Root/fs/befs/linuxvfs.c

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
26MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
27MODULE_AUTHOR("Will Dyson");
28MODULE_LICENSE("GPL");
29
30/* The units the vfs expects inode->i_blocks to be in */
31#define VFS_BLOCK_SIZE 512
32
33static int befs_readdir(struct file *, void *, filldir_t);
34static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
35static int befs_readpage(struct file *file, struct page *page);
36static sector_t befs_bmap(struct address_space *mapping, sector_t block);
37static struct dentry *befs_lookup(struct inode *, struct dentry *, struct nameidata *);
38static struct inode *befs_iget(struct super_block *, unsigned long);
39static struct inode *befs_alloc_inode(struct super_block *sb);
40static void befs_destroy_inode(struct inode *inode);
41static int befs_init_inodecache(void);
42static void befs_destroy_inodecache(void);
43static void *befs_follow_link(struct dentry *, struct nameidata *);
44static void befs_put_link(struct dentry *, struct nameidata *, void *);
45static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
46            char **out, int *out_len);
47static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
48            char **out, int *out_len);
49static void befs_put_super(struct super_block *);
50static int befs_remount(struct super_block *, int *, char *);
51static int befs_statfs(struct dentry *, struct kstatfs *);
52static int parse_options(char *, befs_mount_options *);
53
54static const struct super_operations befs_sops = {
55    .alloc_inode = befs_alloc_inode, /* allocate a new inode */
56    .destroy_inode = befs_destroy_inode, /* deallocate an inode */
57    .put_super = befs_put_super, /* uninit super */
58    .statfs = befs_statfs, /* statfs */
59    .remount_fs = befs_remount,
60    .show_options = generic_show_options,
61};
62
63/* slab cache for befs_inode_info objects */
64static struct kmem_cache *befs_inode_cachep;
65
66static const struct file_operations befs_dir_operations = {
67    .read = generic_read_dir,
68    .readdir = befs_readdir,
69    .llseek = generic_file_llseek,
70};
71
72static const struct inode_operations befs_dir_inode_operations = {
73    .lookup = befs_lookup,
74};
75
76static const struct address_space_operations befs_aops = {
77    .readpage = befs_readpage,
78    .sync_page = block_sync_page,
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 = befs_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           inode->i_ino, block);
130
131    if (block < 0) {
132        befs_error(sb, "befs_get_block() was asked for a block "
133               "number less than zero: block %ld in inode %lu",
134               block, inode->i_ino);
135        return -EIO;
136    }
137
138    if (create) {
139        befs_error(sb, "befs_get_block() was asked to write to "
140               "block %ld in inode %lu", block, inode->i_ino);
141        return -EPERM;
142    }
143
144    res = befs_fblock2brun(sb, ds, block, &run);
145    if (res != BEFS_OK) {
146        befs_error(sb,
147               "<--- befs_get_block() for inode %lu, block "
148               "%ld ERROR", inode->i_ino, 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, "<--- befs_get_block() for inode %lu, block %ld, "
157           "disk address %lu", inode->i_ino, block, disk_off);
158
159    return 0;
160}
161
162static struct dentry *
163befs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
164{
165    struct inode *inode = NULL;
166    struct super_block *sb = dir->i_sb;
167    befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
168    befs_off_t offset;
169    int ret;
170    int utfnamelen;
171    char *utfname;
172    const char *name = dentry->d_name.name;
173
174    befs_debug(sb, "---> befs_lookup() "
175           "name %s inode %ld", dentry->d_name.name, dir->i_ino);
176
177    /* Convert to UTF-8 */
178    if (BEFS_SB(sb)->nls) {
179        ret =
180            befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
181        if (ret < 0) {
182            befs_debug(sb, "<--- befs_lookup() ERROR");
183            return ERR_PTR(ret);
184        }
185        ret = befs_btree_find(sb, ds, utfname, &offset);
186        kfree(utfname);
187
188    } else {
189        ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
190    }
191
192    if (ret == BEFS_BT_NOT_FOUND) {
193        befs_debug(sb, "<--- befs_lookup() %s not found",
194               dentry->d_name.name);
195        return ERR_PTR(-ENOENT);
196
