1/*
2 * linux/fs/befs/linuxvfs.c
3 *
4 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
5 *
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/fs.h>
13#include <linux/errno.h>
14#include <linux/stat.h>
15#include <linux/nls.h>
16#include <linux/buffer_head.h>
17#include <linux/vfs.h>
18#include <linux/parser.h>
19#include <linux/namei.h>
20#include <linux/sched.h>
21
22#include "befs.h"
23#include "btree.h"
24#include "inode.h"
25#include "datastream.h"
26#include "super.h"
27#include "io.h"
28
29MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
30MODULE_AUTHOR("Will Dyson");
31MODULE_LICENSE("GPL");
32
33/* The units the vfs expects inode->i_blocks to be in */
34#define VFS_BLOCK_SIZE 512
35
36static int befs_readdir(struct file *, struct dir_context *);
37static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
38static int befs_readpage(struct file *file, struct page *page);
39static sector_t befs_bmap(struct address_space *mapping, sector_t block);
40static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
41static struct inode *befs_iget(struct super_block *, unsigned long);
42static struct inode *befs_alloc_inode(struct super_block *sb);
43static void befs_destroy_inode(struct inode *inode);
44static void befs_destroy_inodecache(void);
45static void *befs_follow_link(struct dentry *, struct nameidata *);
46static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
47static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
48			char **out, int *out_len);
49static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
50			char **out, int *out_len);
51static void befs_put_super(struct super_block *);
52static int befs_remount(struct super_block *, int *, char *);
53static int befs_statfs(struct dentry *, struct kstatfs *);
54static int parse_options(char *, struct befs_mount_options *);
55
56static const struct super_operations befs_sops = {
57	.alloc_inode	= befs_alloc_inode,	/* allocate a new inode */
58	.destroy_inode	= befs_destroy_inode, /* deallocate an inode */
59	.put_super	= befs_put_super,	/* uninit super */
60	.statfs		= befs_statfs,	/* statfs */
61	.remount_fs	= befs_remount,
62	.show_options	= generic_show_options,
63};
64
65/* slab cache for befs_inode_info objects */
66static struct kmem_cache *befs_inode_cachep;
67
68static const struct file_operations befs_dir_operations = {
69	.read		= generic_read_dir,
70	.iterate	= befs_readdir,
71	.llseek		= generic_file_llseek,
72};
73
74static const struct inode_operations befs_dir_inode_operations = {
75	.lookup		= befs_lookup,
76};
77
78static const struct address_space_operations befs_aops = {
79	.readpage	= befs_readpage,
80	.bmap		= befs_bmap,
81};
82
83static const struct inode_operations befs_fast_symlink_inode_operations = {
84	.readlink	= generic_readlink,
85	.follow_link	= befs_fast_follow_link,
86};
87
88static const struct inode_operations befs_symlink_inode_operations = {
89	.readlink	= generic_readlink,
90	.follow_link	= befs_follow_link,
91	.put_link	= kfree_put_link,
92};
93
94/*
95 * Called by generic_file_read() to read a page of data
96 *
97 * In turn, simply calls a generic block read function and
98 * passes it the address of befs_get_block, for mapping file
99 * positions to disk blocks.
100 */
101static int
102befs_readpage(struct file *file, struct page *page)
103{
104	return block_read_full_page(page, befs_get_block);
105}
106
107static sector_t
108befs_bmap(struct address_space *mapping, sector_t block)
109{
110	return generic_block_bmap(mapping, block, befs_get_block);
111}
112
113/*
114 * Generic function to map a file position (block) to a
115 * disk offset (passed back in bh_result).
116 *
117 * Used by many higher level functions.
118 *
119 * Calls befs_fblock2brun() in datastream.c to do the real work.
