Version:  2.0.40 2.2.26 2.4.37 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9

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 int befs_symlink_readpage(struct file *, struct page *);
 46 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
 47                         char **out, int *out_len);
 48 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
 49                         char **out, int *out_len);
 50 static void befs_put_super(struct super_block *);
 51 static int befs_remount(struct super_block *, int *, char *);
 52 static int befs_statfs(struct dentry *, struct kstatfs *);
 53 static int parse_options(char *, struct befs_mount_options *);
 54 
 55 static const struct super_operations befs_sops = {
 56         .alloc_inode    = befs_alloc_inode,     /* allocate a new inode */
 57         .destroy_inode  = befs_destroy_inode, /* deallocate an inode */
 58         .put_super      = befs_put_super,       /* uninit super */
 59         .statfs         = befs_statfs,  /* statfs */
 60         .remount_fs     = befs_remount,
 61         .show_options   = generic_show_options,
 62 };
 63 
 64 /* slab cache for befs_inode_info objects */
 65 static struct kmem_cache *befs_inode_cachep;
 66 
 67 static const struct file_operations befs_dir_operations = {
 68         .read           = generic_read_dir,
 69         .iterate_shared = befs_readdir,
 70         .llseek         = generic_file_llseek,
 71 };
 72 
 73 static const struct inode_operations befs_dir_inode_operations = {
 74         .lookup         = befs_lookup,
 75 };
 76 
 77 static const struct address_space_operations befs_aops = {
 78         .readpage       = befs_readpage,
 79         .bmap           = befs_bmap,
 80 };
 81 
 82 static const struct address_space_operations befs_symlink_aops = {
 83         .readpage       = befs_symlink_readpage,
 84 };
 85 
 86 /* 
 87  * Called by generic_file_read() to read a page of data
 88  * 
 89  * In turn, simply calls a generic block read function and
 90  * passes it the address of befs_get_block, for mapping file
 91  * positions to disk blocks.
 92  */
 93 static int
 94 befs_readpage(struct file *file, struct page *page)
 95 {
 96         return block_read_full_page(page, befs_get_block);
 97 }
 98 
 99 static sector_t
100 befs_bmap(struct address_space *mapping, sector_t block)
101 {
102         return generic_block_bmap(mapping, block, befs_get_block);
103 }
104 
105 /* 
106  * Generic function to map a file position (block) to a 
107  * disk offset (passed back in bh_result).
108  *
109  * Used by many higher level functions.
110  *
111  * Calls befs_fblock2brun() in datastream.c to do the real work.
112  *
113  * -WD 10-26-01
114  */
115 
116 static int
117 befs_get_block(struct inode *inode, sector_t block,
118                struct buffer_head *bh_result, int create)
119 {
120         struct super_block *sb = inode->i_sb;
121         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
122         befs_block_run run = BAD_IADDR;
123         int res;
124         ulong disk_off;
125 
126         befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
127                    (unsigned long)inode->i_ino, (long)block);
128         if (create) {
129                 befs_error(sb, "befs_get_block() was asked to write to "
130                            "block %ld in inode %lu", (long)block,
131                            (unsigned long)inode->i_ino);
132                 return -EPERM;
133         }
134 
135         res = befs_fblock2brun(sb, ds, block, &run);
136         if (res != BEFS_OK) {
137                 befs_error(sb,
138                            "<--- %s for inode %lu, block %ld ERROR",
139                            __func__, (unsigned long)inode->i_ino,
140                            (long)block);
141                 return -EFBIG;
142         }
143 
144         disk_off = (ulong) iaddr2blockno(sb, &run);
145 
146         map_bh(bh_result, inode->i_sb, disk_off);
147 
148         befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
149                   __func__, (unsigned long)inode->i_ino, (long)block,
150                   (unsigned long)disk_off);
151 
152         return 0;
153 }
154 
155 static struct dentry *
156 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
157 {
158         struct inode *inode;
159         struct super_block *sb = dir->i_sb;
160         const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
161         befs_off_t offset;
162         int ret;
163         int utfnamelen;
164         char *utfname;
165         const char *name = dentry->d_name.name;
166 
167         befs_debug(sb, "---> %s name %pd inode %ld", __func__,
168                    dentry, dir->i_ino);
169 
170         /* Convert to UTF-8 */
171         if (BEFS_SB(sb)->nls) {
172                 ret =
173                     befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
174                 if (ret < 0) {
175                         befs_debug(sb, "<--- %s ERROR", __func__);
176                         return ERR_PTR(ret);
177                 }
178                 ret = befs_btree_find(sb, ds, utfname, &offset);
179                 kfree(utfname);
180 
181         } else {
182                 ret = befs_btree_find(sb, ds, name, &offset);
183         }
184 
185         if (ret == BEFS_BT_NOT_FOUND) {
186                 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
187                 d_add(dentry, NULL);
188                 return ERR_PTR(-ENOENT);
