xref: /linux/fs/hfs/super.c (revision c8b90d40d5bba8e6fba457b8a7c10d3c0d467e37) 
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/fs_context.h>
19 #include <linux/fs_parser.h>
20 #include <linux/mount.h>
21 #include <linux/init.h>
22 #include <linux/nls.h>
23 #include <linux/seq_file.h>
24 #include <linux/slab.h>
25 #include <linux/vfs.h>
26 
27 #include "hfs_fs.h"
28 #include "btree.h"
29 
30 static struct kmem_cache *hfs_inode_cachep;
31 
32 MODULE_DESCRIPTION("Apple Macintosh file system support");
33 MODULE_LICENSE("GPL");
34 
35 static int hfs_sync_fs(struct super_block *sb, int wait)
36 {
37 	hfs_mdb_commit(sb);
38 	return 0;
39 }
40 
41 /*
42  * hfs_put_super()
43  *
44  * This is the put_super() entry in the super_operations structure for
45  * HFS filesystems.  The purpose is to release the resources
46  * associated with the superblock sb.
47  */
48 static void hfs_put_super(struct super_block *sb)
49 {
50 	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
51 	hfs_mdb_close(sb);
52 	/* release the MDB's resources */
53 	hfs_mdb_put(sb);
54 }
55 
56 static void flush_mdb(struct work_struct *work)
57 {
58 	struct hfs_sb_info *sbi;
59 	struct super_block *sb;
60 
61 	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
62 	sb = sbi->sb;
63 
64 	spin_lock(&sbi->work_lock);
65 	sbi->work_queued = 0;
66 	spin_unlock(&sbi->work_lock);
67 
68 	hfs_mdb_commit(sb);
69 }
70 
71 void hfs_mark_mdb_dirty(struct super_block *sb)
72 {
73 	struct hfs_sb_info *sbi = HFS_SB(sb);
74 	unsigned long delay;
75 
76 	if (sb_rdonly(sb))
77 		return;
78 
79 	spin_lock(&sbi->work_lock);
80 	if (!sbi->work_queued) {
81 		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
82 		queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
83 		sbi->work_queued = 1;
84 	}
85 	spin_unlock(&sbi->work_lock);
86 }
87 
88 /*
89  * hfs_statfs()
90  *
91  * This is the statfs() entry in the super_operations structure for
92  * HFS filesystems.  The purpose is to return various data about the
93  * filesystem.
94  *
95  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
96  */
97 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
98 {
99 	struct super_block *sb = dentry->d_sb;
100 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
101 
102 	buf->f_type = HFS_SUPER_MAGIC;
103 	buf->f_bsize = sb->s_blocksize;
104 	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
105 	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
106 	buf->f_bavail = buf->f_bfree;
107 	buf->f_files = HFS_SB(sb)->fs_ablocks;
108 	buf->f_ffree = HFS_SB(sb)->free_ablocks;
109 	buf->f_fsid = u64_to_fsid(id);
110 	buf->f_namelen = HFS_NAMELEN;
111 
112 	return 0;
113 }
114 
115 static int hfs_reconfigure(struct fs_context *fc)
116 {
117 	struct super_block *sb = fc->root->d_sb;
118 
119 	sync_filesystem(sb);
120 	fc->sb_flags |= SB_NODIRATIME;
121 	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
122 		return 0;
123 
124 	if (!(fc->sb_flags & SB_RDONLY)) {
125 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
126 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
127 			sb->s_flags |= SB_RDONLY;
128 			fc->sb_flags |= SB_RDONLY;
129 		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
130 			pr_warn("filesystem is marked locked, leaving read-only.\n");
131 			sb->s_flags |= SB_RDONLY;
132 			fc->sb_flags |= SB_RDONLY;
133 		}
134 	}
135 	return 0;
136 }
137 
138 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
139 {
140 	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
141 
142 	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
143 		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
144 	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
145 		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
146 	seq_printf(seq, ",uid=%u,gid=%u",
147 			from_kuid_munged(&init_user_ns, sbi->s_uid),
148 			from_kgid_munged(&init_user_ns, sbi->s_gid));
149 	if (sbi->s_file_umask != 0133)
150 		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
151 	if (sbi->s_dir_umask != 0022)
152 		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
153 	if (sbi->part >= 0)
154 		seq_printf(seq, ",part=%u", sbi->part);
155 	if (sbi->session >= 0)
156 		seq_printf(seq, ",session=%u", sbi->session);
157 	if (sbi->nls_disk)
158 		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
159 	if (sbi->nls_io)
160 		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
