xref: /linux/fs/befs/linuxvfs.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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 #include <linux/sched.h>
19 
20 #include "befs.h"
21 #include "btree.h"
22 #include "inode.h"
23 #include "datastream.h"
24 #include "super.h"
25 #include "io.h"
26 
27 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
28 MODULE_AUTHOR("Will Dyson");
29 MODULE_LICENSE("GPL");
30 
31 /* The units the vfs expects inode->i_blocks to be in */
32 #define VFS_BLOCK_SIZE 512
33 
34 static int befs_readdir(struct file *, void *, filldir_t);
35 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
36 static int befs_readpage(struct file *file, struct page *page);
37 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
38 static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
39 static struct inode *befs_iget(struct super_block *, unsigned long);
40 static struct inode *befs_alloc_inode(struct super_block *sb);
41 static void befs_destroy_inode(struct inode *inode);
42 static int befs_init_inodecache(void);
43 static void befs_destroy_inodecache(void);
44 static void *befs_follow_link(struct dentry *, struct nameidata *);
45 static void befs_put_link(struct dentry *, struct nameidata *, void *);
46 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
47 			char **out, int *out_len);
48 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
49 			char **out, int *out_len);
50 static void befs_put_super(struct super_block *);
51 static int befs_remount(struct super_block *, int *, char *);
52 static int befs_statfs(struct dentry *, struct kstatfs *);
53 static int parse_options(char *, befs_mount_options *);
54 
55 static const struct super_operations befs_sops = {
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 	.show_options	= generic_show_options,
62 };
63 
64 /* slab cache for befs_inode_info objects */
65 static struct kmem_cache *befs_inode_cachep;
66 
67 static const struct file_operations befs_dir_operations = {
68 	.read		= generic_read_dir,
69 	.readdir	= befs_readdir,
70 	.llseek		= generic_file_llseek,
71 };
72 
73 static const struct inode_operations befs_dir_inode_operations = {
74 	.lookup		= befs_lookup,
75 };
76 
77 static const struct address_space_operations befs_aops = {
78 	.readpage	= befs_readpage,
79 	.bmap		= befs_bmap,
80 };
81 
82 static const struct inode_operations befs_symlink_inode_operations = {
83 	.readlink	= generic_readlink,
84 	.follow_link	= befs_follow_link,
85 	.put_link	= befs_put_link,
86 };
87 
88 /*
89  * Called by generic_file_read() to read a page of data
90  *
91  * In turn, simply calls a generic block read function and
92  * passes it the address of befs_get_block, for mapping file
93  * positions to disk blocks.
94  */
95 static int
96 befs_readpage(struct file *file, struct page *page)
97 {
98 	return block_read_full_page(page, befs_get_block);
99 }
100 
101 static sector_t
102 befs_bmap(struct address_space *mapping, sector_t block)
103 {
104 	return generic_block_bmap(mapping, block, befs_get_block);
105 }
106 
107 /*
108  * Generic function to map a file position (block) to a
109  * disk offset (passed back in bh_result).
110  *
111  * Used by many higher level functions.
112  *
113  * Calls befs_fblock2brun() in datastream.c to do the real work.
