Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

Linux/fs/befs/linuxvfs.c

  1 /*
  2  * linux/fs/befs/linuxvfs.c
  3  *
  4  * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
  5  *
  6  */
  7 
  8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  9 
 10 #include <linux/module.h>
 11 #include <linux/slab.h>
 12 #include <linux/fs.h>
 13 #include <linux/errno.h>
 14 #include <linux/stat.h>
 15 #include <linux/nls.h>
 16 #include <linux/buffer_head.h>
 17 #include <linux/vfs.h>
 18 #include <linux/parser.h>
 19 #include <linux/namei.h>
 20 #include <linux/sched.h>
 21 
 22 #include "befs.h"
 23 #include "btree.h"
 24 #include "inode.h"
 25 #include "datastream.h"
 26 #include "super.h"
 27 #include "io.h"
 28 
 29 MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
 30 MODULE_AUTHOR("Will Dyson");
 31 MODULE_LICENSE("GPL");
 32 
 33 /* The units the vfs expects inode->i_blocks to be in */
 34 #define VFS_BLOCK_SIZE 512
 35 
 36 static int befs_readdir(struct file *, struct dir_context *);
 37 static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
 38 static int befs_readpage(struct file *file, struct page *page);
 39 static sector_t befs_bmap(struct address_space *mapping, sector_t block);
 40 static struct dentry *befs_lookup(struct inode *, struct dentry *, unsigned int);
 41 static struct inode *befs_iget(struct super_block *, unsigned long);
 42 static struct inode *befs_alloc_inode(struct super_block *sb);
 43 static void befs_destroy_inode(struct inode *inode);
 44 static void befs_destroy_inodecache(void);
 45 static int befs_symlink_readpage(struct file *, struct page *);
 46 static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
 47                         char **out, int *out_len);
 48 static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
 49                         char **out, int *out_len);
 50 static void befs_put_super(struct super_block *);
 51 static int befs_remount(struct super_block *, int *, char *);
 52 static int befs_statfs(struct dentry *, struct kstatfs *);
 53 static int parse_options(char *, struct befs_mount_options *);
 54 
 55 static const struct super_operations befs_sops = {
 56         .alloc_inode    = befs_alloc_inode,     /* allocate a new inode */
 57         .destroy_inode  = befs_destroy_inode, /* deallocate an inode */
 58         .put_super      = befs_put_super,       /* uninit super */
 59         .statfs         = befs_statfs,  /* statfs */
 60         .remount_fs     = befs_remount,
 61         .show_options   = generic_show_options,
 62 };
 63 
 64 /* slab cache for befs_inode_info objects */
 65 static struct kmem_cache *befs_inode_cachep;
 66 
 67 static const struct file_operations befs_dir_operations = {
 68         .read           = generic_read_dir,
 69         .iterate        = befs_readdir,
 70         .llseek         = generic_file_llseek,
 71 };
 72 
 73 static const struct inode_operations befs_dir_inode_operations = {
 74         .lookup         = befs_lookup,
 75 };
 76 
 77 static const struct address_space_operations befs_aops = {
 78         .readpage       = befs_readpage,
 79         .bmap           = befs_bmap,
 80 };
 81 
 82 static const struct address_space_operations befs_symlink_aops = {
 83         .readpage       = befs_symlink_readpage,
 84 };
 85 
 86 /* 
 87  * Called by generic_file_read() to read a page of data
 88  * 
 89  * In turn, simply calls a generic block read function and
 90  * passes it the address of befs_get_block, for mapping file
 91  * positions to disk blocks.
 92  */
 93 static int
 94 befs_readpage(struct file *file, struct page *page)
 95 {
 96         return block_read_full_page(page, befs_get_block);
 97 }
 98 
 99 static sector_t
100 befs_bmap(struct address_space *mapping, sector_t block)
101 {
102         return generic_block_bmap(mapping, block, befs_get_block);
103 }
104 
105 /* 
106  * Generic function to map a file position (block) to a 
107  * disk offset (passed back in bh_result).
