xref: /linux/fs/befs/linuxvfs.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  * linux/fs/befs/linuxvfs.c
3  *
4  * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
5  *
6  */
7 
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/fs.h>
11 #include <linux/errno.h>
12 #include <linux/stat.h>
13 #include <linux/nls.h>
14 #include <linux/buffer_head.h>
15 #include <linux/vfs.h>
16 #include <linux/parser.h>
17 #include <linux/namei.h>
18 
19 #include "befs.h"
20 #include "btree.h"
21 #include "inode.h"
22 #include "datastream.h"
23 #include "super.h"
24 #include "io.h"
25 
26 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
27 MODULE_AUTHOR("Will Dyson");
28 MODULE_LICENSE("GPL");
29 
30 /* The units the vfs expects inode->i_blocks to be in */
31 #define VFS_BLOCK_SIZE 512
32 
33 static int befs_readdir(struct file *, void *, filldir_t);
34 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
35 static int befs_readpage(struct file *file, struct page *page);
36 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
37 static struct dentry *befs_lookup(struct inode *, struct dentry *, struct nameidata *);
38 static void befs_read_inode(struct inode *ino);
39 static struct inode *befs_alloc_inode(struct super_block *sb);
40 static void befs_destroy_inode(struct inode *inode);
41 static int befs_init_inodecache(void);
42 static void befs_destroy_inodecache(void);
43 static void *befs_follow_link(struct dentry *, struct nameidata *);
44 static void befs_put_link(struct dentry *, struct nameidata *, void *);
45 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
46 			char **out, int *out_len);
47 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
48 			char **out, int *out_len);
49 static void befs_put_super(struct super_block *);
50 static int befs_remount(struct super_block *, int *, char *);
51 static int befs_statfs(struct dentry *, struct kstatfs *);
52 static int parse_options(char *, befs_mount_options *);
53 
54 static const struct super_operations befs_sops = {
55 	.read_inode	= befs_read_inode,	/* initialize & read inode */
56 	.alloc_inode	= befs_alloc_inode,	/* allocate a new inode */
57 	.destroy_inode	= befs_destroy_inode, /* deallocate an inode */
58 	.put_super	= befs_put_super,	/* uninit super */
59 	.statfs		= befs_statfs,	/* statfs */
60 	.remount_fs	= befs_remount,
61 };
62 
63 /* slab cache for befs_inode_info objects */
64 static struct kmem_cache *befs_inode_cachep;
65 
66 static const struct file_operations befs_dir_operations = {
67 	.read		= generic_read_dir,
68 	.readdir	= befs_readdir,
69 };
70 
71 static const struct inode_operations befs_dir_inode_operations = {
72 	.lookup		= befs_lookup,
73 };
74 
75 static const struct address_space_operations befs_aops = {
76 	.readpage	= befs_readpage,
77 	.sync_page	= block_sync_page,
78 	.bmap		= befs_bmap,
79 };
80 
81 static const struct inode_operations befs_symlink_inode_operations = {
82 	.readlink	= generic_readlink,
83 	.follow_link	= befs_follow_link,
84 	.put_link	= befs_put_link,
85 };
86 
87 /*
88  * Called by generic_file_read() to read a page of data
89  *
90  * In turn, simply calls a generic block read function and
91  * passes it the address of befs_get_block, for mapping file
92  * positions to disk blocks.
93  */
94 static int
95 befs_readpage(struct file *file, struct page *page)
96 {
97 	return block_read_full_page(page, befs_get_block);
98 }
99 
100 static sector_t
101 befs_bmap(struct address_space *mapping, sector_t block)
102 {
103 	return generic_block_bmap(mapping, block, befs_get_block);
104 }
105 
106 /*
107  * Generic function to map a file position (block) to a
108  * disk offset (passed back in bh_result).
109  *
110  * Used by many higher level functions.
111  *
112  * Calls befs_fblock2brun() in datastream.c to do the real work.
