xref: /openbmc/linux/fs/befs/linuxvfs.c (revision 00cd8dd3)
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 *, unsigned int);
38 static struct inode *befs_iget(struct super_block *, unsigned long);
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 	.alloc_inode	= befs_alloc_inode,	/* allocate a new inode */
56 	.destroy_inode	= befs_destroy_inode, /* deallocate an inode */
57 	.put_super	= befs_put_super,	/* uninit super */
58 	.statfs		= befs_statfs,	/* statfs */
59 	.remount_fs	= befs_remount,
60 	.show_options	= generic_show_options,
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 	.llseek		= generic_file_llseek,
70 };
71 
72 static const struct inode_operations befs_dir_inode_operations = {
73 	.lookup		= befs_lookup,
74 };
75 
76 static const struct address_space_operations befs_aops = {
77 	.readpage	= befs_readpage,
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, unsigned int flags)
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 = befs_iget(dir->i_sb, (ino_t) offset);
202 	if (IS_ERR(inode))
203 		return ERR_CAST(inode);
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 befs_i_callback(struct rcu_head *head)
287 {
288 	struct inode *inode = container_of(head, struct inode, i_rcu);
289         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
290 }
291 
292 static void befs_destroy_inode(struct inode *inode)
293 {
294 	call_rcu(&inode->i_rcu, befs_i_callback);
295 }
296 
297 static void init_once(void *foo)
298 {
299         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
300 
301 	inode_init_once(&bi->vfs_inode);
302 }
303 
304 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
305 {
306 	struct buffer_head *bh = NULL;
307 	befs_inode *raw_inode = NULL;
308 
309 	befs_sb_info *befs_sb = BEFS_SB(sb);
310 	befs_inode_info *befs_ino = NULL;
311 	struct inode *inode;
312 	long ret = -EIO;
313 
314 	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
315 
316 	inode = iget_locked(sb, ino);
317 	if (IS_ERR(inode))
318 		return inode;
319 	if (!(inode->i_state & I_NEW))
320 		return inode;
321 
322 	befs_ino = BEFS_I(inode);
323 
324 	/* convert from vfs's inode number to befs's inode number */
325 	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
326 
327 	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
328 		   befs_ino->i_inode_num.allocation_group,
329 		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
330 
331 	bh = befs_bread(sb, inode->i_ino);
332 	if (!bh) {
333 		befs_error(sb, "unable to read inode block - "
334 			   "inode = %lu", inode->i_ino);
335 		goto unacquire_none;
336 	}
337 
338 	raw_inode = (befs_inode *) bh->b_data;
339 
340 	befs_dump_inode(sb, raw_inode);
341 
342 	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
343 		befs_error(sb, "Bad inode: %lu", inode->i_ino);
344 		goto unacquire_bh;
345 	}
346 
347 	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
348 
349 	/*
350 	 * set uid and gid.  But since current BeOS is single user OS, so
351 	 * you can change by "uid" or "gid" options.
352 	 */
353 
354 	inode->i_uid = befs_sb->mount_opts.use_uid ?
355 	    befs_sb->mount_opts.uid : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
356 	inode->i_gid = befs_sb->mount_opts.use_gid ?
357 	    befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
358 
359 	set_nlink(inode, 1);
360 
361 	/*
362 	 * BEFS's time is 64 bits, but current VFS is 32 bits...
363 	 * BEFS don't have access time. Nor inode change time. VFS
364 	 * doesn't have creation time.
365 	 * Also, the lower 16 bits of the last_modified_time and
366 	 * create_time are just a counter to help ensure uniqueness
367 	 * for indexing purposes. (PFD, page 54)
368 	 */
369 
370 	inode->i_mtime.tv_sec =
371 	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
372 	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
373 	inode->i_ctime = inode->i_mtime;
374 	inode->i_atime = inode->i_mtime;
375 
376 	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
377 	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
378 	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
379 	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
380 
381 	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
382 		inode->i_size = 0;
383 		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
384 		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
385 			BEFS_SYMLINK_LEN - 1);
386 		befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
387 	} else {
388 		int num_blks;
389 
390 		befs_ino->i_data.ds =
391 		    fsds_to_cpu(sb, &raw_inode->data.datastream);
392 
393 		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
394 		inode->i_blocks =
395 		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
396 		inode->i_size = befs_ino->i_data.ds.size;
397 	}
398 
399 	inode->i_mapping->a_ops = &befs_aops;
400 
401 	if (S_ISREG(inode->i_mode)) {
402 		inode->i_fop = &generic_ro_fops;
403 	} else if (S_ISDIR(inode->i_mode)) {
404 		inode->i_op = &befs_dir_inode_operations;
405 		inode->i_fop = &befs_dir_operations;
406 	} else if (S_ISLNK(inode->i_mode)) {
407 		inode->i_op = &befs_symlink_inode_operations;
408 	} else {
409 		befs_error(sb, "Inode %lu is not a regular file, "
410 			   "directory or symlink. THAT IS WRONG! BeFS has no "
411 			   "on disk special files", inode->i_ino);
412 		goto unacquire_bh;
413 	}
414 
415 	brelse(bh);
416 	befs_debug(sb, "<--- befs_read_inode()");
417 	unlock_new_inode(inode);
418 	return inode;
419 
420       unacquire_bh:
421 	brelse(bh);
422 
423       unacquire_none:
424 	iget_failed(inode);
425 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
426 	return ERR_PTR(ret);
427 }
428 
429 /* Initialize the inode cache. Called at fs setup.