114  *
115  * -WD 10-26-01
116  */
117 
118 static int
119 befs_get_block(struct inode *inode, sector_t block,
120 	       struct buffer_head *bh_result, int create)
121 {
122 	struct super_block *sb = inode->i_sb;
123 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
124 	befs_block_run run = BAD_IADDR;
125 	int res = 0;
126 	ulong disk_off;
127 
128 	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
129 		   inode->i_ino, block);
130 
131 	if (block < 0) {
132 		befs_error(sb, "befs_get_block() was asked for a block "
133 			   "number less than zero: block %ld in inode %lu",
134 			   block, inode->i_ino);
135 		return -EIO;
136 	}
137 
138 	if (create) {
139 		befs_error(sb, "befs_get_block() was asked to write to "
140 			   "block %ld in inode %lu", block, inode->i_ino);
141 		return -EPERM;
142 	}
143 
144 	res = befs_fblock2brun(sb, ds, block, &run);
145 	if (res != BEFS_OK) {
146 		befs_error(sb,
147 			   "<--- befs_get_block() for inode %lu, block "
148 			   "%ld ERROR", inode->i_ino, block);
149 		return -EFBIG;
150 	}
151 
152 	disk_off = (ulong) iaddr2blockno(sb, &run);
153 
154 	map_bh(bh_result, inode->i_sb, disk_off);
155 
156 	befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
157 		   "disk address %lu", inode->i_ino, block, disk_off);
158 
159 	return 0;
160 }
161 
162 static struct dentry *
163 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
164 {
165 	struct inode *inode = NULL;
166 	struct super_block *sb = dir->i_sb;
167 	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
168 	befs_off_t offset;
169 	int ret;
170 	int utfnamelen;
171 	char *utfname;
172 	const char *name = dentry->d_name.name;
173 
174 	befs_debug(sb, "---> befs_lookup() "
175 		   "name %s inode %ld", dentry->d_name.name, dir->i_ino);
176 
177 	/* Convert to UTF-8 */
178 	if (BEFS_SB(sb)->nls) {
179 		ret =
180 		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
181 		if (ret < 0) {
182 			befs_debug(sb, "<--- befs_lookup() ERROR");
183 			return ERR_PTR(ret);
184 		}
185 		ret = befs_btree_find(sb, ds, utfname, &offset);
186 		kfree(utfname);
187 
188 	} else {
189 		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
190 	}
191 
192 	if (ret == BEFS_BT_NOT_FOUND) {
193 		befs_debug(sb, "<--- befs_lookup() %s not found",
194 			   dentry->d_name.name);
195 		return ERR_PTR(-ENOENT);
196 
197 	} else if (ret != BEFS_OK || offset == 0) {
198 		befs_warning(sb, "<--- befs_lookup() Error");
199 		return ERR_PTR(-ENODATA);
200 	}
201 
202 	inode = befs_iget(dir->i_sb, (ino_t) offset);
203 	if (IS_ERR(inode))
204 		return ERR_CAST(inode);
205 
206 	d_add(dentry, inode);
207 
208 	befs_debug(sb, "<--- befs_lookup()");
209 
210 	return NULL;
211 }
212 
213 static int
214 befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
215 {
216 	struct inode *inode = file_inode(filp);
217 	struct super_block *sb = inode->i_sb;
218 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
219 	befs_off_t value;
220 	int result;
221 	size_t keysize;
222 	unsigned char d_type;
223 	char keybuf[BEFS_NAME_LEN + 1];
224 	char *nlsname;
225 	int nlsnamelen;
226 	const char *dirname = filp->f_path.dentry->d_name.name;
227 
228 	befs_debug(sb, "---> befs_readdir() "
229 		   "name %s, inode %ld, filp->f_pos %Ld",
230 		   dirname, inode->i_ino, filp->f_pos);
231 
232 	result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
233 				 keybuf, &keysize, &value);
234 
235 	if (result == BEFS_ERR) {
236 		befs_debug(sb, "<--- befs_readdir() ERROR");
237 		befs_error(sb, "IO error reading %s (inode %lu)",
238 			   dirname, inode->i_ino);
239 		return -EIO;
240 
241 	} else if (result == BEFS_BT_END) {
242 		befs_debug(sb, "<--- befs_readdir() END");
243 		return 0;
244 
245 	} else if (result == BEFS_BT_EMPTY) {
246 		befs_debug(sb, "<--- befs_readdir() Empty directory");
247 		return 0;
248 	}
249 
250 	d_type = DT_UNKNOWN;
251 
252 	/* Convert to NLS */
253 	if (BEFS_SB(sb)->nls) {
254 		result =
255 		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
256 		if (result < 0) {
257 			befs_debug(sb, "<--- befs_readdir() ERROR");
258 			return result;
259 		}
260 		result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
261 				 (ino_t) value, d_type);
262 		kfree(nlsname);
263 
264 	} else {
265 		result = filldir(dirent, keybuf, keysize, filp->f_pos,
266 				 (ino_t) value, d_type);
267 	}
268 
269 	filp->f_pos++;
270 
271 	befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
272 
273 	return 0;
274 }
275 
276 static struct inode *
277 befs_alloc_inode(struct super_block *sb)
278 {
279         struct befs_inode_info *bi;
280         bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
281 							GFP_KERNEL);
282         if (!bi)
283                 return NULL;