113  *
114  * -WD 10-26-01
115  */
116 
117 static int
118 befs_get_block(struct inode *inode, sector_t block,
119 	       struct buffer_head *bh_result, int create)
120 {
121 	struct super_block *sb = inode->i_sb;
122 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
123 	befs_block_run run = BAD_IADDR;
124 	int res = 0;
125 	ulong disk_off;
126 
127 	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
128 		   inode->i_ino, block);
129 
130 	if (block < 0) {
131 		befs_error(sb, "befs_get_block() was asked for a block "
132 			   "number less than zero: block %ld in inode %lu",
133 			   block, inode->i_ino);
134 		return -EIO;
135 	}
136 
137 	if (create) {
138 		befs_error(sb, "befs_get_block() was asked to write to "
139 			   "block %ld in inode %lu", block, inode->i_ino);
140 		return -EPERM;
141 	}
142 
143 	res = befs_fblock2brun(sb, ds, block, &run);
144 	if (res != BEFS_OK) {
145 		befs_error(sb,
146 			   "<--- befs_get_block() for inode %lu, block "
147 			   "%ld ERROR", inode->i_ino, block);
148 		return -EFBIG;
149 	}
150 
151 	disk_off = (ulong) iaddr2blockno(sb, &run);
152 
153 	map_bh(bh_result, inode->i_sb, disk_off);
154 
155 	befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
156 		   "disk address %lu", inode->i_ino, block, disk_off);
157 
158 	return 0;
159 }
160 
161 static struct dentry *
162 befs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
163 {
164 	struct inode *inode = NULL;
165 	struct super_block *sb = dir->i_sb;
166 	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
167 	befs_off_t offset;
168 	int ret;
169 	int utfnamelen;
170 	char *utfname;
171 	const char *name = dentry->d_name.name;
172 
173 	befs_debug(sb, "---> befs_lookup() "
174 		   "name %s inode %ld", dentry->d_name.name, dir->i_ino);
175 
176 	/* Convert to UTF-8 */
177 	if (BEFS_SB(sb)->nls) {
178 		ret =
179 		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
180 		if (ret < 0) {
181 			befs_debug(sb, "<--- befs_lookup() ERROR");
182 			return ERR_PTR(ret);
183 		}
184 		ret = befs_btree_find(sb, ds, utfname, &offset);
185 		kfree(utfname);
186 
187 	} else {
188 		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
189 	}
190 
191 	if (ret == BEFS_BT_NOT_FOUND) {
192 		befs_debug(sb, "<--- befs_lookup() %s not found",
193 			   dentry->d_name.name);
194 		return ERR_PTR(-ENOENT);
195 
196 	} else if (ret != BEFS_OK || offset == 0) {
197 		befs_warning(sb, "<--- befs_lookup() Error");
198 		return ERR_PTR(-ENODATA);
199 	}
200 
201 	inode = iget(dir->i_sb, (ino_t) offset);
202 	if (!inode)
203 		return ERR_PTR(-EACCES);
204 
205 	d_add(dentry, inode);
206 
207 	befs_debug(sb, "<--- befs_lookup()");
208 
209 	return NULL;
210 }
211 
212 static int
213 befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
214 {
215 	struct inode *inode = filp->f_path.dentry->d_inode;
216 	struct super_block *sb = inode->i_sb;
217 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
218 	befs_off_t value;
219 	int result;
220 	size_t keysize;
221 	unsigned char d_type;
222 	char keybuf[BEFS_NAME_LEN + 1];
223 	char *nlsname;
224 	int nlsnamelen;
225 	const char *dirname = filp->f_path.dentry->d_name.name;
226 
227 	befs_debug(sb, "---> befs_readdir() "
228 		   "name %s, inode %ld, filp->f_pos %Ld",
229 		   dirname, inode->i_ino, filp->f_pos);
230 
231 	result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
232 				 keybuf, &keysize, &value);
233 
234 	if (result == BEFS_ERR) {
235 		befs_debug(sb, "<--- befs_readdir() ERROR");
236 		befs_error(sb, "IO error reading %s (inode %lu)",
237 			   dirname, inode->i_ino);
238 		return -EIO;
239 
240 	} else if (result == BEFS_BT_END) {
241 		befs_debug(sb, "<--- befs_readdir() END");
242 		return 0;
243 
244 	} else if (result == BEFS_BT_EMPTY) {
245 		befs_debug(sb, "<--- befs_readdir() Empty directory");
246 		return 0;
247 	}
248 
249 	d_type = DT_UNKNOWN;
250 
251 	/* Convert to NLS */
252 	if (BEFS_SB(sb)->nls) {
253 		result =
254 		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
255 		if (result < 0) {
256 			befs_debug(sb, "<--- befs_readdir() ERROR");
257 			return result;
258 		}
259 		result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
260 				 (ino_t) value, d_type);
261 		kfree(nlsname);
262 
263 	} else {
264 		result = filldir(dirent, keybuf, keysize, filp->f_pos,
265 				 (ino_t) value, d_type);
266 	}
267 
268 	filp->f_pos++;
269 
270 	befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
271 
272 	return 0;
273 }
274 
275 static struct inode *
276 befs_alloc_inode(struct super_block *sb)
