Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

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 #include <linux/exportfs.h>
 22 
 23 #include "befs.h"
 24 #include "btree.h"
 25 #include "inode.h"
 26 #include "datastream.h"
 27 #include "super.h"
 28 #include "io.h"
 29 
 30 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
 31 MODULE_AUTHOR("Will Dyson");
 32 MODULE_LICENSE("GPL");
 33 
 34 /* The units the vfs expects inode->i_blocks to be in */
 35 #define VFS_BLOCK_SIZE 512
 36 
 37 static int befs_readdir(struct file *, struct dir_context *);
 38 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 39 static int befs_readpage(struct file *file, struct page *page);
 40 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 41 static struct dentry *befs_lookup(struct inode *, struct dentry *,
 42                                   unsigned int);
 43 static struct inode *befs_iget(struct super_block *, unsigned long);
 44 static struct inode *befs_alloc_inode(struct super_block *sb);
 45 static void befs_destroy_inode(struct inode *inode);
 46 static void befs_destroy_inodecache(void);
 47 static int befs_symlink_readpage(struct file *, struct page *);
 48 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
 49                         char **out, int *out_len);
 50 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
 51                         char **out, int *out_len);
 52 static void befs_put_super(struct super_block *);
 53 static int befs_remount(struct super_block *, int *, char *);
 54 static int befs_statfs(struct dentry *, struct kstatfs *);
 55 static int parse_options(char *, struct befs_mount_options *);
 56 static struct dentry *befs_fh_to_dentry(struct super_block *sb,
 57                                 struct fid *fid, int fh_len, int fh_type);
 58 static struct dentry *befs_fh_to_parent(struct super_block *sb,
 59                                 struct fid *fid, int fh_len, int fh_type);
 60 
 61 static const struct super_operations befs_sops = {
 62         .alloc_inode    = befs_alloc_inode,     /* allocate a new inode */
 63         .destroy_inode  = befs_destroy_inode, /* deallocate an inode */
 64         .put_super      = befs_put_super,       /* uninit super */
 65         .statfs         = befs_statfs,  /* statfs */
 66         .remount_fs     = befs_remount,
 67         .show_options   = generic_show_options,
 68 };
 69 
 70 /* slab cache for befs_inode_info objects */
 71 static struct kmem_cache *befs_inode_cachep;
 72 
 73 static const struct file_operations befs_dir_operations = {
 74         .read           = generic_read_dir,
 75         .iterate_shared = befs_readdir,
 76         .llseek         = generic_file_llseek,
 77 };
 78 
 79 static const struct inode_operations befs_dir_inode_operations = {
 80         .lookup         = befs_lookup,
 81 };
 82 
 83 static const struct address_space_operations befs_aops = {
 84         .readpage       = befs_readpage,
 85         .bmap           = befs_bmap,
 86 };
 87 
 88 static const struct address_space_operations befs_symlink_aops = {
 89         .readpage       = befs_symlink_readpage,
 90 };
 91 
 92 static const struct export_operations befs_export_operations = {
 93         .fh_to_dentry   = befs_fh_to_dentry,
 94         .fh_to_parent   = befs_fh_to_parent,
 95 };
 96 
 97 /*
 98  * Called by generic_file_read() to read a page of data
 99  *
100  * In turn, simply calls a generic block read function and
101  * passes it the address of befs_get_block, for mapping file
102  * positions to disk blocks.
103  */
104 static int
105 befs_readpage(struct file *file, struct page *page)
106 {
107         return block_read_full_page(page, befs_get_block);
108 }
109 
110 static sector_t
111 befs_bmap(struct address_space *mapping, sector_t block)
112 {
113         return generic_block_bmap(mapping, block, befs_get_block);
114 }
115 
116 /*
117  * Generic function to map a file position (block) to a
118  * disk offset (passed back in bh_result).
119  *
120  * Used by many higher level functions.
121  *
122  * Calls befs_fblock2brun() in datastream.c to do the real work.