189 
190         } else if (ret != BEFS_OK || offset == 0) {
191                 befs_error(sb, "<--- %s Error", __func__);
192                 return ERR_PTR(-ENODATA);
193         }
194 
195         inode = befs_iget(dir->i_sb, (ino_t) offset);
196         if (IS_ERR(inode))
197                 return ERR_CAST(inode);
198 
199         d_add(dentry, inode);
200 
201         befs_debug(sb, "<--- %s", __func__);
202 
203         return NULL;
204 }
205 
206 static int
207 befs_readdir(struct file *file, struct dir_context *ctx)
208 {
209         struct inode *inode = file_inode(file);
210         struct super_block *sb = inode->i_sb;
211         const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
212         befs_off_t value;
213         int result;
214         size_t keysize;
215         char keybuf[BEFS_NAME_LEN + 1];
216 
217         befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
218                   __func__, file, inode->i_ino, ctx->pos);
219 
220         while (1) {
221                 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
222                                          keybuf, &keysize, &value);
223 
224                 if (result == BEFS_ERR) {
225                         befs_debug(sb, "<--- %s ERROR", __func__);
226                         befs_error(sb, "IO error reading %pD (inode %lu)",
227                                    file, inode->i_ino);
228                         return -EIO;
229 
230                 } else if (result == BEFS_BT_END) {
231                         befs_debug(sb, "<--- %s END", __func__);
232                         return 0;
233 
234                 } else if (result == BEFS_BT_EMPTY) {
235                         befs_debug(sb, "<--- %s Empty directory", __func__);
236                         return 0;
237                 }
238 
239                 /* Convert to NLS */
240                 if (BEFS_SB(sb)->nls) {
241                         char *nlsname;
242                         int nlsnamelen;
243 
244                         result =
245                             befs_utf2nls(sb, keybuf, keysize, &nlsname,
246                                          &nlsnamelen);
247                         if (result < 0) {
248                                 befs_debug(sb, "<--- %s ERROR", __func__);
249                                 return result;
250                         }
251                         if (!dir_emit(ctx, nlsname, nlsnamelen,
252                                       (ino_t) value, DT_UNKNOWN)) {
253                                 kfree(nlsname);
254                                 return 0;
255                         }
256                         kfree(nlsname);
257                 } else {
258                         if (!dir_emit(ctx, keybuf, keysize,
259                                       (ino_t) value, DT_UNKNOWN))
260                                 return 0;
261                 }
262                 ctx->pos++;
263         }
264 }
265 
266 static struct inode *
267 befs_alloc_inode(struct super_block *sb)
268 {
269         struct befs_inode_info *bi;
270 
271         bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
272         if (!bi)
273                 return NULL;
274         return &bi->vfs_inode;
275 }
276 
277 static void befs_i_callback(struct rcu_head *head)
278 {
279         struct inode *inode = container_of(head, struct inode, i_rcu);
280         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
281 }
282 
283 static void befs_destroy_inode(struct inode *inode)
284 {
285         call_rcu(&inode->i_rcu, befs_i_callback);
286 }
287 
288 static void init_once(void *foo)
289 {
290         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
291 
292         inode_init_once(&bi->vfs_inode);
293 }
294 
295 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
296 {
297         struct buffer_head *bh;
298         befs_inode *raw_inode;
299         struct befs_sb_info *befs_sb = BEFS_SB(sb);
300         struct befs_inode_info *befs_ino;
301         struct inode *inode;
302 
303         befs_debug(sb, "---> %s inode = %lu", __func__, ino);
304 
305         inode = iget_locked(sb, ino);
306         if (!inode)
307                 return ERR_PTR(-ENOMEM);
308         if (!(inode->i_state & I_NEW))
309                 return inode;
310 
311         befs_ino = BEFS_I(inode);
312 
313         /* convert from vfs's inode number to befs's inode number */
314         befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
315 
316         befs_debug(sb, "  real inode number [%u, %hu, %hu]",
317                    befs_ino->i_inode_num.allocation_group,
318                    befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
319 
320         bh = sb_bread(sb, inode->i_ino);
321         if (!bh) {
322                 befs_error(sb, "unable to read inode block - "
323                            "inode = %lu", inode->i_ino);
324                 goto unacquire_none;
325         }
326 
327         raw_inode = (befs_inode *) bh->b_data;
328 
329         befs_dump_inode(sb, raw_inode);
330 
331         if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
332                 befs_error(sb, "Bad inode: %lu", inode->i_ino);
333                 goto unacquire_bh;
334         }
335 
336         inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
337 
338         /*
339          * set uid and gid.  But since current BeOS is single user OS, so
340          * you can change by "uid" or "gid" options.