108  *
109  * Used by many higher level functions.
110  *
111  * Calls befs_fblock2brun() in datastream.c to do the real work.
112  *
113  * -WD 10-26-01
114  */
115 
116 static int
117 befs_get_block(struct inode *inode, sector_t block,
118                struct buffer_head *bh_result, int create)
119 {
120         struct super_block *sb = inode->i_sb;
121         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
122         befs_block_run run = BAD_IADDR;
123         int res = 0;
124         ulong disk_off;
125 
126         befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
127                    (unsigned long)inode->i_ino, (long)block);
128         if (create) {
129                 befs_error(sb, "befs_get_block() was asked to write to "
130                            "block %ld in inode %lu", (long)block,
131                            (unsigned long)inode->i_ino);
132                 return -EPERM;
133         }
134 
135         res = befs_fblock2brun(sb, ds, block, &run);
136         if (res != BEFS_OK) {
137                 befs_error(sb,
138                            "<--- %s for inode %lu, block %ld ERROR",
139                            __func__, (unsigned long)inode->i_ino,
140                            (long)block);
141                 return -EFBIG;
142         }
143 
144         disk_off = (ulong) iaddr2blockno(sb, &run);
145 
146         map_bh(bh_result, inode->i_sb, disk_off);
147 
148         befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
149                   __func__, (unsigned long)inode->i_ino, (long)block,
150                   (unsigned long)disk_off);
151 
152         return 0;
153 }
154 
155 static struct dentry *
156 befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
157 {
158         struct inode *inode = NULL;
159         struct super_block *sb = dir->i_sb;
160         befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
161         befs_off_t offset;
162         int ret;
163         int utfnamelen;
164         char *utfname;
165         const char *name = dentry->d_name.name;
166 
167         befs_debug(sb, "---> %s name %pd inode %ld", __func__,
168                    dentry, dir->i_ino);
169 
170         /* Convert to UTF-8 */
171         if (BEFS_SB(sb)->nls) {
172                 ret =
173                     befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
174                 if (ret < 0) {
175                         befs_debug(sb, "<--- %s ERROR", __func__);
176                         return ERR_PTR(ret);
177                 }
178                 ret = befs_btree_find(sb, ds, utfname, &offset);
179                 kfree(utfname);
180 
181         } else {
182                 ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
183         }
184 
185         if (ret == BEFS_BT_NOT_FOUND) {
186                 befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
187                 return ERR_PTR(-ENOENT);
188 
189         } else if (ret != BEFS_OK || offset == 0) {
190                 befs_warning(sb, "<--- %s Error", __func__);
191                 return ERR_PTR(-ENODATA);
192         }
193 
194         inode = befs_iget(dir->i_sb, (ino_t) offset);
195         if (IS_ERR(inode))
196                 return ERR_CAST(inode);
197 
198         d_add(dentry, inode);
199 
200         befs_debug(sb, "<--- %s", __func__);
201 
202         return NULL;
203 }
204 
205 static int
206 befs_readdir(struct file *file, struct dir_context *ctx)
207 {
208         struct inode *inode = file_inode(file);
209         struct super_block *sb = inode->i_sb;
210         befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
211         befs_off_t value;
212         int result;
213         size_t keysize;
214         unsigned char d_type;
215         char keybuf[BEFS_NAME_LEN + 1];
216 
217         befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
218                   __func__, file, inode->i_ino, ctx->pos);
219 
220 more:
221         result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
222                                  keybuf, &keysize, &value);
223 
224         if (result == BEFS_ERR) {
225                 befs_debug(sb, "<--- %s ERROR", __func__);
226                 befs_error(sb, "IO error reading %pD (inode %lu)",
227                            file, inode->i_ino);
228                 return -EIO;
229 
230         } else if (result == BEFS_BT_END) {