120 *
121 * -WD 10-26-01
122 */
123
124static int
125befs_get_block(struct inode *inode, sector_t block,
126	       struct buffer_head *bh_result, int create)
127{
128	struct super_block *sb = inode->i_sb;
129	befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
130	befs_block_run run = BAD_IADDR;
131	int res = 0;
132	ulong disk_off;
133
134	befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
135		   (unsigned long)inode->i_ino, (long)block);
136	if (create) {
137		befs_error(sb, "befs_get_block() was asked to write to "
138			   "block %ld in inode %lu", (long)block,
139			   (unsigned long)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			   "<--- %s for inode %lu, block %ld ERROR",
147			   __func__, (unsigned long)inode->i_ino,
148			   (long)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, "<--- %s for inode %lu, block %ld, disk address %lu",
157		  __func__, (unsigned long)inode->i_ino, (long)block,
158		  (unsigned long)disk_off);
159
160	return 0;
161}
162
163static struct dentry *
164befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
165{
166	struct inode *inode = NULL;
167	struct super_block *sb = dir->i_sb;
168	befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
169	befs_off_t offset;
170	int ret;
171	int utfnamelen;
172	char *utfname;
173	const char *name = dentry->d_name.name;
174
175	befs_debug(sb, "---> %s name %pd inode %ld", __func__,
176		   dentry, dir->i_ino);
177
178	/* Convert to UTF-8 */
179	if (BEFS_SB(sb)->nls) {
180		ret =
181		    befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
182		if (ret < 0) {
183			befs_debug(sb, "<--- %s ERROR", __func__);
184			return ERR_PTR(ret);
185		}
186		ret = befs_btree_find(sb, ds, utfname, &offset);
187		kfree(utfname);
188
189	} else {
190		ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
191	}
192
193	if (ret == BEFS_BT_NOT_FOUND) {
194		befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
195		return ERR_PTR(-ENOENT);
196
197	} else if (ret != BEFS_OK || offset == 0) {
198		befs_warning(sb, "<--- %s Error", __func__);
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, "<--- %s", __func__);
209
210	return NULL;
211}
212
213static int
214befs_readdir(struct file *file, struct dir_context *ctx)
215{
216	struct inode *inode = file_inode(file);
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
225	befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
226		  __func__, file, inode->i_ino, ctx->pos);
227
228more:
229	result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
230				 keybuf, &keysize, &value);
231
232	if (result == BEFS_ERR) {
233		befs_debug(sb, "<--- %s ERROR", __func__);
234		befs_error(sb, "IO error reading %pD (inode %lu)",
235			   file, inode->i_ino);
236		return -EIO;
237
238	} else if (result == BEFS_BT_END) {
239		befs_debug(sb, "<--- %s END", __func__);
240		return 0;
241
242	} else if (result == BEFS_BT_EMPTY) {
243		befs_debug(sb, "<--- %s Empty directory", __func__);
244		return 0;
245	}
246
247	d_type = DT_UNKNOWN;
248
249	/* Convert to NLS */
250	if (BEFS_SB(sb)->nls) {
251		char *nlsname;
252		int nlsnamelen;
253		result =
254		    befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
255		if (result < 0) {
256			befs_debug(sb, "<--- %s ERROR", __func__);
257			return result;
258		}
259		if (!dir_emit(ctx, nlsname, nlsnamelen,
260				 (ino_t) value, d_type)) {
261			kfree(nlsname);
262			return 0;
263		}
264		kfree(nlsname);
265	} else {
266		if (!dir_emit(ctx, keybuf, keysize,
267				 (ino_t) value, d_type))
268			return 0;
269	}
270	ctx->pos++;
271	goto more;
272}
273
274static struct inode *
275befs_alloc_inode(struct super_block *sb)
276{
277	struct befs_inode_info *bi;
278
279	bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
280        if (!bi)
281                return NULL;
282        return &bi->vfs_inode;
283}
284
285static void befs_i_callback(struct rcu_head *head)
286{
287	struct inode *inode = container_of(head, struct inode, i_rcu);
288        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
289}
290
291static void befs_destroy_inode(struct inode *inode)
292{
293	call_rcu(&inode->i_rcu, befs_i_callback);
294}
295
296static void init_once(void *foo)
297{
298        struct befs_inode_info *bi = (struct befs_inode_info *) foo;
299
300	inode_init_once(&bi->vfs_inode);
301}
302
303static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
304{
305	struct buffer_head *bh = NULL;
306	befs_inode *raw_inode = NULL;
307	struct befs_sb_info *befs_sb = BEFS_SB(sb);
308	struct befs_inode_info *befs_ino = NULL;
309	struct inode *inode;
310	long ret = -EIO;
311
312	befs_debug(sb, "---> %s inode = %lu", __func__, ino);
313
314	inode = iget_locked(sb, ino);
315	if (!inode)
316		return ERR_PTR(-ENOMEM);
317	if (!(inode->i_state & I_NEW))
318		return inode;
319
320	befs_ino = BEFS_I(inode);
321
322	/* convert from vfs's inode number to befs's inode number */
323	befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
324
325	befs_debug(sb, "  real inode number [%u, %hu, %hu]",
326		   befs_ino->i_inode_num.allocation_group,
327		   befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
328
329	bh = befs_bread(sb, inode->i_ino);
330	if (!bh) {
331		befs_error(sb, "unable to read inode block - "
332			   "inode = %lu", inode->i_ino);
333		goto unacquire_none;
334	}
335
336	raw_inode = (befs_inode *) bh->b_data;
337
338	befs_dump_inode(sb, raw_inode);
339
340	if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
341		befs_error(sb, "Bad inode: %lu", inode->i_ino);
342		goto unacquire_bh;
343	}
344
345	inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
346
347	/*
348	 * set uid and gid.  But since current BeOS is single user OS, so
349	 * you can change by "uid" or "gid" options.