430  *
431  * Taken from NFS implementation by Al Viro.
432  */
433 static int
434 befs_init_inodecache(void)
435 {
436 	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
437 					      sizeof (struct befs_inode_info),
438 					      0, (SLAB_RECLAIM_ACCOUNT|
439 						SLAB_MEM_SPREAD),
440 					      init_once);
441 	if (befs_inode_cachep == NULL) {
442 		printk(KERN_ERR "befs_init_inodecache: "
443 		       "Couldn't initialize inode slabcache\n");
444 		return -ENOMEM;
445 	}
446 
447 	return 0;
448 }
449 
450 /* Called at fs teardown.
451  *
452  * Taken from NFS implementation by Al Viro.
453  */
454 static void
455 befs_destroy_inodecache(void)
456 {
457 	kmem_cache_destroy(befs_inode_cachep);
458 }
459 
460 /*
461  * The inode of symbolic link is different to data stream.
462  * The data stream become link name. Unless the LONG_SYMLINK
463  * flag is set.
464  */
465 static void *
466 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
467 {
468 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
469 	char *link;
470 
471 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
472 		struct super_block *sb = dentry->d_sb;
473 		befs_data_stream *data = &befs_ino->i_data.ds;
474 		befs_off_t len = data->size;
475 
476 		if (len == 0) {
477 			befs_error(sb, "Long symlink with illegal length");
478 			link = ERR_PTR(-EIO);
479 		} else {
480 			befs_debug(sb, "Follow long symlink");
481 
482 			link = kmalloc(len, GFP_NOFS);
483 			if (!link) {
484 				link = ERR_PTR(-ENOMEM);
485 			} else if (befs_read_lsymlink(sb, data, link, len) != len) {
486 				kfree(link);
487 				befs_error(sb, "Failed to read entire long symlink");
488 				link = ERR_PTR(-EIO);
489 			} else {
490 				link[len - 1] = '\0';
491 			}
492 		}
493 	} else {
494 		link = befs_ino->i_data.symlink;
495 	}
496 
497 	nd_set_link(nd, link);
498 	return NULL;
499 }
500 
501 static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
502 {
503 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
504 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
505 		char *link = nd_get_link(nd);
506 		if (!IS_ERR(link))
507 			kfree(link);
508 	}
509 }
510 
511 /*
512  * UTF-8 to NLS charset  convert routine
513  *
514  *
515  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
516  * the nls tables directly
517  */
518 
519 static int
520 befs_utf2nls(struct super_block *sb, const char *in,
521 	     int in_len, char **out, int *out_len)
522 {
523 	struct nls_table *nls = BEFS_SB(sb)->nls;
524 	int i, o;
525 	unicode_t uni;
526 	int unilen, utflen;
527 	char *result;
528 	/* The utf8->nls conversion won't make the final nls string bigger
529 	 * than the utf one, but if the string is pure ascii they'll have the
530 	 * same width and an extra char is needed to save the additional \0
531 	 */
532 	int maxlen = in_len + 1;
533 
534 	befs_debug(sb, "---> utf2nls()");
535 
536 	if (!nls) {
537 		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
538 		return -EINVAL;
539 	}
540 
541 	*out = result = kmalloc(maxlen, GFP_NOFS);
542 	if (!*out) {
543 		befs_error(sb, "befs_utf2nls() cannot allocate memory");
544 		*out_len = 0;
545 		return -ENOMEM;
546 	}
547 
548 	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
549 
550 		/* convert from UTF-8 to Unicode */
551 		utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
552 		if (utflen < 0)
553 			goto conv_err;
554 
555 		/* convert from Unicode to nls */
556 		if (uni > MAX_WCHAR_T)
557 			goto conv_err;
558 		unilen = nls->uni2char(uni, &result[o], in_len - o);
559 		if (unilen < 0)
560 			goto conv_err;
561 	}
562 	result[o] = '\0';
563 	*out_len = o;
564 
565 	befs_debug(sb, "<--- utf2nls()");
566 
567 	return o;
568 
569       conv_err:
570 	befs_error(sb, "Name using character set %s contains a character that "
571 		   "cannot be converted to unicode.", nls->charset);
572 	befs_debug(sb, "<--- utf2nls()");
573 	kfree(result);
574 	return -EILSEQ;
575 }
576 
577 /**
578  * befs_nls2utf - Convert NLS string to utf8 encodeing
579  * @sb: Superblock
580  * @src: Input string buffer in NLS format
581  * @srclen: Length of input string in bytes
582  * @dest: The output string in UTF-8 format
583  * @destlen: Length of the output buffer
584  *
585  * Converts input string @src, which is in the format of the loaded NLS map,
586  * into a utf8 string.