231                 befs_debug(sb, "<--- %s END", __func__);
232                 return 0;
233 
234         } else if (result == BEFS_BT_EMPTY) {
235                 befs_debug(sb, "<--- %s Empty directory", __func__);
236                 return 0;
237         }
238 
239         d_type = DT_UNKNOWN;
240 
241         /* Convert to NLS */
242         if (BEFS_SB(sb)->nls) {
243                 char *nlsname;
244                 int nlsnamelen;
245                 result =
246                     befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
247                 if (result < 0) {
248                         befs_debug(sb, "<--- %s ERROR", __func__);
249                         return result;
250                 }
251                 if (!dir_emit(ctx, nlsname, nlsnamelen,
252                                  (ino_t) value, d_type)) {
253                         kfree(nlsname);
254                         return 0;
255                 }
256                 kfree(nlsname);
257         } else {
258                 if (!dir_emit(ctx, keybuf, keysize,
259                                  (ino_t) value, d_type))
260                         return 0;
261         }
262         ctx->pos++;
263         goto more;
264 }
265 
266 static struct inode *
267 befs_alloc_inode(struct super_block *sb)
268 {
269         struct befs_inode_info *bi;
270 
271         bi = kmem_cache_alloc(befs_inode_cachep, GFP_KERNEL);
272         if (!bi)
273                 return NULL;
274         return &bi->vfs_inode;
275 }
276 
277 static void befs_i_callback(struct rcu_head *head)
278 {
279         struct inode *inode = container_of(head, struct inode, i_rcu);
280         kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
281 }
282 
283 static void befs_destroy_inode(struct inode *inode)
284 {
285         call_rcu(&inode->i_rcu, befs_i_callback);
286 }
287 
288 static void init_once(void *foo)
289 {
290         struct befs_inode_info *bi = (struct befs_inode_info *) foo;
291 
292         inode_init_once(&bi->vfs_inode);
293 }
294 
295 static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
296 {
297         struct buffer_head *bh = NULL;
298         befs_inode *raw_inode = NULL;
299         struct befs_sb_info *befs_sb = BEFS_SB(sb);
300         struct befs_inode_info *befs_ino = NULL;
301         struct inode *inode;
302         long ret = -EIO;
303 
304         befs_debug(sb, "---> %s inode = %lu", __func__, ino);
305 
306         inode = iget_locked(sb, ino);
307         if (!inode)
308                 return ERR_PTR(-ENOMEM);
309         if (!(inode->i_state & I_NEW))
310                 return inode;
311 
312         befs_ino = BEFS_I(inode);
313 
314         /* convert from vfs's inode number to befs's inode number */
315         befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
316 
317         befs_debug(sb, "  real inode number [%u, %hu, %hu]",
318                    befs_ino->i_inode_num.allocation_group,
319                    befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
320 
321         bh = befs_bread(sb, inode->i_ino);
322         if (!bh) {
323                 befs_error(sb, "unable to read inode block - "
324                            "inode = %lu", inode->i_ino);
325                 goto unacquire_none;
326         }
327 
328         raw_inode = (befs_inode *) bh->b_data;
329 
330         befs_dump_inode(sb, raw_inode);
331 
332         if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
333                 befs_error(sb, "Bad inode: %lu", inode->i_ino);
334                 goto unacquire_bh;
335         }
336 
337         inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
338 
339         /*
340          * set uid and gid.  But since current BeOS is single user OS, so
341          * you can change by "uid" or "gid" options.
342          */   
343 
344         inode->i_uid = befs_sb->mount_opts.use_uid ?
345                 befs_sb->mount_opts.uid :
346                 make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
347         inode->i_gid = befs_sb->mount_opts.use_gid ?
348                 befs_sb->mount_opts.gid :
349                 make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
350 
351         set_nlink(inode, 1);
352 
353         /*
354          * BEFS's time is 64 bits, but current VFS is 32 bits...
355          * BEFS don't have access time. Nor inode change time. VFS
356          * doesn't have creation time.
