xref: /openbmc/linux/fs/hfs/super.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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_module() and cleanup_module().	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/config.h>
16 #include <linux/module.h>
17 #include <linux/blkdev.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/vfs.h>
24 
25 #include "hfs_fs.h"
26 #include "btree.h"
27 
28 static kmem_cache_t *hfs_inode_cachep;
29 
30 MODULE_LICENSE("GPL");
31 
32 /*
33  * hfs_write_super()
34  *
35  * Description:
36  *   This function is called by the VFS only. When the filesystem
37  *   is mounted r/w it updates the MDB on disk.
38  * Input Variable(s):
39  *   struct super_block *sb: Pointer to the hfs superblock
40  * Output Variable(s):
41  *   NONE
42  * Returns:
43  *   void
44  * Preconditions:
45  *   'sb' points to a "valid" (struct super_block).
46  * Postconditions:
47  *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
48  *   (hfs_put_super() must set this flag!). Some MDB fields are updated
49  *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
50  */
51 static void hfs_write_super(struct super_block *sb)
52 {
53 	sb->s_dirt = 0;
54 	if (sb->s_flags & MS_RDONLY)
55 		return;
56 	/* sync everything to the buffers */
57 	hfs_mdb_commit(sb);
58 }
59 
60 /*
61  * hfs_put_super()
62  *
63  * This is the put_super() entry in the super_operations structure for
64  * HFS filesystems.  The purpose is to release the resources
65  * associated with the superblock sb.
66  */
67 static void hfs_put_super(struct super_block *sb)
68 {
69 	hfs_mdb_close(sb);
70 	/* release the MDB's resources */
71 	hfs_mdb_put(sb);
72 }
73 
74 /*
75  * hfs_statfs()
76  *
77  * This is the statfs() entry in the super_operations structure for
78  * HFS filesystems.  The purpose is to return various data about the
79  * filesystem.
80  *
81  * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
82  */
83 static int hfs_statfs(struct super_block *sb, struct kstatfs *buf)
84 {
85 	buf->f_type = HFS_SUPER_MAGIC;
86 	buf->f_bsize = sb->s_blocksize;
87 	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
88 	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
89 	buf->f_bavail = buf->f_bfree;
90 	buf->f_files = HFS_SB(sb)->fs_ablocks;
91 	buf->f_ffree = HFS_SB(sb)->free_ablocks;
92 	buf->f_namelen = HFS_NAMELEN;
93 
94 	return 0;
95 }
96 
97 static int hfs_remount(struct super_block *sb, int *flags, char *data)
98 {
99 	*flags |= MS_NODIRATIME;
100 	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
101 		return 0;
102 	if (!(*flags & MS_RDONLY)) {
103 		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
104 			printk("HFS-fs warning: Filesystem was not cleanly unmounted, "
105 			       "running fsck.hfs is recommended.  leaving read-only.\n");
106 			sb->s_flags |= MS_RDONLY;
107 			*flags |= MS_RDONLY;
108 		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
109 			printk("HFS-fs: Filesystem is marked locked, leaving read-only.\n");
110 			sb->s_flags |= MS_RDONLY;
111 			*flags |= MS_RDONLY;
112 		}
113 	}
114 	return 0;
115 }
116 
117 static int hfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
118 {
119 	struct hfs_sb_info *sbi = HFS_SB(mnt->mnt_sb);
120 
121 	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
122 		seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
123 	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
124 		seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
125 	seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
126 	if (sbi->s_file_umask != 0133)
127 		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
128 	if (sbi->s_dir_umask != 0022)
129 		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
130 	if (sbi->part >= 0)
131 		seq_printf(seq, ",part=%u", sbi->part);
132 	if (sbi->session >= 0)
133 		seq_printf(seq, ",session=%u", sbi->session);
134 	if (sbi->nls_disk)
135 		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
136 	if (sbi->nls_io)
137 		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
138 	if (sbi->s_quiet)
139 		seq_printf(seq, ",quiet");
140 	return 0;
141 }
142 
143 static struct inode *hfs_alloc_inode(struct super_block *sb)
144 {
145 	struct hfs_inode_info *i;
146 
147 	i = kmem_cache_alloc(hfs_inode_cachep, SLAB_KERNEL);
148 	return i ? &i->vfs_inode : NULL;
149 }
150 
151 static void hfs_destroy_inode(struct inode *inode)
152 {
153 	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
154 }
155 
156 static struct super_operations hfs_super_operations = {
157 	.alloc_inode	= hfs_alloc_inode,
158 	.destroy_inode	= hfs_destroy_inode,
159 	.write_inode	= hfs_write_inode,
160 	.clear_inode	= hfs_clear_inode,
161 	.put_super	= hfs_put_super,
162 	.write_super	= hfs_write_super,
163 	.statfs		= hfs_statfs,
164 	.remount_fs     = hfs_remount,
165 	.show_options	= hfs_show_options,
166 };
167 
168 enum {
169 	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
170 	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
171 	opt_codepage, opt_iocharset,
172 	opt_err
173 };
174 
175 static match_table_t tokens = {
176 	{ opt_uid, "uid=%u" },
177 	{ opt_gid, "gid=%u" },
178 	{ opt_umask, "umask=%o" },
179 	{ opt_file_umask, "file_umask=%o" },
180 	{ opt_dir_umask, "dir_umask=%o" },
181 	{ opt_part, "part=%u" },
182 	{ opt_session, "session=%u" },
183 	{ opt_type, "type=%s" },
184 	{ opt_creator, "creator=%s" },
185 	{ opt_quiet, "quiet" },
186 	{ opt_codepage, "codepage=%s" },
187 	{ opt_iocharset, "iocharset=%s" },
188 	{ opt_err, NULL }
189 };
190 
191 static inline int match_fourchar(substring_t *arg, u32 *result)
192 {
193 	if (arg->to - arg->from != 4)
194 		return -EINVAL;
195 	memcpy(result, arg->from, 4);
196 	return 0;
197 }
198 
199 /*
200  * parse_options()
201  *
202  * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
203  * This function is called by hfs_read_super() to parse the mount options.
