xref: /openbmc/linux/fs/befs/linuxvfs.c (revision 483eb062)
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 *, struct dir_context *);
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_fast_follow_link(struct dentry *, struct nameidata *);
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 	.iterate	= 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_fast_symlink_inode_operations = {
83 	.readlink	= generic_readlink,
84 	.follow_link	= befs_fast_follow_link,
85 };
86 
87 static const struct inode_operations befs_symlink_inode_operations = {
88 	.readlink	= generic_readlink,
89 	.follow_link	= befs_follow_link,
90 	.put_link	= kfree_put_link,
91 };
92 
93 /*
94  * Called by generic_file_read() to read a page of data
95  *
96  * In turn, simply calls a generic block read function and
97  * passes it the address of befs_get_block, for mapping file
98  * positions to disk blocks.
99  */
100 static int
101 befs_readpage(struct file *file, struct page *page)
102 {
103 	return block_read_full_page(page, befs_get_block);
104 }
105 
106 static sector_t
107 befs_bmap(struct address_space *mapping, sector_t block)
108 {
109 	return generic_block_bmap(mapping, block, befs_get_block);
110 }
111 
112 /*
113  * Generic function to map a file position (block) to a
114  * disk offset (passed back in bh_result).
115  *
116  * Used by many higher level functions.
117  *
118  * Calls befs_fblock2brun() in datastream.c to do the real work.
119  *
120  * -WD 10-26-01
121  */
122 
123 static int
124 befs_get_block(struct inode *inode, sector_t block,
125 	       struct buffer_head *bh_result, int create)
126 {
127 	struct super_block *sb = inode->i_sb;
128 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
129 	befs_block_run run = BAD_IADDR;
130 	int res = 0;
131 	ulong disk_off;
132 
133 	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
134 		   inode->i_ino, block);
135 
136 	if (block < 0) {
137 		befs_error(sb, "befs_get_block() was asked for a block "
138 			   "number less than zero: block %ld in inode %lu",
139 			   block, inode->i_ino);
140 		return -EIO;
141 	}
142 
143 	if (create) {
144 		befs_error(sb, "befs_get_block() was asked to write to "
145 			   "block %ld in inode %lu", block, inode->i_ino);
146 		return -EPERM;
147 	}
148 
149 	res = befs_fblock2brun(sb, ds, block, &run);
150 	if (res != BEFS_OK) {
151 		befs_error(sb,
152 			   "<--- befs_get_block() for inode %lu, block "
153 			   "%ld ERROR", inode->i_ino, block);
154 		return -EFBIG;
155 	}
156 
157 	disk_off = (ulong) iaddr2blockno(sb, &run);
158 
159 	map_bh(bh_result, inode->i_sb, disk_off);
160 
161 	befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
162 		   "disk address %lu", inode->i_ino, block, disk_off);
163 
164 	return 0;
165 }
166 
167 static struct dentry *
168 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
169 {
170 	struct inode *inode = NULL;
171 	struct super_block *sb = dir->i_sb;
172 	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
173 	befs_off_t offset;
174 	int ret;
175 	int utfnamelen;
176 	char *utfname;
177 	const char *name = dentry->d_name.name;
178 
179 	befs_debug(sb, "---> befs_lookup() "
180 		   "name %s inode %ld", dentry->d_name.name, dir->i_ino);
181 
182 	/* Convert to UTF-8 */
183 	if (BEFS_SB(sb)->nls) {
184 		ret =
185 		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
186 		if (ret < 0) {
187 			befs_debug(sb, "<--- befs_lookup() ERROR");
188 			return ERR_PTR(ret);
189 		}
190 		ret = befs_btree_find(sb, ds, utfname, &offset);
191 		kfree(utfname);
192 
193 	} else {
194 		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
195 	}
196 
197 	if (ret == BEFS_BT_NOT_FOUND) {
198 		befs_debug(sb, "<--- befs_lookup() %s not found",
199 			   dentry->d_name.name);
200 		return ERR_PTR(-ENOENT);
201 
202 	} else if (ret != BEFS_OK || offset == 0) {
203 		befs_warning(sb, "<--- befs_lookup() Error");
204 		return ERR_PTR(-ENODATA);
205 	}
206 
207 	inode = befs_iget(dir->i_sb, (ino_t) offset);
208 	if (IS_ERR(inode))
209 		return ERR_CAST(inode);
210 
211 	d_add(dentry, inode);
212 