357          * Also, the lower 16 bits of the last_modified_time and 
358          * create_time are just a counter to help ensure uniqueness
359          * for indexing purposes. (PFD, page 54)
360          */
361 
362         inode->i_mtime.tv_sec =
363             fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
364         inode->i_mtime.tv_nsec = 0;   /* lower 16 bits are not a time */        
365         inode->i_ctime = inode->i_mtime;
366         inode->i_atime = inode->i_mtime;
367 
368         befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
369         befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
370         befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
371         befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
372 
373         if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
374                 inode->i_size = 0;
375                 inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
376                 strlcpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
377                         BEFS_SYMLINK_LEN);
378         } else {
379                 int num_blks;
380 
381                 befs_ino->i_data.ds =
382                     fsds_to_cpu(sb, &raw_inode->data.datastream);
383 
384                 num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
385                 inode->i_blocks =
386                     num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
387                 inode->i_size = befs_ino->i_data.ds.size;
388         }
389 
390         inode->i_mapping->a_ops = &befs_aops;
391 
392         if (S_ISREG(inode->i_mode)) {
393                 inode->i_fop = &generic_ro_fops;
394         } else if (S_ISDIR(inode->i_mode)) {
395                 inode->i_op = &befs_dir_inode_operations;
396                 inode->i_fop = &befs_dir_operations;
397         } else if (S_ISLNK(inode->i_mode)) {
398                 if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
399                         inode->i_op = &page_symlink_inode_operations;
400                         inode_nohighmem(inode);
401                         inode->i_mapping->a_ops = &befs_symlink_aops;
402                 } else {
403                         inode->i_link = befs_ino->i_data.symlink;
404                         inode->i_op = &simple_symlink_inode_operations;
405                 }
406         } else {
407                 befs_error(sb, "Inode %lu is not a regular file, "
408                            "directory or symlink. THAT IS WRONG! BeFS has no "
409                            "on disk special files", inode->i_ino);
410                 goto unacquire_bh;
411         }
412 
413         brelse(bh);
414         befs_debug(sb, "<--- %s", __func__);
415         unlock_new_inode(inode);
416         return inode;
417 
418       unacquire_bh:
419         brelse(bh);
420 
421       unacquire_none:
422         iget_failed(inode);
423         befs_debug(sb, "<--- %s - Bad inode", __func__);
424         return ERR_PTR(ret);
425 }
426 
427 /* Initialize the inode cache. Called at fs setup.
428  *
429  * Taken from NFS implementation by Al Viro.
430  */
431 static int __init
432 befs_init_inodecache(void)
433 {
434         befs_inode_cachep = kmem_cache_create("befs_inode_cache",
435                                               sizeof (struct befs_inode_info),
436                                               0, (SLAB_RECLAIM_ACCOUNT|
437                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
438                                               init_once);
439         if (befs_inode_cachep == NULL) {
440                 pr_err("%s: Couldn't initialize inode slabcache\n", __func__);
441                 return -ENOMEM;
442         }
443         return 0;
444 }
445 
446 /* Called at fs teardown.
447  * 
448  * Taken from NFS implementation by Al Viro.
449  */
450 static void
451 befs_destroy_inodecache(void)
452 {
453         /*
454          * Make sure all delayed rcu free inodes are flushed before we
455          * destroy cache.
456          */
457         rcu_barrier();
458         kmem_cache_destroy(befs_inode_cachep);
459 }
460 
461 /*
462  * The inode of symbolic link is different to data stream.
463  * The data stream become link name. Unless the LONG_SYMLINK
464  * flag is set.