277 {
278         struct befs_inode_info *bi;
279         bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
280 							GFP_KERNEL);
281         if (!bi)
282                 return NULL;
283         return &bi->vfs_inode;
284 }
285 
286 static void
287 befs_destroy_inode(struct inode *inode)
288 {
289         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
290 }
291 
292 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
293 {
294         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
295 
296 	        if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
297 		            SLAB_CTOR_CONSTRUCTOR) {
298 			inode_init_once(&bi->vfs_inode);
299 		}
300 }
301 
302 static void
303 befs_read_inode(struct inode *inode)
304 {
305 	struct buffer_head *bh = NULL;
306 	befs_inode *raw_inode = NULL;
307 
308 	struct super_block *sb = inode->i_sb;
309 	befs_sb_info *befs_sb = BEFS_SB(sb);
310 	befs_inode_info *befs_ino = NULL;
311 
312 	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", inode->i_ino);
313 
314 	befs_ino = BEFS_I(inode);
315 
316 	/* convert from vfs's inode number to befs's inode number */
317 	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
318 
319 	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
320 		   befs_ino->i_inode_num.allocation_group,
321 		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
322 
323 	bh = befs_bread(sb, inode->i_ino);
324 	if (!bh) {
325 		befs_error(sb, "unable to read inode block - "
326 			   "inode = %lu", inode->i_ino);
327 		goto unacquire_none;
328 	}
329 
330 	raw_inode = (befs_inode *) bh->b_data;
331 
332 	befs_dump_inode(sb, raw_inode);
333 
334 	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
335 		befs_error(sb, "Bad inode: %lu", inode->i_ino);
336 		goto unacquire_bh;
337 	}
338 
339 	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
340 
341 	/*
342 	 * set uid and gid.  But since current BeOS is single user OS, so
343 	 * you can change by "uid" or "gid" options.
344 	 */
345 
346 	inode->i_uid = befs_sb->mount_opts.use_uid ?
347 	    befs_sb->mount_opts.uid : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
348 	inode->i_gid = befs_sb->mount_opts.use_gid ?
349 	    befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
350 
351 	inode->i_nlink = 1;
352 
353 	/*
354 	 * BEFS's time is 64 bits, but current VFS is 32 bits...
355 	 * BEFS don't have access time. Nor inode change time. VFS
356 	 * doesn't have creation time.
357 	 * Also, the lower 16 bits of the last_modified_time and
358 	 * create_time are just a counter to help ensure uniqueness
359 	 * for indexing purposes. (PFD, page 54)
360 	 */
361 
362 	inode->i_mtime.tv_sec =
363 	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
364 	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
365 	inode->i_ctime = inode->i_mtime;
366 	inode->i_atime = inode->i_mtime;
367 
368 	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
369 	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
370 	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
371 	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
372 
373 	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
374 		inode->i_size = 0;
375 		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
376 		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
377 			BEFS_SYMLINK_LEN);
378 	} else {
379 		int num_blks;
380 
381 		befs_ino->i_data.ds =
382 		    fsds_to_cpu(sb, raw_inode->data.datastream);
383 
384 		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
385 		inode->i_blocks =
386 		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
387 		inode->i_size = befs_ino->i_data.ds.size;
388 	}
389 
390 	inode->i_mapping->a_ops = &befs_aops;
391 
392 	if (S_ISREG(inode->i_mode)) {
393 		inode->i_fop = &generic_ro_fops;
394 	} else if (S_ISDIR(inode->i_mode)) {
395 		inode->i_op = &befs_dir_inode_operations;
396 		inode->i_fop = &befs_dir_operations;
397 	} else if (S_ISLNK(inode->i_mode)) {
398 		inode->i_op = &befs_symlink_inode_operations;
399 	} else {
400 		befs_error(sb, "Inode %lu is not a regular file, "
401 			   "directory or symlink. THAT IS WRONG! BeFS has no "
402 			   "on disk special files", inode->i_ino);
403 		goto unacquire_bh;
404 	}
405 
406 	brelse(bh);
407 	befs_debug(sb, "<--- befs_read_inode()");
408 	return;
409 
410       unacquire_bh:
411 	brelse(bh);
412 
413       unacquire_none:
414 	make_bad_inode(inode);
415 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
416 	return;
417 }
418 
419 /* Initialize the inode cache. Called at fs setup.
