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

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