123  */
124 
125 static int
126 befs_get_block(struct inode *inode, sector_t block,
127                struct buffer_head *bh_result, int create)
128 {
129         struct super_block *sb = inode->i_sb;
130         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
131         befs_block_run run = BAD_IADDR;
132         int res;
133         ulong disk_off;
134 
135         befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
136                    (unsigned long)inode->i_ino, (long)block);
137         if (create) {
138                 befs_error(sb, "befs_get_block() was asked to write to "
139                            "block %ld in inode %lu", (long)block,
140                            (unsigned long)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                            "<--- %s for inode %lu, block %ld ERROR",
148                            __func__, (unsigned long)inode->i_ino,
149                            (long)block);
150                 return -EFBIG;
151         }
152 
153         disk_off = (ulong) iaddr2blockno(sb, &run);
154 
155         map_bh(bh_result, inode->i_sb, disk_off);
156 
157         befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
158                   __func__, (unsigned long)inode->i_ino, (long)block,
159                   (unsigned long)disk_off);
160 
161         return 0;
162 }
163 
164 static struct dentry *
165 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
166 {
167         struct inode *inode;
168         struct super_block *sb = dir->i_sb;
169         const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
170         befs_off_t offset;
171         int ret;
172         int utfnamelen;
173         char *utfname;
174         const char *name = dentry->d_name.name;
175 
176         befs_debug(sb, "---> %s name %pd inode %ld", __func__,
177                    dentry, dir->i_ino);
178 
179         /* Convert to UTF-8 */
180         if (BEFS_SB(sb)->nls) {
181                 ret =
182                     befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
183                 if (ret < 0) {
184                         befs_debug(sb, "<--- %s ERROR", __func__);
185                         return ERR_PTR(ret);
186                 }
187                 ret = befs_btree_find(sb, ds, utfname, &offset);
188                 kfree(utfname);
189 
190         } else {
191                 ret = befs_btree_find(sb, ds, name, &offset);
192         }
193 
194         if (ret == BEFS_BT_NOT_FOUND) {
195                 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
196                 d_add(dentry, NULL);
197                 return ERR_PTR(-ENOENT);
198 
199         } else if (ret != BEFS_OK || offset == 0) {
200                 befs_error(sb, "<--- %s Error", __func__);
201                 return ERR_PTR(-ENODATA);
202         }
203 
204         inode = befs_iget(dir->i_sb, (ino_t) offset);
205         if (IS_ERR(inode))
206                 return ERR_CAST(inode);
207 
208         d_add(dentry, inode);
209 
210         befs_debug(sb, "<--- %s", __func__);
211 
212         return NULL;
213 }
214 
215 static int
216 befs_readdir(struct file *file, struct dir_context *ctx)
217 {
218         struct inode *inode = file_inode(file);
219         struct super_block *sb = inode->i_sb;
220         const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
221         befs_off_t value;
222         int result;
223         size_t keysize;
224         char keybuf[BEFS_NAME_LEN + 1];
225 
226         befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
227                   __func__, file, inode->i_ino, ctx->pos);
228 
229         while (1) {
230                 result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
231                                          keybuf, &keysize, &value);
232 
233                 if (result == BEFS_ERR) {
234                         befs_debug(sb, "<--- %s ERROR", __func__);
235                         befs_error(sb, "IO error reading %pD (inode %lu)",
236                                    file, inode->i_ino);
237                         return -EIO;
238 
239                 } else if (result == BEFS_BT_END) {
240                         befs_debug(sb, "<--- %s END", __func__);
241                         return 0;
242 
243                 } else if (result == BEFS_BT_EMPTY) {
244                         befs_debug(sb, "<--- %s Empty directory", __func__);