420  *
421  * Taken from NFS implementation by Al Viro.
422  */
423 static int
424 befs_init_inodecache(void)
425 {
426 	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
427 					      sizeof (struct befs_inode_info),
428 					      0, (SLAB_RECLAIM_ACCOUNT|
429 						SLAB_MEM_SPREAD),
430 					      init_once, NULL);
431 	if (befs_inode_cachep == NULL) {
432 		printk(KERN_ERR "befs_init_inodecache: "
433 		       "Couldn't initalize inode slabcache\n");
434 		return -ENOMEM;
435 	}
436 
437 	return 0;
438 }
439 
440 /* Called at fs teardown.
441  *
442  * Taken from NFS implementation by Al Viro.
443  */
444 static void
445 befs_destroy_inodecache(void)
446 {
447 	kmem_cache_destroy(befs_inode_cachep);
448 }
449 
450 /*
451  * The inode of symbolic link is different to data stream.
452  * The data stream become link name. Unless the LONG_SYMLINK
453  * flag is set.
454  */
455 static void *
456 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
457 {
458 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
459 	char *link;
460 
461 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
462 		struct super_block *sb = dentry->d_sb;
463 		befs_data_stream *data = &befs_ino->i_data.ds;
464 		befs_off_t len = data->size;
465 
466 		befs_debug(sb, "Follow long symlink");
467 
468 		link = kmalloc(len, GFP_NOFS);
469 		if (!link) {
470 			link = ERR_PTR(-ENOMEM);
471 		} else if (befs_read_lsymlink(sb, data, link, len) != len) {
472 			kfree(link);
473 			befs_error(sb, "Failed to read entire long symlink");
474 			link = ERR_PTR(-EIO);
475 		}
476 	} else {
477 		link = befs_ino->i_data.symlink;
478 	}
479 
480 	nd_set_link(nd, link);
481 	return NULL;
482 }
483 
484 static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
485 {
486 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
487 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
488 		char *p = nd_get_link(nd);
489 		if (!IS_ERR(p))
490 			kfree(p);
491 	}
492 }
493 
494 /*
495  * UTF-8 to NLS charset  convert routine
496  *
497  *
498  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
499  * the nls tables directly
500  */
501 
502 static int
503 befs_utf2nls(struct super_block *sb, const char *in,
504 	     int in_len, char **out, int *out_len)
505 {
506 	struct nls_table *nls = BEFS_SB(sb)->nls;
507 	int i, o;
508 	wchar_t uni;
509 	int unilen, utflen;
510 	char *result;
511 	/* The utf8->nls conversion won't make the final nls string bigger
512 	 * than the utf one, but if the string is pure ascii they'll have the
513 	 * same width and an extra char is needed to save the additional \0
514 	 */
515 	int maxlen = in_len + 1;
516 
517 	befs_debug(sb, "---> utf2nls()");
518 
519 	if (!nls) {
520 		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
521 		return -EINVAL;
522 	}
523 
524 	*out = result = kmalloc(maxlen, GFP_NOFS);
525 	if (!*out) {
526 		befs_error(sb, "befs_utf2nls() cannot allocate memory");
527 		*out_len = 0;
528 		return -ENOMEM;
529 	}
530 
531 	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
532 
533 		/* convert from UTF-8 to Unicode */
534 		utflen = utf8_mbtowc(&uni, &in[i], in_len - i);
535 		if (utflen < 0) {
536 			goto conv_err;
537 		}
538 
539 		/* convert from Unicode to nls */
540 		unilen = nls->uni2char(uni, &result[o], in_len - o);
541 		if (unilen < 0) {
542 			goto conv_err;
543 		}
544 	}
545 	result[o] = '\0';
546 	*out_len = o;
547 
548 	befs_debug(sb, "<--- utf2nls()");
549 
550 	return o;
551 
552       conv_err:
553 	befs_error(sb, "Name using character set %s contains a character that "
554 		   "cannot be converted to unicode.", nls->charset);
555 	befs_debug(sb, "<--- utf2nls()");
556 	kfree(result);
557 	return -EILSEQ;
558 }
559 
560 /**
561  * befs_nls2utf - Convert NLS string to utf8 encodeing
562  * @sb: Superblock
563  * @src: Input string buffer in NLS format
564  * @srclen: Length of input string in bytes
565  * @dest: The output string in UTF-8 format
566  * @destlen: Length of the output buffer
567  *
568  * Converts input string @src, which is in the format of the loaded NLS map,
569  * into a utf8 string.