350	 */
351
352	inode->i_uid = befs_sb->mount_opts.use_uid ?
353		befs_sb->mount_opts.uid :
354		make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
355	inode->i_gid = befs_sb->mount_opts.use_gid ?
356		befs_sb->mount_opts.gid :
357		make_kgid(&init_user_ns, 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		strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
385			BEFS_SYMLINK_LEN);
386	} else {
387		int num_blks;
388
389		befs_ino->i_data.ds =
390		    fsds_to_cpu(sb, &raw_inode->data.datastream);
391
392		num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
393		inode->i_blocks =
394		    num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
395		inode->i_size = befs_ino->i_data.ds.size;
396	}
397
398	inode->i_mapping->a_ops = &befs_aops;
399
400	if (S_ISREG(inode->i_mode)) {
401		inode->i_fop = &generic_ro_fops;
402	} else if (S_ISDIR(inode->i_mode)) {
403		inode->i_op = &befs_dir_inode_operations;
404		inode->i_fop = &befs_dir_operations;
405	} else if (S_ISLNK(inode->i_mode)) {
406		if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
407			inode->i_op = &befs_symlink_inode_operations;
408		else
409			inode->i_op = &befs_fast_symlink_inode_operations;
410	} else {
411		befs_error(sb, "Inode %lu is not a regular file, "
412			   "directory or symlink. THAT IS WRONG! BeFS has no "
413			   "on disk special files", inode->i_ino);
414		goto unacquire_bh;
415	}
416
417	brelse(bh);
418	befs_debug(sb, "<--- %s", __func__);
419	unlock_new_inode(inode);
420	return inode;
421
422      unacquire_bh:
423	brelse(bh);
424
425      unacquire_none:
426	iget_failed(inode);
427	befs_debug(sb, "<--- %s - Bad inode", __func__);
428	return ERR_PTR(ret);
429}
430
431/* Initialize the inode cache. Called at fs setup.
432 *
433 * Taken from NFS implementation by Al Viro.
434 */
435static int __init
436befs_init_inodecache(void)
437{
438	befs_inode_cachep = kmem_cache_create("befs_inode_cache",
439					      sizeof (struct befs_inode_info),
440					      0, (SLAB_RECLAIM_ACCOUNT|
441						SLAB_MEM_SPREAD),
442					      init_once);
443	if (befs_inode_cachep == NULL) {
444		pr_err("%s: Couldn't initialize inode slabcache\n", __func__);
445		return -ENOMEM;
446	}
447	return 0;
448}
449
450/* Called at fs teardown.
451 *
452 * Taken from NFS implementation by Al Viro.
453 */
454static void
455befs_destroy_inodecache(void)
456{
457	/*
458	 * Make sure all delayed rcu free inodes are flushed before we
459	 * destroy cache.
460	 */
461	rcu_barrier();
462	kmem_cache_destroy(befs_inode_cachep);
463}
464
465/*
466 * The inode of symbolic link is different to data stream.
467 * The data stream become link name. Unless the LONG_SYMLINK
468 * flag is set.
