xref: /linux/fs/hfs/super.c (revision b226804532a875c10276168dc55ce752944096bd)
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 	is_hfs_cnid_counts_valid(sb);
38 	hfs_mdb_commit(sb);
39 	return 0;
40 }
41 
42 /*
43  * hfs_put_super()
44  *
45  * This is the put_super() entry in the super_operations structure for
46  * HFS filesystems.  The purpose is to release the resources
47  * associated with the superblock sb.
48  */
49 static void hfs_put_super(struct super_block *sb)
50 {
51 	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
52 	hfs_mdb_close(sb);
53 	/* release the MDB's resources */
54 	hfs_mdb_put(sb);
55 }
56 
57 static void flush_mdb(struct work_struct *work)
58 {
59 	struct hfs_sb_info *sbi;
60 	struct super_block *sb;
61 
62 	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
63 	sb = sbi->sb;
64 
65 	spin_lock(&sbi->work_lock);
66 	sbi->work_queued = 0;
67 	spin_unlock(&sbi->work_lock);
68 
69 	is_hfs_cnid_counts_valid(sb);
70 
71 	hfs_mdb_commit(sb);
72 }
73 
74 void hfs_mark_mdb_dirty(struct super_block *sb)
75 {
76 	struct hfs_sb_info *sbi = HFS_SB(sb);
77 	unsigned long delay;
78 
79 	if (sb_rdonly(sb))
80 		return;
81 
82 	spin_lock(&sbi->work_lock);
83 	if (!sbi->work_queued) {
84 		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
85 		queue_delayed_work(system_long_wq, &sbi->mdb_work, delay);
86 		sbi->work_queued = 1;
87 	}
88 	spin_unlock(&sbi->work_lock);
89 }
90 
91 /*
92  * hfs_statfs()
93  *
94  * This is the statfs() entry in the super_operations structure for
95  * HFS filesystems.  The purpose is to return various data about the
96  * filesystem.
97  *
98  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
99  */
100 static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
101 {
102 	struct super_block *sb = dentry->d_sb;
103 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
104 
105 	buf->f_type = HFS_SUPER_MAGIC;
106 	buf->f_bsize = sb->s_blocksize;
107 	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
108 	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
109 	buf->f_bavail = buf->f_bfree;
110 	buf->f_files = HFS_SB(sb)->fs_ablocks;
111 	buf->f_ffree = HFS_SB(sb)->free_ablocks;
112 	buf->f_fsid = u64_to_fsid(id);
113 	buf->f_namelen = HFS_NAMELEN;
114 
115 	return 0;
116 }
117 
118 static int hfs_reconfigure(struct fs_context *fc)
119 {
120 	struct super_block *sb = fc->root->d_sb;
121 
122 	sync_filesystem(sb);
123 	fc->sb_flags |= SB_NODIRATIME;
124 	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
125 		return 0;
126 
127 	if (!(fc->sb_flags & SB_RDONLY)) {
128 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
129 			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
130 			sb->s_flags |= SB_RDONLY;
131 			fc->sb_flags |= SB_RDONLY;
132 		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
133 			pr_warn("filesystem is marked locked, leaving read-only.\n");
134 			sb->s_flags |= SB_RDONLY;
135 			fc->sb_flags |= SB_RDONLY;
136 		}
137 	}
138 	return 0;
139 }
140 
141 static int hfs_show_options(struct seq_file *seq, struct dentry *root)
142 {
143 	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
144 
145 	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
146 		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
147 	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
148 		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
149 	seq_printf(seq, ",uid=%u,gid=%u",
150 			from_kuid_munged(&init_user_ns, sbi->s_uid),
151 			from_kgid_munged(&init_user_ns, sbi->s_gid));
152 	if (sbi->s_file_umask != 0133)
153 		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
154 	if (sbi->s_dir_umask != 0022)
155 		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
156 	if (sbi->part >= 0)
157 		seq_printf(seq, ",part=%u", sbi->part);
158 	if (sbi->session >= 0)
159 		seq_printf(seq, ",session=%u", sbi->session);
160 	if (sbi->nls_disk)
161 		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
162 	if (sbi->nls_io)
163 		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
164 	if (sbi->s_quiet)
165 		seq_printf(seq, ",quiet");
166 	return 0;
167 }
168 
169 static struct inode *hfs_alloc_inode(struct super_block *sb)
170 {
171 	struct hfs_inode_info *i;
172 
173 	i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
174 	return i ? &i->vfs_inode : NULL;
175 }
176 
177 static void hfs_free_inode(struct inode *inode)
178 {
179 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
180 }
181 
182 static const struct super_operations hfs_super_operations = {
183 	.alloc_inode	= hfs_alloc_inode,
184 	.free_inode	= hfs_free_inode,
185 	.write_inode	= hfs_write_inode,
186 	.evict_inode	= hfs_evict_inode,
187 	.put_super	= hfs_put_super,
188 	.sync_fs	= hfs_sync_fs,
189 	.statfs		= hfs_statfs,
190 	.show_options	= hfs_show_options,
191 };
192 
193 enum {
194 	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
195 	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
196 	opt_codepage, opt_iocharset,
197 };
198 
199 static const struct fs_parameter_spec hfs_param_spec[] = {
200 	fsparam_u32	("uid",		opt_uid),
201 	fsparam_u32	("gid",		opt_gid),
202 	fsparam_u32oct	("umask",	opt_umask),
203 	fsparam_u32oct	("file_umask",	opt_file_umask),
204 	fsparam_u32oct	("dir_umask",	opt_dir_umask),
205 	fsparam_u32	("part",	opt_part),
206 	fsparam_u32	("session",	opt_session),
207 	fsparam_string	("type",	opt_type),
208 	fsparam_string	("creator",	opt_creator),
209 	fsparam_flag	("quiet",	opt_quiet),
210 	fsparam_string	("codepage",	opt_codepage),
211 	fsparam_string	("iocharset",	opt_iocharset),
212 	{}
213 };
214 
215 /*
216  * hfs_parse_param()
217  *
218  * This function is called by the vfs to parse the mount options.