245                         return 0;
246                 }
247 
248                 /* Convert to NLS */
249                 if (BEFS_SB(sb)->nls) {
250                         char *nlsname;
251                         int nlsnamelen;
252 
253                         result =
254                             befs_utf2nls(sb, keybuf, keysize, &nlsname,
255                                          &nlsnamelen);
256                         if (result < 0) {
257                                 befs_debug(sb, "<--- %s ERROR", __func__);
258                                 return result;
259                         }
260                         if (!dir_emit(ctx, nlsname, nlsnamelen,
261                                       (ino_t) value, DT_UNKNOWN)) {
262                                 kfree(nlsname);
263                                 return 0;
264                         }
265                         kfree(nlsname);
266                 } else {
267                         if (!dir_emit(ctx, keybuf, keysize,
268                                       (ino_t) value, DT_UNKNOWN))
269                                 return 0;
270                 }
271                 ctx->pos++;
272         }
273 }
274 
275 static struct inode *
276 befs_alloc_inode(struct super_block *sb)
277 {
278         struct befs_inode_info *bi;
279 
280         bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
281         if (!bi)
282                 return NULL;
283         return &bi->vfs_inode;
284 }
285 
286 static void befs_i_callback(struct rcu_head *head)
287 {
288         struct inode *inode = container_of(head, struct inode, i_rcu);
289         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
290 }
291 
292 static void befs_destroy_inode(struct inode *inode)
293 {
294         call_rcu(&inode->i_rcu, befs_i_callback);
295 }
296 
297 static void init_once(void *foo)
298 {
299         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
300 
301         inode_init_once(&bi->vfs_inode);
302 }
303 
304 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
305 {
306         struct buffer_head *bh;
307         befs_inode *raw_inode;
308         struct befs_sb_info *befs_sb = BEFS_SB(sb);
309         struct befs_inode_info *befs_ino;
310         struct inode *inode;
311 
312         befs_debug(sb, "---> %s inode = %lu", __func__, ino);
313 
314         inode = iget_locked(sb, ino);
315         if (!inode)
316                 return ERR_PTR(-ENOMEM);
317         if (!(inode->i_state & I_NEW))
318                 return inode;
319 
320         befs_ino = BEFS_I(inode);
321 
322         /* convert from vfs's inode number to befs's inode number */
323         befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
324 
325         befs_debug(sb, "  real inode number [%u, %hu, %hu]",
326                    befs_ino->i_inode_num.allocation_group,
327                    befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
328 
329         bh = sb_bread(sb, inode->i_ino);
330         if (!bh) {
331                 befs_error(sb, "unable to read inode block - "
332                            "inode = %lu", inode->i_ino);
333                 goto unacquire_none;
334         }
335 
336         raw_inode = (befs_inode *) bh->b_data;
337 
338         befs_dump_inode(sb, raw_inode);
339 
340         if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
341                 befs_error(sb, "Bad inode: %lu", inode->i_ino);
342                 goto unacquire_bh;
343         }
344 
345         inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
346 
347         /*
348          * set uid and gid.  But since current BeOS is single user OS, so
349          * you can change by "uid" or "gid" options.
350          */
351 
352         inode->i_uid = befs_sb->mount_opts.use_uid ?
353                 befs_sb->mount_opts.uid :
354                 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
355         inode->i_gid = befs_sb->mount_opts.use_gid ?
356                 befs_sb->mount_opts.gid :
357                 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
358 
359         set_nlink(inode, 1);
360 
361         /*
362          * BEFS's time is 64 bits, but current VFS is 32 bits...
363          * BEFS don't have access time. Nor inode change time. VFS
364          * doesn't have creation time.
