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Linux/fs/befs/linuxvfs.c

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  1 /*
  2  * linux/fs/befs/linuxvfs.c
  3  *
  4  * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
  5  *
  6  */
  7 
  8 #include <linux/module.h>
  9 #include <linux/slab.h>
 10 #include <linux/fs.h>
 11 #include <linux/errno.h>
 12 #include <linux/stat.h>
 13 #include <linux/nls.h>
 14 #include <linux/buffer_head.h>
 15 #include <linux/vfs.h>
 16 #include <linux/parser.h>
 17 #include <linux/namei.h>
 18 #include <linux/sched.h>
 19 
 20 #include "befs.h"
 21 #include "btree.h"
 22 #include "inode.h"
 23 #include "datastream.h"
 24 #include "super.h"
 25 #include "io.h"
 26 
 27 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
 28 MODULE_AUTHOR("Will Dyson");
 29 MODULE_LICENSE("GPL");
 30 
 31 /* The units the vfs expects inode->i_blocks to be in */
 32 #define VFS_BLOCK_SIZE 512
 33 
 34 static int befs_readdir(struct file *, struct dir_context *);
 35 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 36 static int befs_readpage(struct file *file, struct page *page);
 37 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 38 static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
 39 static struct inode *befs_iget(struct super_block *, unsigned long);
 40 static struct inode *befs_alloc_inode(struct super_block *sb);
 41 static void befs_destroy_inode(struct inode *inode);
 42 static int befs_init_inodecache(void);
 43 static void befs_destroy_inodecache(void);
 44 static void *befs_follow_link(struct dentry *, struct nameidata *);
 45 static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
 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 *, 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_fast_symlink_inode_operations = {
 83         .readlink       = generic_readlink,
 84         .follow_link    = befs_fast_follow_link,
 85 };
 86 
 87 static const struct inode_operations befs_symlink_inode_operations = {
 88         .readlink       = generic_readlink,
 89         .follow_link    = befs_follow_link,
 90         .put_link       = kfree_put_link,
 91 };
 92 
 93 /* 
 94  * Called by generic_file_read() to read a page of data
 95  * 
 96  * In turn, simply calls a generic block read function and
 97  * passes it the address of befs_get_block, for mapping file
 98  * positions to disk blocks.
 99  */
100 static int
101 befs_readpage(struct file *file, struct page *page)
102 {
103         return block_read_full_page(page, befs_get_block);
104 }
105 
106 static sector_t
107 befs_bmap(struct address_space *mapping, sector_t block)
108 {
109         return generic_block_bmap(mapping, block, befs_get_block);
110 }
111 
112 /* 
113  * Generic function to map a file position (block) to a 
114  * disk offset (passed back in bh_result).
115  *
116  * Used by many higher level functions.
117  *
118  * Calls befs_fblock2brun() in datastream.c to do the real work.
119  *
120  * -WD 10-26-01
121  */
122 
123 static int
124 befs_get_block(struct inode *inode, sector_t block,
125                struct buffer_head *bh_result, int create)
126 {
127         struct super_block *sb = inode->i_sb;
128         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
129         befs_block_run run = BAD_IADDR;
130         int res = 0;
131         ulong disk_off;
132 
133         befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
134                    inode->i_ino, block);
135 
136         if (block < 0) {
137                 befs_error(sb, "befs_get_block() was asked for a block "
138                            "number less than zero: block %ld in inode %lu",
139                            block, inode->i_ino);
140                 return -EIO;
141         }
142 
143         if (create) {
144                 befs_error(sb, "befs_get_block() was asked to write to "
145                            "block %ld in inode %lu", block, inode->i_ino);
146                 return -EPERM;
147         }
148 
149         res = befs_fblock2brun(sb, ds, block, &run);
150         if (res != BEFS_OK) {
151                 befs_error(sb,
152                            "<--- befs_get_block() for inode %lu, block "
153                            "%ld ERROR", inode->i_ino, block);
154                 return -EFBIG;
155         }
156 
157         disk_off = (ulong) iaddr2blockno(sb, &run);
158 
159         map_bh(bh_result, inode->i_sb, disk_off);
160 
161         befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
162                    "disk address %lu", inode->i_ino, block, disk_off);
163 
164         return 0;
165 }
166 
167 static struct dentry *
168 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
169 {
170         struct inode *inode = NULL;
171         struct super_block *sb = dir->i_sb;
172         befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
173         befs_off_t offset;
174         int ret;
175         int utfnamelen;
176         char *utfname;
177         const char *name = dentry->d_name.name;