465  */
466 static int befs_symlink_readpage(struct file *unused, struct page *page)
467 {
468         struct inode *inode = page->mapping->host;
469         struct super_block *sb = inode->i_sb;
470         struct befs_inode_info *befs_ino = BEFS_I(inode);
471         befs_data_stream *data = &befs_ino->i_data.ds;
472         befs_off_t len = data->size;
473         char *link = page_address(page);
474 
475         if (len == 0 || len > PAGE_SIZE) {
476                 befs_error(sb, "Long symlink with illegal length");
477                 goto fail;
478         }
479         befs_debug(sb, "Follow long symlink");
480 
481         if (befs_read_lsymlink(sb, data, link, len) != len) {
482                 befs_error(sb, "Failed to read entire long symlink");
483                 goto fail;
484         }
485         link[len - 1] = '\0';
486         SetPageUptodate(page);
487         unlock_page(page);
488         return 0;
489 fail:
490         SetPageError(page);
491         unlock_page(page);
492         return -EIO;
493 }
494 
495 /*
496  * UTF-8 to NLS charset  convert routine
497  * 
498  *
499  * Changed 8/10/01 by Will Dyson. Now use uni2char() / char2uni() rather than
500  * the nls tables directly
501  */
502 
503 static int
504 befs_utf2nls(struct super_block *sb, const char *in,
505              int in_len, char **out, int *out_len)
506 {
507         struct nls_table *nls = BEFS_SB(sb)->nls;
508         int i, o;
509         unicode_t uni;
510         int unilen, utflen;
511         char *result;
512         /* The utf8->nls conversion won't make the final nls string bigger
513          * than the utf one, but if the string is pure ascii they'll have the
514          * same width and an extra char is needed to save the additional \0
515          */
516         int maxlen = in_len + 1;
517 
518         befs_debug(sb, "---> %s", __func__);
519 
520         if (!nls) {
521                 befs_error(sb, "%s called with no NLS table loaded", __func__);
522                 return -EINVAL;
523         }
524 
525         *out = result = kmalloc(maxlen, GFP_NOFS);
526         if (!*out) {
527                 befs_error(sb, "%s cannot allocate memory", __func__);
528                 *out_len = 0;
529                 return -ENOMEM;
530         }
531 
532         for (i = o = 0; i < in_len; i += utflen, o += unilen) {
533 
534                 /* convert from UTF-8 to Unicode */
535                 utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
536                 if (utflen < 0)
537                         goto conv_err;
538 
539                 /* convert from Unicode to nls */
540                 if (uni > MAX_WCHAR_T)
541                         goto conv_err;
542                 unilen = nls->uni2char(uni, &result[o], in_len - o);
543                 if (unilen < 0)
544                         goto conv_err;
545         }
546         result[o] = '\0';
547         *out_len = o;
548 
549         befs_debug(sb, "<--- %s", __func__);
550 
551         return o;
552 
553       conv_err:
554         befs_error(sb, "Name using character set %s contains a character that "
555                    "cannot be converted to unicode.", nls->charset);
556         befs_debug(sb, "<--- %s", __func__);
557         kfree(result);
558         return -EILSEQ;
559 }
560 
561 /**
562  * befs_nls2utf - Convert NLS string to utf8 encodeing
563  * @sb: Superblock
564  * @in: Input string buffer in NLS format
565  * @in_len: Length of input string in bytes
566  * @out: The output string in UTF-8 format
567  * @out_len: Length of the output buffer
568  * 
569  * Converts input string @in, which is in the format of the loaded NLS map,
570  * into a utf8 string.
571  * 
572  * The destination string @out is allocated by this function and the caller is
573  * responsible for freeing it with kfree()
574  * 
575  * On return, *@out_len is the length of @out in bytes.
576  *
577  * On success, the return value is the number of utf8 characters written to
578  * the output buffer @out.
579  *  
580  * On Failure, a negative number coresponding to the error code is returned.
