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