178 
179         befs_debug(sb, "---> befs_lookup() "
180                    "name %s inode %ld", dentry->d_name.name, dir->i_ino);
181 
182         /* Convert to UTF-8 */
183         if (BEFS_SB(sb)->nls) {
184                 ret =
185                     befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
186                 if (ret < 0) {
187                         befs_debug(sb, "<--- befs_lookup() ERROR");
188                         return ERR_PTR(ret);
189                 }
190                 ret = befs_btree_find(sb, ds, utfname, &offset);
191                 kfree(utfname);
192 
193         } else {
194                 ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
195         }
196 
197         if (ret == BEFS_BT_NOT_FOUND) {
198                 befs_debug(sb, "<--- befs_lookup() %s not found",
199                            dentry->d_name.name);
200                 return ERR_PTR(-ENOENT);
201 
202         } else if (ret != BEFS_OK || offset == 0) {
203                 befs_warning(sb, "<--- befs_lookup() Error");
204                 return ERR_PTR(-ENODATA);
205         }
206 
207         inode = befs_iget(dir->i_sb, (ino_t) offset);
208         if (IS_ERR(inode))
209                 return ERR_CAST(inode);
210 
211         d_add(dentry, inode);
212 
213         befs_debug(sb, "<--- befs_lookup()");
214 
215         return NULL;
216 }
217 
218 static int
219 befs_readdir(struct file *file, struct dir_context *ctx)
220 {
221         struct inode *inode = file_inode(file);
222         struct super_block *sb = inode->i_sb;
223         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
224         befs_off_t value;
225         int result;
226         size_t keysize;
227         unsigned char d_type;
228         char keybuf[BEFS_NAME_LEN + 1];
229         const char *dirname = file->f_path.dentry->d_name.name;
230 
231         befs_debug(sb, "---> befs_readdir() "
232                    "name %s, inode %ld, ctx->pos %Ld",
233                    dirname, inode->i_ino, ctx->pos);
234 
235 more:
236         result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
237                                  keybuf, &keysize, &value);
238 
239         if (result == BEFS_ERR) {
240                 befs_debug(sb, "<--- befs_readdir() ERROR");
241                 befs_error(sb, "IO error reading %s (inode %lu)",
242                            dirname, inode->i_ino);
243                 return -EIO;
244 
245         } else if (result == BEFS_BT_END) {
246                 befs_debug(sb, "<--- befs_readdir() END");
247                 return 0;
248 
249         } else if (result == BEFS_BT_EMPTY) {
250                 befs_debug(sb, "<--- befs_readdir() Empty directory");
251                 return 0;
252         }
253 
254         d_type = DT_UNKNOWN;
255 
256         /* Convert to NLS */
257         if (BEFS_SB(sb)->nls) {
258                 char *nlsname;
259                 int nlsnamelen;
260                 result =
261                     befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
262                 if (result < 0) {
263                         befs_debug(sb, "<--- befs_readdir() ERROR");
264                         return result;
265                 }
266                 if (!dir_emit(ctx, nlsname, nlsnamelen,
267                                  (ino_t) value, d_type)) {
268                         kfree(nlsname);
269                         return 0;
270                 }
271                 kfree(nlsname);
272         } else {
273                 if (!dir_emit(ctx, keybuf, keysize,
274                                  (ino_t) value, d_type))
275                         return 0;
276         }
277         ctx->pos++;
278         goto more;
279 
280         befs_debug(sb, "<--- befs_readdir() pos %Ld", ctx->pos);
281 
282         return 0;
283 }
284 
285 static struct inode *
286 befs_alloc_inode(struct super_block *sb)
287 {
288         struct befs_inode_info *bi;
289         bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
290                                                         GFP_KERNEL);
291         if (!bi)
292                 return NULL;
293         return &bi->vfs_inode;
294 }
295 
296 static void befs_i_callback(struct rcu_head *head)
297 {
298         struct inode *inode = container_of(head, struct inode, i_rcu);
299         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
300 }
301 
302 static void befs_destroy_inode(struct inode *inode)
303 {
304         call_rcu(&inode->i_rcu, befs_i_callback);
305 }
306 
307 static void init_once(void *foo)
308 {
309         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
310 
311         inode_init_once(&bi->vfs_inode);
312 }
313 
314 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
315 {
316         struct buffer_head *bh = NULL;
317         befs_inode *raw_inode = NULL;
318 
319         befs_sb_info *befs_sb = BEFS_SB(sb);
320         befs_inode_info *befs_ino = NULL;
321         struct inode *inode;
322         long ret = -EIO;