197    } else if (ret != BEFS_OK || offset == 0) {
198        befs_warning(sb, "<--- befs_lookup() Error");
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, "<--- befs_lookup()");
209
210    return NULL;
211}
212
213static int
214befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
215{
216    struct inode *inode = filp->f_path.dentry->d_inode;
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    char *nlsname;
225    int nlsnamelen;
226    const char *dirname = filp->f_path.dentry->d_name.name;
227
228    befs_debug(sb, "---> befs_readdir() "
229           "name %s, inode %ld, filp->f_pos %Ld",
230           dirname, inode->i_ino, filp->f_pos);
231
232    result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
233                 keybuf, &keysize, &value);
234
235    if (result == BEFS_ERR) {
236        befs_debug(sb, "<--- befs_readdir() ERROR");
237        befs_error(sb, "IO error reading %s (inode %lu)",
238               dirname, inode->i_ino);
239        return -EIO;
240
241    } else if (result == BEFS_BT_END) {
242        befs_debug(sb, "<--- befs_readdir() END");
243        return 0;
244
245    } else if (result == BEFS_BT_EMPTY) {
246        befs_debug(sb, "<--- befs_readdir() Empty directory");
247        return 0;
248    }
249
250    d_type = DT_UNKNOWN;
251
252    /* Convert to NLS */
253    if (BEFS_SB(sb)->nls) {
254        result =
255            befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
256        if (result < 0) {
257            befs_debug(sb, "<--- befs_readdir() ERROR");
258            return result;
259        }
260        result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
261                 (ino_t) value, d_type);
262        kfree(nlsname);
263
264    } else {
265        result = filldir(dirent, keybuf, keysize, filp->f_pos,
266                 (ino_t) value, d_type);
267    }
268
269    filp->f_pos++;
270
271    befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
272
273    return 0;
274}
275
276static struct inode *
277befs_alloc_inode(struct super_block *sb)
278{
279        struct befs_inode_info *bi;
280        bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
281                            GFP_KERNEL);
282        if (!bi)
283                return NULL;
284        return &bi->vfs_inode;
285}
286
287static void
288befs_destroy_inode(struct inode *inode)
289{
290        kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
291}
292
293static void init_once(void *foo)
294{
295        struct befs_inode_info *bi = (struct befs_inode_info *) foo;
296
297    inode_init_once(&bi->vfs_inode);
298}
299
300static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
301{
302    struct buffer_head *bh = NULL;
303    befs_inode *raw_inode = NULL;
304
305    befs_sb_info *befs_sb = BEFS_SB(sb);
306    befs_inode_info *befs_ino = NULL;
307    struct inode *inode;
308    long ret = -EIO;
309
310    befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
311
312    inode = iget_locked(sb, ino);
313    if (IS_ERR(inode))
314        return inode;
315    if (!(inode->i_state & I_NEW))
316        return inode;
317
318    befs_ino = BEFS_I(inode);
319
320    /* convert from vfs's inode number to befs's inode number */
321    befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
322
323    befs_debug(sb, " real inode number [%u, %hu, %hu]",
324           befs_ino->i_inode_num.allocation_group,
325           befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
326
327    bh = befs_bread(sb, inode->i_ino);
328    if (!bh) {
329        befs_error(sb, "unable to read inode block - "
330               "inode = %lu", inode->i_ino);
331        goto unacquire_none;
332    }
333
334    raw_inode = (befs_inode *) bh->b_data;
335
336    befs_dump_inode(sb, raw_inode);
337
338    if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
339        befs_error(sb, "Bad inode: %lu", inode->i_ino);
340        goto unacquire_bh;
341    }
342
343    inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
344
345    /*
346     * set uid and gid. But since current BeOS is single user OS, so
347     * you can change by "uid" or "gid" options.
348     */
349
350    inode->i_uid = befs_sb->mount_opts.use_uid ?
351        befs_sb->mount_opts.uid : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
352    inode->i_gid = befs_sb->mount_opts.use_gid ?
353        befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
354
355    inode->i_nlink = 1;
356
357    /*
358     * BEFS's time is 64 bits, but current VFS is 32 bits...