365          * Also, the lower 16 bits of the last_modified_time and
366          * create_time are just a counter to help ensure uniqueness
367          * for indexing purposes. (PFD, page 54)
368          */
369 
370         inode->i_mtime.tv_sec =
371             fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
372         inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */
373         inode->i_ctime = inode->i_mtime;
374         inode->i_atime = inode->i_mtime;
375 
376         befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
377         befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
378         befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
379         befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
380 
381         if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
382                 inode->i_size = 0;
383                 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
384                 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
385                         BEFS_SYMLINK_LEN);
386         } else {
387                 int num_blks;
388 
389                 befs_ino->i_data.ds =
390                     fsds_to_cpu(sb, &raw_inode->data.datastream);
391 
392                 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
393                 inode->i_blocks =
394                     num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
395                 inode->i_size = befs_ino->i_data.ds.size;
396         }
397 
398         inode->i_mapping->a_ops = &befs_aops;
399 
400         if (S_ISREG(inode->i_mode)) {
401                 inode->i_fop = &generic_ro_fops;
402         } else if (S_ISDIR(inode->i_mode)) {
403                 inode->i_op = &befs_dir_inode_operations;
404                 inode->i_fop = &befs_dir_operations;
405         } else if (S_ISLNK(inode->i_mode)) {
406                 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
407                         inode->i_op = &page_symlink_inode_operations;
408                         inode_nohighmem(inode);
409                         inode->i_mapping->a_ops = &befs_symlink_aops;
410                 } else {
411                         inode->i_link = befs_ino->i_data.symlink;
412                         inode->i_op = &simple_symlink_inode_operations;
413                 }
414         } else {
415                 befs_error(sb, "Inode %lu is not a regular file, "
416                            "directory or symlink. THAT IS WRONG! BeFS has no "
417                            "on disk special files", inode->i_ino);
418                 goto unacquire_bh;
419         }
420 
421         brelse(bh);
422         befs_debug(sb, "<--- %s", __func__);
423         unlock_new_inode(inode);
424         return inode;
425 
426 unacquire_bh:
427         brelse(bh);
428 
429 unacquire_none:
430         iget_failed(inode);
431         befs_debug(sb, "<--- %s - Bad inode", __func__);
432         return ERR_PTR(-EIO);
433 }
434 
435 /* Initialize the inode cache. Called at fs setup.
436  *
437  * Taken from NFS implementation by Al Viro.
438  */
439 static int __init
440 befs_init_inodecache(void)
441 {
442         befs_inode_cachep = kmem_cache_create("befs_inode_cache",
443                                               sizeof (struct befs_inode_info),
444                                               0, (SLAB_RECLAIM_ACCOUNT|
445                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
446                                               init_once);
447         if (befs_inode_cachep == NULL)
448                 return -ENOMEM;
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 int befs_symlink_readpage(struct file *unused, struct page *page)
474 {
475         struct inode *inode = page->mapping->host;
476         struct super_block *sb = inode->i_sb;
477         struct befs_inode_info *befs_ino = BEFS_I(inode);
478         befs_data_stream *data = &befs_ino->i_data.ds;
479         befs_off_t len = data->size;
480         char *link = page_address(page);
481 
482         if (len == 0 || len > PAGE_SIZE) {
483                 befs_error(sb, "Long symlink with illegal length");
484                 goto fail;
485         }
486         befs_debug(sb, "Follow long symlink");
487 
488         if (befs_read_lsymlink(sb, data, link, len) != len) {
489                 befs_error(sb, "Failed to read entire long symlink");
490                 goto fail;
491         }
492         link[len - 1] = '\0';
493         SetPageUptodate(page);
494         unlock_page(page);
495         return 0;
496 fail:
497         SetPageError(page);
498         unlock_page(page);
499         return -EIO;
500 }
501 
502 /*
503  * UTF-8 to NLS charset convert routine
504  *
505  * Uses uni2char() / char2uni() rather than the nls tables directly
506  */
507 static int
508 befs_utf2nls(struct super_block *sb, const char *in,
509              int in_len, char **out, int *out_len)
510 {
511         struct nls_table *nls = BEFS_SB(sb)->nls;
512         int i, o;
513         unicode_t uni;
514         int unilen, utflen;
515         char *result;
516         /* The utf8->nls conversion won't make the final nls string bigger
517          * than the utf one, but if the string is pure ascii they'll have the
518          * same width and an extra char is needed to save the additional \0
519          */
520         int maxlen = in_len + 1;
521 
522         befs_debug(sb, "---> %s", __func__);
523 
524         if (!nls) {
525                 befs_error(sb, "%s called with no NLS table loaded", __func__);
526                 return -EINVAL;
527         }
528 
529         *out = result = kmalloc(maxlen, GFP_NOFS);
530         if (!*out)
531                 return -ENOMEM;
532 
533         for (i = o = 0; i < in_len; i += utflen, o += unilen) {
534 
535                 /* convert from UTF-8 to Unicode */
536                 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
537                 if (utflen < 0)
538                         goto conv_err;
539 
540                 /* convert from Unicode to nls */
541                 if (uni > MAX_WCHAR_T)
542                         goto conv_err;
543                 unilen = nls->uni2char(uni, &result[o], in_len - o);
544                 if (unilen < 0)
545                         goto conv_err;
546         }
547         result[o] = '\0';
548         *out_len = o;
549 
550         befs_debug(sb, "<--- %s", __func__);
551 
552         return o;
553 
554 conv_err:
555         befs_error(sb, "Name using character set %s contains a character that "
556                    "cannot be converted to unicode.", nls->charset);
557         befs_debug(sb, "<--- %s", __func__);
558         kfree(result);
559         return -EILSEQ;
560 }
561 
562 /**
563  * befs_nls2utf - Convert NLS string to utf8 encodeing
564  * @sb: Superblock
565  * @in: Input string buffer in NLS format
566  * @in_len: Length of input string in bytes
567  * @out: The output string in UTF-8 format
568  * @out_len: Length of the output buffer
569  *
570  * Converts input string @in, which is in the format of the loaded NLS map,
571  * into a utf8 string.