323 
324         befs_debug(sb, "---> befs_read_inode() " "inode = %lu", ino);
325 
326         inode = iget_locked(sb, ino);
327         if (IS_ERR(inode))
328                 return inode;
329         if (!(inode->i_state & I_NEW))
330                 return inode;
331 
332         befs_ino = BEFS_I(inode);
333 
334         /* convert from vfs's inode number to befs's inode number */
335         befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
336 
337         befs_debug(sb, "  real inode number [%u, %hu, %hu]",
338                    befs_ino->i_inode_num.allocation_group,
339                    befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
340 
341         bh = befs_bread(sb, inode->i_ino);
342         if (!bh) {
343                 befs_error(sb, "unable to read inode block - "
344                            "inode = %lu", inode->i_ino);
345                 goto unacquire_none;
346         }
347 
348         raw_inode = (befs_inode *) bh->b_data;
349 
350         befs_dump_inode(sb, raw_inode);
351 
352         if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
353                 befs_error(sb, "Bad inode: %lu", inode->i_ino);
354                 goto unacquire_bh;
355         }
356 
357         inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
358 
359         /*
360          * set uid and gid.  But since current BeOS is single user OS, so
361          * you can change by "uid" or "gid" options.
362          */   
363 
364         inode->i_uid = befs_sb->mount_opts.use_uid ?
365                 befs_sb->mount_opts.uid :
366                 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
367         inode->i_gid = befs_sb->mount_opts.use_gid ?
368                 befs_sb->mount_opts.gid :
369                 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
370 
371         set_nlink(inode, 1);
372 
373         /*
374          * BEFS's time is 64 bits, but current VFS is 32 bits...
375          * BEFS don't have access time. Nor inode change time. VFS
376          * doesn't have creation time.
377          * Also, the lower 16 bits of the last_modified_time and 
378          * create_time are just a counter to help ensure uniqueness
379          * for indexing purposes. (PFD, page 54)
380          */
381 
382         inode->i_mtime.tv_sec =
383             fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
384         inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */        
385         inode->i_ctime = inode->i_mtime;
386         inode->i_atime = inode->i_mtime;
387 
388         befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
389         befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
390         befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
391         befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
392 
393         if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
394                 inode->i_size = 0;
395                 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
396                 strncpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
397                         BEFS_SYMLINK_LEN - 1);
398                 befs_ino->i_data.symlink[BEFS_SYMLINK_LEN - 1] = '\0';
399         } else {
400                 int num_blks;
401 
402                 befs_ino->i_data.ds =
403                     fsds_to_cpu(sb, &raw_inode->data.datastream);
404 
405                 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
406                 inode->i_blocks =
407                     num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
408                 inode->i_size = befs_ino->i_data.ds.size;
409         }
410 
411         inode->i_mapping->a_ops = &befs_aops;
412 
413         if (S_ISREG(inode->i_mode)) {
414                 inode->i_fop = &generic_ro_fops;
415         } else if (S_ISDIR(inode->i_mode)) {
416                 inode->i_op = &befs_dir_inode_operations;
417                 inode->i_fop = &befs_dir_operations;
418         } else if (S_ISLNK(inode->i_mode)) {
419                 if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
420                         inode->i_op = &befs_symlink_inode_operations;
421                 else
422                         inode->i_op = &befs_fast_symlink_inode_operations;
423         } else {
424                 befs_error(sb, "Inode %lu is not a regular file, "
425                            "directory or symlink. THAT IS WRONG! BeFS has no "
426                            "on disk special files", inode->i_ino);
427                 goto unacquire_bh;
428         }
429 
430         brelse(bh);
431         befs_debug(sb, "<--- befs_read_inode()");
432         unlock_new_inode(inode);
433         return inode;
434 
435       unacquire_bh:
436         brelse(bh);
437 
438       unacquire_none:
439         iget_failed(inode);
440         befs_debug(sb, "<--- befs_read_inode() - Bad inode");
441         return ERR_PTR(ret);
442 }
443 
444 /* Initialize the inode cache. Called at fs setup.