213 	befs_debug(sb, "<--- befs_lookup()");
214 
215 	return NULL;
216 }
217 
218 static int
219 befs_readdir(struct file *file, struct dir_context *ctx)
220 {
221 	struct inode *inode = file_inode(file);
222 	struct super_block *sb = inode->i_sb;
223 	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
224 	befs_off_t value;
225 	int result;
226 	size_t keysize;
227 	unsigned char d_type;
228 	char keybuf[BEFS_NAME_LEN + 1];
229 	const char *dirname = file->f_path.dentry->d_name.name;
230 
231 	befs_debug(sb, "---> befs_readdir() "
232 		   "name %s, inode %ld, ctx->pos %Ld",
233 		   dirname, inode->i_ino, ctx->pos);
234 
235 more:
236 	result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
237 				 keybuf, &keysize, &value);
238 
239 	if (result == BEFS_ERR) {
240 		befs_debug(sb, "<--- befs_readdir() ERROR");
241 		befs_error(sb, "IO error reading %s (inode %lu)",
242 			   dirname, inode->i_ino);
243 		return -EIO;
244 
245 	} else if (result == BEFS_BT_END) {
246 		befs_debug(sb, "<--- befs_readdir() END");
247 		return 0;
248 
249 	} else if (result == BEFS_BT_EMPTY) {
250 		befs_debug(sb, "<--- befs_readdir() Empty directory");
251 		return 0;
252 	}
253 
254 	d_type = DT_UNKNOWN;
255 
256 	/* Convert to NLS */
257 	if (BEFS_SB(sb)->nls) {
258 		char *nlsname;
259 		int nlsnamelen;
260 		result =
261 		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
262 		if (result < 0) {
263 			befs_debug(sb, "<--- befs_readdir() ERROR");
264 			return result;
265 		}
266 		if (!dir_emit(ctx, nlsname, nlsnamelen,
267 				 (ino_t) value, d_type)) {
268 			kfree(nlsname);
269 			return 0;
270 		}
271 		kfree(nlsname);
272 	} else {
273 		if (!dir_emit(ctx, keybuf, keysize,
274 				 (ino_t) value, d_type))
275 			return 0;
276 	}
277 	ctx->pos++;
278 	goto more;
279 
280 	befs_debug(sb, "<--- befs_readdir() pos %Ld", ctx->pos);
281 
282 	return 0;
283 }
284 
285 static struct inode *
286 befs_alloc_inode(struct super_block *sb)
287 {
288         struct befs_inode_info *bi;
289         bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
290 							GFP_KERNEL);
291         if (!bi)
292                 return NULL;
293         return &bi->vfs_inode;
294 }
295 
296 static void befs_i_callback(struct rcu_head *head)
297 {
298 	struct inode *inode = container_of(head, struct inode, i_rcu);
299         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
300 }
301 
302 static void befs_destroy_inode(struct inode *inode)
303 {
304 	call_rcu(&inode->i_rcu, befs_i_callback);
305 }
306 
307 static void init_once(void *foo)
308 {
309         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
310 
311 	inode_init_once(&bi->vfs_inode);
312 }
313 
314 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
315 {
316 	struct buffer_head *bh = NULL;
317 	befs_inode *raw_inode = NULL;
318 
319 	befs_sb_info *befs_sb = BEFS_SB(sb);
320 	befs_inode_info *befs_ino = NULL;
321 	struct inode *inode;
322 	long ret = -EIO;
323 
324 	befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
325 
326 	inode = iget_locked(sb, ino);
327 	if (!inode)
328 		return ERR_PTR(-ENOMEM);
329 	if (!(inode->i_state & I_NEW))
330 		return inode;
331 
332 	befs_ino = BEFS_I(inode);
333 
334 	/* convert from vfs's inode number to befs's inode number */
335 	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
336 
337 	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
338 		   befs_ino->i_inode_num.allocation_group,
339 		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
340 
341 	bh = befs_bread(sb, inode->i_ino);
342 	if (!bh) {
343 		befs_error(sb, "unable to read inode block - "
344 			   "inode = %lu", inode->i_ino);
345 		goto unacquire_none;
346 	}
347 
348 	raw_inode = (befs_inode *) bh->b_data;
349 
350 	befs_dump_inode(sb, raw_inode);
351 
352 	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
353 		befs_error(sb, "Bad inode: %lu", inode->i_ino);
354 		goto unacquire_bh;
355 	}
356 
357 	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
358 
359 	/*
360 	 * set uid and gid.  But since current BeOS is single user OS, so
361 	 * you can change by "uid" or "gid" options.