572  *
573  * The destination string @out is allocated by this function and the caller is
574  * responsible for freeing it with kfree()
575  *
576  * On return, *@out_len is the length of @out in bytes.
577  *
578  * On success, the return value is the number of utf8 characters written to
579  * the output buffer @out.
580  *
581  * On Failure, a negative number coresponding to the error code is returned.
582  */
583 
584 static int
585 befs_nls2utf(struct super_block *sb, const char *in,
586              int in_len, char **out, int *out_len)
587 {
588         struct nls_table *nls = BEFS_SB(sb)->nls;
589         int i, o;
590         wchar_t uni;
591         int unilen, utflen;
592         char *result;
593         /*
594          * There are nls characters that will translate to 3-chars-wide UTF-8
595          * characters, an additional byte is needed to save the final \0
596          * in special cases
597          */
598         int maxlen = (3 * in_len) + 1;
599 
600         befs_debug(sb, "---> %s\n", __func__);
601 
602         if (!nls) {
603                 befs_error(sb, "%s called with no NLS table loaded.",
604                            __func__);
605                 return -EINVAL;
606         }
607 
608         *out = result = kmalloc(maxlen, GFP_NOFS);
609         if (!*out) {
610                 *out_len = 0;
611                 return -ENOMEM;
612         }
613 
614         for (i = o = 0; i < in_len; i += unilen, o += utflen) {
615 
616                 /* convert from nls to unicode */
617                 unilen = nls->char2uni(&in[i], in_len - i, &uni);
618                 if (unilen < 0)
619                         goto conv_err;
620 
621                 /* convert from unicode to UTF-8 */
622                 utflen = utf32_to_utf8(uni, &result[o], 3);
623                 if (utflen <= 0)
624                         goto conv_err;
625         }
626 
627         result[o] = '\0';
628         *out_len = o;
629 
630         befs_debug(sb, "<--- %s", __func__);
631 
632         return i;
633 
634 conv_err:
635         befs_error(sb, "Name using character set %s contains a character that "
636                    "cannot be converted to unicode.", nls->charset);
637         befs_debug(sb, "<--- %s", __func__);
638         kfree(result);
639         return -EILSEQ;
640 }
641 
642 static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
643                                          uint32_t generation)
644 {
645         /* No need to handle i_generation */
646         return befs_iget(sb, ino);
647 }
648 
649 /*
650  * Map a NFS file handle to a corresponding dentry
651  */
652 static struct dentry *befs_fh_to_dentry(struct super_block *sb,
653                                 struct fid *fid, int fh_len, int fh_type)
654 {
655         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
656                                     befs_nfs_get_inode);
657 }
658 
659 /*
660  * Find the parent for a file specified by NFS handle
661  */
662 static struct dentry *befs_fh_to_parent(struct super_block *sb,
663                                 struct fid *fid, int fh_len, int fh_type)
664 {
665         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
666                                     befs_nfs_get_inode);
667 }
668 
669 enum {
670         Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
671 };
672 
673 static const match_table_t befs_tokens = {
674         {Opt_uid, "uid=%d"},
675         {Opt_gid, "gid=%d"},
676         {Opt_charset, "iocharset=%s"},
677         {Opt_debug, "debug"},
678         {Opt_err, NULL}
679 };
680 
681 static int
682 parse_options(char *options, struct befs_mount_options *opts)
683 {
684         char *p;
685         substring_t args[MAX_OPT_ARGS];
686         int option;
687         kuid_t uid;
688         kgid_t gid;
689 
690         /* Initialize options */
691         opts->uid = GLOBAL_ROOT_UID;
692         opts->gid = GLOBAL_ROOT_GID;
693         opts->use_uid = 0;
694         opts->use_gid = 0;
695         opts->iocharset = NULL;
696         opts->debug = 0;
697 
698         if (!options)
699                 return 1;
700 
701         while ((p = strsep(&options, ",")) != NULL) {
702                 int token;
703 
704                 if (!*p)
705                         continue;
706 