284         return &bi->vfs_inode;
285 }
286 
287 static void befs_i_callback(struct rcu_head *head)
288 {
289 	struct inode *inode = container_of(head, struct inode, i_rcu);
290         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
291 }
292 
293 static void befs_destroy_inode(struct inode *inode)
294 {
295 	call_rcu(&inode->i_rcu, befs_i_callback);
296 }
297 
298 static void init_once(void *foo)
299 {
300         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
301 
302 	inode_init_once(&bi->vfs_inode);
303 }
304 
305 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
306 {
307 	struct buffer_head *bh = NULL;
308 	befs_inode *raw_inode = NULL;
309 
310 	befs_sb_info *befs_sb = BEFS_SB(sb);
311 	befs_inode_info *befs_ino = NULL;
312 	struct inode *inode;
313 	long ret = -EIO;
314 
315 	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
316 
317 	inode = iget_locked(sb, ino);
318 	if (IS_ERR(inode))
319 		return inode;
320 	if (!(inode->i_state & I_NEW))
321 		return inode;
322 
323 	befs_ino = BEFS_I(inode);
324 
325 	/* convert from vfs's inode number to befs's inode number */
326 	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
327 
328 	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
329 		   befs_ino->i_inode_num.allocation_group,
330 		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
331 
332 	bh = befs_bread(sb, inode->i_ino);
333 	if (!bh) {
334 		befs_error(sb, "unable to read inode block - "
335 			   "inode = %lu", inode->i_ino);
336 		goto unacquire_none;
337 	}
338 
339 	raw_inode = (befs_inode *) bh->b_data;
340 
341 	befs_dump_inode(sb, raw_inode);
342 
343 	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
344 		befs_error(sb, "Bad inode: %lu", inode->i_ino);
345 		goto unacquire_bh;
346 	}
347 
348 	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
349 
350 	/*
351 	 * set uid and gid.  But since current BeOS is single user OS, so
352 	 * you can change by "uid" or "gid" options.
353 	 */
354 
355 	inode->i_uid = befs_sb->mount_opts.use_uid ?
356 		befs_sb->mount_opts.uid :
357 		make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
358 	inode->i_gid = befs_sb->mount_opts.use_gid ?
359 		befs_sb->mount_opts.gid :
360 		make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
361 
362 	set_nlink(inode, 1);
363 
364 	/*
365 	 * BEFS's time is 64 bits, but current VFS is 32 bits...
366 	 * BEFS don't have access time. Nor inode change time. VFS
367 	 * doesn't have creation time.
368 	 * Also, the lower 16 bits of the last_modified_time and
369 	 * create_time are just a counter to help ensure uniqueness
370 	 * for indexing purposes. (PFD, page 54)
371 	 */
372 
373 	inode->i_mtime.tv_sec =
374 	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
375 	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
376 	inode->i_ctime = inode->i_mtime;
377 	inode->i_atime = inode->i_mtime;
378 
379 	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
380 	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
381 	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
382 	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
383 
384 	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
385 		inode->i_size = 0;
386 		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
387 		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
388 			BEFS_SYMLINK_LEN - 1);
389 		befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
390 	} else {
391 		int num_blks;
392 
393 		befs_ino->i_data.ds =
394 		    fsds_to_cpu(sb, &raw_inode->data.datastream);
395 
396 		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
397 		inode->i_blocks =
398 		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
399 		inode->i_size = befs_ino->i_data.ds.size;
400 	}
401 
402 	inode->i_mapping->a_ops = &befs_aops;
403 
404 	if (S_ISREG(inode->i_mode)) {
405 		inode->i_fop = &generic_ro_fops;
406 	} else if (S_ISDIR(inode->i_mode)) {
407 		inode->i_op = &befs_dir_inode_operations;
408 		inode->i_fop = &befs_dir_operations;
409 	} else if (S_ISLNK(inode->i_mode)) {
410 		inode->i_op = &befs_symlink_inode_operations;
411 	} else {
412 		befs_error(sb, "Inode %lu is not a regular file, "
413 			   "directory or symlink. THAT IS WRONG! BeFS has no "
414 			   "on disk special files", inode->i_ino);
415 		goto unacquire_bh;
416 	}
417 
418 	brelse(bh);
419 	befs_debug(sb, "<--- befs_read_inode()");
420 	unlock_new_inode(inode);
421 	return inode;
422 
423       unacquire_bh:
424 	brelse(bh);
425 
426       unacquire_none:
427 	iget_failed(inode);
428 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
429 	return ERR_PTR(ret);
430 }
431 
432 /* Initialize the inode cache. Called at fs setup.
433  *
434  * Taken from NFS implementation by Al Viro.