359     * BEFS don't have access time. Nor inode change time. VFS
360     * doesn't have creation time.
361     * Also, the lower 16 bits of the last_modified_time and
362     * create_time are just a counter to help ensure uniqueness
363     * for indexing purposes. (PFD, page 54)
364     */
365
366    inode->i_mtime.tv_sec =
367        fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
368    inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
369    inode->i_ctime = inode->i_mtime;
370    inode->i_atime = inode->i_mtime;
371
372    befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
373    befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
374    befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
375    befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
376
377    if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
378        inode->i_size = 0;
379        inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
380        strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
381            BEFS_SYMLINK_LEN - 1);
382        befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
383    } else {
384        int num_blks;
385
386        befs_ino->i_data.ds =
387            fsds_to_cpu(sb, raw_inode->data.datastream);
388
389        num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
390        inode->i_blocks =
391            num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
392        inode->i_size = befs_ino->i_data.ds.size;
393    }
394
395    inode->i_mapping->a_ops = &befs_aops;
396
397    if (S_ISREG(inode->i_mode)) {
398        inode->i_fop = &generic_ro_fops;
399    } else if (S_ISDIR(inode->i_mode)) {
400        inode->i_op = &befs_dir_inode_operations;
401        inode->i_fop = &befs_dir_operations;
402    } else if (S_ISLNK(inode->i_mode)) {
403        inode->i_op = &befs_symlink_inode_operations;
404    } else {
405        befs_error(sb, "Inode %lu is not a regular file, "
406               "directory or symlink. THAT IS WRONG! BeFS has no "
407               "on disk special files", inode->i_ino);
408        goto unacquire_bh;
409    }
410
411    brelse(bh);
412    befs_debug(sb, "<--- befs_read_inode()");
413    unlock_new_inode(inode);
414    return inode;
415
416      unacquire_bh:
417    brelse(bh);
418
419      unacquire_none:
420    iget_failed(inode);
421    befs_debug(sb, "<--- befs_read_inode() - Bad inode");
422    return ERR_PTR(ret);
423}
424
425/* Initialize the inode cache. Called at fs setup.
426 *
427 * Taken from NFS implementation by Al Viro.
428 */
429static int
430befs_init_inodecache(void)
431{
432    befs_inode_cachep = kmem_cache_create("befs_inode_cache",
433                          sizeof (struct befs_inode_info),
434                          0, (SLAB_RECLAIM_ACCOUNT|
435                        SLAB_MEM_SPREAD),
436                          init_once);
437    if (befs_inode_cachep == NULL) {
438        printk(KERN_ERR "befs_init_inodecache: "
439               "Couldn't initalize inode slabcache\n");
440        return -ENOMEM;
441    }
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    kmem_cache_destroy(befs_inode_cachep);
454}
455
456/*
457 * The inode of symbolic link is different to data stream.
458 * The data stream become link name. Unless the LONG_SYMLINK
459 * flag is set.
460 */
461static void *
462befs_follow_link(struct dentry *dentry, struct nameidata *nd)
463{
464    befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
465    char *link;
466
467    if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
468        struct super_block *sb = dentry->d_sb;
469        befs_data_stream *data = &befs_ino->i_data.ds;
470        befs_off_t len = data->size;
471
472        befs_debug(sb, "Follow long symlink");
473
474        link = kmalloc(len, GFP_NOFS);
475        if (!link) {
476            link = ERR_PTR(-ENOMEM);
477        } else if (befs_read_lsymlink(sb, data, link, len) != len) {
478            kfree(link);
479            befs_error(sb, "Failed to read entire long symlink");