161 	if (sbi->s_quiet)
162 		seq_printf(seq, ",quiet");
163 	return 0;
164 }
165 
166 static struct inode *hfs_alloc_inode(struct super_block *sb)
167 {
168 	struct hfs_inode_info *i;
169 
170 	i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
171 	return i ? &i->vfs_inode : NULL;
172 }
173 
174 static void hfs_free_inode(struct inode *inode)
175 {
176 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
177 }
178 
179 static const struct super_operations hfs_super_operations = {
180 	.alloc_inode	= hfs_alloc_inode,
181 	.free_inode	= hfs_free_inode,
182 	.write_inode	= hfs_write_inode,
183 	.evict_inode	= hfs_evict_inode,
184 	.put_super	= hfs_put_super,
185 	.sync_fs	= hfs_sync_fs,
186 	.statfs		= hfs_statfs,
187 	.show_options	= hfs_show_options,
188 };
189 
190 enum {
191 	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
192 	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
193 	opt_codepage, opt_iocharset,
194 };
195 
196 static const struct fs_parameter_spec hfs_param_spec[] = {
197 	fsparam_u32	("uid",		opt_uid),
198 	fsparam_u32	("gid",		opt_gid),
199 	fsparam_u32oct	("umask",	opt_umask),
200 	fsparam_u32oct	("file_umask",	opt_file_umask),
201 	fsparam_u32oct	("dir_umask",	opt_dir_umask),
202 	fsparam_u32	("part",	opt_part),
203 	fsparam_u32	("session",	opt_session),
204 	fsparam_string	("type",	opt_type),
205 	fsparam_string	("creator",	opt_creator),
206 	fsparam_flag	("quiet",	opt_quiet),
207 	fsparam_string	("codepage",	opt_codepage),
208 	fsparam_string	("iocharset",	opt_iocharset),
209 	{}
210 };
211 
212 /*
213  * hfs_parse_param()
214  *
215  * This function is called by the vfs to parse the mount options.
216  */
217 static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
218 {
219 	struct hfs_sb_info *hsb = fc->s_fs_info;
220 	struct fs_parse_result result;
221 	int opt;
222 
223 	/* hfs does not honor any fs-specific options on remount */
224 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
225 		return 0;
226 
227 	opt = fs_parse(fc, hfs_param_spec, param, &result);
228 	if (opt < 0)
229 		return opt;
230 
231 	switch (opt) {
232 	case opt_uid:
233 		hsb->s_uid = result.uid;
234 		break;
235 	case opt_gid:
236 		hsb->s_gid = result.gid;
237 		break;
238 	case opt_umask:
239 		hsb->s_file_umask = (umode_t)result.uint_32;
240 		hsb->s_dir_umask = (umode_t)result.uint_32;
241 		break;
242 	case opt_file_umask:
243 		hsb->s_file_umask = (umode_t)result.uint_32;
244 		break;
245 	case opt_dir_umask:
246 		hsb->s_dir_umask = (umode_t)result.uint_32;
247 		break;
248 	case opt_part:
249 		hsb->part = result.uint_32;
250 		break;
251 	case opt_session:
252 		hsb->session = result.uint_32;
253 		break;
254 	case opt_type:
255 		if (strlen(param->string) != 4) {
256 			pr_err("type requires a 4 character value\n");
257 			return -EINVAL;
258 		}
259 		memcpy(&hsb->s_type, param->string, 4);
260 		break;
261 	case opt_creator:
262 		if (strlen(param->string) != 4) {
263 			pr_err("creator requires a 4 character value\n");
264 			return -EINVAL;
265 		}
266 		memcpy(&hsb->s_creator, param->string, 4);
267 		break;
268 	case opt_quiet:
269 		hsb->s_quiet = 1;
270 		break;
271 	case opt_codepage:
272 		if (hsb->nls_disk) {
273 			pr_err("unable to change codepage\n");
274 			return -EINVAL;
275 		}
276 		hsb->nls_disk = load_nls(param->string);
277 		if (!hsb->nls_disk) {
278 			pr_err("unable to load codepage \"%s\"\n",
279 					param->string);
280 			return -EINVAL;
281 		}
282 		break;
283 	case opt_iocharset:
284 		if (hsb->nls_io) {
285 			pr_err("unable to change iocharset\n");
286 			return -EINVAL;
287 		}
288 		hsb->nls_io = load_nls(param->string);
289 		if (!hsb->nls_io) {
290 			pr_err("unable to load iocharset \"%s\"\n",
291 					param->string);
292 			return -EINVAL;
293 		}
294 		break;
295 	default:
296 		return -EINVAL;
297 	}
298 
299 	return 0;
300 }
301 
302 /*
303  * hfs_read_super()
304  *
305  * This is the function that is responsible for mounting an HFS
306  * filesystem.	It performs all the tasks necessary to get enough data
307  * from the disk to read the root inode.  This includes parsing the
308  * mount options, dealing with Macintosh partitions, reading the
309  * superblock and the allocation bitmap blocks, calling
310  * hfs_btree_init() to get the necessary data about the extents and
311  * catalog B-trees and, finally, reading the root inode into memory.