341          */   
342 
343         inode->i_uid = befs_sb->mount_opts.use_uid ?
344                 befs_sb->mount_opts.uid :
345                 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
346         inode->i_gid = befs_sb->mount_opts.use_gid ?
347                 befs_sb->mount_opts.gid :
348                 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
349 
350         set_nlink(inode, 1);
351 
352         /*
353          * BEFS's time is 64 bits, but current VFS is 32 bits...
354          * BEFS don't have access time. Nor inode change time. VFS
355          * doesn't have creation time.
356          * Also, the lower 16 bits of the last_modified_time and 
357          * create_time are just a counter to help ensure uniqueness
358          * for indexing purposes. (PFD, page 54)
359          */
360 
361         inode->i_mtime.tv_sec =
362             fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
363         inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */        
364         inode->i_ctime = inode->i_mtime;
365         inode->i_atime = inode->i_mtime;
366 
367         befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
368         befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
369         befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
370         befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
371 
372         if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
373                 inode->i_size = 0;
374                 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
375                 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
376                         BEFS_SYMLINK_LEN);
377         } else {
378                 int num_blks;
379 
380                 befs_ino->i_data.ds =
381                     fsds_to_cpu(sb, &raw_inode->data.datastream);
382 
383                 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
384                 inode->i_blocks =
385                     num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
386                 inode->i_size = befs_ino->i_data.ds.size;
387         }
388 
389         inode->i_mapping->a_ops = &befs_aops;
390 
391         if (S_ISREG(inode->i_mode)) {
392                 inode->i_fop = &generic_ro_fops;
393         } else if (S_ISDIR(inode->i_mode)) {
394                 inode->i_op = &befs_dir_inode_operations;
395                 inode->i_fop = &befs_dir_operations;
396         } else if (S_ISLNK(inode->i_mode)) {
397                 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
398                         inode->i_op = &page_symlink_inode_operations;
399                         inode_nohighmem(inode);
400                         inode->i_mapping->a_ops = &befs_symlink_aops;
401                 } else {
402                         inode->i_link = befs_ino->i_data.symlink;
403                         inode->i_op = &simple_symlink_inode_operations;
404                 }
405         } else {
406                 befs_error(sb, "Inode %lu is not a regular file, "
407                            "directory or symlink. THAT IS WRONG! BeFS has no "
408                            "on disk special files", inode->i_ino);
409                 goto unacquire_bh;
410         }
411 
412         brelse(bh);
413         befs_debug(sb, "<--- %s", __func__);
414         unlock_new_inode(inode);
415         return inode;
416 
417       unacquire_bh:
418         brelse(bh);
419 
420       unacquire_none:
421         iget_failed(inode);
422         befs_debug(sb, "<--- %s - Bad inode", __func__);
423         return ERR_PTR(-EIO);
424 }
425 
426 /* Initialize the inode cache. Called at fs setup.
427  *
428  * Taken from NFS implementation by Al Viro.