581  */
582 
583 static int
584 befs_nls2utf(struct super_block *sb, const char *in,
585              int in_len, char **out, int *out_len)
586 {
587         struct nls_table *nls = BEFS_SB(sb)->nls;
588         int i, o;
589         wchar_t uni;
590         int unilen, utflen;
591         char *result;
592         /* There're nls characters that will translate to 3-chars-wide UTF-8
593          * characters, a additional byte is needed to save the final \0
594          * in special cases */
595         int maxlen = (3 * in_len) + 1;
596 
597         befs_debug(sb, "---> %s\n", __func__);
598 
599         if (!nls) {
600                 befs_error(sb, "%s called with no NLS table loaded.",
601                            __func__);
602                 return -EINVAL;
603         }
604 
605         *out = result = kmalloc(maxlen, GFP_NOFS);
606         if (!*out) {
607                 befs_error(sb, "%s cannot allocate memory", __func__);
608                 *out_len = 0;
609                 return -ENOMEM;
610         }
611 
612         for (i = o = 0; i < in_len; i += unilen, o += utflen) {
613 
614                 /* convert from nls to unicode */
615                 unilen = nls->char2uni(&in[i], in_len - i, &uni);
616                 if (unilen < 0)
617                         goto conv_err;
618 
619                 /* convert from unicode to UTF-8 */
620                 utflen = utf32_to_utf8(uni, &result[o], 3);
621                 if (utflen <= 0)
622                         goto conv_err;
623         }
624 
625         result[o] = '\0';
626         *out_len = o;
627 
628         befs_debug(sb, "<--- %s", __func__);
629 
630         return i;
631 
632       conv_err:
633         befs_error(sb, "Name using charecter set %s contains a charecter that "
634                    "cannot be converted to unicode.", nls->charset);
635         befs_debug(sb, "<--- %s", __func__);
636         kfree(result);
637         return -EILSEQ;
638 }
639 
640 /**
641  * Use the
642  *
643  */
644 enum {
645         Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
646 };
647 
648 static const match_table_t befs_tokens = {
649         {Opt_uid, "uid=%d"},
650         {Opt_gid, "gid=%d"},
651         {Opt_charset, "iocharset=%s"},
652         {Opt_debug, "debug"},
653         {Opt_err, NULL}
654 };
655 
656 static int
657 parse_options(char *options, struct befs_mount_options *opts)
658 {
659         char *p;
660         substring_t args[MAX_OPT_ARGS];
661         int option;
662         kuid_t uid;
663         kgid_t gid;
664 
665         /* Initialize options */
666         opts->uid = GLOBAL_ROOT_UID;
667         opts->gid = GLOBAL_ROOT_GID;
668         opts->use_uid = 0;
669         opts->use_gid = 0;
670         opts->iocharset = NULL;
671         opts->debug = 0;
672 
673         if (!options)
674                 return 1;
675 
676         while ((p = strsep(&options, ",")) != NULL) {
677                 int token;
678                 if (!*p)
679                         continue;
680 
681                 token = match_token(p, befs_tokens, args);
682                 switch (token) {
683                 case Opt_uid:
684                         if (match_int(&args[0], &option))
685                                 return 0;
686                         uid = INVALID_UID;
687                         if (option >= 0)
688                                 uid = make_kuid(current_user_ns(), option);
689                         if (!uid_valid(uid)) {
690                                 pr_err("Invalid uid %d, "
691                                        "using default\n", option);
692                                 break;
693                         }
694                         opts->uid = uid;
695                         opts->use_uid = 1;
696                         break;
697                 case Opt_gid:
698                         if (match_int(&args[0], &option))
699                                 return 0;
700                         gid = INVALID_GID;
701                         if (option >= 0)
702                                 gid = make_kgid(current_user_ns(), option);
703                         if (!gid_valid(gid)) {
704                                 pr_err("Invalid gid %d, "
705                                        "using default\n", option);
706                                 break;
707                         }
708                         opts->gid = gid;
709                         opts->use_gid = 1;
710                         break;
711                 case Opt_charset:
712                         kfree(opts->iocharset);
713                         opts->iocharset = match_strdup(&args[0]);
714                         if (!opts->iocharset) {
715                                 pr_err("allocation failure for "
716                                        "iocharset string\n");
717                                 return 0;
718                         }
719                         break;
720                 case Opt_debug:
721                         opts->debug = 1;
722                         break;
723                 default:
724                         pr_err("Unrecognized mount option \"%s\" "
725                                "or missing value\n", p);
726                         return 0;
727                 }
728         }
729         return 1;
730 }
731 
732 /* This function has the responsibiltiy of getting the
733  * filesystem ready for unmounting. 