204  */
205 static int parse_options(char *options, struct hfs_sb_info *hsb)
206 {
207 	char *p;
208 	substring_t args[MAX_OPT_ARGS];
209 	int tmp, token;
210 
211 	/* initialize the sb with defaults */
212 	hsb->s_uid = current->uid;
213 	hsb->s_gid = current->gid;
214 	hsb->s_file_umask = 0133;
215 	hsb->s_dir_umask = 0022;
216 	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
217 	hsb->s_quiet = 0;
218 	hsb->part = -1;
219 	hsb->session = -1;
220 
221 	if (!options)
222 		return 1;
223 
224 	while ((p = strsep(&options, ",")) != NULL) {
225 		if (!*p)
226 			continue;
227 
228 		token = match_token(p, tokens, args);
229 		switch (token) {
230 		case opt_uid:
231 			if (match_int(&args[0], &tmp)) {
232 				printk("HFS: uid requires an argument\n");
233 				return 0;
234 			}
235 			hsb->s_uid = (uid_t)tmp;
236 			break;
237 		case opt_gid:
238 			if (match_int(&args[0], &tmp)) {
239 				printk("HFS: gid requires an argument\n");
240 				return 0;
241 			}
242 			hsb->s_gid = (gid_t)tmp;
243 			break;
244 		case opt_umask:
245 			if (match_octal(&args[0], &tmp)) {
246 				printk("HFS: umask requires a value\n");
247 				return 0;
248 			}
249 			hsb->s_file_umask = (umode_t)tmp;
250 			hsb->s_dir_umask = (umode_t)tmp;
251 			break;
252 		case opt_file_umask:
253 			if (match_octal(&args[0], &tmp)) {
254 				printk("HFS: file_umask requires a value\n");
255 				return 0;
256 			}
257 			hsb->s_file_umask = (umode_t)tmp;
258 			break;
259 		case opt_dir_umask:
260 			if (match_octal(&args[0], &tmp)) {
261 				printk("HFS: dir_umask requires a value\n");
262 				return 0;
263 			}
264 			hsb->s_dir_umask = (umode_t)tmp;
265 			break;
266 		case opt_part:
267 			if (match_int(&args[0], &hsb->part)) {
268 				printk("HFS: part requires an argument\n");
269 				return 0;
270 			}
271 			break;
272 		case opt_session:
273 			if (match_int(&args[0], &hsb->session)) {
274 				printk("HFS: session requires an argument\n");
275 				return 0;
276 			}
277 			break;
278 		case opt_type:
279 			if (match_fourchar(&args[0], &hsb->s_type)) {
280 				printk("HFS+-fs: type requires a 4 character value\n");
281 				return 0;
282 			}
283 			break;
284 		case opt_creator:
285 			if (match_fourchar(&args[0], &hsb->s_creator)) {
286 				printk("HFS+-fs: creator requires a 4 character value\n");
287 				return 0;
288 			}
289 			break;
290 		case opt_quiet:
291 			hsb->s_quiet = 1;
292 			break;
293 		case opt_codepage:
294 			if (hsb->nls_disk) {
295 				printk("HFS+-fs: unable to change codepage\n");
296 				return 0;
297 			}
298 			p = match_strdup(&args[0]);
299 			hsb->nls_disk = load_nls(p);
300 			if (!hsb->nls_disk) {
301 				printk("HFS+-fs: unable to load codepage \"%s\"\n", p);
302 				kfree(p);
303 				return 0;
304 			}
305 			kfree(p);
306 			break;
307 		case opt_iocharset:
308 			if (hsb->nls_io) {
309 				printk("HFS: unable to change iocharset\n");
310 				return 0;
311 			}
312 			p = match_strdup(&args[0]);
313 			hsb->nls_io = load_nls(p);
314 			if (!hsb->nls_io) {
315 				printk("HFS: unable to load iocharset \"%s\"\n", p);
316 				kfree(p);
317 				return 0;
318 			}
319 			kfree(p);
320 			break;
321 		default:
322 			return 0;
323 		}
324 	}
325 
326 	if (hsb->nls_disk && !hsb->nls_io) {
327 		hsb->nls_io = load_nls_default();
328 		if (!hsb->nls_io) {
329 			printk("HFS: unable to load default iocharset\n");
330 			return 0;
331 		}
332 	}
333 	hsb->s_dir_umask &= 0777;
334 	hsb->s_file_umask &= 0577;
335 
336 	return 1;
337 }
338 
339 /*
340  * hfs_read_super()
341  *
342  * This is the function that is responsible for mounting an HFS
343  * filesystem.	It performs all the tasks necessary to get enough data
344  * from the disk to read the root inode.  This includes parsing the
345  * mount options, dealing with Macintosh partitions, reading the
346  * superblock and the allocation bitmap blocks, calling
347  * hfs_btree_init() to get the necessary data about the extents and
348  * catalog B-trees and, finally, reading the root inode into memory.
