Version:  2.0.40 2.2.26 2.4.37 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 3.16 3.17 3.18 3.19

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

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