xref: /openbmc/linux/fs/befs/linuxvfs.c (revision 643d1f7f)
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(struct kmem_cache *cachep, void *foo)
293 {
294         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
295 
296 	inode_init_once(&bi->vfs_inode);
297 }
298 
299 static void
300 befs_read_inode(struct inode *inode)
301 {
302 	struct buffer_head *bh = NULL;
303 	befs_inode *raw_inode = NULL;
304 
305 	struct super_block *sb = inode->i_sb;
306 	befs_sb_info *befs_sb = BEFS_SB(sb);
307 	befs_inode_info *befs_ino = NULL;
308 
309 	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", inode->i_ino);
310 
311 	befs_ino = BEFS_I(inode);
312 
313 	/* convert from vfs's inode number to befs's inode number */
314 	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
315 
316 	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
317 		   befs_ino->i_inode_num.allocation_group,
318 		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
319 
320 	bh = befs_bread(sb, inode->i_ino);
321 	if (!bh) {
322 		befs_error(sb, "unable to read inode block - "
323 			   "inode = %lu", inode->i_ino);
324 		goto unacquire_none;
325 	}
326 
327 	raw_inode = (befs_inode *) bh->b_data;
328 
329 	befs_dump_inode(sb, raw_inode);
330 
331 	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
332 		befs_error(sb, "Bad inode: %lu", inode->i_ino);
333 		goto unacquire_bh;
334 	}
335 
336 	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
337 
338 	/*
339 	 * set uid and gid.  But since current BeOS is single user OS, so
340 	 * you can change by "uid" or "gid" options.
341 	 */
342 
343 	inode->i_uid = befs_sb->mount_opts.use_uid ?
344 	    befs_sb->mount_opts.uid : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
345 	inode->i_gid = befs_sb->mount_opts.use_gid ?
346 	    befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
347 
348 	inode->i_nlink = 1;
349 
350 	/*
351 	 * BEFS's time is 64 bits, but current VFS is 32 bits...
352 	 * BEFS don't have access time. Nor inode change time. VFS
353 	 * doesn't have creation time.
354 	 * Also, the lower 16 bits of the last_modified_time and
355 	 * create_time are just a counter to help ensure uniqueness
356 	 * for indexing purposes. (PFD, page 54)
357 	 */
358 
359 	inode->i_mtime.tv_sec =
360 	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
361 	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
362 	inode->i_ctime = inode->i_mtime;
363 	inode->i_atime = inode->i_mtime;
364 
365 	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
366 	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
367 	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
368 	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
369 
370 	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
371 		inode->i_size = 0;
372 		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
373 		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
374 			BEFS_SYMLINK_LEN);
375 	} else {
376 		int num_blks;
377 
378 		befs_ino->i_data.ds =
379 		    fsds_to_cpu(sb, raw_inode->data.datastream);
380 
381 		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
382 		inode->i_blocks =
383 		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
384 		inode->i_size = befs_ino->i_data.ds.size;
385 	}
386 
387 	inode->i_mapping->a_ops = &befs_aops;
388 
389 	if (S_ISREG(inode->i_mode)) {
390 		inode->i_fop = &generic_ro_fops;
391 	} else if (S_ISDIR(inode->i_mode)) {
392 		inode->i_op = &befs_dir_inode_operations;
393 		inode->i_fop = &befs_dir_operations;
394 	} else if (S_ISLNK(inode->i_mode)) {
395 		inode->i_op = &befs_symlink_inode_operations;
396 	} else {
397 		befs_error(sb, "Inode %lu is not a regular file, "
398 			   "directory or symlink. THAT IS WRONG! BeFS has no "
399 			   "on disk special files", inode->i_ino);
400 		goto unacquire_bh;
401 	}
402 
403 	brelse(bh);
404 	befs_debug(sb, "<--- befs_read_inode()");
405 	return;
406 
407       unacquire_bh:
408 	brelse(bh);
409 
410       unacquire_none:
411 	make_bad_inode(inode);
412 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
413 	return;
414 }
415 
416 /* Initialize the inode cache. Called at fs setup.
417  *
418  * Taken from NFS implementation by Al Viro.