362 	 */
363 
364 	inode->i_uid = befs_sb->mount_opts.use_uid ?
365 		befs_sb->mount_opts.uid :
366 		make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
367 	inode->i_gid = befs_sb->mount_opts.use_gid ?
368 		befs_sb->mount_opts.gid :
369 		make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
370 
371 	set_nlink(inode, 1);
372 
373 	/*
374 	 * BEFS's time is 64 bits, but current VFS is 32 bits...
375 	 * BEFS don't have access time. Nor inode change time. VFS
376 	 * doesn't have creation time.
377 	 * Also, the lower 16 bits of the last_modified_time and
378 	 * create_time are just a counter to help ensure uniqueness
379 	 * for indexing purposes. (PFD, page 54)
380 	 */
381 
382 	inode->i_mtime.tv_sec =
383 	    fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
384 	inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
385 	inode->i_ctime = inode->i_mtime;
386 	inode->i_atime = inode->i_mtime;
387 
388 	befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
389 	befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
390 	befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
391 	befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
392 
393 	if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
394 		inode->i_size = 0;
395 		inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
396 		strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
397 			BEFS_SYMLINK_LEN - 1);
398 		befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
399 	} else {
400 		int num_blks;
401 
402 		befs_ino->i_data.ds =
403 		    fsds_to_cpu(sb, &raw_inode->data.datastream);
404 
405 		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
406 		inode->i_blocks =
407 		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
408 		inode->i_size = befs_ino->i_data.ds.size;
409 	}
410 
411 	inode->i_mapping->a_ops = &befs_aops;
412 
413 	if (S_ISREG(inode->i_mode)) {
414 		inode->i_fop = &generic_ro_fops;
415 	} else if (S_ISDIR(inode->i_mode)) {
416 		inode->i_op = &befs_dir_inode_operations;
417 		inode->i_fop = &befs_dir_operations;
418 	} else if (S_ISLNK(inode->i_mode)) {
419 		if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
420 			inode->i_op = &befs_symlink_inode_operations;
421 		else
422 			inode->i_op = &befs_fast_symlink_inode_operations;
423 	} else {
424 		befs_error(sb, "Inode %lu is not a regular file, "
425 			   "directory or symlink. THAT IS WRONG! BeFS has no "
426 			   "on disk special files", inode->i_ino);
427 		goto unacquire_bh;
428 	}
429 
430 	brelse(bh);
431 	befs_debug(sb, "<--- befs_read_inode()");
432 	unlock_new_inode(inode);
433 	return inode;
434 
435       unacquire_bh:
436 	brelse(bh);
437 
438       unacquire_none:
439 	iget_failed(inode);
440 	befs_debug(sb, "<--- befs_read_inode() - Bad inode");
441 	return ERR_PTR(ret);
442 }
443 
444 /* Initialize the inode cache. Called at fs setup.
445  *
446  * Taken from NFS implementation by Al Viro.
447  */
448 static int
449 befs_init_inodecache(void)
450 {
451 	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
452 					      sizeof (struct befs_inode_info),
453 					      0, (SLAB_RECLAIM_ACCOUNT|
454 						SLAB_MEM_SPREAD),
455 					      init_once);
456 	if (befs_inode_cachep == NULL) {
457 		printk(KERN_ERR "befs_init_inodecache: "
458 		       "Couldn't initialize inode slabcache\n");
459 		return -ENOMEM;
460 	}
461 
462 	return 0;
463 }
464 
465 /* Called at fs teardown.
466  *
467  * Taken from NFS implementation by Al Viro.
468  */
469 static void
470 befs_destroy_inodecache(void)
471 {
472 	/*
473 	 * Make sure all delayed rcu free inodes are flushed before we
474 	 * destroy cache.