445  *
446  * Taken from NFS implementation by Al Viro.
447  */
448 static int
449 befs_init_inodecache(void)
450 {
451         befs_inode_cachep = kmem_cache_create("befs_inode_cache",
452                                               sizeof (struct befs_inode_info),
453                                               0, (SLAB_RECLAIM_ACCOUNT|
454                                                 SLAB_MEM_SPREAD),
455                                               init_once);
456         if (befs_inode_cachep == NULL) {
457                 printk(KERN_ERR "befs_init_inodecache: "
458                        "Couldn't initialize inode slabcache\n");
459                 return -ENOMEM;
460         }
461 
462         return 0;
463 }
464 
465 /* Called at fs teardown.
466  * 
467  * Taken from NFS implementation by Al Viro.
468  */
469 static void
470 befs_destroy_inodecache(void)
471 {
472         /*
473          * Make sure all delayed rcu free inodes are flushed before we
474          * destroy cache.
475          */
476         rcu_barrier();
477         kmem_cache_destroy(befs_inode_cachep);
478 }
479 
480 /*
481  * The inode of symbolic link is different to data stream.
482  * The data stream become link name. Unless the LONG_SYMLINK
483  * flag is set.
484  */
485 static void *
486 befs_follow_link(struct dentry *dentry, struct nameidata *nd)
487 {
488         struct super_block *sb = dentry->d_sb;
489         befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
490         befs_data_stream *data = &befs_ino->i_data.ds;
491         befs_off_t len = data->size;
492         char *link;
493 
494         if (len == 0) {
495                 befs_error(sb, "Long symlink with illegal length");
496                 link = ERR_PTR(-EIO);
497         } else {
498                 befs_debug(sb, "Follow long symlink");
499 
500                 link = kmalloc(len, GFP_NOFS);
501                 if (!link) {
502                         link = ERR_PTR(-ENOMEM);
503                 } else if (befs_read_lsymlink(sb, data, link, len) != len) {
504                         kfree(link);
505                         befs_error(sb, "Failed to read entire long symlink");
506                         link = ERR_PTR(-EIO);
507                 } else {
508                         link[len - 1] = '\0';
509                 }
510         }
511         nd_set_link(nd, link);
512         return NULL;
513 }
514 
515 
516 static void *
517 befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
518 {
519         befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
520         nd_set_link(nd, befs_ino->i_data.symlink);
521         return NULL;
522 }
523 
524 /*
525  * UTF-8 to NLS charset  convert routine
526  * 
527  *
528  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
529  * the nls tables directly
530  */
531 
532 static int
533 befs_utf2nls(struct super_block *sb, const char *in,
534              int in_len, char **out, int *out_len)
535 {
536         struct nls_table *nls = BEFS_SB(sb)->nls;
537         int i, o;
538         unicode_t uni;
539         int unilen, utflen;
540         char *result;
541         /* The utf8->nls conversion won't make the final nls string bigger
542          * than the utf one, but if the string is pure ascii they'll have the
543          * same width and an extra char is needed to save the additional \0
544          */
545         int maxlen = in_len + 1;
546 
547         befs_debug(sb, "---> utf2nls()");
548 
549         if (!nls) {
550                 befs_error(sb, "befs_utf2nls called with no NLS table loaded");
551                 return -EINVAL;
552         }
553 
554         *out = result = kmalloc(maxlen, GFP_NOFS);
555         if (!*out) {
556                 befs_error(sb, "befs_utf2nls() cannot allocate memory");
557                 *out_len = 0;
558                 return -ENOMEM;
559         }
560 
561         for (i = o = 0; i < in_len; i += utflen, o += unilen) {
562 
563                 /* convert from UTF-8 to Unicode */
564                 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
565                 if (utflen < 0)
566                         goto conv_err;
567 
568                 /* convert from Unicode to nls */
569                 if (uni > MAX_WCHAR_T)
570                         goto conv_err;
571                 unilen = nls->uni2char(uni, &result[o], in_len - o);
572                 if (unilen < 0)
573                         goto conv_err;
574         }
575         result[o] = '\0';
576         *out_len = o;
577 
578         befs_debug(sb, "<--- utf2nls()");
579 
580         return o;
581 
582       conv_err:
583         befs_error(sb, "Name using character set %s contains a character that "
584                    "cannot be converted to unicode.", nls->charset);
585         befs_debug(sb, "<--- utf2nls()");
586         kfree(result);
587         return -EILSEQ;
588 }
589 
590 /**
591  * befs_nls2utf - Convert NLS string to utf8 encodeing
592  * @sb: Superblock
593  * @src: Input string buffer in NLS format
594  * @srclen: Length of input string in bytes
595  * @dest: The output string in UTF-8 format
596  * @destlen: Length of the output buffer
597  * 
598  * Converts input string @src, which is in the format of the loaded NLS map,
599  * into a utf8 string.