429  */
430 static int __init
431 befs_init_inodecache(void)
432 {
433         befs_inode_cachep = kmem_cache_create("befs_inode_cache",
434                                               sizeof (struct befs_inode_info),
435                                               0, (SLAB_RECLAIM_ACCOUNT|
436                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
437                                               init_once);
438         if (befs_inode_cachep == NULL)
439                 return -ENOMEM;
440 
441         return 0;
442 }
443 
444 /* Called at fs teardown.
445  * 
446  * Taken from NFS implementation by Al Viro.
447  */
448 static void
449 befs_destroy_inodecache(void)
450 {
451         /*
452          * Make sure all delayed rcu free inodes are flushed before we
453          * destroy cache.
454          */
455         rcu_barrier();
456         kmem_cache_destroy(befs_inode_cachep);
457 }
458 
459 /*
460  * The inode of symbolic link is different to data stream.
461  * The data stream become link name. Unless the LONG_SYMLINK
462  * flag is set.
463  */
464 static int befs_symlink_readpage(struct file *unused, struct page *page)
465 {
466         struct inode *inode = page->mapping->host;
467         struct super_block *sb = inode->i_sb;
468         struct befs_inode_info *befs_ino = BEFS_I(inode);
469         befs_data_stream *data = &befs_ino->i_data.ds;
470         befs_off_t len = data->size;
471         char *link = page_address(page);
472 
473         if (len == 0 || len > PAGE_SIZE) {
474                 befs_error(sb, "Long symlink with illegal length");
475                 goto fail;
476         }
477         befs_debug(sb, "Follow long symlink");
478 
479         if (befs_read_lsymlink(sb, data, link, len) != len) {
480                 befs_error(sb, "Failed to read entire long symlink");
481                 goto fail;
482         }
483         link[len - 1] = '\0';
484         SetPageUptodate(page);
485         unlock_page(page);
486         return 0;
487 fail:
488         SetPageError(page);
489         unlock_page(page);
490         return -EIO;
491 }
492 
493 /*
494  * UTF-8 to NLS charset  convert routine
495  * 
496  *
497  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
498  * the nls tables directly
499  */
500 
501 static int
502 befs_utf2nls(struct super_block *sb, const char *in,
503              int in_len, char **out, int *out_len)
504 {
505         struct nls_table *nls = BEFS_SB(sb)->nls;
506         int i, o;
507         unicode_t uni;
508         int unilen, utflen;
509         char *result;
510         /* The utf8->nls conversion won't make the final nls string bigger
511          * than the utf one, but if the string is pure ascii they'll have the
512          * same width and an extra char is needed to save the additional \0
513          */
514         int maxlen = in_len + 1;
515 
516         befs_debug(sb, "---> %s", __func__);
517 
518         if (!nls) {
519                 befs_error(sb, "%s called with no NLS table loaded", __func__);
520                 return -EINVAL;
521         }
522 
523         *out = result = kmalloc(maxlen, GFP_NOFS);
524         if (!*out) {
525                 return -ENOMEM;
526         }
527 
528         for (i = o = 0; i < in_len; i += utflen, o += unilen) {
529 
530                 /* convert from UTF-8 to Unicode */
531                 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
532                 if (utflen < 0)
533                         goto conv_err;
534 
535                 /* convert from Unicode to nls */
536                 if (uni > MAX_WCHAR_T)
537                         goto conv_err;
538                 unilen = nls->uni2char(uni, &result[o], in_len - o);
539                 if (unilen < 0)
540                         goto conv_err;
541         }
542         result[o] = '\0';
543         *out_len = o;
544 
545         befs_debug(sb, "<--- %s", __func__);
546 
547         return o;
548 
549       conv_err:
550         befs_error(sb, "Name using character set %s contains a character that "
551                    "cannot be converted to unicode.", nls->charset);
552         befs_debug(sb, "<--- %s", __func__);
553         kfree(result);
554         return -EILSEQ;
555 }
556 
557 /**
558  * befs_nls2utf - Convert NLS string to utf8 encodeing
559  * @sb: Superblock
560  * @in: Input string buffer in NLS format
561  * @in_len: Length of input string in bytes
562  * @out: The output string in UTF-8 format
563  * @out_len: Length of the output buffer
564  * 
565  * Converts input string @in, which is in the format of the loaded NLS map,
566  * into a utf8 string.