570  *
571  * The destination string @dest is allocated by this function and the caller is
572  * responsible for freeing it with kfree()
573  *
574  * On return, *@destlen is the length of @dest in bytes.
575  *
576  * On success, the return value is the number of utf8 characters written to
577  * the output buffer @dest.
578  *
579  * On Failure, a negative number coresponding to the error code is returned.
580  */
581 
582 static int
583 befs_nls2utf(struct super_block *sb, const char *in,
584 	     int in_len, char **out, int *out_len)
585 {
586 	struct nls_table *nls = BEFS_SB(sb)->nls;
587 	int i, o;
588 	wchar_t uni;
589 	int unilen, utflen;
590 	char *result;
591 	/* There're nls characters that will translate to 3-chars-wide UTF-8
592 	 * characters, a additional byte is needed to save the final \0
593 	 * in special cases */
594 	int maxlen = (3 * in_len) + 1;
595 
596 	befs_debug(sb, "---> nls2utf()\n");
597 
598 	if (!nls) {
599 		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
600 		return -EINVAL;
601 	}
602 
603 	*out = result = kmalloc(maxlen, GFP_NOFS);
604 	if (!*out) {
605 		befs_error(sb, "befs_nls2utf() cannot allocate memory");
606 		*out_len = 0;
607 		return -ENOMEM;
608 	}
609 
610 	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
611 
612 		/* convert from nls to unicode */
613 		unilen = nls->char2uni(&in[i], in_len - i, &uni);
614 		if (unilen < 0) {
615 			goto conv_err;
616 		}
617 
618 		/* convert from unicode to UTF-8 */
619 		utflen = utf8_wctomb(&result[o], uni, 3);
620 		if (utflen <= 0) {
621 			goto conv_err;
622 		}
623 	}
624 
625 	result[o] = '\0';
626 	*out_len = o;
627 
628 	befs_debug(sb, "<--- nls2utf()");
629 
630 	return i;
631 
632       conv_err:
633 	befs_error(sb, "Name using charecter set %s contains a charecter that "
634 		   "cannot be converted to unicode.", nls->charset);
635 	befs_debug(sb, "<--- nls2utf()");
636 	kfree(result);
637 	return -EILSEQ;
638 }
639 
640 /**
641  * Use the
642  *
643  */
644 enum {
645 	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
646 };
647 
648 static match_table_t befs_tokens = {
649 	{Opt_uid, "uid=%d"},
650 	{Opt_gid, "gid=%d"},
651 	{Opt_charset, "iocharset=%s"},
652 	{Opt_debug, "debug"},
653 	{Opt_err, NULL}
654 };
655 
656 static int
657 parse_options(char *options, befs_mount_options * opts)
658 {
659 	char *p;
660 	substring_t args[MAX_OPT_ARGS];
661 	int option;
662 
663 	/* Initialize options */
664 	opts->uid = 0;
665 	opts->gid = 0;
666 	opts->use_uid = 0;
667 	opts->use_gid = 0;
668 	opts->iocharset = NULL;
669 	opts->debug = 0;
670 
671 	if (!options)
672 		return 1;
673 
674 	while ((p = strsep(&options, ",")) != NULL) {
675 		int token;
676 		if (!*p)
677 			continue;
678 
679 		token = match_token(p, befs_tokens, args);
680 		switch (token) {
681 		case Opt_uid:
682 			if (match_int(&args[0], &option))
683 				return 0;
684 			if (option < 0) {
685 				printk(KERN_ERR "BeFS: Invalid uid %d, "
686 						"using default\n", option);
687 				break;
688 			}
689 			opts->uid = option;
690 			opts->use_uid = 1;
691 			break;
692 		case Opt_gid:
693 			if (match_int(&args[0], &option))
694 				return 0;
695 			if (option < 0) {
696 				printk(KERN_ERR "BeFS: Invalid gid %d, "
697 						"using default\n", option);
698 				break;
699 			}
700 			opts->gid = option;
701 			opts->use_gid = 1;
702 			break;
703 		case Opt_charset:
704 			kfree(opts->iocharset);
705 			opts->iocharset = match_strdup(&args[0]);
706 			if (!opts->iocharset) {
707 				printk(KERN_ERR "BeFS: allocation failure for "
708 						"iocharset string\n");
709 				return 0;
710 			}
711 			break;
712 		case Opt_debug:
713 			opts->debug = 1;
714 			break;
715 		default:
716 			printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
717 					"or missing value\n", p);
718 			return 0;
719 		}
720 	}
721 	return 1;
722 }
723 
724 /* This function has the responsibiltiy of getting the
725  * filesystem ready for unmounting.