469 */
470static void *
471befs_follow_link(struct dentry *dentry, struct nameidata *nd)
472{
473	struct super_block *sb = dentry->d_sb;
474	struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
475	befs_data_stream *data = &befs_ino->i_data.ds;
476	befs_off_t len = data->size;
477	char *link;
478
479	if (len == 0) {
480		befs_error(sb, "Long symlink with illegal length");
481		link = ERR_PTR(-EIO);
482	} else {
483		befs_debug(sb, "Follow long symlink");
484
485		link = kmalloc(len, GFP_NOFS);
486		if (!link) {
487			link = ERR_PTR(-ENOMEM);
488		} else if (befs_read_lsymlink(sb, data, link, len) != len) {
489			kfree(link);
490			befs_error(sb, "Failed to read entire long symlink");
491			link = ERR_PTR(-EIO);
492		} else {
493			link[len - 1] = '\0';
494		}
495	}
496	nd_set_link(nd, link);
497	return NULL;
498}
499
500
501static void *
502befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
503{
504	struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
505
506	nd_set_link(nd, befs_ino->i_data.symlink);
507	return NULL;
508}
509
510/*
511 * UTF-8 to NLS charset  convert routine
512 *
513 *
514 * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
515 * the nls tables directly
516 */
517
518static int
519befs_utf2nls(struct super_block *sb, const char *in,
520	     int in_len, char **out, int *out_len)
521{
522	struct nls_table *nls = BEFS_SB(sb)->nls;
523	int i, o;
524	unicode_t uni;
525	int unilen, utflen;
526	char *result;
527	/* The utf8->nls conversion won't make the final nls string bigger
528	 * than the utf one, but if the string is pure ascii they'll have the
529	 * same width and an extra char is needed to save the additional \0
530	 */
531	int maxlen = in_len + 1;
532
533	befs_debug(sb, "---> %s", __func__);
534
535	if (!nls) {
536		befs_error(sb, "%s called with no NLS table loaded", __func__);
537		return -EINVAL;
538	}
539
540	*out = result = kmalloc(maxlen, GFP_NOFS);
541	if (!*out) {
542		befs_error(sb, "%s cannot allocate memory", __func__);
543		*out_len = 0;
544		return -ENOMEM;
545	}
546
547	for (i = o = 0; i < in_len; i += utflen, o += unilen) {
548
549		/* convert from UTF-8 to Unicode */
550		utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
551		if (utflen < 0)
552			goto conv_err;
553
554		/* convert from Unicode to nls */
555		if (uni > MAX_WCHAR_T)
556			goto conv_err;
557		unilen = nls->uni2char(uni, &result[o], in_len - o);
558		if (unilen < 0)
559			goto conv_err;
560	}
561	result[o] = '\0';
562	*out_len = o;
563
564	befs_debug(sb, "<--- %s", __func__);
565
566	return o;
567
568      conv_err:
569	befs_error(sb, "Name using character set %s contains a character that "
570		   "cannot be converted to unicode.", nls->charset);
571	befs_debug(sb, "<--- %s", __func__);
572	kfree(result);
573	return -EILSEQ;
574}
575
576/**
577 * befs_nls2utf - Convert NLS string to utf8 encodeing
578 * @sb: Superblock
579 * @in: Input string buffer in NLS format
580 * @in_len: Length of input string in bytes
581 * @out: The output string in UTF-8 format
582 * @out_len: Length of the output buffer
583 *
584 * Converts input string @in, which is in the format of the loaded NLS map,
585 * into a utf8 string.
586 *
587 * The destination string @out is allocated by this function and the caller is
588 * responsible for freeing it with kfree()
589 *
590 * On return, *@out_len is the length of @out in bytes.
591 *
592 * On success, the return value is the number of utf8 characters written to
593 * the output buffer @out.
594 *
595 * On Failure, a negative number coresponding to the error code is returned.
596 */
597
598static int
599befs_nls2utf(struct super_block *sb, const char *in,
600	     int in_len, char **out, int *out_len)
601{
602	struct nls_table *nls = BEFS_SB(sb)->nls;
603	int i, o;
604	wchar_t uni;
605	int unilen, utflen;
606	char *result;
607	/* There're nls characters that will translate to 3-chars-wide UTF-8
608	 * characters, a additional byte is needed to save the final \0
609	 * in special cases */
610	int maxlen = (3 * in_len) + 1;
611
612	befs_debug(sb, "---> %s\n", __func__);
613
614	if (!nls) {
615		befs_error(sb, "%s called with no NLS table loaded.",
616			   __func__);