567  * 
568  * The destination string @out is allocated by this function and the caller is
569  * responsible for freeing it with kfree()
570  * 
571  * On return, *@out_len is the length of @out in bytes.
572  *
573  * On success, the return value is the number of utf8 characters written to
574  * the output buffer @out.
575  *  
576  * On Failure, a negative number coresponding to the error code is returned.
577  */
578 
579 static int
580 befs_nls2utf(struct super_block *sb, const char *in,
581              int in_len, char **out, int *out_len)
582 {
583         struct nls_table *nls = BEFS_SB(sb)->nls;
584         int i, o;
585         wchar_t uni;
586         int unilen, utflen;
587         char *result;
588         /* There're nls characters that will translate to 3-chars-wide UTF-8
589          * characters, a additional byte is needed to save the final \0
590          * in special cases */
591         int maxlen = (3 * in_len) + 1;
592 
593         befs_debug(sb, "---> %s\n", __func__);
594 
595         if (!nls) {
596                 befs_error(sb, "%s called with no NLS table loaded.",
597                            __func__);
598                 return -EINVAL;
599         }
600 
601         *out = result = kmalloc(maxlen, GFP_NOFS);
602         if (!*out) {
603                 *out_len = 0;
604                 return -ENOMEM;
605         }
606 
607         for (i = o = 0; i < in_len; i += unilen, o += utflen) {
608 
609                 /* convert from nls to unicode */
610                 unilen = nls->char2uni(&in[i], in_len - i, &uni);
611                 if (unilen < 0)
612                         goto conv_err;
613 
614                 /* convert from unicode to UTF-8 */
615                 utflen = utf32_to_utf8(uni, &result[o], 3);
616                 if (utflen <= 0)
617                         goto conv_err;
618         }
619 
620         result[o] = '\0';
621         *out_len = o;
622 
623         befs_debug(sb, "<--- %s", __func__);
624 
625         return i;
626 
627       conv_err:
628         befs_error(sb, "Name using charecter set %s contains a charecter that "
629                    "cannot be converted to unicode.", nls->charset);
630         befs_debug(sb, "<--- %s", __func__);
631         kfree(result);
632         return -EILSEQ;
633 }
634 
635 enum {
636         Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
637 };
638 
639 static const match_table_t befs_tokens = {
640         {Opt_uid, "uid=%d"},
641         {Opt_gid, "gid=%d"},
642         {Opt_charset, "iocharset=%s"},
643         {Opt_debug, "debug"},
644         {Opt_err, NULL}
645 };
646 
647 static int
648 parse_options(char *options, struct befs_mount_options *opts)
649 {
650         char *p;
651         substring_t args[MAX_OPT_ARGS];
652         int option;
653         kuid_t uid;
654         kgid_t gid;
655 
656         /* Initialize options */
657         opts->uid = GLOBAL_ROOT_UID;
658         opts->gid = GLOBAL_ROOT_GID;
659         opts->use_uid = 0;
660         opts->use_gid = 0;
661         opts->iocharset = NULL;
662         opts->debug = 0;
663 
664         if (!options)
665                 return 1;
666 
667         while ((p = strsep(&options, ",")) != NULL) {
668                 int token;
669                 if (!*p)
670                         continue;
671 
672                 token = match_token(p, befs_tokens, args);
673                 switch (token) {
674                 case Opt_uid:
675                         if (match_int(&args[0], &option))
676                                 return 0;
677                         uid = INVALID_UID;
678                         if (option >= 0)
679                                 uid = make_kuid(current_user_ns(), option);
680                         if (!uid_valid(uid)) {
681                                 pr_err("Invalid uid %d, "
682                                        "using default\n", option);
683                                 break;
684                         }
685                         opts->uid = uid;
686                         opts->use_uid = 1;
687                         break;
688                 case Opt_gid:
689                         if (match_int(&args[0], &option))
690                                 return 0;
691                         gid = INVALID_GID;
692                         if (option >= 0)
693                                 gid = make_kgid(current_user_ns(), option);
694                         if (!gid_valid(gid)) {
695                                 pr_err("Invalid gid %d, "
696                                        "using default\n", option);
697                                 break;
698                         }
699                         opts->gid = gid;
700                         opts->use_gid = 1;
701                         break;
702                 case Opt_charset:
703                         kfree(opts->iocharset);
704                         opts->iocharset = match_strdup(&args[0]);
705                         if (!opts->iocharset) {
706                                 pr_err("allocation failure for "
707                                        "iocharset string\n");
708                                 return 0;
709                         }
710                         break;
711                 case Opt_debug:
712                         opts->debug = 1;
713                         break;
714                 default:
715                         pr_err("Unrecognized mount option \"%s\" "
716                                "or missing value\n", p);
717                         return 0;
718                 }
719         }
720         return 1;
721 }
722 
723 /* This function has the responsibiltiy of getting the
724  * filesystem ready for unmounting. 