480            link = ERR_PTR(-EIO);
481        } else {
482            link[len - 1] = '\0';
483        }
484    } else {
485        link = befs_ino->i_data.symlink;
486    }
487
488    nd_set_link(nd, link);
489    return NULL;
490}
491
492static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
493{
494    befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
495    if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
496        char *link = nd_get_link(nd);
497        if (!IS_ERR(link))
498            kfree(link);
499    }
500}
501
502/*
503 * UTF-8 to NLS charset convert routine
504 *
505 *
506 * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
507 * the nls tables directly
508 */
509
510static int
511befs_utf2nls(struct super_block *sb, const char *in,
512         int in_len, char **out, int *out_len)
513{
514    struct nls_table *nls = BEFS_SB(sb)->nls;
515    int i, o;
516    unicode_t uni;
517    int unilen, utflen;
518    char *result;
519    /* The utf8->nls conversion won't make the final nls string bigger
520     * than the utf one, but if the string is pure ascii they'll have the
521     * same width and an extra char is needed to save the additional \0
522     */
523    int maxlen = in_len + 1;
524
525    befs_debug(sb, "---> utf2nls()");
526
527    if (!nls) {
528        befs_error(sb, "befs_utf2nls called with no NLS table loaded");
529        return -EINVAL;
530    }
531
532    *out = result = kmalloc(maxlen, GFP_NOFS);
533    if (!*out) {
534        befs_error(sb, "befs_utf2nls() cannot allocate memory");
535        *out_len = 0;
536        return -ENOMEM;
537    }
538
539    for (i = o = 0; i < in_len; i += utflen, o += unilen) {
540
541        /* convert from UTF-8 to Unicode */
542        utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
543        if (utflen < 0)
544            goto conv_err;
545
546        /* convert from Unicode to nls */
547        if (uni > MAX_WCHAR_T)
548            goto conv_err;
549        unilen = nls->uni2char(uni, &result[o], in_len - o);
550        if (unilen < 0)
551            goto conv_err;
552    }
553    result[o] = '\0';
554    *out_len = o;
555
556    befs_debug(sb, "<--- utf2nls()");
557
558    return o;
559
560      conv_err:
561    befs_error(sb, "Name using character set %s contains a character that "
562           "cannot be converted to unicode.", nls->charset);
563    befs_debug(sb, "<--- utf2nls()");
564    kfree(result);
565    return -EILSEQ;
566}
567
568/**
569 * befs_nls2utf - Convert NLS string to utf8 encodeing
570 * @sb: Superblock
571 * @src: Input string buffer in NLS format
572 * @srclen: Length of input string in bytes
573 * @dest: The output string in UTF-8 format
574 * @destlen: Length of the output buffer
575 *
576 * Converts input string @src, which is in the format of the loaded NLS map,
577 * into a utf8 string.
578 *
579 * The destination string @dest is allocated by this function and the caller is
580 * responsible for freeing it with kfree()
581 *
582 * On return, *@destlen is the length of @dest in bytes.
583 *
584 * On success, the return value is the number of utf8 characters written to
585 * the output buffer @dest.
586 *
587 * On Failure, a negative number coresponding to the error code is returned.
588 */
589
590static int
591befs_nls2utf(struct super_block *sb, const char *in,
592         int in_len, char **out, int *out_len)
593{
594    struct nls_table *nls = BEFS_SB(sb)->nls;
595    int i, o;
596    wchar_t uni;
597    int unilen, utflen;
598    char *result;
599    /* There're nls characters that will translate to 3-chars-wide UTF-8
600     * characters, a additional byte is needed to save the final \0
601     * in special cases */
602    int maxlen = (3 * in_len) + 1;
603
604    befs_debug(sb, "---> nls2utf()\n");
605
606    if (!nls) {
607        befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
608        return -EINVAL;
609    }
610
611    *out = result = kmalloc(maxlen, GFP_NOFS);
612    if (!*out) {