435  */
436 static int
437 befs_init_inodecache(void)
438 {
439 	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
440 					      sizeof (struct befs_inode_info),
441 					      0, (SLAB_RECLAIM_ACCOUNT|
442 						SLAB_MEM_SPREAD),
443 					      init_once);
444 	if (befs_inode_cachep == NULL) {
445 		printk(KERN_ERR "befs_init_inodecache: "
446 		       "Couldn't initialize inode slabcache\n");
447 		return -ENOMEM;
448 	}
449 
450 	return 0;
451 }
452 
453 /* Called at fs teardown.
454  *
455  * Taken from NFS implementation by Al Viro.
456  */
457 static void
458 befs_destroy_inodecache(void)
459 {
460 	/*
461 	 * Make sure all delayed rcu free inodes are flushed before we
462 	 * destroy cache.
463 	 */
464 	rcu_barrier();
465 	kmem_cache_destroy(befs_inode_cachep);
466 }
467 
468 /*
469  * The inode of symbolic link is different to data stream.
470  * The data stream become link name. Unless the LONG_SYMLINK
471  * flag is set.
472  */
473 static void *
474 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
475 {
476 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
477 	char *link;
478 
479 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
480 		struct super_block *sb = dentry->d_sb;
481 		befs_data_stream *data = &befs_ino->i_data.ds;
482 		befs_off_t len = data->size;
483 
484 		if (len == 0) {
485 			befs_error(sb, "Long symlink with illegal length");
486 			link = ERR_PTR(-EIO);
487 		} else {
488 			befs_debug(sb, "Follow long symlink");
489 
490 			link = kmalloc(len, GFP_NOFS);
491 			if (!link) {
492 				link = ERR_PTR(-ENOMEM);
493 			} else if (befs_read_lsymlink(sb, data, link, len) != len) {
494 				kfree(link);
495 				befs_error(sb, "Failed to read entire long symlink");
496 				link = ERR_PTR(-EIO);
497 			} else {
498 				link[len - 1] = '\0';
499 			}
500 		}
501 	} else {
502 		link = befs_ino->i_data.symlink;
503 	}
504 
505 	nd_set_link(nd, link);
506 	return NULL;
507 }
508 
509 static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
510 {
511 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
512 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
513 		char *link = nd_get_link(nd);
514 		if (!IS_ERR(link))
515 			kfree(link);
516 	}
517 }
518 
519 /*
520  * UTF-8 to NLS charset  convert routine
521  *
522  *
523  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
524  * the nls tables directly
525  */
526 
527 static int
528 befs_utf2nls(struct super_block *sb, const char *in,
529 	     int in_len, char **out, int *out_len)
530 {
531 	struct nls_table *nls = BEFS_SB(sb)->nls;
532 	int i, o;
533 	unicode_t uni;
534 	int unilen, utflen;
535 	char *result;
536 	/* The utf8->nls conversion won't make the final nls string bigger
537 	 * than the utf one, but if the string is pure ascii they'll have the
538 	 * same width and an extra char is needed to save the additional \0
539 	 */
540 	int maxlen = in_len + 1;
541 
542 	befs_debug(sb, "---> utf2nls()");
543 
544 	if (!nls) {
545 		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
546 		return -EINVAL;
547 	}
548 
549 	*out = result = kmalloc(maxlen, GFP_NOFS);
550 	if (!*out) {
551 		befs_error(sb, "befs_utf2nls() cannot allocate memory");
552 		*out_len = 0;
553 		return -ENOMEM;
554 	}
555 
556 	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
557 
558 		/* convert from UTF-8 to Unicode */
559 		utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
560 		if (utflen < 0)
561 			goto conv_err;
562 
563 		/* convert from Unicode to nls */
564 		if (uni > MAX_WCHAR_T)
565 			goto conv_err;
566 		unilen = nls->uni2char(uni, &result[o], in_len - o);
567 		if (unilen < 0)
568 			goto conv_err;
569 	}
570 	result[o] = '\0';
571 	*out_len = o;
572 
573 	befs_debug(sb, "<--- utf2nls()");
574 
575 	return o;
576 
577       conv_err:
578 	befs_error(sb, "Name using character set %s contains a character that "
579 		   "cannot be converted to unicode.", nls->charset);
580 	befs_debug(sb, "<--- utf2nls()");
581 	kfree(result);
582 	return -EILSEQ;
583 }
584 
585 /**
586  * befs_nls2utf - Convert NLS string to utf8 encodeing
587  * @sb: Superblock
588  * @src: Input string buffer in NLS format
589  * @srclen: Length of input string in bytes
590  * @dest: The output string in UTF-8 format
591  * @destlen: Length of the output buffer
592  *
593  * Converts input string @src, which is in the format of the loaded NLS map,
594  * into a utf8 string.