419  */
420 static int
421 befs_init_inodecache(void)
422 {
423 	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
424 					      sizeof (struct befs_inode_info),
425 					      0, (SLAB_RECLAIM_ACCOUNT|
426 						SLAB_MEM_SPREAD),
427 					      init_once);
428 	if (befs_inode_cachep == NULL) {
429 		printk(KERN_ERR "befs_init_inodecache: "
430 		       "Couldn't initalize inode slabcache\n");
431 		return -ENOMEM;
432 	}
433 
434 	return 0;
435 }
436 
437 /* Called at fs teardown.
438  *
439  * Taken from NFS implementation by Al Viro.
440  */
441 static void
442 befs_destroy_inodecache(void)
443 {
444 	kmem_cache_destroy(befs_inode_cachep);
445 }
446 
447 /*
448  * The inode of symbolic link is different to data stream.
449  * The data stream become link name. Unless the LONG_SYMLINK
450  * flag is set.
451  */
452 static void *
453 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
454 {
455 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
456 	char *link;
457 
458 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
459 		struct super_block *sb = dentry->d_sb;
460 		befs_data_stream *data = &befs_ino->i_data.ds;
461 		befs_off_t len = data->size;
462 
463 		befs_debug(sb, "Follow long symlink");
464 
465 		link = kmalloc(len, GFP_NOFS);
466 		if (!link) {
467 			link = ERR_PTR(-ENOMEM);
468 		} else if (befs_read_lsymlink(sb, data, link, len) != len) {
469 			kfree(link);
470 			befs_error(sb, "Failed to read entire long symlink");
471 			link = ERR_PTR(-EIO);
472 		}
473 	} else {
474 		link = befs_ino->i_data.symlink;
475 	}
476 
477 	nd_set_link(nd, link);
478 	return NULL;
479 }
480 
481 static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
482 {
483 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
484 	if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
485 		char *p = nd_get_link(nd);
486 		if (!IS_ERR(p))
487 			kfree(p);
488 	}
489 }
490 
491 /*
492  * UTF-8 to NLS charset  convert routine
493  *
494  *
495  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
496  * the nls tables directly
497  */
498 
499 static int
500 befs_utf2nls(struct super_block *sb, const char *in,
501 	     int in_len, char **out, int *out_len)
502 {
503 	struct nls_table *nls = BEFS_SB(sb)->nls;
504 	int i, o;
505 	wchar_t uni;
506 	int unilen, utflen;
507 	char *result;
508 	/* The utf8->nls conversion won't make the final nls string bigger
509 	 * than the utf one, but if the string is pure ascii they'll have the
510 	 * same width and an extra char is needed to save the additional \0
511 	 */
512 	int maxlen = in_len + 1;
513 
514 	befs_debug(sb, "---> utf2nls()");
515 
516 	if (!nls) {
517 		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
518 		return -EINVAL;
519 	}
520 
521 	*out = result = kmalloc(maxlen, GFP_NOFS);
522 	if (!*out) {
523 		befs_error(sb, "befs_utf2nls() cannot allocate memory");
524 		*out_len = 0;
525 		return -ENOMEM;
526 	}
527 
528 	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
529 
530 		/* convert from UTF-8 to Unicode */
531 		utflen = utf8_mbtowc(&uni, &in[i], in_len - i);
532 		if (utflen < 0) {
533 			goto conv_err;
534 		}
535 
536 		/* convert from Unicode to nls */
537 		unilen = nls->uni2char(uni, &result[o], in_len - o);
538 		if (unilen < 0) {
539 			goto conv_err;
540 		}
541 	}
542 	result[o] = '\0';
543 	*out_len = o;
544 
545 	befs_debug(sb, "<--- utf2nls()");
546 
547 	return o;
548 
549       conv_err:
550 	befs_error(sb, "Name using character set %s contains a character that "
551 		   "cannot be converted to unicode.", nls->charset);
552 	befs_debug(sb, "<--- utf2nls()");
553 	kfree(result);
554 	return -EILSEQ;
555 }
556 
557 /**
558  * befs_nls2utf - Convert NLS string to utf8 encodeing
559  * @sb: Superblock
560  * @src: Input string buffer in NLS format
561  * @srclen: Length of input string in bytes
562  * @dest: The output string in UTF-8 format
563  * @destlen: Length of the output buffer
564  *
565  * Converts input string @src, which is in the format of the loaded NLS map,
566  * into a utf8 string.
