Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/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 #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 
 29 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
 30 MODULE_AUTHOR("Will Dyson");
 31 MODULE_LICENSE("GPL");
 32 
 33 /* The units the vfs expects inode->i_blocks to be in */
 34 #define VFS_BLOCK_SIZE 512
 35 
 36 static int befs_readdir(struct file *, struct dir_context *);
 37 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 38 static int befs_readpage(struct file *file, struct page *page);
 39 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 40 static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
 41 static struct inode *befs_iget(struct super_block *, unsigned long);
 42 static struct inode *befs_alloc_inode(struct super_block *sb);
 43 static void befs_destroy_inode(struct inode *inode);
 44 static void befs_destroy_inodecache(void);
 45 static void *befs_follow_link(struct dentry *, struct nameidata *);
 46 static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
 47 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
 48                         char **out, int *out_len);
 49 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
 50                         char **out, int *out_len);
 51 static void befs_put_super(struct super_block *);
 52 static int befs_remount(struct super_block *, int *, char *);
 53 static int befs_statfs(struct dentry *, struct kstatfs *);
 54 static int parse_options(char *, befs_mount_options *);
 55 
 56 static 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 */
 66 static struct kmem_cache *befs_inode_cachep;
 67 
 68 static const struct file_operations befs_dir_operations = {
 69         .read           = generic_read_dir,
 70         .iterate        = befs_readdir,
 71         .llseek         = generic_file_llseek,
 72 };
 73 
 74 static const struct inode_operations befs_dir_inode_operations = {
 75         .lookup         = befs_lookup,
 76 };
 77 
 78 static const struct address_space_operations befs_aops = {
 79         .readpage       = befs_readpage,
 80         .bmap           = befs_bmap,
 81 };
 82 
 83 static const struct inode_operations befs_fast_symlink_inode_operations = {
 84         .readlink       = generic_readlink,
 85         .follow_link    = befs_fast_follow_link,
 86 };
 87 
 88 static 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  */
101 static int
102 befs_readpage(struct file *file, struct page *page)
103 {
104         return block_read_full_page(page, befs_get_block);
105 }
106 
107 static sector_t
108 befs_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 
124 static int
125 befs_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 
137         if (block < 0) {
138                 befs_error(sb, "befs_get_block() was asked for a block "
139                            "number less than zero: block %ld in inode %lu",
140                            (long)block, (unsigned long)inode->i_ino);
141                 return -EIO;
142         }
143 
144         if (create) {
145                 befs_error(sb, "befs_get_block() was asked to write to "
146                            "block %ld in inode %lu", (long)block,
147                            (unsigned long)inode->i_ino);
148                 return -EPERM;
149         }
150 
151         res = befs_fblock2brun(sb, ds, block, &run);
152         if (res != BEFS_OK) {
153                 befs_error(sb,
154                            "<--- %s for inode %lu, block %ld ERROR",
155                            __func__, (unsigned long)inode->i_ino,
156                            (long)block);
157                 return -EFBIG;
158         }
159 
160         disk_off = (ulong) iaddr2blockno(sb, &run);
161 
162         map_bh(bh_result, inode->i_sb, disk_off);
163 
164         befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
165                   __func__, (unsigned long)inode->i_ino, (long)block,
166                   (unsigned long)disk_off);
167 
168         return 0;
169 }
170 
171 static struct dentry *
172 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
173 {
174         struct inode *inode = NULL;
175         struct super_block *sb = dir->i_sb;
176         befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
177         befs_off_t offset;
178         int ret;
179         int utfnamelen;
180         char *utfname;
181         const char *name = dentry->d_name.name;
182 
183         befs_debug(sb, "---> %s name %s inode %ld", __func__,
184                    dentry->d_name.name, dir->i_ino);
185 
186         /* Convert to UTF-8 */
187         if (BEFS_SB(sb)->nls) {
188                 ret =
189                     befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
190                 if (ret < 0) {
191                         befs_debug(sb, "<--- %s ERROR", __func__);
192                         return ERR_PTR(ret);
193                 }
194                 ret = befs_btree_find(sb, ds, utfname, &offset);
195                 kfree(utfname);
196 
197         } else {
198                 ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
199         }
200 
201         if (ret == BEFS_BT_NOT_FOUND) {
202                 befs_debug(sb, "<--- %s %s not found", __func__,
203                            dentry->d_name.name);
204                 return ERR_PTR(-ENOENT);
205 
206         } else if (ret != BEFS_OK || offset == 0) {