475 	 */
476 	rcu_barrier();
477 	kmem_cache_destroy(befs_inode_cachep);
478 }
479 
480 /*
481  * The inode of symbolic link is different to data stream.
482  * The data stream become link name. Unless the LONG_SYMLINK
483  * flag is set.
484  */
485 static void *
486 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
487 {
488 	struct super_block *sb = dentry->d_sb;
489 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
490 	befs_data_stream *data = &befs_ino->i_data.ds;
491 	befs_off_t len = data->size;
492 	char *link;
493 
494 	if (len == 0) {
495 		befs_error(sb, "Long symlink with illegal length");
496 		link = ERR_PTR(-EIO);
497 	} else {
498 		befs_debug(sb, "Follow long symlink");
499 
500 		link = kmalloc(len, GFP_NOFS);
501 		if (!link) {
502 			link = ERR_PTR(-ENOMEM);
503 		} else if (befs_read_lsymlink(sb, data, link, len) != len) {
504 			kfree(link);
505 			befs_error(sb, "Failed to read entire long symlink");
506 			link = ERR_PTR(-EIO);
507 		} else {
508 			link[len - 1] = '\0';
509 		}
510 	}
511 	nd_set_link(nd, link);
512 	return NULL;
513 }
514 
515 
516 static void *
517 befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
518 {
519 	befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
520 	nd_set_link(nd, befs_ino->i_data.symlink);
521 	return NULL;
522 }
523 
524 /*
525  * UTF-8 to NLS charset  convert routine
526  *
527  *
528  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
529  * the nls tables directly
530  */
531 
532 static int
533 befs_utf2nls(struct super_block *sb, const char *in,
534 	     int in_len, char **out, int *out_len)
535 {
536 	struct nls_table *nls = BEFS_SB(sb)->nls;
537 	int i, o;
538 	unicode_t uni;
539 	int unilen, utflen;
540 	char *result;
541 	/* The utf8->nls conversion won't make the final nls string bigger
542 	 * than the utf one, but if the string is pure ascii they'll have the
543 	 * same width and an extra char is needed to save the additional \0
544 	 */
545 	int maxlen = in_len + 1;
546 
547 	befs_debug(sb, "---> utf2nls()");
548 
549 	if (!nls) {
550 		befs_error(sb, "befs_utf2nls called with no NLS table loaded");
551 		return -EINVAL;
552 	}
553 
554 	*out = result = kmalloc(maxlen, GFP_NOFS);
555 	if (!*out) {
556 		befs_error(sb, "befs_utf2nls() cannot allocate memory");
557 		*out_len = 0;
558 		return -ENOMEM;
559 	}
560 
561 	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
562 
563 		/* convert from UTF-8 to Unicode */
564 		utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
565 		if (utflen < 0)
566 			goto conv_err;
567 
568 		/* convert from Unicode to nls */
569 		if (uni > MAX_WCHAR_T)
570 			goto conv_err;
571 		unilen = nls->uni2char(uni, &result[o], in_len - o);
572 		if (unilen < 0)
573 			goto conv_err;
574 	}
575 	result[o] = '\0';
576 	*out_len = o;
577 
578 	befs_debug(sb, "<--- utf2nls()");
579 
580 	return o;
581 
582       conv_err:
583 	befs_error(sb, "Name using character set %s contains a character that "
584 		   "cannot be converted to unicode.", nls->charset);
585 	befs_debug(sb, "<--- utf2nls()");
586 	kfree(result);
587 	return -EILSEQ;
588 }
589 
590 /**
591  * befs_nls2utf - Convert NLS string to utf8 encodeing
592  * @sb: Superblock
593  * @src: Input string buffer in NLS format
594  * @srclen: Length of input string in bytes
595  * @dest: The output string in UTF-8 format
596  * @destlen: Length of the output buffer
597  *
598  * Converts input string @src, which is in the format of the loaded NLS map,
599  * into a utf8 string.
600  *
601  * The destination string @dest is allocated by this function and the caller is
602  * responsible for freeing it with kfree()
603  *
604  * On return, *@destlen is the length of @dest in bytes.