567  *
568  * The destination string @dest is allocated by this function and the caller is
569  * responsible for freeing it with kfree()
570  *
571  * On return, *@destlen is the length of @dest in bytes.
572  *
573  * On success, the return value is the number of utf8 characters written to
574  * the output buffer @dest.
575  *
576  * On Failure, a negative number coresponding to the error code is returned.
577  */
578 
579 static int
580 befs_nls2utf(struct super_block *sb, const char *in,
581 	     int in_len, char **out, int *out_len)
582 {
583 	struct nls_table *nls = BEFS_SB(sb)->nls;
584 	int i, o;
585 	wchar_t uni;
586 	int unilen, utflen;
587 	char *result;
588 	/* There're nls characters that will translate to 3-chars-wide UTF-8
589 	 * characters, a additional byte is needed to save the final \0
590 	 * in special cases */
591 	int maxlen = (3 * in_len) + 1;
592 
593 	befs_debug(sb, "---> nls2utf()\n");
594 
595 	if (!nls) {
596 		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
597 		return -EINVAL;
598 	}
599 
600 	*out = result = kmalloc(maxlen, GFP_NOFS);
601 	if (!*out) {
602 		befs_error(sb, "befs_nls2utf() cannot allocate memory");
603 		*out_len = 0;
604 		return -ENOMEM;
605 	}
606 
607 	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
608 
609 		/* convert from nls to unicode */
610 		unilen = nls->char2uni(&in[i], in_len - i, &uni);
611 		if (unilen < 0) {
612 			goto conv_err;
613 		}
614 
615 		/* convert from unicode to UTF-8 */
616 		utflen = utf8_wctomb(&result[o], uni, 3);
617 		if (utflen <= 0) {
618 			goto conv_err;
619 		}
620 	}
621 
622 	result[o] = '\0';
623 	*out_len = o;
624 
625 	befs_debug(sb, "<--- nls2utf()");
626 
627 	return i;
628 
629       conv_err:
630 	befs_error(sb, "Name using charecter set %s contains a charecter that "
631 		   "cannot be converted to unicode.", nls->charset);
632 	befs_debug(sb, "<--- nls2utf()");
633 	kfree(result);
634 	return -EILSEQ;
635 }
636 
637 /**
638  * Use the
639  *
640  */
641 enum {
642 	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
643 };
644 
645 static match_table_t befs_tokens = {
646 	{Opt_uid, "uid=%d"},
647 	{Opt_gid, "gid=%d"},
648 	{Opt_charset, "iocharset=%s"},
649 	{Opt_debug, "debug"},
650 	{Opt_err, NULL}
651 };
652 
653 static int
654 parse_options(char *options, befs_mount_options * opts)
655 {
656 	char *p;
657 	substring_t args[MAX_OPT_ARGS];
658 	int option;
659 
660 	/* Initialize options */
661 	opts->uid = 0;
662 	opts->gid = 0;
663 	opts->use_uid = 0;
664 	opts->use_gid = 0;
665 	opts->iocharset = NULL;
666 	opts->debug = 0;
667 
668 	if (!options)
669 		return 1;
670 
671 	while ((p = strsep(&options, ",")) != NULL) {
672 		int token;
673 		if (!*p)
674 			continue;
675 
676 		token = match_token(p, befs_tokens, args);
677 		switch (token) {
678 		case Opt_uid:
679 			if (match_int(&args[0], &option))
680 				return 0;
681 			if (option < 0) {
682 				printk(KERN_ERR "BeFS: Invalid uid %d, "
683 						"using default\n", option);
684 				break;
685 			}
686 			opts->uid = option;
687 			opts->use_uid = 1;
688 			break;
689 		case Opt_gid:
690 			if (match_int(&args[0], &option))
691 				return 0;
692 			if (option < 0) {
693 				printk(KERN_ERR "BeFS: Invalid gid %d, "
694 						"using default\n", option);
695 				break;
696 			}
697 			opts->gid = option;
698 			opts->use_gid = 1;
699 			break;
700 		case Opt_charset:
701 			kfree(opts->iocharset);
702 			opts->iocharset = match_strdup(&args[0]);
703 			if (!opts->iocharset) {
704 				printk(KERN_ERR "BeFS: allocation failure for "
705 						"iocharset string\n");
706 				return 0;
707 			}
708 			break;
709 		case Opt_debug:
710 			opts->debug = 1;
711 			break;
712 		default:
713 			printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
714 					"or missing value\n", p);
715 			return 0;
716 		}
717 	}
718 	return 1;
719 }
720 
721 /* This function has the responsibiltiy of getting the
722  * filesystem ready for unmounting.