219  */
220 static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
221 {
222 	struct hfs_sb_info *hsb = fc->s_fs_info;
223 	struct fs_parse_result result;
224 	int opt;
225 
226 	/* hfs does not honor any fs-specific options on remount */
227 	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
228 		return 0;
229 
230 	opt = fs_parse(fc, hfs_param_spec, param, &result);
231 	if (opt < 0)
232 		return opt;
233 
234 	switch (opt) {
235 	case opt_uid:
236 		hsb->s_uid = result.uid;
237 		break;
238 	case opt_gid:
239 		hsb->s_gid = result.gid;
240 		break;
241 	case opt_umask:
242 		hsb->s_file_umask = (umode_t)result.uint_32;
243 		hsb->s_dir_umask = (umode_t)result.uint_32;
244 		break;
245 	case opt_file_umask:
246 		hsb->s_file_umask = (umode_t)result.uint_32;
247 		break;
248 	case opt_dir_umask:
249 		hsb->s_dir_umask = (umode_t)result.uint_32;
250 		break;
251 	case opt_part:
252 		hsb->part = result.uint_32;
253 		break;
254 	case opt_session:
255 		hsb->session = result.uint_32;
256 		break;
257 	case opt_type:
258 		if (strlen(param->string) != 4) {
259 			pr_err("type requires a 4 character value\n");
260 			return -EINVAL;
261 		}
262 		memcpy(&hsb->s_type, param->string, 4);
263 		break;
264 	case opt_creator:
265 		if (strlen(param->string) != 4) {
266 			pr_err("creator requires a 4 character value\n");
267 			return -EINVAL;
268 		}
269 		memcpy(&hsb->s_creator, param->string, 4);
270 		break;
271 	case opt_quiet:
272 		hsb->s_quiet = 1;
273 		break;
274 	case opt_codepage:
275 		if (hsb->nls_disk) {
276 			pr_err("unable to change codepage\n");
277 			return -EINVAL;
278 		}
279 		hsb->nls_disk = load_nls(param->string);
280 		if (!hsb->nls_disk) {
281 			pr_err("unable to load codepage \"%s\"\n",
282 					param->string);
283 			return -EINVAL;
284 		}
285 		break;
286 	case opt_iocharset:
287 		if (hsb->nls_io) {
288 			pr_err("unable to change iocharset\n");
289 			return -EINVAL;
290 		}
291 		hsb->nls_io = load_nls(param->string);
292 		if (!hsb->nls_io) {
293 			pr_err("unable to load iocharset \"%s\"\n",
294 					param->string);
295 			return -EINVAL;
296 		}
297 		break;
298 	default:
299 		return -EINVAL;
300 	}
301 
302 	return 0;
303 }
304 
305 /*
306  * hfs_read_super()
307  *
308  * This is the function that is responsible for mounting an HFS
309  * filesystem.	It performs all the tasks necessary to get enough data
310  * from the disk to read the root inode.  This includes parsing the
311  * mount options, dealing with Macintosh partitions, reading the
312  * superblock and the allocation bitmap blocks, calling
313  * hfs_btree_init() to get the necessary data about the extents and
314  * catalog B-trees and, finally, reading the root inode into memory.