707                 token = match_token(p, befs_tokens, args);
708                 switch (token) {
709                 case Opt_uid:
710                         if (match_int(&args[0], &option))
711                                 return 0;
712                         uid = INVALID_UID;
713                         if (option >= 0)
714                                 uid = make_kuid(current_user_ns(), option);
715                         if (!uid_valid(uid)) {
716                                 pr_err("Invalid uid %d, "
717                                        "using default\n", option);
718                                 break;
719                         }
720                         opts->uid = uid;
721                         opts->use_uid = 1;
722                         break;
723                 case Opt_gid:
724                         if (match_int(&args[0], &option))
725                                 return 0;
726                         gid = INVALID_GID;
727                         if (option >= 0)
728                                 gid = make_kgid(current_user_ns(), option);
729                         if (!gid_valid(gid)) {
730                                 pr_err("Invalid gid %d, "
731                                        "using default\n", option);
732                                 break;
733                         }
734                         opts->gid = gid;
735                         opts->use_gid = 1;
736                         break;
737                 case Opt_charset:
738                         kfree(opts->iocharset);
739                         opts->iocharset = match_strdup(&args[0]);
740                         if (!opts->iocharset) {
741                                 pr_err("allocation failure for "
742                                        "iocharset string\n");
743                                 return 0;
744                         }
745                         break;
746                 case Opt_debug:
747                         opts->debug = 1;
748                         break;
749                 default:
750                         pr_err("Unrecognized mount option \"%s\" "
751                                "or missing value\n", p);
752                         return 0;
753                 }
754         }
755         return 1;
756 }
757 
758 /* This function has the responsibiltiy of getting the
759  * filesystem ready for unmounting.
760  * Basically, we free everything that we allocated in
761  * befs_read_inode
762  */
763 static void
764 befs_put_super(struct super_block *sb)
765 {
766         kfree(BEFS_SB(sb)->mount_opts.iocharset);
767         BEFS_SB(sb)->mount_opts.iocharset = NULL;
768         unload_nls(BEFS_SB(sb)->nls);
769         kfree(sb->s_fs_info);
770         sb->s_fs_info = NULL;
771 }
772 
773 /* Allocate private field of the superblock, fill it.
774  *
775  * Finish filling the public superblock fields
776  * Make the root directory
777  * Load a set of NLS translations if needed.
778  */
779 static int
780 befs_fill_super(struct super_block *sb, void *data, int silent)
781 {
782         struct buffer_head *bh;
783         struct befs_sb_info *befs_sb;
784         befs_super_block *disk_sb;
785         struct inode *root;
786         long ret = -EINVAL;
787         const unsigned long sb_block = 0;
788         const off_t x86_sb_off = 512;
789         int blocksize;
790 
791         save_mount_options(sb, data);
792 
793         sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
794         if (sb->s_fs_info == NULL)
795                 goto unacquire_none;
796 
797         befs_sb = BEFS_SB(sb);
798 
799         if (!parse_options((char *) data, &befs_sb->mount_opts)) {
800                 if (!silent)
801                         befs_error(sb, "cannot parse mount options");
802                 goto unacquire_priv_sbp;
803         }
804 
805         befs_debug(sb, "---> %s", __func__);
806 
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 
813         /*
814          * Set dummy blocksize to read super block.
815          * Will be set to real fs blocksize later.
816          *
817          * Linux 2.4.10 and later refuse to read blocks smaller than
818          * the logical block size for the device. But we also need to read at
819          * least 1k to get the second 512 bytes of the volume.