587  *
588  * The destination string @dest is allocated by this function and the caller is
589  * responsible for freeing it with kfree()
590  *
591  * On return, *@destlen is the length of @dest in bytes.
592  *
593  * On success, the return value is the number of utf8 characters written to
594  * the output buffer @dest.
595  *
596  * On Failure, a negative number coresponding to the error code is returned.
597  */
598 
599 static int
600 befs_nls2utf(struct super_block *sb, const char *in,
601 	     int in_len, char **out, int *out_len)
602 {
603 	struct nls_table *nls = BEFS_SB(sb)->nls;
604 	int i, o;
605 	wchar_t uni;
606 	int unilen, utflen;
607 	char *result;
608 	/* There're nls characters that will translate to 3-chars-wide UTF-8
609 	 * characters, a additional byte is needed to save the final \0
610 	 * in special cases */
611 	int maxlen = (3 * in_len) + 1;
612 
613 	befs_debug(sb, "---> nls2utf()\n");
614 
615 	if (!nls) {
616 		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
617 		return -EINVAL;
618 	}
619 
620 	*out = result = kmalloc(maxlen, GFP_NOFS);
621 	if (!*out) {
622 		befs_error(sb, "befs_nls2utf() cannot allocate memory");
623 		*out_len = 0;
624 		return -ENOMEM;
625 	}
626 
627 	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
628 
629 		/* convert from nls to unicode */
630 		unilen = nls->char2uni(&in[i], in_len - i, &uni);
631 		if (unilen < 0)
632 			goto conv_err;
633 
634 		/* convert from unicode to UTF-8 */
635 		utflen = utf32_to_utf8(uni, &result[o], 3);
636 		if (utflen <= 0)
637 			goto conv_err;
638 	}
639 
640 	result[o] = '\0';
641 	*out_len = o;
642 
643 	befs_debug(sb, "<--- nls2utf()");
644 
645 	return i;
646 
647       conv_err:
648 	befs_error(sb, "Name using charecter set %s contains a charecter that "
649 		   "cannot be converted to unicode.", nls->charset);
650 	befs_debug(sb, "<--- nls2utf()");
651 	kfree(result);
652 	return -EILSEQ;
653 }
654 
655 /**
656  * Use the
657  *
658  */
659 enum {
660 	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
661 };
662 
663 static const match_table_t befs_tokens = {
664 	{Opt_uid, "uid=%d"},
665 	{Opt_gid, "gid=%d"},
666 	{Opt_charset, "iocharset=%s"},
667 	{Opt_debug, "debug"},
668 	{Opt_err, NULL}
669 };
670 
671 static int
672 parse_options(char *options, befs_mount_options * opts)
673 {
674 	char *p;
675 	substring_t args[MAX_OPT_ARGS];
676 	int option;
677 
678 	/* Initialize options */
679 	opts->uid = 0;
680 	opts->gid = 0;
681 	opts->use_uid = 0;
682 	opts->use_gid = 0;
683 	opts->iocharset = NULL;
684 	opts->debug = 0;
685 
686 	if (!options)
687 		return 1;
688 
689 	while ((p = strsep(&options, ",")) != NULL) {
690 		int token;
691 		if (!*p)
692 			continue;
693 
694 		token = match_token(p, befs_tokens, args);
695 		switch (token) {
696 		case Opt_uid:
697 			if (match_int(&args[0], &option))
698 				return 0;
699 			if (option < 0) {
700 				printk(KERN_ERR "BeFS: Invalid uid %d, "
701 						"using default\n", option);
702 				break;
703 			}
704 			opts->uid = option;
705 			opts->use_uid = 1;
706 			break;
707 		case Opt_gid:
708 			if (match_int(&args[0], &option))
709 				return 0;
710 			if (option < 0) {
711 				printk(KERN_ERR "BeFS: Invalid gid %d, "
712 						"using default\n", option);
713 				break;
714 			}
715 			opts->gid = option;
716 			opts->use_gid = 1;
717 			break;
718 		case Opt_charset:
719 			kfree(opts->iocharset);
720 			opts->iocharset = match_strdup(&args[0]);
721 			if (!opts->iocharset) {
722 				printk(KERN_ERR "BeFS: allocation failure for "
723 						"iocharset string\n");
724 				return 0;
725 			}
726 			break;
727 		case Opt_debug:
728 			opts->debug = 1;
729 			break;
730 		default:
731 			printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
732 					"or missing value\n", p);
733 			return 0;
734 		}
735 	}
736 	return 1;
737 }
738 
739 /* This function has the responsibiltiy of getting the
740  * filesystem ready for unmounting.
