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TOMOYO Linux Cross Reference
Linux/fs/romfs/super.c

Version: ~ [ linux-5.5-rc7 ] ~ [ linux-5.4.13 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.97 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.166 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.210 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.210 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /* Block- or MTD-based romfs
  2  *
  3  * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * Derived from: ROMFS file system, Linux implementation
  7  *
  8  * Copyright © 1997-1999  Janos Farkas <chexum@shadow.banki.hu>
  9  *
 10  * Using parts of the minix filesystem
 11  * Copyright © 1991, 1992  Linus Torvalds
 12  *
 13  * and parts of the affs filesystem additionally
 14  * Copyright © 1993  Ray Burr
 15  * Copyright © 1996  Hans-Joachim Widmaier
 16  *
 17  * Changes
 18  *                                      Changed for 2.1.19 modules
 19  *      Jan 1997                        Initial release
 20  *      Jun 1997                        2.1.43+ changes
 21  *                                      Proper page locking in readpage
 22  *                                      Changed to work with 2.1.45+ fs
 23  *      Jul 1997                        Fixed follow_link
 24  *                      2.1.47
 25  *                                      lookup shouldn't return -ENOENT
 26  *                                      from Horst von Brand:
 27  *                                        fail on wrong checksum
 28  *                                        double unlock_super was possible
 29  *                                        correct namelen for statfs
 30  *                                      spotted by Bill Hawes:
 31  *                                        readlink shouldn't iput()
 32  *      Jun 1998        2.1.106         from Avery Pennarun: glibc scandir()
 33  *                                        exposed a problem in readdir
 34  *                      2.1.107         code-freeze spellchecker run
 35  *      Aug 1998                        2.1.118+ VFS changes
 36  *      Sep 1998        2.1.122         another VFS change (follow_link)
 37  *      Apr 1999        2.2.7           no more EBADF checking in
 38  *                                        lookup/readdir, use ERR_PTR
 39  *      Jun 1999        2.3.6           d_alloc_root use changed
 40  *                      2.3.9           clean up usage of ENOENT/negative
 41  *                                        dentries in lookup
 42  *                                      clean up page flags setting
 43  *                                        (error, uptodate, locking) in
 44  *                                        in readpage
 45  *                                      use init_special_inode for
 46  *                                        fifos/sockets (and streamline) in
 47  *                                        read_inode, fix _ops table order
 48  *      Aug 1999        2.3.16          __initfunc() => __init change
 49  *      Oct 1999        2.3.24          page->owner hack obsoleted
 50  *      Nov 1999        2.3.27          2.3.25+ page->offset => index change
 51  *
 52  *
 53  * This program is free software; you can redistribute it and/or
 54  * modify it under the terms of the GNU General Public Licence
 55  * as published by the Free Software Foundation; either version
 56  * 2 of the Licence, or (at your option) any later version.
 57  */
 58 
 59 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 60 
 61 #include <linux/module.h>
 62 #include <linux/string.h>
 63 #include <linux/fs.h>
 64 #include <linux/time.h>
 65 #include <linux/slab.h>
 66 #include <linux/init.h>
 67 #include <linux/blkdev.h>
 68 #include <linux/parser.h>
 69 #include <linux/mount.h>
 70 #include <linux/namei.h>
 71 #include <linux/statfs.h>
 72 #include <linux/mtd/super.h>
 73 #include <linux/ctype.h>
 74 #include <linux/highmem.h>
 75 #include <linux/pagemap.h>
 76 #include <linux/uaccess.h>
 77 #include <linux/major.h>
 78 #include "internal.h"
 79 
 80 static struct kmem_cache *romfs_inode_cachep;
 81 
 82 static const umode_t romfs_modemap[8] = {
 83         0,                      /* hard link */
 84         S_IFDIR  | 0644,        /* directory */
 85         S_IFREG  | 0644,        /* regular file */
 86         S_IFLNK  | 0777,        /* symlink */
 87         S_IFBLK  | 0600,        /* blockdev */
 88         S_IFCHR  | 0600,        /* chardev */
 89         S_IFSOCK | 0644,        /* socket */
 90         S_IFIFO  | 0644         /* FIFO */
 91 };
 92 
 93 static const unsigned char romfs_dtype_table[] = {
 94         DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO
 95 };
 96 
 97 static struct inode *romfs_iget(struct super_block *sb, unsigned long pos);