605  *
606  * On success, the return value is the number of utf8 characters written to
607  * the output buffer @dest.
608  *
609  * On Failure, a negative number coresponding to the error code is returned.
610  */
611 
612 static int
613 befs_nls2utf(struct super_block *sb, const char *in,
614 	     int in_len, char **out, int *out_len)
615 {
616 	struct nls_table *nls = BEFS_SB(sb)->nls;
617 	int i, o;
618 	wchar_t uni;
619 	int unilen, utflen;
620 	char *result;
621 	/* There're nls characters that will translate to 3-chars-wide UTF-8
622 	 * characters, a additional byte is needed to save the final \0
623 	 * in special cases */
624 	int maxlen = (3 * in_len) + 1;
625 
626 	befs_debug(sb, "---> nls2utf()\n");
627 
628 	if (!nls) {
629 		befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
630 		return -EINVAL;
631 	}
632 
633 	*out = result = kmalloc(maxlen, GFP_NOFS);
634 	if (!*out) {
635 		befs_error(sb, "befs_nls2utf() cannot allocate memory");
636 		*out_len = 0;
637 		return -ENOMEM;
638 	}
639 
640 	for (i = o = 0; i < in_len; i += unilen, o += utflen) {
641 
642 		/* convert from nls to unicode */
643 		unilen = nls->char2uni(&in[i], in_len - i, &uni);
644 		if (unilen < 0)
645 			goto conv_err;
646 
647 		/* convert from unicode to UTF-8 */
648 		utflen = utf32_to_utf8(uni, &result[o], 3);
649 		if (utflen <= 0)
650 			goto conv_err;
651 	}
652 
653 	result[o] = '\0';
654 	*out_len = o;
655 
656 	befs_debug(sb, "<--- nls2utf()");
657 
658 	return i;
659 
660       conv_err:
661 	befs_error(sb, "Name using charecter set %s contains a charecter that "
662 		   "cannot be converted to unicode.", nls->charset);
663 	befs_debug(sb, "<--- nls2utf()");
664 	kfree(result);
665 	return -EILSEQ;
666 }
667 
668 /**
669  * Use the
670  *
671  */
672 enum {
673 	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
674 };
675 
676 static const match_table_t befs_tokens = {
677 	{Opt_uid, "uid=%d"},
678 	{Opt_gid, "gid=%d"},
679 	{Opt_charset, "iocharset=%s"},
680 	{Opt_debug, "debug"},
681 	{Opt_err, NULL}
682 };
683 
684 static int
685 parse_options(char *options, befs_mount_options * opts)
686 {
687 	char *p;
688 	substring_t args[MAX_OPT_ARGS];
689 	int option;
690 	kuid_t uid;
691 	kgid_t gid;
692 
693 	/* Initialize options */
694 	opts->uid = GLOBAL_ROOT_UID;
695 	opts->gid = GLOBAL_ROOT_GID;
696 	opts->use_uid = 0;
697 	opts->use_gid = 0;
698 	opts->iocharset = NULL;
699 	opts->debug = 0;
700 
701 	if (!options)
702 		return 1;
703 
704 	while ((p = strsep(&options, ",")) != NULL) {
705 		int token;
706 		if (!*p)
707 			continue;
708 
709 		token = match_token(p, befs_tokens, args);
710 		switch (token) {
711 		case Opt_uid:
712 			if (match_int(&args[0], &option))
713 				return 0;
714 			uid = INVALID_UID;
715 			if (option >= 0)
716 				uid = make_kuid(current_user_ns(), option);
717 			if (!uid_valid(uid)) {
718 				printk(KERN_ERR "BeFS: Invalid uid %d, "
719 						"using default\n", option);
720 				break;
721 			}
722 			opts->uid = uid;
723 			opts->use_uid = 1;
724 			break;
725 		case Opt_gid:
726 			if (match_int(&args[0], &option))
727 				return 0;
728 			gid = INVALID_GID;
729 			if (option >= 0)
730 				gid = make_kgid(current_user_ns(), option);
731 			if (!gid_valid(gid)) {
732 				printk(KERN_ERR "BeFS: Invalid gid %d, "
733 						"using default\n", option);
734 				break;
735 			}
736 			opts->gid = gid;
737 			opts->use_gid = 1;
738 			break;
739 		case Opt_charset:
740 			kfree(opts->iocharset);
741 			opts->iocharset = match_strdup(&args[0]);
742 			if (!opts->iocharset) {
743 				printk(KERN_ERR "BeFS: allocation failure for "
744 						"iocharset string\n");
745 				return 0;
746 			}
747 			break;
748 		case Opt_debug:
749 			opts->debug = 1;
750 			break;
751 		default:
752 			printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
753 					"or missing value\n", p);
754 			return 0;
755 		}
756 	}
757 	return 1;
758 }
759 
760 /* This function has the responsibiltiy of getting the
761  * filesystem ready for unmounting.