207                 befs_warning(sb, "<--- %s Error", __func__);
208                 return ERR_PTR(-ENODATA);
209         }
210 
211         inode = befs_iget(dir->i_sb, (ino_t) offset);
212         if (IS_ERR(inode))
213                 return ERR_CAST(inode);
214 
215         d_add(dentry, inode);
216 
217         befs_debug(sb, "<--- %s", __func__);
218 
219         return NULL;
220 }
221 
222 static int
223 befs_readdir(struct file *file, struct dir_context *ctx)
224 {
225         struct inode *inode = file_inode(file);
226         struct super_block *sb = inode->i_sb;
227         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
228         befs_off_t value;
229         int result;
230         size_t keysize;
231         unsigned char d_type;
232         char keybuf[BEFS_NAME_LEN + 1];
233         const char *dirname = file->f_path.dentry->d_name.name;
234 
235         befs_debug(sb, "---> %s name %s, inode %ld, ctx->pos %lld",
236                   __func__, dirname, inode->i_ino, ctx->pos);
237 
238 more:
239         result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
240                                  keybuf, &keysize, &value);
241 
242         if (result == BEFS_ERR) {
243                 befs_debug(sb, "<--- %s ERROR", __func__);
244                 befs_error(sb, "IO error reading %s (inode %lu)",
245                            dirname, inode->i_ino);
246                 return -EIO;
247 
248         } else if (result == BEFS_BT_END) {
249                 befs_debug(sb, "<--- %s END", __func__);
250                 return 0;
251 
252         } else if (result == BEFS_BT_EMPTY) {
253                 befs_debug(sb, "<--- %s Empty directory", __func__);
254                 return 0;
255         }
256 
257         d_type = DT_UNKNOWN;
258 
259         /* Convert to NLS */
260         if (BEFS_SB(sb)->nls) {
261                 char *nlsname;
262                 int nlsnamelen;
263                 result =
264                     befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
265                 if (result < 0) {
266                         befs_debug(sb, "<--- %s ERROR", __func__);
267                         return result;
268                 }
269                 if (!dir_emit(ctx, nlsname, nlsnamelen,
270                                  (ino_t) value, d_type)) {
271                         kfree(nlsname);
272                         return 0;
273                 }
274                 kfree(nlsname);
275         } else {
276                 if (!dir_emit(ctx, keybuf, keysize,
277                                  (ino_t) value, d_type))
278                         return 0;
279         }
280         ctx->pos++;
281         goto more;
282 
283         befs_debug(sb, "<--- %s pos %lld", __func__, ctx->pos);
284 
285         return 0;
286 }
287 
288 static struct inode *
289 befs_alloc_inode(struct super_block *sb)
290 {
291         struct befs_inode_info *bi;
292         bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
293                                                         GFP_KERNEL);
294         if (!bi)
295                 return NULL;
296         return &bi->vfs_inode;
297 }
298 
299 static void befs_i_callback(struct rcu_head *head)
300 {
301         struct inode *inode = container_of(head, struct inode, i_rcu);
302         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
303 }
304 
305 static void befs_destroy_inode(struct inode *inode)
306 {
307         call_rcu(&inode->i_rcu, befs_i_callback);
308 }
309 
310 static void init_once(void *foo)
311 {
312         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
313 
314         inode_init_once(&bi->vfs_inode);
315 }
316 
317 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
318 {
319         struct buffer_head *bh = NULL;
320         befs_inode *raw_inode = NULL;
321 
322         befs_sb_info *befs_sb = BEFS_SB(sb);
323         befs_inode_info *befs_ino = NULL;
324         struct inode *inode;
325         long ret = -EIO;
326 
327         befs_debug(sb, "---> %s inode = %lu", __func__, ino);
328 
329         inode = iget_locked(sb, ino);
330         if (!inode)
331                 return ERR_PTR(-ENOMEM);
332         if (!(inode->i_state & I_NEW))
333                 return inode;
334 
335         befs_ino = BEFS_I(inode);
336 
337         /* convert from vfs's inode number to befs's inode number */
338         befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
339 
340         befs_debug(sb, "  real inode number [%u, %hu, %hu]",
341                    befs_ino->i_inode_num.allocation_group,
342                    befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
343 
344         bh = befs_bread(sb, inode->i_ino);
345         if (!bh) {
346                 befs_error(sb, "unable to read inode block - "
347                            "inode = %lu", inode->i_ino);
348                 goto unacquire_none;
349         }
350 
351         raw_inode = (befs_inode *) bh->b_data;
352 
353         befs_dump_inode(sb, raw_inode);
354 
355         if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
356                 befs_error(sb, "Bad inode: %lu", inode->i_ino);
357                 goto unacquire_bh;
358         }
359 
360         inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
361 
362         /*
363          * set uid and gid.  But since current BeOS is single user OS, so
364          * you can change by "uid" or "gid" options.
