Version:  2.0.40 2.2.26 2.4.37 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 4.0 4.1 4.2

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