734  * Basically, we free everything that we allocated in
735  * befs_read_inode
736  */
737 static void
738 befs_put_super(struct super_block *sb)
739 {
740         kfree(BEFS_SB(sb)->mount_opts.iocharset);
741         BEFS_SB(sb)->mount_opts.iocharset = NULL;
742         unload_nls(BEFS_SB(sb)->nls);
743         kfree(sb->s_fs_info);
744         sb->s_fs_info = NULL;
745 }
746 
747 /* Allocate private field of the superblock, fill it.
748  *
749  * Finish filling the public superblock fields
750  * Make the root directory
751  * Load a set of NLS translations if needed.
752  */
753 static int
754 befs_fill_super(struct super_block *sb, void *data, int silent)
755 {
756         struct buffer_head *bh;
757         struct befs_sb_info *befs_sb;
758         befs_super_block *disk_sb;
759         struct inode *root;
760         long ret = -EINVAL;
761         const unsigned long sb_block = 0;
762         const off_t x86_sb_off = 512;
763 
764         save_mount_options(sb, data);
765 
766         sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
767         if (sb->s_fs_info == NULL) {
768                 pr_err("(%s): Unable to allocate memory for private "
769                        "portion of superblock. Bailing.\n", sb->s_id);
770                 goto unacquire_none;
771         }
772         befs_sb = BEFS_SB(sb);
773 
774         if (!parse_options((char *) data, &befs_sb->mount_opts)) {
775                 befs_error(sb, "cannot parse mount options");
776                 goto unacquire_priv_sbp;
777         }
778 
779         befs_debug(sb, "---> %s", __func__);
780 
781         if (!(sb->s_flags & MS_RDONLY)) {
782                 befs_warning(sb,
783                              "No write support. Marking filesystem read-only");
784                 sb->s_flags |= MS_RDONLY;
785         }
786 
787         /*
788          * Set dummy blocksize to read super block.
789          * Will be set to real fs blocksize later.
790          *
791          * Linux 2.4.10 and later refuse to read blocks smaller than
792          * the hardsect size for the device. But we also need to read at 
793          * least 1k to get the second 512 bytes of the volume.
794          * -WD 10-26-01
795          */ 
796         sb_min_blocksize(sb, 1024);
797 
798         if (!(bh = sb_bread(sb, sb_block))) {
799                 befs_error(sb, "unable to read superblock");
800                 goto unacquire_priv_sbp;
801         }
802 
803         /* account for offset of super block on x86 */
804         disk_sb = (befs_super_block *) bh->b_data;
805         if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
806             (disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
807                 befs_debug(sb, "Using PPC superblock location");
808         } else {
809                 befs_debug(sb, "Using x86 superblock location");
810                 disk_sb =
811                     (befs_super_block *) ((void *) bh->b_data + x86_sb_off);
812         }
813 
814         if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
815             (befs_check_sb(sb) != BEFS_OK))
816                 goto unacquire_bh;
817 
818         befs_dump_super_block(sb, disk_sb);
819 
820         brelse(bh);
821 
822         if( befs_sb->num_blocks > ~((sector_t)0) ) {
823                 befs_error(sb, "blocks count: %llu "
824                         "is larger than the host can use",
825                         befs_sb->num_blocks);
826                 goto unacquire_priv_sbp;
827         }
828 
829         /*
830          * set up enough so that it can read an inode
831          * Fill in kernel superblock fields from private sb
832          */
833         sb->s_magic = BEFS_SUPER_MAGIC;
834         /* Set real blocksize of fs */
835         sb_set_blocksize(sb, (ulong) befs_sb->block_size);
836         sb->s_op = &befs_sops;
837         root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
838         if (IS_ERR(root)) {