613        befs_error(sb, "befs_nls2utf() cannot allocate memory");
614        *out_len = 0;
615        return -ENOMEM;
616    }
617
618    for (i = o = 0; i < in_len; i += unilen, o += utflen) {
619
620        /* convert from nls to unicode */
621        unilen = nls->char2uni(&in[i], in_len - i, &uni);
622        if (unilen < 0)
623            goto conv_err;
624
625        /* convert from unicode to UTF-8 */
626        utflen = utf32_to_utf8(uni, &result[o], 3);
627        if (utflen <= 0)
628            goto conv_err;
629    }
630
631    result[o] = '\0';
632    *out_len = o;
633
634    befs_debug(sb, "<--- nls2utf()");
635
636    return i;
637
638      conv_err:
639    befs_error(sb, "Name using charecter set %s contains a charecter that "
640           "cannot be converted to unicode.", nls->charset);
641    befs_debug(sb, "<--- nls2utf()");
642    kfree(result);
643    return -EILSEQ;
644}
645
646/**
647 * Use the
648 *
649 */
650enum {
651    Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
652};
653
654static const match_table_t befs_tokens = {
655    {Opt_uid, "uid=%d"},
656    {Opt_gid, "gid=%d"},
657    {Opt_charset, "iocharset=%s"},
658    {Opt_debug, "debug"},
659    {Opt_err, NULL}
660};
661
662static int
663parse_options(char *options, befs_mount_options * opts)
664{
665    char *p;
666    substring_t args[MAX_OPT_ARGS];
667    int option;
668
669    /* Initialize options */
670    opts->uid = 0;
671    opts->gid = 0;
672    opts->use_uid = 0;
673    opts->use_gid = 0;
674    opts->iocharset = NULL;
675    opts->debug = 0;
676
677    if (!options)
678        return 1;
679
680    while ((p = strsep(&options, ",")) != NULL) {
681        int token;
682        if (!*p)
683            continue;
684
685        token = match_token(p, befs_tokens, args);
686        switch (token) {
687        case Opt_uid:
688            if (match_int(&args[0], &option))
689                return 0;
690            if (option < 0) {
691                printk(KERN_ERR "BeFS: Invalid uid %d, "
692                        "using default\n", option);
693                break;
694            }
695            opts->uid = option;
696            opts->use_uid = 1;
697            break;
698        case Opt_gid:
699            if (match_int(&args[0], &option))
700                return 0;
701            if (option < 0) {
702                printk(KERN_ERR "BeFS: Invalid gid %d, "
703                        "using default\n", option);
704                break;
705            }
706            opts->gid = option;
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                printk(KERN_ERR "BeFS: 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            printk(KERN_ERR "BeFS: 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 * Basicly, 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    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 = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
765    if (sb->s_fs_info == NULL) {
766        printk(KERN_ERR
767               "BeFS(%s): Unable to allocate memory for private "
768               "portion of superblock. Bailing.\n", sb->s_id);
769        goto unacquire_none;
770    }
771    befs_sb = BEFS_SB(sb);
772    memset(befs_sb, 0, sizeof(befs_sb_info));
773
774    if (!parse_options((char *) data, &befs_sb->mount_opts)) {
775        befs_error(sb, "cannot parse mount options");
776        goto unacquire_priv_sbp;
777    }
778
779    befs_debug(sb, "---> befs_fill_super()");
780
781#ifndef CONFIG_BEFS_RW
782    if (!(sb->s_flags & MS_RDONLY)) {
783        befs_warning(sb,
784                 "No write support. Marking filesystem read-only");
785        sb->s_flags |= MS_RDONLY;
786    }
787#endif /* CONFIG_BEFS_RW */
788
789    /*
790     * Set dummy blocksize to read super block.
791     * Will be set to real fs blocksize later.
792     *
793     * Linux 2.4.10 and later refuse to read blocks smaller than
794     * the hardsect size for the device. But we also need to read at
795     * least 1k to get the second 512 bytes of the volume.