723  * Basicly, we free everything that we allocated in
724  * befs_read_inode
725  */
726 static void
727 befs_put_super(struct super_block *sb)
728 {
729 	kfree(BEFS_SB(sb)->mount_opts.iocharset);
730 	BEFS_SB(sb)->mount_opts.iocharset = NULL;
731 
732 	if (BEFS_SB(sb)->nls) {
733 		unload_nls(BEFS_SB(sb)->nls);
734 		BEFS_SB(sb)->nls = NULL;
735 	}
736 
737 	kfree(sb->s_fs_info);
738 	sb->s_fs_info = NULL;
739 	return;
740 }
741 
742 /* Allocate private field of the superblock, fill it.
743  *
744  * Finish filling the public superblock fields
745  * Make the root directory
746  * Load a set of NLS translations if needed.
747  */
748 static int
749 befs_fill_super(struct super_block *sb, void *data, int silent)
750 {
751 	struct buffer_head *bh;
752 	befs_sb_info *befs_sb;
753 	befs_super_block *disk_sb;
754 	struct inode *root;
755 
756 	const unsigned long sb_block = 0;
757 	const off_t x86_sb_off = 512;
758 
759 	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
760 	if (sb->s_fs_info == NULL) {
761 		printk(KERN_ERR
762 		       "BeFS(%s): Unable to allocate memory for private "
763 		       "portion of superblock. Bailing.\n", sb->s_id);
764 		goto unacquire_none;
765 	}
766 	befs_sb = BEFS_SB(sb);
767 	memset(befs_sb, 0, sizeof(befs_sb_info));
768 
769 	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
770 		befs_error(sb, "cannot parse mount options");
771 		goto unacquire_priv_sbp;
772 	}
773 
774 	befs_debug(sb, "---> befs_fill_super()");
775 
776 #ifndef CONFIG_BEFS_RW
777 	if (!(sb->s_flags & MS_RDONLY)) {
778 		befs_warning(sb,
779 			     "No write support. Marking filesystem read-only");
780 		sb->s_flags |= MS_RDONLY;
781 	}
782 #endif				/* CONFIG_BEFS_RW */
783 
784 	/*
785 	 * Set dummy blocksize to read super block.
786 	 * Will be set to real fs blocksize later.
787 	 *
788 	 * Linux 2.4.10 and later refuse to read blocks smaller than
789 	 * the hardsect size for the device. But we also need to read at
790 	 * least 1k to get the second 512 bytes of the volume.