726  * Basicly, we free everything that we allocated in
727  * befs_read_inode
728  */
729 static void
730 befs_put_super(struct super_block *sb)
731 {
732 	kfree(BEFS_SB(sb)->mount_opts.iocharset);
733 	BEFS_SB(sb)->mount_opts.iocharset = NULL;
734 
735 	if (BEFS_SB(sb)->nls) {
736 		unload_nls(BEFS_SB(sb)->nls);
737 		BEFS_SB(sb)->nls = NULL;
738 	}
739 
740 	kfree(sb->s_fs_info);
741 	sb->s_fs_info = NULL;
742 	return;
743 }
744 
745 /* Allocate private field of the superblock, fill it.
746  *
747  * Finish filling the public superblock fields
748  * Make the root directory
749  * Load a set of NLS translations if needed.
750  */
751 static int
752 befs_fill_super(struct super_block *sb, void *data, int silent)
753 {
754 	struct buffer_head *bh;
755 	befs_sb_info *befs_sb;
756 	befs_super_block *disk_sb;
757 	struct inode *root;
758 
759 	const unsigned long sb_block = 0;
760 	const off_t x86_sb_off = 512;
761 
762 	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
763 	if (sb->s_fs_info == NULL) {
764 		printk(KERN_ERR
765 		       "BeFS(%s): Unable to allocate memory for private "
766 		       "portion of superblock. Bailing.\n", sb->s_id);
767 		goto unacquire_none;
768 	}
769 	befs_sb = BEFS_SB(sb);
770 	memset(befs_sb, 0, sizeof(befs_sb_info));
771 
772 	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
773 		befs_error(sb, "cannot parse mount options");
774 		goto unacquire_priv_sbp;
775 	}
776 
777 	befs_debug(sb, "---> befs_fill_super()");
778 
779 #ifndef CONFIG_BEFS_RW
780 	if (!(sb->s_flags & MS_RDONLY)) {
781 		befs_warning(sb,
782 			     "No write support. Marking filesystem read-only");
783 		sb->s_flags |= MS_RDONLY;
784 	}
785 #endif				/* CONFIG_BEFS_RW */
786 
787 	/*
788 	 * Set dummy blocksize to read super block.
789 	 * Will be set to real fs blocksize later.
790 	 *
791 	 * Linux 2.4.10 and later refuse to read blocks smaller than
792 	 * the hardsect size for the device. But we also need to read at
793 	 * least 1k to get the second 512 bytes of the volume.