 98 
 99 /*
100  * read a page worth of data from the image
101  */
102 static int romfs_readpage(struct file *file, struct page *page)
103 {
104         struct inode *inode = page->mapping->host;
105         loff_t offset, size;
106         unsigned long fillsize, pos;
107         void *buf;
108         int ret;
109 
110         buf = kmap(page);
111         if (!buf)
112                 return -ENOMEM;
113 
114         /* 32 bit warning -- but not for us :) */
115         offset = page_offset(page);
116         size = i_size_read(inode);
117         fillsize = 0;
118         ret = 0;
119         if (offset < size) {
120                 size -= offset;
121                 fillsize = size > PAGE_SIZE ? PAGE_SIZE : size;
122 
123                 pos = ROMFS_I(inode)->i_dataoffset + offset;
124 
125                 ret = romfs_dev_read(inode->i_sb, pos, buf, fillsize);
126                 if (ret < 0) {
127                         SetPageError(page);
128                         fillsize = 0;
129                         ret = -EIO;
130                 }
131         }
132 
133         if (fillsize < PAGE_SIZE)
134                 memset(buf + fillsize, 0, PAGE_SIZE - fillsize);
135         if (ret == 0)
136                 SetPageUptodate(page);
137 
138         flush_dcache_page(page);
139         kunmap(page);
140         unlock_page(page);
141         return ret;
142 }
143 
144 static const struct address_space_operations romfs_aops = {
145         .readpage       = romfs_readpage
146 };
147 
148 /*
149  * read the entries from a directory
150  */
151 static int romfs_readdir(struct file *file, struct dir_context *ctx)
152 {
153         struct inode *i = file_inode(file);
154         struct romfs_inode ri;
155         unsigned long offset, maxoff;
156         int j, ino, nextfh;
157         char fsname[ROMFS_MAXFN];       /* XXX dynamic? */
158         int ret;
159 
160         maxoff = romfs_maxsize(i->i_sb);
161 
162         offset = ctx->pos;
163         if (!offset) {
164                 offset = i->i_ino & ROMFH_MASK;
165                 ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
166                 if (ret < 0)
167                         goto out;
168                 offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
169         }
170 
171         /* Not really failsafe, but we are read-only... */
172         for (;;) {
173                 if (!offset || offset >= maxoff) {
174                         offset = maxoff;
175                         ctx->pos = offset;
176                         goto out;
177                 }
178                 ctx->pos = offset;
179 
180                 /* Fetch inode info */
181                 ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
182                 if (ret < 0)
183                         goto out;
184 
185                 j = romfs_dev_strnlen(i->i_sb, offset + ROMFH_SIZE,
186                                       sizeof(fsname) - 1);
187                 if (j < 0)
188                         goto out;
189 
190                 ret = romfs_dev_read(i->i_sb, offset + ROMFH_SIZE, fsname, j);
191                 if (ret < 0)
192                         goto out;
193                 fsname[j] = '\0';
194 
195                 ino = offset;
196                 nextfh = be32_to_cpu(ri.next);
197                 if ((nextfh & ROMFH_TYPE) == ROMFH_HRD)
198                         ino = be32_to_cpu(ri.spec);
199                 if (!dir_emit(ctx, fsname, j, ino,
200                             romfs_dtype_table[nextfh & ROMFH_TYPE]))
201                         goto out;
202 
203                 offset = nextfh & ROMFH_MASK;
204         }
205 out:
206         return 0;
207 }
208 
209 /*
210  * look up an entry in a directory
211  */
212 static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
213                                    unsigned int flags)
214 {
215         unsigned long offset, maxoff;
216         struct inode *inode = NULL;
217         struct romfs_inode ri;
218         const char *name;               /* got from dentry */
219         int len, ret;
220 
221         offset = dir->i_ino & ROMFH_MASK;
222         ret = romfs_dev_read(dir->i_sb, offset, &ri, ROMFH_SIZE);
223         if (ret < 0)
224                 goto error;
225 
226         /* search all the file entries in the list starting from the one
227          * pointed to by the directory's special data */
228         maxoff = romfs_maxsize(dir->i_sb);
229         offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
230 
231         name = dentry->d_name.name;
232         len = dentry->d_name.len;
233 
234         for (;;) {
235                 if (!offset || offset >= maxoff)
236                         break;
237 
238                 ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri));