600  * 
601  * The destination string @dest is allocated by this function and the caller is
602  * responsible for freeing it with kfree()
603  * 
604  * On return, *@destlen is the length of @dest in bytes.
605  *
606  * On success, the return value is the number of utf8 characters written to
607  * the output buffer @dest.
608  *  
609  * On Failure, a negative number coresponding to the error code is returned.
610  */
611 
612 static int
613 befs_nls2utf(struct super_block *sb, const char *in,
614              int in_len, char **out, int *out_len)
615 {
616         struct nls_table *nls = BEFS_SB(sb)->nls;
617         int i, o;
618         wchar_t uni;
619         int unilen, utflen;
620         char *result;
621         /* There're nls characters that will translate to 3-chars-wide UTF-8
622          * characters, a additional byte is needed to save the final \0
623          * in special cases */
624         int maxlen = (3 * in_len) + 1;
625 
626         befs_debug(sb, "---> nls2utf()\n");
627 
628         if (!nls) {
629                 befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
630                 return -EINVAL;
631         }
632 
633         *out = result = kmalloc(maxlen, GFP_NOFS);
634         if (!*out) {
635                 befs_error(sb, "befs_nls2utf() cannot allocate memory");
636                 *out_len = 0;
637                 return -ENOMEM;
638         }
639 
640         for (i = o = 0; i < in_len; i += unilen, o += utflen) {
641 
642                 /* convert from nls to unicode */
643                 unilen = nls->char2uni(&in[i], in_len - i, &uni);
644                 if (unilen < 0)
645                         goto conv_err;
646 
647                 /* convert from unicode to UTF-8 */
648                 utflen = utf32_to_utf8(uni, &result[o], 3);
649                 if (utflen <= 0)
650                         goto conv_err;
651         }
652 
653         result[o] = '\0';
654         *out_len = o;
655 
656         befs_debug(sb, "<--- nls2utf()");
657 
658         return i;
659 
660       conv_err:
661         befs_error(sb, "Name using charecter set %s contains a charecter that "
662                    "cannot be converted to unicode.", nls->charset);
663         befs_debug(sb, "<--- nls2utf()");
664         kfree(result);
665         return -EILSEQ;
666 }
667 
668 /**
669  * Use the
670  *
671  */
672 enum {
673         Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
674 };
675 
676 static const match_table_t befs_tokens = {
677         {Opt_uid, "uid=%d"},
678         {Opt_gid, "gid=%d"},
679         {Opt_charset, "iocharset=%s"},
680         {Opt_debug, "debug"},
681         {Opt_err, NULL}
682 };
683 
684 static int
685 parse_options(char *options, befs_mount_options * opts)
686 {
687         char *p;
688         substring_t args[MAX_OPT_ARGS];
689         int option;
690         kuid_t uid;
691         kgid_t gid;
692 
693         /* Initialize options */
694         opts->uid = GLOBAL_ROOT_UID;
695         opts->gid = GLOBAL_ROOT_GID;
696         opts->use_uid = 0;
697         opts->use_gid = 0;
698         opts->iocharset = NULL;
699         opts->debug = 0;
700 
701         if (!options)
702                 return 1;
703 
704         while ((p = strsep(&options, ",")) != NULL) {
705                 int token;
706                 if (!*p)
707                         continue;
708 
709                 token = match_token(p, befs_tokens, args);
710                 switch (token) {
711                 case Opt_uid:
712                         if (match_int(&args[0], &option))
713                                 return 0;
714                         uid = INVALID_UID;
715                         if (option >= 0)
716                                 uid = make_kuid(current_user_ns(), option);
717                         if (!uid_valid(uid)) {
718                                 printk(KERN_ERR "BeFS: Invalid uid %d, "
719                                                 "using default\n", option);
720                                 break;
721                         }
722                         opts->uid = uid;
723                         opts->use_uid = 1;
724                         break;
725                 case Opt_gid:
726                         if (match_int(&args[0], &option))
727                                 return 0;
728                         gid = INVALID_GID;
729                         if (option >= 0)
730                                 gid = make_kgid(current_user_ns(), option);
731                         if (!gid_valid(gid)) {
732                                 printk(KERN_ERR "BeFS: Invalid gid %d, "
733                                                 "using default\n", option);
734                                 break;
735                         }
736                         opts->gid = gid;
737                         opts->use_gid = 1;
738                         break;
739                 case Opt_charset:
740                         kfree(opts->iocharset);
741                         opts->iocharset = match_strdup(&args[0]);
742                         if (!opts->iocharset) {
743                                 printk(KERN_ERR "BeFS: allocation failure for "
744                                                 "iocharset string\n");
745                                 return 0;
746                         }
747                         break;
748                 case Opt_debug:
749                         opts->debug = 1;
750                         break;
751                 default:
752                         printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
753                                         "or missing value\n", p);
754                         return 0;
755                 }
756         }
757         return 1;
758 }
759 
760 /* This function has the responsibiltiy of getting the
761  * filesystem ready for unmounting. 