312  */
313 static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
314 {
315 	struct hfs_sb_info *sbi = HFS_SB(sb);
316 	struct hfs_find_data fd;
317 	hfs_cat_rec rec;
318 	struct inode *root_inode;
319 	int silent = fc->sb_flags & SB_SILENT;
320 	int res;
321 
322 	/* load_nls_default does not fail */
323 	if (sbi->nls_disk && !sbi->nls_io)
324 		sbi->nls_io = load_nls_default();
325 	sbi->s_dir_umask &= 0777;
326 	sbi->s_file_umask &= 0577;
327 
328 	spin_lock_init(&sbi->work_lock);
329 	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
330 
331 	sbi->sb = sb;
332 	sb->s_op = &hfs_super_operations;
333 	sb->s_xattr = hfs_xattr_handlers;
334 	sb->s_flags |= SB_NODIRATIME;
335 	mutex_init(&sbi->bitmap_lock);
336 
337 	res = hfs_mdb_get(sb);
338 	if (res) {
339 		if (!silent)
340 			pr_warn("can't find a HFS filesystem on dev %s\n",
341 				hfs_mdb_name(sb));
342 		res = -EINVAL;
343 		goto bail;
344 	}
345 
346 	/* try to get the root inode */
347 	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
348 	if (res)
349 		goto bail_no_root;
350 	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
351 	if (!res) {
352 		if (fd.entrylength != sizeof(rec.dir)) {
353 			res =  -EIO;
354 			goto bail_hfs_find;
355 		}
356 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
357 		if (rec.type != HFS_CDR_DIR)
358 			res = -EIO;
359 	}
360 	if (res)
361 		goto bail_hfs_find;
362 	res = -EINVAL;
363 	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
364 	hfs_find_exit(&fd);
365 	if (!root_inode)
366 		goto bail_no_root;
367 
368 	sb->s_d_op = &hfs_dentry_operations;
369 	res = -ENOMEM;
370 	sb->s_root = d_make_root(root_inode);
371 	if (!sb->s_root)
372 		goto bail_no_root;
373 
374 	/* everything's okay */
375 	return 0;
376 
377 bail_hfs_find:
378 	hfs_find_exit(&fd);
379 bail_no_root:
380 	pr_err("get root inode failed\n");
381 bail:
382 	hfs_mdb_put(sb);
383 	return res;
384 }
385 
386 static int hfs_get_tree(struct fs_context *fc)
387 {
388 	return get_tree_bdev(fc, hfs_fill_super);
389 }
390 
391 static void hfs_free_fc(struct fs_context *fc)
392 {
393 	kfree(fc->s_fs_info);
394 }
395 
396 static const struct fs_context_operations hfs_context_ops = {
397 	.parse_param	= hfs_parse_param,
398 	.get_tree	= hfs_get_tree,
399 	.reconfigure	= hfs_reconfigure,
400 	.free		= hfs_free_fc,
401 };
402 
403 static int hfs_init_fs_context(struct fs_context *fc)
404 {
405 	struct hfs_sb_info *hsb;
406 
407 	hsb = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
408 	if (!hsb)
409 		return -ENOMEM;
410 
411 	fc->s_fs_info = hsb;
412 	fc->ops = &hfs_context_ops;
413 
414 	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
415 		/* initialize options with defaults */
416 		hsb->s_uid = current_uid();
417 		hsb->s_gid = current_gid();
418 		hsb->s_file_umask = 0133;
419 		hsb->s_dir_umask = 0022;
420 		hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
421 		hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
422 		hsb->s_quiet = 0;
423 		hsb->part = -1;
424 		hsb->session = -1;
425 	}
426 
427 	return 0;
428 }
429 
430 static struct file_system_type hfs_fs_type = {
431 	.owner		= THIS_MODULE,
432 	.name		= "hfs",
433 	.kill_sb	= kill_block_super,
434 	.fs_flags	= FS_REQUIRES_DEV,
435 	.init_fs_context = hfs_init_fs_context,
436 };
437 MODULE_ALIAS_FS("hfs");
438 
439 static void hfs_init_once(void *p)
440 {
441 	struct hfs_inode_info *i = p;
442 
443 	inode_init_once(&i->vfs_inode);
444 }
445 
446 static int __init init_hfs_fs(void)
447 {
448 	int err;
449 
450 	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
451 		sizeof(struct hfs_inode_info), 0,
452 		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
453 	if (!hfs_inode_cachep)
454 		return -ENOMEM;
455 	err = register_filesystem(&hfs_fs_type);
456 	if (err)
457 		kmem_cache_destroy(hfs_inode_cachep);
458 	return err;
459 }
460 
461 static void __exit exit_hfs_fs(void)
462 {
463 	unregister_filesystem(&hfs_fs_type);
464 
465 	/*
466 	 * Make sure all delayed rcu free inodes are flushed before we
467 	 * destroy cache.
468 	 */
469 	rcu_barrier();
470 	kmem_cache_destroy(hfs_inode_cachep);
471 }
472 
473 module_init(init_hfs_fs)
474 module_exit(exit_hfs_fs)
475