;
277 			hsb->s_dir_umask = (umode_t)tmp;
278 			break;
279 		case opt_file_umask:
280 			if (match_octal(&args[0], &tmp)) {
281 				pr_err("file_umask requires a value\n");
282 				return 0;
283 			}
284 			hsb->s_file_umask = (umode_t)tmp;
285 			break;
286 		case opt_dir_umask:
287 			if (match_octal(&args[0], &tmp)) {
288 				pr_err("dir_umask requires a value\n");
289 				return 0;
290 			}
291 			hsb->s_dir_umask = (umode_t)tmp;
292 			break;
293 		case opt_part:
294 			if (match_int(&args[0], &hsb->part)) {
295 				pr_err("part requires an argument\n");
296 				return 0;
297 			}
298 			break;
299 		case opt_session:
300 			if (match_int(&args[0], &hsb->session)) {
301 				pr_err("session requires an argument\n");
302 				return 0;
303 			}
304 			break;
305 		case opt_type:
306 			if (match_fourchar(&args[0], &hsb->s_type)) {
307 				pr_err("type requires a 4 character value\n");
308 				return 0;
309 			}
310 			break;
311 		case opt_creator:
312 			if (match_fourchar(&args[0], &hsb->s_creator)) {
313 				pr_err("creator requires a 4 character value\n");
314 				return 0;
315 			}
316 			break;
317 		case opt_quiet:
318 			hsb->s_quiet = 1;
319 			break;
320 		case opt_codepage:
321 			if (hsb->nls_disk) {
322 				pr_err("unable to change codepage\n");
323 				return 0;
324 			}
325 			p = match_strdup(&args[0]);
326 			if (p)
327 				hsb->nls_disk = load_nls(p);
328 			if (!hsb->nls_disk) {
329 				pr_err("unable to load codepage \"%s\"\n", p);
330 				kfree(p);
331 				return 0;
332 			}
333 			kfree(p);
334 			break;
335 		case opt_iocharset:
336 			if (hsb->nls_io) {
337 				pr_err("unable to change iocharset\n");
338 				return 0;
339 			}
340 			p = match_strdup(&args[0]);
341 			if (p)
342 				hsb->nls_io = load_nls(p);
343 			if (!hsb->nls_io) {
344 				pr_err("unable to load iocharset \"%s\"\n", p);
345 				kfree(p);
346 				return 0;
347 			}
348 			kfree(p);
349 			break;
350 		default:
351 			return 0;
352 		}
353 	}
354 
355 	if (hsb->nls_disk && !hsb->nls_io) {
356 		hsb->nls_io = load_nls_default();
357 		if (!hsb->nls_io) {
358 			pr_err("unable to load default iocharset\n");
359 			return 0;
360 		}
361 	}
362 	hsb->s_dir_umask &= 0777;
363 	hsb->s_file_umask &= 0577;
364 
365 	return 1;
366 }
367 
368 /*
369  * hfs_read_super()
370  *
371  * This is the function that is responsible for mounting an HFS
372  * filesystem.	It performs all the tasks necessary to get enough data
373  * from the disk to read the root inode.  This includes parsing the
374  * mount options, dealing with Macintosh partitions, reading the
375  * superblock and the allocation bitmap blocks, calling
376  * hfs_btree_init() to get the necessary data about the extents and
377  * catalog B-trees and, finally, reading the root inode into memory.
378  */
379 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
380 {
381 	struct hfs_sb_info *sbi;
382 	struct hfs_find_data fd;
383 	hfs_cat_rec rec;
384 	struct inode *root_inode;
385 	int res;
386 
387 	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
388 	if (!sbi)
389 		return -ENOMEM;
390 
391 	sbi->sb = sb;
392 	sb->s_fs_info = sbi;
393 	spin_lock_init(&sbi->work_lock);
394 	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
395 
396 	res = -EINVAL;
397 	if (!parse_options((char *)data, sbi)) {
398 		pr_err("unable to parse mount options\n");
399 		goto bail;
400 	}
401 
402 	sb->s_op = &hfs_super_operations;
403 	sb->s_xattr = hfs_xattr_handlers;
404 	sb->s_flags |= SB_NODIRATIME;
405 	mutex_init(&sbi->bitmap_lock);
406 
407 	res = hfs_mdb_get(sb);
408 	if (res) {
409 		if (!silent)
410 			pr_warn("can't find a HFS filesystem on dev %s\n",
411 				hfs_mdb_name(sb));
412 		res = -EINVAL;
413 		goto bail;
414 	}
415 
416 	/* try to get the root inode */
417 	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
418 	if (res)
419 		goto bail_no_root;
420 	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
421 	if (!res) {
422 		if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
423 			res =  -EIO;
424 			goto bail;
425 		}
426 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
427 	}
428 	if (res) {
429 		hfs_find_exit(&fd);
430 		goto bail_no_root;
431 	}
432 	res = -EINVAL;
433 	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
434 	hfs_find_exit(&fd);
435 	if (!root_inode)
436 		goto bail_no_root;
437 
438 	sb->s_d_op = &hfs_dentry_operations;
439 	res = -ENOMEM;
440 	sb->s_root = d_make_root(root_inode);
441 	if (!sb->s_root)
442 		goto bail_no_root;
443 
444 	/* everything's okay */
445 	return 0;
446 
447 bail_no_root:
448 	pr_err("get root inode failed\n");
449 bail:
450 	hfs_mdb_put(sb);
451 	return res;
452 }
453 
454 static struct dentry *hfs_mount(struct file_system_type *fs_type,
455 		      int flags, const char *dev_name, void *data)
456 {
457 	return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
458 }
459 
460 static struct file_system_type hfs_fs_type = {
461 	.owner		= THIS_MODULE,
462 	.name		= "hfs",
463 	.mount		= hfs_mount,
464 	.kill_sb	= kill_block_super,
465 	.fs_flags	= FS_REQUIRES_DEV,
466 };
467 MODULE_ALIAS_FS("hfs");
468 
469 static void hfs_init_once(void *p)
470 {
471 	struct hfs_inode_info *i = p;
472 
473 	inode_init_once(&i->vfs_inode);
474 }
475 
476 static int __init init_hfs_fs(void)
477 {
478 	int err;
479 
480 	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
481 		sizeof(struct hfs_inode_info), 0,
482 		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
483 	if (!hfs_inode_cachep)
484 		return -ENOMEM;
485 	err = register_filesystem(&hfs_fs_type);
486 	if (err)
487 		kmem_cache_destroy(hfs_inode_cachep);
488 	return err;
489 }
490 
491 static void __exit exit_hfs_fs(void)
492 {
493 	unregister_filesystem(&hfs_fs_type);
494 
495 	/*
496 	 * Make sure all delayed rcu free inodes are flushed before we
497 	 * destroy cache.
498 	 */
499 	rcu_barrier();
500 	kmem_cache_destroy(hfs_inode_cachep);
501 }
502 
503 module_init(init_hfs_fs)
504 module_exit(exit_hfs_fs)
505