365          */   
366 
367         inode->i_uid = befs_sb->mount_opts.use_uid ?
368                 befs_sb->mount_opts.uid :
369                 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
370         inode->i_gid = befs_sb->mount_opts.use_gid ?
371                 befs_sb->mount_opts.gid :
372                 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
373 
374         set_nlink(inode, 1);
375 
376         /*
377          * BEFS's time is 64 bits, but current VFS is 32 bits...
378          * BEFS don't have access time. Nor inode change time. VFS
379          * doesn't have creation time.
380          * Also, the lower 16 bits of the last_modified_time and 
381          * create_time are just a counter to help ensure uniqueness
382          * for indexing purposes. (PFD, page 54)
383          */
384 
385         inode->i_mtime.tv_sec =
386             fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
387         inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */        
388         inode->i_ctime = inode->i_mtime;
389         inode->i_atime = inode->i_mtime;
390 
391         befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
392         befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
393         befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
394         befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
395 
396         if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
397                 inode->i_size = 0;
398                 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
399                 strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
400                         BEFS_SYMLINK_LEN - 1);
401                 befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
402         } else {
403                 int num_blks;
404 
405                 befs_ino->i_data.ds =
406                     fsds_to_cpu(sb, &raw_inode->data.datastream);
407 
408                 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
409                 inode->i_blocks =
410                     num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
411                 inode->i_size = befs_ino->i_data.ds.size;
412         }
413 
414         inode->i_mapping->a_ops = &befs_aops;
415 
416         if (S_ISREG(inode->i_mode)) {
417                 inode->i_fop = &generic_ro_fops;
418         } else if (S_ISDIR(inode->i_mode)) {
419                 inode->i_op = &befs_dir_inode_operations;
420                 inode->i_fop = &befs_dir_operations;
421         } else if (S_ISLNK(inode->i_mode)) {
422                 if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
423                         inode->i_op = &befs_symlink_inode_operations;
424                 else
425                         inode->i_op = &befs_fast_symlink_inode_operations;
426         } else {
427                 befs_error(sb, "Inode %lu is not a regular file, "
428                            "directory or symlink. THAT IS WRONG! BeFS has no "
429                            "on disk special files", inode->i_ino);
430                 goto unacquire_bh;
431         }
432 
433         brelse(bh);
434         befs_debug(sb, "<--- %s", __func__);
435         unlock_new_inode(inode);
436         return inode;
437 
438       unacquire_bh:
439         brelse(bh);
440 
441       unacquire_none:
442         iget_failed(inode);
443         befs_debug(sb, "<--- %s - Bad inode", __func__);
444         return ERR_PTR(ret);
445 }
446 
447 /* Initialize the inode cache. Called at fs setup.
448  *
449  * Taken from NFS implementation by Al Viro.
450  */
451 static int __init
452 befs_init_inodecache(void)
453 {
454         befs_inode_cachep = kmem_cache_create("befs_inode_cache",
455                                               sizeof (struct befs_inode_info),
456                                               0, (SLAB_RECLAIM_ACCOUNT|
457                                                 SLAB_MEM_SPREAD),
458                                               init_once);
459         if (befs_inode_cachep == NULL) {
460                 pr_err("%s: Couldn't initialize inode slabcache\n", __func__);
461                 return -ENOMEM;
462         }
463         return 0;
464 }
465 
466 /* Called at fs teardown.
467  * 
468  * Taken from NFS implementation by Al Viro.