741  * Basically, we free everything that we allocated in
742  * befs_read_inode
743  */
744 static void
745 befs_put_super(struct super_block *sb)
746 {
747 	kfree(BEFS_SB(sb)->mount_opts.iocharset);
748 	BEFS_SB(sb)->mount_opts.iocharset = NULL;
749 	unload_nls(BEFS_SB(sb)->nls);
750 	kfree(sb->s_fs_info);
751 	sb->s_fs_info = NULL;
752 }
753 
754 /* Allocate private field of the superblock, fill it.
755  *
756  * Finish filling the public superblock fields
757  * Make the root directory
758  * Load a set of NLS translations if needed.
759  */
760 static int
761 befs_fill_super(struct super_block *sb, void *data, int silent)
762 {
763 	struct buffer_head *bh;
764 	befs_sb_info *befs_sb;
765 	befs_super_block *disk_sb;
766 	struct inode *root;
767 	long ret = -EINVAL;
768 	const unsigned long sb_block = 0;
769 	const off_t x86_sb_off = 512;
770 
771 	save_mount_options(sb, data);
772 
773 	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
774 	if (sb->s_fs_info == NULL) {
775 		printk(KERN_ERR
776 		       "BeFS(%s): Unable to allocate memory for private "
777 		       "portion of superblock. Bailing.\n", sb->s_id);
778 		goto unacquire_none;
779 	}
780 	befs_sb = BEFS_SB(sb);
781 	memset(befs_sb, 0, sizeof(befs_sb_info));
782 
783 	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
784 		befs_error(sb, "cannot parse mount options");
785 		goto unacquire_priv_sbp;
786 	}
787 
788 	befs_debug(sb, "---> befs_fill_super()");
789 
790 #ifndef CONFIG_BEFS_RW
791 	if (!(sb->s_flags & MS_RDONLY)) {
792 		befs_warning(sb,
793 			     "No write support. Marking filesystem read-only");
794 		sb->s_flags |= MS_RDONLY;
795 	}
796 #endif				/* CONFIG_BEFS_RW */
797 
798 	/*
799 	 * Set dummy blocksize to read super block.
800 	 * Will be set to real fs blocksize later.
801 	 *
802 	 * Linux 2.4.10 and later refuse to read blocks smaller than
803 	 * the hardsect size for the device. But we also need to read at
804 	 * least 1k to get the second 512 bytes of the volume.