595  *
596  * The destination string @dest is allocated by this function and the caller is
597  * responsible for freeing it with kfree()
598  *
599  * On return, *@destlen is the length of @dest in bytes.
600  *
601  * On success, the return value is the number of utf8 characters written to
602  * the output buffer @dest.
603  *
604  * On Failure, a negative number coresponding to the error code is returned.
605  */
606 
607 static int
608 befs_nls2utf(struct super_block *sb, const char *in,
609 	     int in_len, char **out, int *out_len)
610 {
611 	struct nls_table *nls = BEFS_SB(sb)->nls;
612 	int i, o;
613 	wchar_t uni;
614 	int unilen, utflen;
615 	char *result;
616 	/* There're nls characters that will translate to 3-chars-wide UTF-8
617 	 * characters, a additional byte is needed to save the final \0
618 	 * in special cases */
619 	int maxlen = (3 * in_len) + 1;
620 
621 	befs_debug(sb, "---> nls2utf()\n");
622 
623 	if (!nls) {
624 		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
625 		return -EINVAL;
626 	}
627 
628 	*out = result = kmalloc(maxlen, GFP_NOFS);
629 	if (!*out) {
630 		befs_error(sb, "befs_nls2utf() cannot allocate memory");
631 		*out_len = 0;
632 		return -ENOMEM;
633 	}
634 
635 	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
636 
637 		/* convert from nls to unicode */
638 		unilen = nls->char2uni(&in[i], in_len - i, &uni);
639 		if (unilen < 0)
640 			goto conv_err;
641 
642 		/* convert from unicode to UTF-8 */
643 		utflen = utf32_to_utf8(uni, &result[o], 3);
644 		if (utflen <= 0)
645 			goto conv_err;
646 	}
647 
648 	result[o] = '\0';
649 	*out_len = o;
650 
651 	befs_debug(sb, "<--- nls2utf()");
652 
653 	return i;
654 
655       conv_err:
656 	befs_error(sb, "Name using charecter set %s contains a charecter that "
657 		   "cannot be converted to unicode.", nls->charset);
658 	befs_debug(sb, "<--- nls2utf()");
659 	kfree(result);
660 	return -EILSEQ;
661 }
662 
663 /**
664  * Use the
665  *
666  */
667 enum {
668 	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
669 };
670 
671 static const match_table_t befs_tokens = {
672 	{Opt_uid, "uid=%d"},
673 	{Opt_gid, "gid=%d"},
674 	{Opt_charset, "iocharset=%s"},
675 	{Opt_debug, "debug"},
676 	{Opt_err, NULL}
677 };
678 
679 static int
680 parse_options(char *options, befs_mount_options * opts)
681 {
682 	char *p;
683 	substring_t args[MAX_OPT_ARGS];
684 	int option;
685 	kuid_t uid;
686 	kgid_t gid;
687 
688 	/* Initialize options */
689 	opts->uid = GLOBAL_ROOT_UID;
690 	opts->gid = GLOBAL_ROOT_GID;
691 	opts->use_uid = 0;
692 	opts->use_gid = 0;
693 	opts->iocharset = NULL;
694 	opts->debug = 0;
695 
696 	if (!options)
697 		return 1;
698 
699 	while ((p = strsep(&options, ",")) != NULL) {
700 		int token;
701 		if (!*p)
702 			continue;
703 
704 		token = match_token(p, befs_tokens, args);
705 		switch (token) {
706 		case Opt_uid:
707 			if (match_int(&args[0], &option))
708 				return 0;
709 			uid = INVALID_UID;
710 			if (option >= 0)
711 				uid = make_kuid(current_user_ns(), option);
712 			if (!uid_valid(uid)) {
713 				printk(KERN_ERR "BeFS: Invalid uid %d, "
714 						"using default\n", option);
715 				break;
716 			}
717 			opts->uid = uid;
718 			opts->use_uid = 1;
719 			break;
720 		case Opt_gid:
721 			if (match_int(&args[0], &option))
722 				return 0;
723 			gid = INVALID_GID;
724 			if (option >= 0)
725 				gid = make_kgid(current_user_ns(), option);
726 			if (!gid_valid(gid)) {
727 				printk(KERN_ERR "BeFS: Invalid gid %d, "
728 						"using default\n", option);
729 				break;
730 			}
731 			opts->gid = gid;
732 			opts->use_gid = 1;
733 			break;
734 		case Opt_charset:
735 			kfree(opts->iocharset);
736 			opts->iocharset = match_strdup(&args[0]);
737 			if (!opts->iocharset) {
738 				printk(KERN_ERR "BeFS: allocation failure for "
739 						"iocharset string\n");
740 				return 0;
741 			}
742 			break;
743 		case Opt_debug:
744 			opts->debug = 1;
745 			break;
746 		default:
747 			printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
748 					"or missing value\n", p);
749 			return 0;
750 		}
751 	}
752 	return 1;
753 }
754 
755 /* This function has the responsibiltiy of getting the
756  * filesystem ready for unmounting.