762  * Basically, we free everything that we allocated in
763  * befs_read_inode
764  */
765 static void
766 befs_put_super(struct super_block *sb)
767 {
768 	kfree(BEFS_SB(sb)->mount_opts.iocharset);
769 	BEFS_SB(sb)->mount_opts.iocharset = NULL;
770 	unload_nls(BEFS_SB(sb)->nls);
771 	kfree(sb->s_fs_info);
772 	sb->s_fs_info = NULL;
773 }
774 
775 /* Allocate private field of the superblock, fill it.
776  *
777  * Finish filling the public superblock fields
778  * Make the root directory
779  * Load a set of NLS translations if needed.
780  */
781 static int
782 befs_fill_super(struct super_block *sb, void *data, int silent)
783 {
784 	struct buffer_head *bh;
785 	befs_sb_info *befs_sb;
786 	befs_super_block *disk_sb;
787 	struct inode *root;
788 	long ret = -EINVAL;
789 	const unsigned long sb_block = 0;
790 	const off_t x86_sb_off = 512;
791 
792 	save_mount_options(sb, data);
793 
794 	sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
795 	if (sb->s_fs_info == NULL) {
796 		printk(KERN_ERR
797 		       "BeFS(%s): Unable to allocate memory for private "
798 		       "portion of superblock. Bailing.\n", sb->s_id);
799 		goto unacquire_none;
800 	}
801 	befs_sb = BEFS_SB(sb);
802 	memset(befs_sb, 0, sizeof(befs_sb_info));
803 
804 	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
805 		befs_error(sb, "cannot parse mount options");
806 		goto unacquire_priv_sbp;
807 	}
808 
809 	befs_debug(sb, "---> befs_fill_super()");
810 
811 #ifndef CONFIG_BEFS_RW
812 	if (!(sb->s_flags & MS_RDONLY)) {
813 		befs_warning(sb,
814 			     "No write support. Marking filesystem read-only");
815 		sb->s_flags |= MS_RDONLY;
816 	}
817 #endif				/* CONFIG_BEFS_RW */
818 
819 	/*
820 	 * Set dummy blocksize to read super block.
821 	 * Will be set to real fs blocksize later.
822 	 *
823 	 * Linux 2.4.10 and later refuse to read blocks smaller than
824 	 * the hardsect size for the device. But we also need to read at
825 	 * least 1k to get the second 512 bytes of the volume.