315  */
316 static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
317 {
318 	struct hfs_sb_info *sbi = HFS_SB(sb);
319 	struct hfs_find_data fd;
320 	hfs_cat_rec rec;
321 	struct inode *root_inode;
322 	int silent = fc->sb_flags & SB_SILENT;
323 	int res;
324 
325 	atomic64_set(&sbi->file_count, 0);
326 	atomic64_set(&sbi->folder_count, 0);
327 	atomic64_set(&sbi->next_id, 0);
328 
329 	/* load_nls_default does not fail */
330 	if (sbi->nls_disk && !sbi->nls_io)
331 		sbi->nls_io = load_nls_default();
332 	sbi->s_dir_umask &= 0777;
333 	sbi->s_file_umask &= 0577;
334 
335 	spin_lock_init(&sbi->work_lock);
336 	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
337 
338 	sbi->sb = sb;
339 	sb->s_op = &hfs_super_operations;
340 	sb->s_xattr = hfs_xattr_handlers;
341 	sb->s_flags |= SB_NODIRATIME;
342 	mutex_init(&sbi->bitmap_lock);
343 
344 	res = hfs_mdb_get(sb);
345 	if (res) {
346 		if (!silent)
347 			pr_warn("can't find a HFS filesystem on dev %s\n",
348 				hfs_mdb_name(sb));
349 		res = -EINVAL;
350 		goto bail;
351 	}
352 
353 	/* try to get the root inode */
354 	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
355 	if (res)
356 		goto bail_no_root;
357 	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
358 	if (!res) {
359 		if (fd.entrylength != sizeof(rec.dir)) {
360 			res =  -EIO;
361 			goto bail_hfs_find;
362 		}
363 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
364 		if (rec.type != HFS_CDR_DIR)
365 			res = -EIO;
366 	}
367 	if (res)
368 		goto bail_hfs_find;
369 	res = -EINVAL;
370 	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
371 	hfs_find_exit(&fd);
372 	if (!root_inode)
373 		goto bail_no_root;
374 
375 	set_default_d_op(sb, &hfs_dentry_operations);
376 	res = -ENOMEM;
377 	sb->s_root = d_make_root(root_inode);
378 	if (!sb->s_root)
379 		goto bail_no_root;
380 
381 	/* everything's okay */
382 	return 0;
383 
384 bail_hfs_find:
385 	hfs_find_exit(&fd);
386 bail_no_root:
387 	pr_err("get root inode failed\n");
388 bail:
389 	hfs_mdb_put(sb);
390 	return res;
391 }
392 
393 static int hfs_get_tree(struct fs_context *fc)
394 {
395 	return get_tree_bdev(fc, hfs_fill_super);
396 }
397 
398 static void hfs_free_fc(struct fs_context *fc)
399 {
400 	kfree(fc->s_fs_info);
401 }
402 
403 static const struct fs_context_operations hfs_context_ops = {
404 	.parse_param	= hfs_parse_param,
405 	.get_tree	= hfs_get_tree,
406 	.reconfigure	= hfs_reconfigure,
407 	.free		= hfs_free_fc,
408 };
409 
410 static int hfs_init_fs_context(struct fs_context *fc)
411 {
412 	struct hfs_sb_info *hsb;
413 
414 	hsb = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
415 	if (!hsb)
416 		return -ENOMEM;
417 
418 	fc->s_fs_info = hsb;
419 	fc->ops = &hfs_context_ops;
420 
421 	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
422 		/* initialize options with defaults */
423 		hsb->s_uid = current_uid();
424 		hsb->s_gid = current_gid();
425 		hsb->s_file_umask = 0133;
426 		hsb->s_dir_umask = 0022;
427 		hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
428 		hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
429 		hsb->s_quiet = 0;
430 		hsb->part = -1;
431 		hsb->session = -1;
432 	}
433 
434 	return 0;
435 }
436 
437 static void hfs_kill_super(struct super_block *sb)
438 {
439 	struct hfs_sb_info *hsb = HFS_SB(sb);
440 
441 	kill_block_super(sb);
442 	kfree(hsb);
443 }
444 
445 static struct file_system_type hfs_fs_type = {
446 	.owner		= THIS_MODULE,
447 	.name		= "hfs",
448 	.kill_sb	= hfs_kill_super,
449 	.fs_flags	= FS_REQUIRES_DEV,
450 	.init_fs_context = hfs_init_fs_context,
451 };
452 MODULE_ALIAS_FS("hfs");
453 
454 static void hfs_init_once(void *p)
455 {
456 	struct hfs_inode_info *i = p;
457 
458 	inode_init_once(&i->vfs_inode);
459 }
460 
461 static int __init init_hfs_fs(void)
462 {
463 	int err;
464 
465 	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
466 		sizeof(struct hfs_inode_info), 0,
467 		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
468 	if (!hfs_inode_cachep)
469 		return -ENOMEM;
470 	err = register_filesystem(&hfs_fs_type);
471 	if (err)
472 		kmem_cache_destroy(hfs_inode_cachep);
473 	return err;
474 }
475 
476 static void __exit exit_hfs_fs(void)
477 {
478 	unregister_filesystem(&hfs_fs_type);
479 
480 	/*
481 	 * Make sure all delayed rcu free inodes are flushed before we
482 	 * destroy cache.
483 	 */
484 	rcu_barrier();
485 	kmem_cache_destroy(hfs_inode_cachep);
486 }
487 
488 module_init(init_hfs_fs)
489 module_exit(exit_hfs_fs)
490