757  * Basically, we free everything that we allocated in
758  * befs_read_inode
759  */
760 static void
761 befs_put_super(struct super_block *sb)
762 {
763 	kfree(BEFS_SB(sb)->mount_opts.iocharset);
764 	BEFS_SB(sb)->mount_opts.iocharset = NULL;
765 	unload_nls(BEFS_SB(sb)->nls);
766 	kfree(sb->s_fs_info);
767 	sb->s_fs_info = NULL;
768 }
769 
770 /* Allocate private field of the superblock, fill it.
771  *
772  * Finish filling the public superblock fields
773  * Make the root directory
774  * Load a set of NLS translations if needed.
775  */
776 static int
777 befs_fill_super(struct super_block *sb, void *data, int silent)
778 {
779 	struct buffer_head *bh;
780 	befs_sb_info *befs_sb;
781 	befs_super_block *disk_sb;
782 	struct inode *root;
783 	long ret = -EINVAL;
784 	const unsigned long sb_block = 0;
785 	const off_t x86_sb_off = 512;
786 
787 	save_mount_options(sb, data);
788 
789 	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
790 	if (sb->s_fs_info == NULL) {
791 		printk(KERN_ERR
792 		       "BeFS(%s): Unable to allocate memory for private "
793 		       "portion of superblock. Bailing.\n", sb->s_id);
794 		goto unacquire_none;
795 	}
796 	befs_sb = BEFS_SB(sb);
797 	memset(befs_sb, 0, sizeof(befs_sb_info));
798 
799 	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
800 		befs_error(sb, "cannot parse mount options");
801 		goto unacquire_priv_sbp;
802 	}
803 
804 	befs_debug(sb, "---> befs_fill_super()");
805 
806 #ifndef CONFIG_BEFS_RW
807 	if (!(sb->s_flags & MS_RDONLY)) {
808 		befs_warning(sb,
809 			     "No write support. Marking filesystem read-only");
810 		sb->s_flags |= MS_RDONLY;
811 	}
812 #endif				/* CONFIG_BEFS_RW */
813 
814 	/*
815 	 * Set dummy blocksize to read super block.
816 	 * Will be set to real fs blocksize later.
817 	 *
818 	 * Linux 2.4.10 and later refuse to read blocks smaller than
819 	 * the hardsect size for the device. But we also need to read at
820 	 * least 1k to get the second 512 bytes of the volume.