617		return -EINVAL;
618	}
619
620	*out = result = kmalloc(maxlen, GFP_NOFS);
621	if (!*out) {
622		befs_error(sb, "%s cannot allocate memory", __func__);
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, "<--- %s", __func__);
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, "<--- %s", __func__);
651	kfree(result);
652	return -EILSEQ;
653}
654
655/**
656 * Use the
657 *
658 */
659enum {
660	Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
661};
662
663static 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
671static int
672parse_options(char *options, struct befs_mount_options *opts)
673{
674	char *p;
675	substring_t args[MAX_OPT_ARGS];
676	int option;
677	kuid_t uid;
678	kgid_t gid;
679
680	/* Initialize options */
681	opts->uid = GLOBAL_ROOT_UID;
682	opts->gid = GLOBAL_ROOT_GID;
683	opts->use_uid = 0;
684	opts->use_gid = 0;
685	opts->iocharset = NULL;
686	opts->debug = 0;
687
688	if (!options)
689		return 1;
690
691	while ((p = strsep(&options, ",")) != NULL) {
692		int token;
693		if (!*p)
694			continue;
695
696		token = match_token(p, befs_tokens, args);
697		switch (token) {
698		case Opt_uid:
699			if (match_int(&args[0], &option))
700				return 0;
701			uid = INVALID_UID;
702			if (option >= 0)
703				uid = make_kuid(current_user_ns(), option);
704			if (!uid_valid(uid)) {
705				pr_err("Invalid uid %d, "
706				       "using default\n", option);
707				break;
708			}
709			opts->uid = uid;
710			opts->use_uid = 1;
711			break;
712		case Opt_gid:
713			if (match_int(&args[0], &option))
714				return 0;
715			gid = INVALID_GID;
716			if (option >= 0)
717				gid = make_kgid(current_user_ns(), option);
718			if (!gid_valid(gid)) {
719				pr_err("Invalid gid %d, "
720				       "using default\n", option);
721				break;
722			}
723			opts->gid = gid;
724			opts->use_gid = 1;
725			break;
726		case Opt_charset:
727			kfree(opts->iocharset);
728			opts->iocharset = match_strdup(&args[0]);
729			if (!opts->iocharset) {
730				pr_err("allocation failure for "
731				       "iocharset string\n");
732				return 0;
733			}
734			break;
735		case Opt_debug:
736			opts->debug = 1;
737			break;
738		default:
739			pr_err("Unrecognized mount option \"%s\" "
740			       "or missing value\n", p);
741			return 0;
742		}
743	}
744	return 1;
745}
746
747/* This function has the responsibiltiy of getting the
748 * filesystem ready for unmounting.
749 * Basically, we free everything that we allocated in
750 * befs_read_inode
751 */
752static void
753befs_put_super(struct super_block *sb)
754{
755	kfree(BEFS_SB(sb)->mount_opts.iocharset);
756	BEFS_SB(sb)->mount_opts.iocharset = NULL;
757	unload_nls(BEFS_SB(sb)->nls);
758	kfree(sb->s_fs_info);
759	sb->s_fs_info = NULL;
760}
761
762/* Allocate private field of the superblock, fill it.
763 *
764 * Finish filling the public superblock fields
765 * Make the root directory
766 * Load a set of NLS translations if needed.
767 */
768static int
769befs_fill_super(struct super_block *sb, void *data, int silent)
770{
771	struct buffer_head *bh;
772	struct befs_sb_info *befs_sb;
773	befs_super_block *disk_sb;
774	struct inode *root;
775	long ret = -EINVAL;
776	const unsigned long sb_block = 0;
777	const off_t x86_sb_off = 512;
778
779	save_mount_options(sb, data);
780
781	sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
782	if (sb->s_fs_info == NULL) {
783		pr_err("(%s): Unable to allocate memory for private "
784		       "portion of superblock. Bailing.\n", sb->s_id);
785		goto unacquire_none;
786	}
787	befs_sb = BEFS_SB(sb);
788
789	if (!parse_options((char *) data, &befs_sb->mount_opts)) {
790		befs_error(sb, "cannot parse mount options");
791		goto unacquire_priv_sbp;
792	}
793
794	befs_debug(sb, "---> %s", __func__);
795
796	if (!(sb->s_flags & MS_RDONLY)) {
797		befs_warning(sb,
798			     "No write support. Marking filesystem read-only");
799		sb->s_flags |= MS_RDONLY;
800	}
801
802	/*
803	 * Set dummy blocksize to read super block.
804	 * Will be set to real fs blocksize later.
805	 *
806	 * Linux 2.4.10 and later refuse to read blocks smaller than
807	 * the hardsect size for the device. But we also need to read at
808	 * least 1k to get the second 512 bytes of the volume.