469  */
470 static void
471 befs_destroy_inodecache(void)
472 {
473         /*
474          * Make sure all delayed rcu free inodes are flushed before we
475          * destroy cache.
476          */
477         rcu_barrier();
478         kmem_cache_destroy(befs_inode_cachep);
479 }
480 
481 /*
482  * The inode of symbolic link is different to data stream.
483  * The data stream become link name. Unless the LONG_SYMLINK
484  * flag is set.
485  */
486 static void *
487 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
488 {
489         struct super_block *sb = dentry->d_sb;
490         befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
491         befs_data_stream *data = &befs_ino->i_data.ds;
492         befs_off_t len = data->size;
493         char *link;
494 
495         if (len == 0) {
496                 befs_error(sb, "Long symlink with illegal length");
497                 link = ERR_PTR(-EIO);
498         } else {
499                 befs_debug(sb, "Follow long symlink");
500 
501                 link = kmalloc(len, GFP_NOFS);
502                 if (!link) {
503                         link = ERR_PTR(-ENOMEM);
504                 } else if (befs_read_lsymlink(sb, data, link, len) != len) {
505                         kfree(link);
506                         befs_error(sb, "Failed to read entire long symlink");
507                         link = ERR_PTR(-EIO);
508                 } else {
509                         link[len - 1] = '\0';
510                 }
511         }
512         nd_set_link(nd, link);
513         return NULL;
514 }
515 
516 
517 static void *
518 befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
519 {
520         befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
521         nd_set_link(nd, befs_ino->i_data.symlink);
522         return NULL;
523 }
524 
525 /*
526  * UTF-8 to NLS charset  convert routine
527  * 
528  *
529  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
530  * the nls tables directly
531  */
532 
533 static int
534 befs_utf2nls(struct super_block *sb, const char *in,
535              int in_len, char **out, int *out_len)
536 {
537         struct nls_table *nls = BEFS_SB(sb)->nls;
538         int i, o;
539         unicode_t uni;
540         int unilen, utflen;
541         char *result;
542         /* The utf8->nls conversion won't make the final nls string bigger
543          * than the utf one, but if the string is pure ascii they'll have the
544          * same width and an extra char is needed to save the additional \0
545          */
546         int maxlen = in_len + 1;
547 
548         befs_debug(sb, "---> %s", __func__);
549 
550         if (!nls) {
551                 befs_error(sb, "%s called with no NLS table loaded", __func__);
552                 return -EINVAL;
553         }
554 
555         *out = result = kmalloc(maxlen, GFP_NOFS);
556         if (!*out) {
557                 befs_error(sb, "%s cannot allocate memory", __func__);
558                 *out_len = 0;
559                 return -ENOMEM;
560         }
561 
562         for (i = o = 0; i < in_len; i += utflen, o += unilen) {
563 
564                 /* convert from UTF-8 to Unicode */
565                 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
566                 if (utflen < 0)
567                         goto conv_err;
568 
569                 /* convert from Unicode to nls */
570                 if (uni > MAX_WCHAR_T)
571                         goto conv_err;
572                 unilen = nls->uni2char(uni, &result[o], in_len - o);
573                 if (unilen < 0)
574                         goto conv_err;
575         }
576         result[o] = '\0';
577         *out_len = o;
578 
579         befs_debug(sb, "<--- %s", __func__);
580 
581         return o;
582 
583       conv_err:
584         befs_error(sb, "Name using character set %s contains a character that "
585                    "cannot be converted to unicode.", nls->charset);
586         befs_debug(sb, "<--- %s", __func__);
587         kfree(result);
588         return -EILSEQ;
589 }
590 
591 /**
592  * befs_nls2utf - Convert NLS string to utf8 encodeing
593  * @sb: Superblock
594  * @src: Input string buffer in NLS format
595  * @srclen: Length of input string in bytes
596  * @dest: The output string in UTF-8 format
597  * @destlen: Length of the output buffer
598  * 
599  * Converts input string @src, which is in the format of the loaded NLS map,
600  * into a utf8 string.
601  * 
602  * The destination string @dest is allocated by this function and the caller is
603  * responsible for freeing it with kfree()
604  * 
605  * On return, *@destlen is the length of @dest in bytes.
606  *
607  * On success, the return value is the number of utf8 characters written to
608  * the output buffer @dest.