349  */
350 static int hfs_fill_super(struct super_block *sb, void *data, int silent)
351 {
352 	struct hfs_sb_info *sbi;
353 	struct hfs_find_data fd;
354 	hfs_cat_rec rec;
355 	struct inode *root_inode;
356 	int res;
357 
358 	sbi = kmalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);
359 	if (!sbi)
360 		return -ENOMEM;
361 	sb->s_fs_info = sbi;
362 	memset(sbi, 0, sizeof(struct hfs_sb_info));
363 	INIT_HLIST_HEAD(&sbi->rsrc_inodes);
364 
365 	res = -EINVAL;
366 	if (!parse_options((char *)data, sbi)) {
367 		hfs_warn("hfs_fs: unable to parse mount options.\n");
368 		goto bail;
369 	}
370 
371 	sb->s_op = &hfs_super_operations;
372 	sb->s_flags |= MS_NODIRATIME;
373 	init_MUTEX(&sbi->bitmap_lock);
374 
375 	res = hfs_mdb_get(sb);
376 	if (res) {
377 		if (!silent)
378 			hfs_warn("VFS: Can't find a HFS filesystem on dev %s.\n",
379 				hfs_mdb_name(sb));
380 		res = -EINVAL;
381 		goto bail;
382 	}
383 
384 	/* try to get the root inode */
385 	hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
386 	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
387 	if (!res)
388 		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
389 	if (res) {
390 		hfs_find_exit(&fd);
391 		goto bail_no_root;
392 	}
393 	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
394 	hfs_find_exit(&fd);
395 	if (!root_inode)
396 		goto bail_no_root;
397 
398 	sb->s_root = d_alloc_root(root_inode);
399 	if (!sb->s_root)
400 		goto bail_iput;
401 
402 	sb->s_root->d_op = &hfs_dentry_operations;
403 
404 	/* everything's okay */
405 	return 0;
406 
407 bail_iput:
408 	iput(root_inode);
409 bail_no_root:
410 	hfs_warn("hfs_fs: get root inode failed.\n");
411 bail:
412 	hfs_mdb_put(sb);
413 	return res;
414 }
415 
416 static struct super_block *hfs_get_sb(struct file_system_type *fs_type,
417 				      int flags, const char *dev_name, void *data)
418 {
419 	return get_sb_bdev(fs_type, flags, dev_name, data, hfs_fill_super);
420 }
421 
422 static struct file_system_type hfs_fs_type = {
423 	.owner		= THIS_MODULE,
424 	.name		= "hfs",
425 	.get_sb		= hfs_get_sb,
426 	.kill_sb	= kill_block_super,
427 	.fs_flags	= FS_REQUIRES_DEV,
428 };
429 
430 static void hfs_init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
431 {
432 	struct hfs_inode_info *i = p;
433 
434 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
435 		inode_init_once(&i->vfs_inode);
436 }
437 
438 static int __init init_hfs_fs(void)
439 {
440 	int err;
441 
442 	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
443 		sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,
444 		hfs_init_once, NULL);
445 	if (!hfs_inode_cachep)
446 		return -ENOMEM;
447 	err = register_filesystem(&hfs_fs_type);
448 	if (err)
449 		kmem_cache_destroy(hfs_inode_cachep);
450 	return err;
451 }
452 
453 static void __exit exit_hfs_fs(void)
454 {
455 	unregister_filesystem(&hfs_fs_type);
456 	if (kmem_cache_destroy(hfs_inode_cachep))
457 		printk(KERN_INFO "hfs_inode_cache: not all structures were freed\n");
458 }
459 
460 module_init(init_hfs_fs)
461 module_exit(exit_hfs_fs)
462