826 	 * -WD 10-26-01
827 	 */
828 	sb_min_blocksize(sb, 1024);
829 
830 	if (!(bh = sb_bread(sb, sb_block))) {
831 		befs_error(sb, "unable to read superblock");
832 		goto unacquire_priv_sbp;
833 	}
834 
835 	/* account for offset of super block on x86 */
836 	disk_sb = (befs_super_block *) bh->b_data;
837 	if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
838 	    (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
839 		befs_debug(sb, "Using PPC superblock location");
840 	} else {
841 		befs_debug(sb, "Using x86 superblock location");
842 		disk_sb =
843 		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
844 	}
845 
846 	if (befs_load_sb(sb, disk_sb) != BEFS_OK)
847 		goto unacquire_bh;
848 
849 	befs_dump_super_block(sb, disk_sb);
850 
851 	brelse(bh);
852 
853 	if (befs_check_sb(sb) != BEFS_OK)
854 		goto unacquire_priv_sbp;
855 
856 	if( befs_sb->num_blocks > ~((sector_t)0) ) {
857 		befs_error(sb, "blocks count: %Lu "
858 			"is larger than the host can use",
859 			befs_sb->num_blocks);
860 		goto unacquire_priv_sbp;
861 	}
862 
863 	/*
864 	 * set up enough so that it can read an inode
865 	 * Fill in kernel superblock fields from private sb
866 	 */
867 	sb->s_magic = BEFS_SUPER_MAGIC;
868 	/* Set real blocksize of fs */
869 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
870 	sb->s_op = &befs_sops;
871 	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
872 	if (IS_ERR(root)) {
873 		ret = PTR_ERR(root);
874 		goto unacquire_priv_sbp;
875 	}
876 	sb->s_root = d_make_root(root);
877 	if (!sb->s_root) {
878 		befs_error(sb, "get root inode failed");
879 		goto unacquire_priv_sbp;
880 	}
881 
882 	/* load nls library */
883 	if (befs_sb->mount_opts.iocharset) {
884 		befs_debug(sb, "Loading nls: %s",
885 			   befs_sb->mount_opts.iocharset);
886 		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
887 		if (!befs_sb->nls) {
888 			befs_warning(sb, "Cannot load nls %s"
889 					" loading default nls",
890 					befs_sb->mount_opts.iocharset);
891 			befs_sb->nls = load_nls_default();
892 		}
893 	/* load default nls if none is specified  in mount options */
894 	} else {
895 		befs_debug(sb, "Loading default nls");
896 		befs_sb->nls = load_nls_default();
897 	}
898 
899 	return 0;
900 /*****************/
901       unacquire_bh:
902 	brelse(bh);
903 
904       unacquire_priv_sbp:
905 	kfree(befs_sb->mount_opts.iocharset);
906 	kfree(sb->s_fs_info);
907 
908       unacquire_none:
909 	sb->s_fs_info = NULL;
910 	return ret;
911 }
912 
913 static int
914 befs_remount(struct super_block *sb, int *flags, char *data)
915 {
916 	if (!(*flags & MS_RDONLY))
917 		return -EINVAL;
918 	return 0;
919 }
920 
921 static int
922 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
923 {
924 	struct super_block *sb = dentry->d_sb;
925 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
926 
927 	befs_debug(sb, "---> befs_statfs()");
928 
929 	buf->f_type = BEFS_SUPER_MAGIC;
930 	buf->f_bsize = sb->s_blocksize;
931 	buf->f_blocks = BEFS_SB(sb)->num_blocks;
932 	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
933 	buf->f_bavail = buf->f_bfree;
934 	buf->f_files = 0;	/* UNKNOWN */
935 	buf->f_ffree = 0;	/* UNKNOWN */
936 	buf->f_fsid.val[0] = (u32)id;
937 	buf->f_fsid.val[1] = (u32)(id >> 32);
938 	buf->f_namelen = BEFS_NAME_LEN;
939 
940 	befs_debug(sb, "<--- befs_statfs()");
941 
942 	return 0;
943 }
944 
945 static struct dentry *
946 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
947 	    void *data)
948 {
949 	return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
950 }
951 
952 static struct file_system_type befs_fs_type = {
953 	.owner		= THIS_MODULE,
954 	.name		= "befs",
955 	.mount		= befs_mount,
956 	.kill_sb	= kill_block_super,
957 	.fs_flags	= FS_REQUIRES_DEV,
958 };
959 MODULE_ALIAS_FS("befs");
960 
961 static int __init
962 init_befs_fs(void)
963 {
964 	int err;
965 
966 	printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
967 
968 	err = befs_init_inodecache();
969 	if (err)
970 		goto unacquire_none;
971 
972 	err = register_filesystem(&befs_fs_type);
973 	if (err)
974 		goto unacquire_inodecache;
975 
976 	return 0;
977 
978 unacquire_inodecache:
979 	befs_destroy_inodecache();
980 
981 unacquire_none:
982 	return err;
983 }
984 
985 static void __exit
986 exit_befs_fs(void)
987 {
988 	befs_destroy_inodecache();
989 
990 	unregister_filesystem(&befs_fs_type);
991 }
992 
993 /*
994 Macros that typecheck the init and exit functions,
995 ensures that they are called at init and cleanup,
996 and eliminates warnings about unused functions.
997 */
998 module_init(init_befs_fs)
999 module_exit(exit_befs_fs)
1000