794 	 * -WD 10-26-01
795 	 */
796 	sb_min_blocksize(sb, 1024);
797 
798 	if (!(bh = sb_bread(sb, sb_block))) {
799 		befs_error(sb, "unable to read superblock");
800 		goto unacquire_priv_sbp;
801 	}
802 
803 	/* account for offset of super block on x86 */
804 	disk_sb = (befs_super_block *) bh->b_data;
805 	if ((le32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1) ||
806 	    (be32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1)) {
807 		befs_debug(sb, "Using PPC superblock location");
808 	} else {
809 		befs_debug(sb, "Using x86 superblock location");
810 		disk_sb =
811 		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
812 	}
813 
814 	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
815 		goto unacquire_bh;
816 
817 	befs_dump_super_block(sb, disk_sb);
818 
819 	brelse(bh);
820 
821 	if (befs_check_sb(sb) != BEFS_OK)
822 		goto unacquire_priv_sbp;
823 
824 	if( befs_sb->num_blocks > ~((sector_t)0) ) {
825 		befs_error(sb, "blocks count: %Lu "
826 			"is larger than the host can use",
827 			befs_sb->num_blocks);
828 		goto unacquire_priv_sbp;
829 	}
830 
831 	/*
832 	 * set up enough so that it can read an inode
833 	 * Fill in kernel superblock fields from private sb
834 	 */
835 	sb->s_magic = BEFS_SUPER_MAGIC;
836 	/* Set real blocksize of fs */
837 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
838 	sb->s_op = (struct super_operations *) &befs_sops;
839 	root = iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
840 	sb->s_root = d_alloc_root(root);
841 	if (!sb->s_root) {
842 		iput(root);
843 		befs_error(sb, "get root inode failed");
844 		goto unacquire_priv_sbp;
845 	}
846 
847 	/* load nls library */
848 	if (befs_sb->mount_opts.iocharset) {
849 		befs_debug(sb, "Loading nls: %s",
850 			   befs_sb->mount_opts.iocharset);
851 		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
852 		if (!befs_sb->nls) {
853 			befs_warning(sb, "Cannot load nls %s"
854 					" loading default nls",
855 					befs_sb->mount_opts.iocharset);
856 			befs_sb->nls = load_nls_default();
857 		}
858 	/* load default nls if none is specified  in mount options */
859 	} else {
860 		befs_debug(sb, "Loading default nls");
861 		befs_sb->nls = load_nls_default();
862 	}
863 
864 	return 0;
865 /*****************/
866       unacquire_bh:
867 	brelse(bh);
868 
869       unacquire_priv_sbp:
870 	kfree(sb->s_fs_info);
871 
872       unacquire_none:
873 	sb->s_fs_info = NULL;
874 	return -EINVAL;
875 }
876 
877 static int
878 befs_remount(struct super_block *sb, int *flags, char *data)
879 {
880 	if (!(*flags & MS_RDONLY))
881 		return -EINVAL;
882 	return 0;
883 }
884 
885 static int
886 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
887 {
888 	struct super_block *sb = dentry->d_sb;
889 
890 	befs_debug(sb, "---> befs_statfs()");
891 
892 	buf->f_type = BEFS_SUPER_MAGIC;
893 	buf->f_bsize = sb->s_blocksize;
894 	buf->f_blocks = BEFS_SB(sb)->num_blocks;
895 	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
896 	buf->f_bavail = buf->f_bfree;
897 	buf->f_files = 0;	/* UNKNOWN */
898 	buf->f_ffree = 0;	/* UNKNOWN */
899 	buf->f_namelen = BEFS_NAME_LEN;
900 
901 	befs_debug(sb, "<--- befs_statfs()");
902 
903 	return 0;
904 }
905 
906 static int
907 befs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name,
908 	    void *data, struct vfsmount *mnt)
909 {
910 	return get_sb_bdev(fs_type, flags, dev_name, data, befs_fill_super,
911 			   mnt);
912 }
913 
914 static struct file_system_type befs_fs_type = {
915 	.owner		= THIS_MODULE,
916 	.name		= "befs",
917 	.get_sb		= befs_get_sb,
918 	.kill_sb	= kill_block_super,
919 	.fs_flags	= FS_REQUIRES_DEV,
920 };
921 
922 static int __init
923 init_befs_fs(void)
924 {
925 	int err;
926 
927 	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
928 
929 	err = befs_init_inodecache();
930 	if (err)
931 		goto unacquire_none;
932 
933 	err = register_filesystem(&befs_fs_type);
934 	if (err)
935 		goto unacquire_inodecache;
936 
937 	return 0;
938 
939 unacquire_inodecache:
940 	befs_destroy_inodecache();
941 
942 unacquire_none:
943 	return err;
944 }
945 
946 static void __exit
947 exit_befs_fs(void)
948 {
949 	befs_destroy_inodecache();
950 
951 	unregister_filesystem(&befs_fs_type);
952 }
953 
954 /*
955 Macros that typecheck the init and exit functions,
956 ensures that they are called at init and cleanup,
957 and eliminates warnings about unused functions.
958 */
959 module_init(init_befs_fs)
960 module_exit(exit_befs_fs)
961