809	 * -WD 10-26-01
810	 */
811	sb_min_blocksize(sb, 1024);
812
813	if (!(bh = sb_bread(sb, sb_block))) {
814		befs_error(sb, "unable to read superblock");
815		goto unacquire_priv_sbp;
816	}
817
818	/* account for offset of super block on x86 */
819	disk_sb = (befs_super_block *) bh->b_data;
820	if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
821	    (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
822		befs_debug(sb, "Using PPC superblock location");
823	} else {
824		befs_debug(sb, "Using x86 superblock location");
825		disk_sb =
826		    (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
827	}
828
829	if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
830	    (befs_check_sb(sb) != BEFS_OK))
831		goto unacquire_bh;
832
833	befs_dump_super_block(sb, disk_sb);
834
835	brelse(bh);
836
837	if( befs_sb->num_blocks > ~((sector_t)0) ) {
838		befs_error(sb, "blocks count: %llu "
839			"is larger than the host can use",
840			befs_sb->num_blocks);
841		goto unacquire_priv_sbp;
842	}
843
844	/*
845	 * set up enough so that it can read an inode
846	 * Fill in kernel superblock fields from private sb
847	 */
848	sb->s_magic = BEFS_SUPER_MAGIC;
849	/* Set real blocksize of fs */
850	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
851	sb->s_op = &befs_sops;
852	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
853	if (IS_ERR(root)) {
854		ret = PTR_ERR(root);
855		goto unacquire_priv_sbp;
856	}
857	sb->s_root = d_make_root(root);
858	if (!sb->s_root) {
859		befs_error(sb, "get root inode failed");
860		goto unacquire_priv_sbp;
861	}
862
863	/* load nls library */
864	if (befs_sb->mount_opts.iocharset) {
865		befs_debug(sb, "Loading nls: %s",
866			   befs_sb->mount_opts.iocharset);
867		befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
868		if (!befs_sb->nls) {
869			befs_warning(sb, "Cannot load nls %s"
870					" loading default nls",
871					befs_sb->mount_opts.iocharset);
872			befs_sb->nls = load_nls_default();
873		}
874	/* load default nls if none is specified  in mount options */
875	} else {
876		befs_debug(sb, "Loading default nls");
877		befs_sb->nls = load_nls_default();
878	}
879
880	return 0;
881/*****************/
882      unacquire_bh:
883	brelse(bh);
884
885      unacquire_priv_sbp:
886	kfree(befs_sb->mount_opts.iocharset);
887	kfree(sb->s_fs_info);
888
889      unacquire_none:
890	sb->s_fs_info = NULL;
891	return ret;
892}
893
894static int
895befs_remount(struct super_block *sb, int *flags, char *data)
896{
897	sync_filesystem(sb);
898	if (!(*flags & MS_RDONLY))
899		return -EINVAL;
900	return 0;
901}
902
903static int
904befs_statfs(struct dentry *dentry, struct kstatfs *buf)
905{
906	struct super_block *sb = dentry->d_sb;
907	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
908
909	befs_debug(sb, "---> %s", __func__);
910
911	buf->f_type = BEFS_SUPER_MAGIC;
912	buf->f_bsize = sb->s_blocksize;
913	buf->f_blocks = BEFS_SB(sb)->num_blocks;
914	buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
915	buf->f_bavail = buf->f_bfree;
916	buf->f_files = 0;	/* UNKNOWN */
917	buf->f_ffree = 0;	/* UNKNOWN */
918	buf->f_fsid.val[0] = (u32)id;
919	buf->f_fsid.val[1] = (u32)(id >> 32);
920	buf->f_namelen = BEFS_NAME_LEN;
921
922	befs_debug(sb, "<--- %s", __func__);
923
924	return 0;
925}
926
927static struct dentry *
928befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
929	    void *data)
930{
931	return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
932}
933
934static struct file_system_type befs_fs_type = {
935	.owner		= THIS_MODULE,
936	.name		= "befs",
937	.mount		= befs_mount,
938	.kill_sb	= kill_block_super,
939	.fs_flags	= FS_REQUIRES_DEV,
940};
941MODULE_ALIAS_FS("befs");
942
943static int __init
944init_befs_fs(void)
945{
946	int err;
947
948	pr_info("version: %s\n", BEFS_VERSION);
949
950	err = befs_init_inodecache();
951	if (err)
952		goto unacquire_none;
953
954	err = register_filesystem(&befs_fs_type);
955	if (err)
956		goto unacquire_inodecache;
957
958	return 0;
959
960unacquire_inodecache:
961	befs_destroy_inodecache();
962
963unacquire_none:
964	return err;
965}
966
967static void __exit
968exit_befs_fs(void)
969{
970	befs_destroy_inodecache();
971
972	unregister_filesystem(&befs_fs_type);
973}
974
975/*
976Macros that typecheck the init and exit functions,
977ensures that they are called at init and cleanup,
978and eliminates warnings about unused functions.
979*/
980module_init(init_befs_fs)
981module_exit(exit_befs_fs)
982