796     * -WD 10-26-01
797     */
798    sb_min_blocksize(sb, 1024);
799
800    if (!(bh = sb_bread(sb, sb_block))) {
801        befs_error(sb, "unable to read superblock");
802        goto unacquire_priv_sbp;
803    }
804
805    /* account for offset of super block on x86 */
806    disk_sb = (befs_super_block *) bh->b_data;
807    if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
808        (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
809        befs_debug(sb, "Using PPC superblock location");
810    } else {
811        befs_debug(sb, "Using x86 superblock location");
812        disk_sb =
813            (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
814    }
815
816    if (befs_load_sb(sb, disk_sb) != BEFS_OK)
817        goto unacquire_bh;
818
819    befs_dump_super_block(sb, disk_sb);
820
821    brelse(bh);
822
823    if (befs_check_sb(sb) != BEFS_OK)
824        goto unacquire_priv_sbp;
825
826    if( befs_sb->num_blocks > ~((sector_t)0) ) {
827        befs_error(sb, "blocks count: %Lu "
828            "is larger than the host can use",
829            befs_sb->num_blocks);
830        goto unacquire_priv_sbp;
831    }
832
833    /*
834     * set up enough so that it can read an inode
835     * Fill in kernel superblock fields from private sb
836     */
837    sb->s_magic = BEFS_SUPER_MAGIC;
838    /* Set real blocksize of fs */
839    sb_set_blocksize(sb, (ulong) befs_sb->block_size);
840    sb->s_op = &befs_sops;
841    root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
842    if (IS_ERR(root)) {
843        ret = PTR_ERR(root);
844        goto unacquire_priv_sbp;
845    }
846    sb->s_root = d_alloc_root(root);
847    if (!sb->s_root) {
848        iput(root);
849        befs_error(sb, "get root inode failed");
850        goto unacquire_priv_sbp;
851    }
852
853    /* load nls library */
854    if (befs_sb->mount_opts.iocharset) {
855        befs_debug(sb, "Loading nls: %s",
856               befs_sb->mount_opts.iocharset);
857        befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
858        if (!befs_sb->nls) {
859            befs_warning(sb, "Cannot load nls %s"
860                    " loading default nls",
861                    befs_sb->mount_opts.iocharset);
862            befs_sb->nls = load_nls_default();
863        }
864    /* load default nls if none is specified in mount options */
865    } else {
866        befs_debug(sb, "Loading default nls");
867        befs_sb->nls = load_nls_default();
868    }
869
870    return 0;
871/*****************/
872      unacquire_bh:
873    brelse(bh);
874
875      unacquire_priv_sbp:
876    kfree(befs_sb->mount_opts.iocharset);
877    kfree(sb->s_fs_info);
878
879      unacquire_none:
880    sb->s_fs_info = NULL;
881    return ret;
882}
883
884static int
885befs_remount(struct super_block *sb, int *flags, char *data)
886{
887    if (!(*flags & MS_RDONLY))
888        return -EINVAL;
889    return 0;
890}
891
892static int
893befs_statfs(struct dentry *dentry, struct kstatfs *buf)
894{
895    struct super_block *sb = dentry->d_sb;
896    u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
897
898    befs_debug(sb, "---> befs_statfs()");
899
900    buf->f_type = BEFS_SUPER_MAGIC;
901    buf->f_bsize = sb->s_blocksize;
902    buf->f_blocks = BEFS_SB(sb)->num_blocks;
903    buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
904    buf->f_bavail = buf->f_bfree;
905    buf->f_files = 0; /* UNKNOWN */
906    buf->f_ffree = 0; /* UNKNOWN */
907    buf->f_fsid.val[0] = (u32)id;
908    buf->f_fsid.val[1] = (u32)(id >> 32);
909    buf->f_namelen = BEFS_NAME_LEN;
910
911    befs_debug(sb, "<--- befs_statfs()");
912
913    return 0;
914}
915
916static int
917befs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name,
918        void *data, struct vfsmount *mnt)
919{
920    return get_sb_bdev(fs_type, flags, dev_name, data, befs_fill_super,
921               mnt);
922}
923
924static struct file_system_type befs_fs_type = {
925    .owner = THIS_MODULE,
926    .name = "befs",
927    .get_sb = befs_get_sb,
928    .kill_sb = kill_block_super,
929    .fs_flags = FS_REQUIRES_DEV,
930};
931
932static int __init
933init_befs_fs(void)
934{
935    int err;
936
937    printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
938
939    err = befs_init_inodecache();
940    if (err)
941        goto unacquire_none;
942
943    err = register_filesystem(&befs_fs_type);
944    if (err)
945        goto unacquire_inodecache;
946
947    return 0;
948
949unacquire_inodecache:
950    befs_destroy_inodecache();
951
952unacquire_none:
953    return err;
954}
955
956static void __exit
957exit_befs_fs(void)
958{
959    befs_destroy_inodecache();
960
961    unregister_filesystem(&befs_fs_type);
962}
963
964/*
965Macros that typecheck the init and exit functions,
966ensures that they are called at init and cleanup,
967and eliminates warnings about unused functions.
968*/
969module_init(init_befs_fs)
970module_exit(exit_befs_fs)
971

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