805 	 * -WD 10-26-01
806 	 */
807 	sb_min_blocksize(sb, 1024);
808 
809 	if (!(bh = sb_bread(sb, sb_block))) {
810 		befs_error(sb, "unable to read superblock");
811 		goto unacquire_priv_sbp;
812 	}
813 
814 	/* account for offset of super block on x86 */
815 	disk_sb = (befs_super_block *) bh->b_data;
816 	if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
817 	    (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
818 		befs_debug(sb, "Using PPC superblock location");
819 	} else {
820 		befs_debug(sb, "Using x86 superblock location");
821 		disk_sb =
822 		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
823 	}
824 
825 	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
826 		goto unacquire_bh;
827 
828 	befs_dump_super_block(sb, disk_sb);
829 
830 	brelse(bh);
831 
832 	if (befs_check_sb(sb) != BEFS_OK)
833 		goto unacquire_priv_sbp;
834 
835 	if( befs_sb->num_blocks > ~((sector_t)0) ) {
836 		befs_error(sb, "blocks count: %Lu "
837 			"is larger than the host can use",
838 			befs_sb->num_blocks);
839 		goto unacquire_priv_sbp;
840 	}
841 
842 	/*
843 	 * set up enough so that it can read an inode
844 	 * Fill in kernel superblock fields from private sb
845 	 */
846 	sb->s_magic = BEFS_SUPER_MAGIC;
847 	/* Set real blocksize of fs */
848 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
849 	sb->s_op = &befs_sops;
850 	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
851 	if (IS_ERR(root)) {
852 		ret = PTR_ERR(root);
853 		goto unacquire_priv_sbp;
854 	}
855 	sb->s_root = d_make_root(root);
856 	if (!sb->s_root) {
857 		befs_error(sb, "get root inode failed");
858 		goto unacquire_priv_sbp;
859 	}
860 
861 	/* load nls library */
862 	if (befs_sb->mount_opts.iocharset) {
863 		befs_debug(sb, "Loading nls: %s",
864 			   befs_sb->mount_opts.iocharset);
865 		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
866 		if (!befs_sb->nls) {
867 			befs_warning(sb, "Cannot load nls %s"
868 					" loading default nls",
869 					befs_sb->mount_opts.iocharset);
870 			befs_sb->nls = load_nls_default();
871 		}
872 	/* load default nls if none is specified  in mount options */
873 	} else {
874 		befs_debug(sb, "Loading default nls");
875 		befs_sb->nls = load_nls_default();
876 	}
877 
878 	return 0;
879 /*****************/
880       unacquire_bh:
881 	brelse(bh);
882 
883       unacquire_priv_sbp:
884 	kfree(befs_sb->mount_opts.iocharset);
885 	kfree(sb->s_fs_info);
886 
887       unacquire_none:
888 	sb->s_fs_info = NULL;
889 	return ret;
890 }
891 
892 static int
893 befs_remount(struct super_block *sb, int *flags, char *data)
894 {
895 	if (!(*flags & MS_RDONLY))
896 		return -EINVAL;
897 	return 0;
898 }
899 
900 static int
901 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
902 {
903 	struct super_block *sb = dentry->d_sb;
904 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
905 
906 	befs_debug(sb, "---> befs_statfs()");
907 
908 	buf->f_type = BEFS_SUPER_MAGIC;
909 	buf->f_bsize = sb->s_blocksize;
910 	buf->f_blocks = BEFS_SB(sb)->num_blocks;
911 	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
912 	buf->f_bavail = buf->f_bfree;
913 	buf->f_files = 0;	/* UNKNOWN */
914 	buf->f_ffree = 0;	/* UNKNOWN */
915 	buf->f_fsid.val[0] = (u32)id;
916 	buf->f_fsid.val[1] = (u32)(id >> 32);
917 	buf->f_namelen = BEFS_NAME_LEN;
918 
919 	befs_debug(sb, "<--- befs_statfs()");
920 
921 	return 0;
922 }
923 
924 static struct dentry *
925 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
926 	    void *data)
927 {
928 	return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
929 }
930 
931 static struct file_system_type befs_fs_type = {
932 	.owner		= THIS_MODULE,
933 	.name		= "befs",
934 	.mount		= befs_mount,
935 	.kill_sb	= kill_block_super,
936 	.fs_flags	= FS_REQUIRES_DEV,
937 };
938 
939 static int __init
940 init_befs_fs(void)
941 {
942 	int err;
943 
944 	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
945 
946 	err = befs_init_inodecache();
947 	if (err)
948 		goto unacquire_none;
949 
950 	err = register_filesystem(&befs_fs_type);
951 	if (err)
952 		goto unacquire_inodecache;
953 
954 	return 0;
955 
956 unacquire_inodecache:
957 	befs_destroy_inodecache();
958 
959 unacquire_none:
960 	return err;
961 }
962 
963 static void __exit
964 exit_befs_fs(void)
965 {
966 	befs_destroy_inodecache();
967 
968 	unregister_filesystem(&befs_fs_type);
969 }
970 
971 /*
972 Macros that typecheck the init and exit functions,
973 ensures that they are called at init and cleanup,
974 and eliminates warnings about unused functions.
975 */
976 module_init(init_befs_fs)
977 module_exit(exit_befs_fs)
978