820          */
821         blocksize = sb_min_blocksize(sb, 1024);
822         if (!blocksize) {
823                 if (!silent)
824                         befs_error(sb, "unable to set blocksize");
825                 goto unacquire_priv_sbp;
826         }
827 
828         bh = sb_bread(sb, sb_block);
829         if (!bh) {
830                 if (!silent)
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             (befs_check_sb(sb) != BEFS_OK))
848                 goto unacquire_bh;
849 
850         befs_dump_super_block(sb, disk_sb);
851 
852         brelse(bh);
853 
854         if (befs_sb->num_blocks > ~((sector_t)0)) {
855                 if (!silent)
856                         befs_error(sb, "blocks count: %llu is larger than the host can use",
857                                         befs_sb->num_blocks);
858                 goto unacquire_priv_sbp;
859         }
860 
861         /*
862          * set up enough so that it can read an inode
863          * Fill in kernel superblock fields from private sb
864          */
865         sb->s_magic = BEFS_SUPER_MAGIC;
866         /* Set real blocksize of fs */
867         sb_set_blocksize(sb, (ulong) befs_sb->block_size);
868         sb->s_op = &befs_sops;
869         sb->s_export_op = &befs_export_operations;
870         root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
871         if (IS_ERR(root)) {
872                 ret = PTR_ERR(root);
873                 goto unacquire_priv_sbp;
874         }
875         sb->s_root = d_make_root(root);
876         if (!sb->s_root) {
877                 if (!silent)
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         sb->s_fs_info = NULL;
908 
909 unacquire_none:
910         return ret;
911 }
912 
913 static int
914 befs_remount(struct super_block *sb, int *flags, char *data)
915 {
916         sync_filesystem(sb);
917         if (!(*flags & MS_RDONLY))
918                 return -EINVAL;
919         return 0;
920 }
921 
922 static int
923 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
924 {
925         struct super_block *sb = dentry->d_sb;
926         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
927 
928         befs_debug(sb, "---> %s", __func__);
929 
930         buf->f_type = BEFS_SUPER_MAGIC;
931         buf->f_bsize = sb->s_blocksize;
932         buf->f_blocks = BEFS_SB(sb)->num_blocks;
933         buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
934         buf->f_bavail = buf->f_bfree;
935         buf->f_files = 0;       /* UNKNOWN */
936         buf->f_ffree = 0;       /* UNKNOWN */
937         buf->f_fsid.val[0] = (u32)id;
938         buf->f_fsid.val[1] = (u32)(id >> 32);
939         buf->f_namelen = BEFS_NAME_LEN;
940 
941         befs_debug(sb, "<--- %s", __func__);
942 
943         return 0;
944 }
945 
946 static struct dentry *
947 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
948             void *data)
949 {
950         return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
951 }
952 
953 static struct file_system_type befs_fs_type = {
954         .owner          = THIS_MODULE,
955         .name           = "befs",
956         .mount          = befs_mount,
957         .kill_sb        = kill_block_super,
958         .fs_flags       = FS_REQUIRES_DEV,
959 };
960 MODULE_ALIAS_FS("befs");
961 
962 static int __init
963 init_befs_fs(void)
964 {
965         int err;
966 
967         pr_info("version: %s\n", BEFS_VERSION);
968 
969         err = befs_init_inodecache();
970         if (err)
971                 goto unacquire_none;
972 
973         err = register_filesystem(&befs_fs_type);
974         if (err)
975                 goto unacquire_inodecache;
976 
977         return 0;
978 
979 unacquire_inodecache:
980         befs_destroy_inodecache();
981 
982 unacquire_none:
983         return err;
984 }
985 
986 static void __exit
987 exit_befs_fs(void)
988 {
989         befs_destroy_inodecache();
990 
991         unregister_filesystem(&befs_fs_type);
992 }
993 
994 /*
995  * Macros that typecheck the init and exit functions,
996  * ensures that they are called at init and cleanup,
997  * and eliminates warnings about unused functions.
998  */
999 module_init(init_befs_fs)
1000 module_exit(exit_befs_fs)
1001 

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