791 	 * -WD 10-26-01
792 	 */
793 	sb_min_blocksize(sb, 1024);
794 
795 	if (!(bh = sb_bread(sb, sb_block))) {
796 		befs_error(sb, "unable to read superblock");
797 		goto unacquire_priv_sbp;
798 	}
799 
800 	/* account for offset of super block on x86 */
801 	disk_sb = (befs_super_block *) bh->b_data;
802 	if ((le32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1) ||
803 	    (be32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1)) {
804 		befs_debug(sb, "Using PPC superblock location");
805 	} else {
806 		befs_debug(sb, "Using x86 superblock location");
807 		disk_sb =
808 		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
809 	}
810 
811 	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
812 		goto unacquire_bh;
813 
814 	befs_dump_super_block(sb, disk_sb);
815 
816 	brelse(bh);
817 
818 	if (befs_check_sb(sb) != BEFS_OK)
819 		goto unacquire_priv_sbp;
820 
821 	if( befs_sb->num_blocks > ~((sector_t)0) ) {
822 		befs_error(sb, "blocks count: %Lu "
823 			"is larger than the host can use",
824 			befs_sb->num_blocks);
825 		goto unacquire_priv_sbp;
826 	}
827 
828 	/*
829 	 * set up enough so that it can read an inode
830 	 * Fill in kernel superblock fields from private sb
831 	 */
832 	sb->s_magic = BEFS_SUPER_MAGIC;
833 	/* Set real blocksize of fs */
834 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
835 	sb->s_op = (struct super_operations *) &befs_sops;
836 	root = iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
837 	sb->s_root = d_alloc_root(root);
838 	if (!sb->s_root) {
839 		iput(root);
840 		befs_error(sb, "get root inode failed");
841 		goto unacquire_priv_sbp;
842 	}
843 
844 	/* load nls library */
845 	if (befs_sb->mount_opts.iocharset) {
846 		befs_debug(sb, "Loading nls: %s",
847 			   befs_sb->mount_opts.iocharset);
848 		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
849 		if (!befs_sb->nls) {
850 			befs_warning(sb, "Cannot load nls %s"
851 					" loading default nls",
852 					befs_sb->mount_opts.iocharset);
853 			befs_sb->nls = load_nls_default();
854 		}
855 	/* load default nls if none is specified  in mount options */
856 	} else {
857 		befs_debug(sb, "Loading default nls");
858 		befs_sb->nls = load_nls_default();
859 	}
860 
861 	return 0;
862 /*****************/
863       unacquire_bh:
864 	brelse(bh);
865 
866       unacquire_priv_sbp:
867 	kfree(sb->s_fs_info);
868 
869       unacquire_none:
870 	sb->s_fs_info = NULL;
871 	return -EINVAL;
872 }
873 
874 static int
875 befs_remount(struct super_block *sb, int *flags, char *data)
876 {
877 	if (!(*flags & MS_RDONLY))
878 		return -EINVAL;
879 	return 0;
880 }
881 
882 static int
883 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
884 {
885 	struct super_block *sb = dentry->d_sb;
886 
887 	befs_debug(sb, "---> befs_statfs()");
888 
889 	buf->f_type = BEFS_SUPER_MAGIC;
890 	buf->f_bsize = sb->s_blocksize;
891 	buf->f_blocks = BEFS_SB(sb)->num_blocks;
892 	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
893 	buf->f_bavail = buf->f_bfree;
894 	buf->f_files = 0;	/* UNKNOWN */
895 	buf->f_ffree = 0;	/* UNKNOWN */
896 	buf->f_namelen = BEFS_NAME_LEN;
897 
898 	befs_debug(sb, "<--- befs_statfs()");
899 
900 	return 0;
901 }
902 
903 static int
904 befs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name,
905 	    void *data, struct vfsmount *mnt)
906 {
907 	return get_sb_bdev(fs_type, flags, dev_name, data, befs_fill_super,
908 			   mnt);
909 }
910 
911 static struct file_system_type befs_fs_type = {
912 	.owner		= THIS_MODULE,
913 	.name		= "befs",
914 	.get_sb		= befs_get_sb,
915 	.kill_sb	= kill_block_super,
916 	.fs_flags	= FS_REQUIRES_DEV,
917 };
918 
919 static int __init
920 init_befs_fs(void)
921 {
922 	int err;
923 
924 	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
925 
926 	err = befs_init_inodecache();
927 	if (err)
928 		goto unacquire_none;
929 
930 	err = register_filesystem(&befs_fs_type);
931 	if (err)
932 		goto unacquire_inodecache;
933 
934 	return 0;
935 
936 unacquire_inodecache:
937 	befs_destroy_inodecache();
938 
939 unacquire_none:
940 	return err;
941 }
942 
943 static void __exit
944 exit_befs_fs(void)
945 {
946 	befs_destroy_inodecache();
947 
948 	unregister_filesystem(&befs_fs_type);
949 }
950 
951 /*
952 Macros that typecheck the init and exit functions,
953 ensures that they are called at init and cleanup,
954 and eliminates warnings about unused functions.
955 */
956 module_init(init_befs_fs)
957 module_exit(exit_befs_fs)
958