839                 ret = PTR_ERR(root);
840                 goto unacquire_priv_sbp;
841         }
842         sb->s_root = d_make_root(root);
843         if (!sb->s_root) {
844                 befs_error(sb, "get root inode failed");
845                 goto unacquire_priv_sbp;
846         }
847 
848         /* load nls library */
849         if (befs_sb->mount_opts.iocharset) {
850                 befs_debug(sb, "Loading nls: %s",
851                            befs_sb->mount_opts.iocharset);
852                 befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
853                 if (!befs_sb->nls) {
854                         befs_warning(sb, "Cannot load nls %s"
855                                         " loading default nls",
856                                         befs_sb->mount_opts.iocharset);
857                         befs_sb->nls = load_nls_default();
858                 }
859         /* load default nls if none is specified  in mount options */
860         } else {
861                 befs_debug(sb, "Loading default nls");
862                 befs_sb->nls = load_nls_default();
863         }
864 
865         return 0;
866 /*****************/
867       unacquire_bh:
868         brelse(bh);
869 
870       unacquire_priv_sbp:
871         kfree(befs_sb->mount_opts.iocharset);
872         kfree(sb->s_fs_info);
873 
874       unacquire_none:
875         sb->s_fs_info = NULL;
876         return ret;
877 }
878 
879 static int
880 befs_remount(struct super_block *sb, int *flags, char *data)
881 {
882         sync_filesystem(sb);
883         if (!(*flags & MS_RDONLY))
884                 return -EINVAL;
885         return 0;
886 }
887 
888 static int
889 befs_statfs(struct dentry *dentry, struct kstatfs *buf)
890 {
891         struct super_block *sb = dentry->d_sb;
892         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
893 
894         befs_debug(sb, "---> %s", __func__);
895 
896         buf->f_type = BEFS_SUPER_MAGIC;
897         buf->f_bsize = sb->s_blocksize;
898         buf->f_blocks = BEFS_SB(sb)->num_blocks;
899         buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
900         buf->f_bavail = buf->f_bfree;
901         buf->f_files = 0;       /* UNKNOWN */
902         buf->f_ffree = 0;       /* UNKNOWN */
903         buf->f_fsid.val[0] = (u32)id;
904         buf->f_fsid.val[1] = (u32)(id >> 32);
905         buf->f_namelen = BEFS_NAME_LEN;
906 
907         befs_debug(sb, "<--- %s", __func__);
908 
909         return 0;
910 }
911 
912 static struct dentry *
913 befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
914             void *data)
915 {
916         return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
917 }
918 
919 static struct file_system_type befs_fs_type = {
920         .owner          = THIS_MODULE,
921         .name           = "befs",
922         .mount          = befs_mount,
923         .kill_sb        = kill_block_super,
924         .fs_flags       = FS_REQUIRES_DEV,      
925 };
926 MODULE_ALIAS_FS("befs");
927 
928 static int __init
929 init_befs_fs(void)
930 {
931         int err;
932 
933         pr_info("version: %s\n", BEFS_VERSION);
934 
935         err = befs_init_inodecache();
936         if (err)
937                 goto unacquire_none;
938 
939         err = register_filesystem(&befs_fs_type);
940         if (err)
941                 goto unacquire_inodecache;
942 
943         return 0;
944 
945 unacquire_inodecache:
946         befs_destroy_inodecache();
947 
948 unacquire_none:
949         return err;
950 }
951 
952 static void __exit
953 exit_befs_fs(void)
954 {
955         befs_destroy_inodecache();
956 
957         unregister_filesystem(&befs_fs_type);
958 }
959 
960 /*
961 Macros that typecheck the init and exit functions,
962 ensures that they are called at init and cleanup,
963 and eliminates warnings about unused functions.
964 */
965 module_init(init_befs_fs)
966 module_exit(exit_befs_fs)
967 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us