762  * Basically, we free everything that we allocated in
763  * befs_read_inode
764  */
765 static void
766 befs_put_super(struct super_block *sb)
767 {
768         kfree(BEFS_SB(sb)->mount_opts.iocharset);
769         BEFS_SB(sb)->mount_opts.iocharset = NULL;
770         unload_nls(BEFS_SB(sb)->nls);
771         kfree(sb->s_fs_info);
772         sb->s_fs_info = NULL;
773 }
774 
775 /* Allocate private field of the superblock, fill it.
776  *
777  * Finish filling the public superblock fields
778  * Make the root directory
779  * Load a set of NLS translations if needed.
780  */
781 static int
782 befs_fill_super(struct super_block *sb, void *data, int silent)
783 {
784         struct buffer_head *bh;
785         befs_sb_info *befs_sb;
786         befs_super_block *disk_sb;
787         struct inode *root;
788         long ret = -EINVAL;
789         const unsigned long sb_block = 0;
790         const off_t x86_sb_off = 512;
791 
792         save_mount_options(sb, data);
793 
794         sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
795         if (sb->s_fs_info == NULL) {
796                 printk(KERN_ERR
797                        "BeFS(%s): Unable to allocate memory for private "
798                        "portion of superblock. Bailing.\n", sb->s_id);
799                 goto unacquire_none;
800         }
801         befs_sb = BEFS_SB(sb);
802         memset(befs_sb, 0, sizeof(befs_sb_info));
803 
804         if (!parse_options((char *) data, &befs_sb->mount_opts)) {
805                 befs_error(sb, "cannot parse mount options");
806                 goto unacquire_priv_sbp;
807         }
808 
809         befs_debug(sb, "---> befs_fill_super()");
810 
811 #ifndef CONFIG_BEFS_RW
812         if (!(sb->s_flags & MS_RDONLY)) {
813                 befs_warning(sb,
814                              "No write support. Marking filesystem read-only");
815                 sb->s_flags |= MS_RDONLY;
816         }
817 #endif                          /* CONFIG_BEFS_RW */
818 
819         /*
820          * Set dummy blocksize to read super block.
821          * Will be set to real fs blocksize later.
822          *
823          * Linux 2.4.10 and later refuse to read blocks smaller than
824          * the hardsect size for the device. But we also need to read at 
825          * least 1k to get the second 512 bytes of the volume.