609  *  
610  * On Failure, a negative number coresponding to the error code is returned.
611  */
612 
613 static int
614 befs_nls2utf(struct super_block *sb, const char *in,
615              int in_len, char **out, int *out_len)
616 {
617         struct nls_table *nls = BEFS_SB(sb)->nls;
618         int i, o;
619         wchar_t uni;
620         int unilen, utflen;
621         char *result;
622         /* There're nls characters that will translate to 3-chars-wide UTF-8
623          * characters, a additional byte is needed to save the final \0
624          * in special cases */
625         int maxlen = (3 * in_len) + 1;
626 
627         befs_debug(sb, "---> %s\n", __func__);
628 
629         if (!nls) {
630                 befs_error(sb, "%s called with no NLS table loaded.",
631                            __func__);
632                 return -EINVAL;
633         }
634 
635         *out = result = kmalloc(maxlen, GFP_NOFS);
636         if (!*out) {
637                 befs_error(sb, "%s cannot allocate memory", __func__);
638                 *out_len = 0;
639                 return -ENOMEM;
640         }
641 
642         for (i = o = 0; i < in_len; i += unilen, o += utflen) {
643 
644                 /* convert from nls to unicode */
645                 unilen = nls->char2uni(&in[i], in_len - i, &uni);
646                 if (unilen < 0)
647                         goto conv_err;
648 
649                 /* convert from unicode to UTF-8 */
650                 utflen = utf32_to_utf8(uni, &result[o], 3);
651                 if (utflen <= 0)
652                         goto conv_err;
653         }
654 
655         result[o] = '\0';
656         *out_len = o;
657 
658         befs_debug(sb, "<--- %s", __func__);
659 
660         return i;
661 
662       conv_err:
663         befs_error(sb, "Name using charecter set %s contains a charecter that "
664                    "cannot be converted to unicode.", nls->charset);
665         befs_debug(sb, "<--- %s", __func__);
666         kfree(result);
667         return -EILSEQ;
668 }
669 
670 /**
671  * Use the
672  *
673  */
674 enum {
675         Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
676 };
677 
678 static const match_table_t befs_tokens = {
679         {Opt_uid, "uid=%d"},
680         {Opt_gid, "gid=%d"},
681         {Opt_charset, "iocharset=%s"},
682         {Opt_debug, "debug"},
683         {Opt_err, NULL}
684 };
685 
686 static int
687 parse_options(char *options, befs_mount_options * opts)
688 {
689         char *p;
690         substring_t args[MAX_OPT_ARGS];
691         int option;
692         kuid_t uid;
693         kgid_t gid;
694 
695         /* Initialize options */
696         opts->uid = GLOBAL_ROOT_UID;
697         opts->gid = GLOBAL_ROOT_GID;
698         opts->use_uid = 0;
699         opts->use_gid = 0;
700         opts->iocharset = NULL;
701         opts->debug = 0;
702 
703         if (!options)
704                 return 1;
705 
706         while ((p = strsep(&options, ",")) != NULL) {
707                 int token;
708                 if (!*p)
709                         continue;
710 
711                 token = match_token(p, befs_tokens, args);
712                 switch (token) {
713                 case Opt_uid:
714                         if (match_int(&args[0], &option))
715                                 return 0;
716                         uid = INVALID_UID;
717                         if (option >= 0)
718                                 uid = make_kuid(current_user_ns(), option);
719                         if (!uid_valid(uid)) {
720                                 pr_err("Invalid uid %d, "
721                                        "using default\n", option);
722                                 break;
723                         }
724                         opts->uid = uid;
725                         opts->use_uid = 1;
726                         break;
727                 case Opt_gid:
728                         if (match_int(&args[0], &option))
729                                 return 0;
730                         gid = INVALID_GID;
731                         if (option >= 0)
732                                 gid = make_kgid(current_user_ns(), option);
733                         if (!gid_valid(gid)) {
734                                 pr_err("Invalid gid %d, "
735                                        "using default\n", option);
736                                 break;
737                         }
738                         opts->gid = gid;
739                         opts->use_gid = 1;
740                         break;
741                 case Opt_charset:
742                         kfree(opts->iocharset);
743                         opts->iocharset = match_strdup(&args[0]);
744                         if (!opts->iocharset) {
745                                 pr_err("allocation failure for "
746                                        "iocharset string\n");
747                                 return 0;
748                         }
749                         break;
750                 case Opt_debug:
751                         opts->debug = 1;
752                         break;
753                 default:
754                         pr_err("Unrecognized mount option \"%s\" "
755                                "or missing value\n", p);
756                         return 0;
757                 }
758         }
759         return 1;
760 }
761 
762 /* This function has the responsibiltiy of getting the
763  * filesystem ready for unmounting. 