725  * Basically, we free everything that we allocated in
726  * befs_read_inode
727  */
728 static void
729 befs_put_super(struct super_block *sb)
730 {
731         kfree(BEFS_SB(sb)->mount_opts.iocharset);
732         BEFS_SB(sb)->mount_opts.iocharset = NULL;
733         unload_nls(BEFS_SB(sb)->nls);
734         kfree(sb->s_fs_info);
735         sb->s_fs_info = NULL;
736 }
737 
738 /* Allocate private field of the superblock, fill it.
739  *
740  * Finish filling the public superblock fields
741  * Make the root directory
742  * Load a set of NLS translations if needed.
743  */
744 static int
745 befs_fill_super(struct super_block *sb, void *data, int silent)
746 {
747         struct buffer_head *bh;
748         struct befs_sb_info *befs_sb;
749         befs_super_block *disk_sb;
750         struct inode *root;
751         long ret = -EINVAL;
752         const unsigned long sb_block = 0;
753         const off_t x86_sb_off = 512;
754         int blocksize;
755 
756         save_mount_options(sb, data);
757 
758         sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
759         if (sb->s_fs_info == NULL)
760                 goto unacquire_none;
761 
762         befs_sb = BEFS_SB(sb);
763 
764         if (!parse_options((char *) data, &befs_sb->mount_opts)) {
765                 if (!silent)
766                         befs_error(sb, "cannot parse mount options");
767                 goto unacquire_priv_sbp;
768         }
769 
770         befs_debug(sb, "---> %s", __func__);
771 
772         if (!(sb->s_flags & MS_RDONLY)) {
773                 befs_warning(sb,
774                              "No write support. Marking filesystem read-only");
775                 sb->s_flags |= MS_RDONLY;
776         }
777 
778         /*
779          * Set dummy blocksize to read super block.
780          * Will be set to real fs blocksize later.
781          *
782          * Linux 2.4.10 and later refuse to read blocks smaller than
783          * the logical block size for the device. But we also need to read at
784          * least 1k to get the second 512 bytes of the volume.
785          * -WD 10-26-01
786          */ 
787         blocksize = sb_min_blocksize(sb, 1024);
788         if (!blocksize) {
789                 if (!silent)
790                         befs_error(sb, "unable to set blocksize");
791                 goto unacquire_priv_sbp;
792         }
793 
794         if (!(bh = sb_bread(sb, sb_block))) {
795                 if (!silent)
796                         befs_error(sb, "unable to read superblock");
797                 goto unacquire_priv_sbp;
798         }
799 
800         /* account for offset of super block on x86 */
801         disk_sb = (befs_super_block *) bh->b_data;
802         if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
803             (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
804                 befs_debug(sb, "Using PPC superblock location");
805         } else {
806                 befs_debug(sb, "Using x86 superblock location");
807                 disk_sb =
808                     (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
809         }
810 
811         if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
812             (befs_check_sb(sb) != BEFS_OK))
813                 goto unacquire_bh;
814 
815         befs_dump_super_block(sb, disk_sb);
816 
817         brelse(bh);
818 
819         if( befs_sb->num_blocks > ~((sector_t)0) ) {
820                 if (!silent)
821                         befs_error(sb, "blocks count: %llu is larger than the host can use",
822                                         befs_sb->num_blocks);
823                 goto unacquire_priv_sbp;
824         }
825 
826         /*
827          * set up enough so that it can read an inode
828          * Fill in kernel superblock fields from private sb
829          */
830         sb->s_magic = BEFS_SUPER_MAGIC;
831         /* Set real blocksize of fs */
832         sb_set_blocksize(sb, (ulong) befs_sb->block_size);
833         sb->s_op = &befs_sops;
834         root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