821 	 * -WD 10-26-01
822 	 */
823 	sb_min_blocksize(sb, 1024);
824 
825 	if (!(bh = sb_bread(sb, sb_block))) {
826 		befs_error(sb, "unable to read superblock");
827 		goto unacquire_priv_sbp;
828 	}
829 
830 	/* account for offset of super block on x86 */
831 	disk_sb = (befs_super_block *) bh->b_data;
832 	if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
833 	    (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
834 		befs_debug(sb, "Using PPC superblock location");
835 	} else {
836 		befs_debug(sb, "Using x86 superblock location");
837 		disk_sb =
838 		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
839 	}
840 
841 	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
842 		goto unacquire_bh;
843 
844 	befs_dump_super_block(sb, disk_sb);
845 
846 	brelse(bh);
847 
848 	if (befs_check_sb(sb) != BEFS_OK)
849 		goto unacquire_priv_sbp;
850 
851 	if( befs_sb->num_blocks > ~((sector_t)0) ) {
852 		befs_error(sb, "blocks count: %Lu "
853 			"is larger than the host can use",
854 			befs_sb->num_blocks);
855 		goto unacquire_priv_sbp;
856 	}
857 
858 	/*
859 	 * set up enough so that it can read an inode
860 	 * Fill in kernel superblock fields from private sb
861 	 */
862 	sb->s_magic = BEFS_SUPER_MAGIC;
863 	/* Set real blocksize of fs */
864 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
865 	sb->s_op = &befs_sops;
866 	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
867 	if (IS_ERR(root)) {
868 		ret = PTR_ERR(root);
869 		goto unacquire_priv_sbp;
870 	}
871 	sb->s_root = d_make_root(root);
872 	if (!sb->s_root) {
873 		befs_error(sb, "get root inode failed");
874 		goto unacquire_priv_sbp;
875 	}
876 
877 	/* load nls library */
878 	if (befs_sb->mount_opts.iocharset) {
879 		befs_debug(sb, "Loading nls: %s",
880 			   befs_sb->mount_opts.iocharset);
881 		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
882 		if (!befs_sb->nls) {
883 			befs_warning(sb, "Cannot load nls %s"
884 					" loading default nls",
885 					befs_sb->mount_opts.iocharset);
886 			befs_sb->nls = load_nls_default();
887 		}
888 	/* load default nls if none is specified  in mount options */
889 	} else {
890 		befs_debug(sb, "Loading default nls");
891 		befs_sb->nls = load_nls_default();
892 	}
893 
894 	return 0;
895 /*****************/
896       unacquire_bh:
897 	brelse(bh);
898 
899       unacquire_priv_sbp:
900 	kfree(befs_sb->mount_opts.iocharset);
901 	kfree(sb->s_fs_info);
902 
903       unacquire_none:
904 	sb->s_fs_info = NULL;
905 	return ret;
906 }
907 
908 static int
909 befs_remount(struct super_block *sb, int *flags, char *data)
910 {
911 	if (!(*flags & MS_RDONLY))
912 		return -EINVAL;
913 	return 0;
914 }
915 
916 static int
917 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
918 {
919 	struct super_block *sb = dentry->d_sb;
920 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
921 
922 	befs_debug(sb, "---> befs_statfs()");
923 
924 	buf->f_type = BEFS_SUPER_MAGIC;
925 	buf->f_bsize = sb->s_blocksize;
926 	buf->f_blocks = BEFS_SB(sb)->num_blocks;
927 	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
928 	buf->f_bavail = buf->f_bfree;
929 	buf->f_files = 0;	/* UNKNOWN */
930 	buf->f_ffree = 0;	/* UNKNOWN */
931 	buf->f_fsid.val[0] = (u32)id;
932 	buf->f_fsid.val[1] = (u32)(id >> 32);
933 	buf->f_namelen = BEFS_NAME_LEN;
934 
935 	befs_debug(sb, "<--- befs_statfs()");
936 
937 	return 0;
938 }
939 
940 static struct dentry *
941 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
942 	    void *data)
943 {
944 	return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
945 }
946 
947 static struct file_system_type befs_fs_type = {
948 	.owner		= THIS_MODULE,
949 	.name		= "befs",
950 	.mount		= befs_mount,
951 	.kill_sb	= kill_block_super,
952 	.fs_flags	= FS_REQUIRES_DEV,
953 };
954 MODULE_ALIAS_FS("befs");
955 
956 static int __init
957 init_befs_fs(void)
958 {
959 	int err;
960 
961 	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
962 
963 	err = befs_init_inodecache();
964 	if (err)
965 		goto unacquire_none;
966 
967 	err = register_filesystem(&befs_fs_type);
968 	if (err)
969 		goto unacquire_inodecache;
970 
971 	return 0;
972 
973 unacquire_inodecache:
974 	befs_destroy_inodecache();
975 
976 unacquire_none:
977 	return err;
978 }
979 
980 static void __exit
981 exit_befs_fs(void)
982 {
983 	befs_destroy_inodecache();
984 
985 	unregister_filesystem(&befs_fs_type);
986 }
987 
988 /*
989 Macros that typecheck the init and exit functions,
990 ensures that they are called at init and cleanup,
991 and eliminates warnings about unused functions.
992 */
993 module_init(init_befs_fs)
994 module_exit(exit_befs_fs)
995