764  * Basically, we free everything that we allocated in
765  * befs_read_inode
766  */
767 static void
768 befs_put_super(struct super_block *sb)
769 {
770         kfree(BEFS_SB(sb)->mount_opts.iocharset);
771         BEFS_SB(sb)->mount_opts.iocharset = NULL;
772         unload_nls(BEFS_SB(sb)->nls);
773         kfree(sb->s_fs_info);
774         sb->s_fs_info = NULL;
775 }
776 
777 /* Allocate private field of the superblock, fill it.
778  *
779  * Finish filling the public superblock fields
780  * Make the root directory
781  * Load a set of NLS translations if needed.
782  */
783 static int
784 befs_fill_super(struct super_block *sb, void *data, int silent)
785 {
786         struct buffer_head *bh;
787         befs_sb_info *befs_sb;
788         befs_super_block *disk_sb;
789         struct inode *root;
790         long ret = -EINVAL;
791         const unsigned long sb_block = 0;
792         const off_t x86_sb_off = 512;
793 
794         save_mount_options(sb, data);
795 
796         sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
797         if (sb->s_fs_info == NULL) {
798                 pr_err("(%s): Unable to allocate memory for private "
799                        "portion of superblock. Bailing.\n", sb->s_id);
800                 goto unacquire_none;
801         }
802         befs_sb = BEFS_SB(sb);
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, "---> %s", __func__);
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: %llu "
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         sync_filesystem(sb);
917         if (!(*flags & MS_RDONLY))
918                 return -EINVAL;
919         return 0;
920 }
921 
922 static int
923 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
924 {
925         struct super_block *sb = dentry->d_sb;
926         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
927 
928         befs_debug(sb, "---> %s", __func__);
929 
930         buf->f_type = BEFS_SUPER_MAGIC;
931         buf->f_bsize = sb->s_blocksize;
932         buf->f_blocks = BEFS_SB(sb)->num_blocks;
933         buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
934         buf->f_bavail = buf->f_bfree;
935         buf->f_files = 0;       /* UNKNOWN */
936         buf->f_ffree = 0;       /* UNKNOWN */
937         buf->f_fsid.val[0] = (u32)id;
938         buf->f_fsid.val[1] = (u32)(id >> 32);
939         buf->f_namelen = BEFS_NAME_LEN;
940 
941         befs_debug(sb, "<--- %s", __func__);
942 
943         return 0;
944 }
945 
946 static struct dentry *
947 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
948             void *data)
949 {
950         return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
951 }
952 
953 static struct file_system_type befs_fs_type = {
954         .owner          = THIS_MODULE,
955         .name           = "befs",
956         .mount          = befs_mount,
957         .kill_sb        = kill_block_super,
958         .fs_flags       = FS_REQUIRES_DEV,      
959 };
960 MODULE_ALIAS_FS("befs");
961 
962 static int __init
963 init_befs_fs(void)
964 {
965         int err;
966 
967         pr_info("version: %s\n", BEFS_VERSION);
968 
969         err = befs_init_inodecache();
970         if (err)
971                 goto unacquire_none;
972 
973         err = register_filesystem(&befs_fs_type);
974         if (err)
975                 goto unacquire_inodecache;
976 
977         return 0;
978 
979 unacquire_inodecache:
980         befs_destroy_inodecache();
981 
982 unacquire_none:
983         return err;
984 }
985 
986 static void __exit
987 exit_befs_fs(void)
988 {
989         befs_destroy_inodecache();
990 
991         unregister_filesystem(&befs_fs_type);
992 }
993 
994 /*
995 Macros that typecheck the init and exit functions,
996 ensures that they are called at init and cleanup,
997 and eliminates warnings about unused functions.
998 */
999 module_init(init_befs_fs)
1000 module_exit(exit_befs_fs)
1001 

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