835         if (IS_ERR(root)) {
836                 ret = PTR_ERR(root);
837                 goto unacquire_priv_sbp;
838         }
839         sb->s_root = d_make_root(root);
840         if (!sb->s_root) {
841                 if (!silent)
842                         befs_error(sb, "get root inode failed");
843                 goto unacquire_priv_sbp;
844         }
845 
846         /* load nls library */
847         if (befs_sb->mount_opts.iocharset) {
848                 befs_debug(sb, "Loading nls: %s",
849                            befs_sb->mount_opts.iocharset);
850                 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
851                 if (!befs_sb->nls) {
852                         befs_warning(sb, "Cannot load nls %s"
853                                         " loading default nls",
854                                         befs_sb->mount_opts.iocharset);
855                         befs_sb->nls = load_nls_default();
856                 }
857         /* load default nls if none is specified  in mount options */
858         } else {
859                 befs_debug(sb, "Loading default nls");
860                 befs_sb->nls = load_nls_default();
861         }
862 
863         return 0;
864 /*****************/
865       unacquire_bh:
866         brelse(bh);
867 
868       unacquire_priv_sbp:
869         kfree(befs_sb->mount_opts.iocharset);
870         kfree(sb->s_fs_info);
871         sb->s_fs_info = NULL;
872 
873       unacquire_none:
874         return ret;
875 }
876 
877 static int
878 befs_remount(struct super_block *sb, int *flags, char *data)
879 {
880         sync_filesystem(sb);
881         if (!(*flags & MS_RDONLY))
882                 return -EINVAL;
883         return 0;
884 }
885 
886 static int
887 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
888 {
889         struct super_block *sb = dentry->d_sb;
890         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
891 
892         befs_debug(sb, "---> %s", __func__);
893 
894         buf->f_type = BEFS_SUPER_MAGIC;
895         buf->f_bsize = sb->s_blocksize;
896         buf->f_blocks = BEFS_SB(sb)->num_blocks;
897         buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
898         buf->f_bavail = buf->f_bfree;
899         buf->f_files = 0;       /* UNKNOWN */
900         buf->f_ffree = 0;       /* UNKNOWN */
901         buf->f_fsid.val[0] = (u32)id;
902         buf->f_fsid.val[1] = (u32)(id >> 32);
903         buf->f_namelen = BEFS_NAME_LEN;
904 
905         befs_debug(sb, "<--- %s", __func__);
906 
907         return 0;
908 }
909 
910 static struct dentry *
911 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
912             void *data)
913 {
914         return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
915 }
916 
917 static struct file_system_type befs_fs_type = {
918         .owner          = THIS_MODULE,
919         .name           = "befs",
920         .mount          = befs_mount,
921         .kill_sb        = kill_block_super,
922         .fs_flags       = FS_REQUIRES_DEV,      
923 };
924 MODULE_ALIAS_FS("befs");
925 
926 static int __init
927 init_befs_fs(void)
928 {
929         int err;
930 
931         pr_info("version: %s\n", BEFS_VERSION);
932 
933         err = befs_init_inodecache();
934         if (err)
935                 goto unacquire_none;
936 
937         err = register_filesystem(&befs_fs_type);
938         if (err)
939                 goto unacquire_inodecache;
940 
941         return 0;
942 
943 unacquire_inodecache:
944         befs_destroy_inodecache();
945 
946 unacquire_none:
947         return err;
948 }
949 
950 static void __exit
951 exit_befs_fs(void)
952 {
953         befs_destroy_inodecache();
954 
955         unregister_filesystem(&befs_fs_type);
956 }
957 
958 /*
959 Macros that typecheck the init and exit functions,
960 ensures that they are called at init and cleanup,
961 and eliminates warnings about unused functions.
962 */
963 module_init(init_befs_fs)
964 module_exit(exit_befs_fs)
965 

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