826          * -WD 10-26-01
827          */ 
828         sb_min_blocksize(sb, 1024);
829 
830         if (!(bh = sb_bread(sb, sb_block))) {
831                 befs_error(sb, "unable to read superblock");
832                 goto unacquire_priv_sbp;
833         }
834 
835         /* account for offset of super block on x86 */
836         disk_sb = (befs_super_block *) bh->b_data;
837         if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
838             (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
839                 befs_debug(sb, "Using PPC superblock location");
840         } else {
841                 befs_debug(sb, "Using x86 superblock location");
842                 disk_sb =
843                     (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
844         }
845 
846         if (befs_load_sb(sb, disk_sb) != BEFS_OK)
847                 goto unacquire_bh;
848 
849         befs_dump_super_block(sb, disk_sb);
850 
851         brelse(bh);
852 
853         if (befs_check_sb(sb) != BEFS_OK)
854                 goto unacquire_priv_sbp;
855 
856         if( befs_sb->num_blocks > ~((sector_t)0) ) {
857                 befs_error(sb, "blocks count: %Lu "
858                         "is larger than the host can use",
859                         befs_sb->num_blocks);
860                 goto unacquire_priv_sbp;
861         }
862 
863         /*
864          * set up enough so that it can read an inode
865          * Fill in kernel superblock fields from private sb
866          */
867         sb->s_magic = BEFS_SUPER_MAGIC;
868         /* Set real blocksize of fs */
869         sb_set_blocksize(sb, (ulong) befs_sb->block_size);
870         sb->s_op = &befs_sops;
871         root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
872         if (IS_ERR(root)) {
873                 ret = PTR_ERR(root);
874                 goto unacquire_priv_sbp;
875         }
876         sb->s_root = d_make_root(root);
877         if (!sb->s_root) {
878                 befs_error(sb, "get root inode failed");
879                 goto unacquire_priv_sbp;
880         }
881 
882         /* load nls library */
883         if (befs_sb->mount_opts.iocharset) {
884                 befs_debug(sb, "Loading nls: %s",
885                            befs_sb->mount_opts.iocharset);
886                 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
887                 if (!befs_sb->nls) {
888                         befs_warning(sb, "Cannot load nls %s"
889                                         " loading default nls",
890                                         befs_sb->mount_opts.iocharset);
891                         befs_sb->nls = load_nls_default();
892                 }
893         /* load default nls if none is specified  in mount options */
894         } else {
895                 befs_debug(sb, "Loading default nls");
896                 befs_sb->nls = load_nls_default();
897         }
898 
899         return 0;
900 /*****************/
901       unacquire_bh:
902         brelse(bh);
903 
904       unacquire_priv_sbp:
905         kfree(befs_sb->mount_opts.iocharset);
906         kfree(sb->s_fs_info);
907 
908       unacquire_none:
909         sb->s_fs_info = NULL;
910         return ret;
911 }
912 
913 static int
914 befs_remount(struct super_block *sb, int *flags, char *data)
915 {
916         if (!(*flags & MS_RDONLY))
917                 return -EINVAL;
918         return 0;
919 }
920 
921 static int
922 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
923 {
924         struct super_block *sb = dentry->d_sb;
925         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
926 
927         befs_debug(sb, "---> befs_statfs()");
928 
929         buf->f_type = BEFS_SUPER_MAGIC;
930         buf->f_bsize = sb->s_blocksize;
931         buf->f_blocks = BEFS_SB(sb)->num_blocks;
932         buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
933         buf->f_bavail = buf->f_bfree;
934         buf->f_files = 0;       /* UNKNOWN */
935         buf->f_ffree = 0;       /* UNKNOWN */
936         buf->f_fsid.val[0] = (u32)id;
937         buf->f_fsid.val[1] = (u32)(id >> 32);
938         buf->f_namelen = BEFS_NAME_LEN;
939 
940         befs_debug(sb, "<--- befs_statfs()");
941 
942         return 0;
943 }
944 
945 static struct dentry *
946 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
947             void *data)
948 {
949         return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
950 }
951 
952 static struct file_system_type befs_fs_type = {
953         .owner          = THIS_MODULE,
954         .name           = "befs",
955         .mount          = befs_mount,
956         .kill_sb        = kill_block_super,
957         .fs_flags       = FS_REQUIRES_DEV,      
958 };
959 MODULE_ALIAS_FS("befs");
960 
961 static int __init
962 init_befs_fs(void)
963 {
964         int err;
965 
966         printk(KERN_INFO "BeFS version: %s\n", BEFS_VERSION);
967 
968         err = befs_init_inodecache();
969         if (err)
970                 goto unacquire_none;
971 
972         err = register_filesystem(&befs_fs_type);
973         if (err)
974                 goto unacquire_inodecache;
975 
976         return 0;
977 
978 unacquire_inodecache:
979         befs_destroy_inodecache();
980 
981 unacquire_none:
982         return err;
983 }
984 
985 static void __exit
986 exit_befs_fs(void)
987 {
988         befs_destroy_inodecache();
989 
990         unregister_filesystem(&befs_fs_type);
991 }
992 
993 /*
994 Macros that typecheck the init and exit functions,
995 ensures that they are called at init and cleanup,
996 and eliminates warnings about unused functions.
997 */
998 module_init(init_befs_fs)
999 module_exit(exit_befs_fs)
1000 

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