239                 if (ret < 0)
240                         goto error;
241 
242                 /* try to match the first 16 bytes of name */
243                 ret = romfs_dev_strcmp(dir->i_sb, offset + ROMFH_SIZE, name,
244                                        len);
245                 if (ret < 0)
246                         goto error;
247                 if (ret == 1) {
248                         /* Hard link handling */
249                         if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
250                                 offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
251                         inode = romfs_iget(dir->i_sb, offset);
252                         break;
253                 }
254 
255                 /* next entry */
256                 offset = be32_to_cpu(ri.next) & ROMFH_MASK;
257         }
258 
259         return d_splice_alias(inode, dentry);
260 error:
261         return ERR_PTR(ret);
262 }
263 
264 static const struct file_operations romfs_dir_operations = {
265         .read           = generic_read_dir,
266         .iterate_shared = romfs_readdir,
267         .llseek         = generic_file_llseek,
268 };
269 
270 static const struct inode_operations romfs_dir_inode_operations = {
271         .lookup         = romfs_lookup,
272 };
273 
274 /*
275  * get a romfs inode based on its position in the image (which doubles as the
276  * inode number)
277  */
278 static struct inode *romfs_iget(struct super_block *sb, unsigned long pos)
279 {
280         struct romfs_inode_info *inode;
281         struct romfs_inode ri;
282         struct inode *i;
283         unsigned long nlen;
284         unsigned nextfh;
285         int ret;
286         umode_t mode;
287 
288         /* we might have to traverse a chain of "hard link" file entries to get
289          * to the actual file */
290         for (;;) {
291                 ret = romfs_dev_read(sb, pos, &ri, sizeof(ri));
292                 if (ret < 0)
293                         goto error;
294 
295                 /* XXX: do romfs_checksum here too (with name) */
296 
297                 nextfh = be32_to_cpu(ri.next);
298                 if ((nextfh & ROMFH_TYPE) != ROMFH_HRD)
299                         break;
300 
301                 pos = be32_to_cpu(ri.spec) & ROMFH_MASK;
302         }
303 
304         /* determine the length of the filename */
305         nlen = romfs_dev_strnlen(sb, pos + ROMFH_SIZE, ROMFS_MAXFN);
306         if (IS_ERR_VALUE(nlen))
307                 goto eio;
308 
309         /* get an inode for this image position */
310         i = iget_locked(sb, pos);
311         if (!i)
312                 return ERR_PTR(-ENOMEM);
313 
314         if (!(i->i_state & I_NEW))
315                 return i;
316 
317         /* precalculate the data offset */
318         inode = ROMFS_I(i);
319         inode->i_metasize = (ROMFH_SIZE + nlen + 1 + ROMFH_PAD) & ROMFH_MASK;
320         inode->i_dataoffset = pos + inode->i_metasize;
321 
322         set_nlink(i, 1);                /* Hard to decide.. */
323         i->i_size = be32_to_cpu(ri.size);
324         i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0;
325         i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0;
326 
327         /* set up mode and ops */
328         mode = romfs_modemap[nextfh & ROMFH_TYPE];
329 
330         switch (nextfh & ROMFH_TYPE) {
331         case ROMFH_DIR:
332                 i->i_size = ROMFS_I(i)->i_metasize;
333                 i->i_op = &romfs_dir_inode_operations;
334                 i->i_fop = &romfs_dir_operations;
335                 if (nextfh & ROMFH_EXEC)
336                         mode |= S_IXUGO;
337                 break;
338         case ROMFH_REG:
339                 i->i_fop = &romfs_ro_fops;
340                 i->i_data.a_ops = &romfs_aops;
341                 if (nextfh & ROMFH_EXEC)
342                         mode |= S_IXUGO;
343                 break;
344         case ROMFH_SYM:
345                 i->i_op = &page_symlink_inode_operations;
346                 inode_nohighmem(i);
347                 i->i_data.a_ops = &romfs_aops;
348                 mode |= S_IRWXUGO;
349                 break;
350         default:
351                 /* depending on MBZ for sock/fifos */
352                 nextfh = be32_to_cpu(ri.spec);
353                 init_special_inode(i, mode, MKDEV(nextfh >> 16,
354                                                   nextfh & 0xffff));
355                 break;
356         }
357 
358         i->i_mode = mode;
359 
360         unlock_new_inode(i);
361         return i;
362 
363 eio:
364         ret = -EIO;
365 error:
366         pr_err("read error for inode 0x%lx\n", pos);
367         return ERR_PTR(ret);
368 }
369 
370 /*
371  * allocate a new inode
372  */
373 static struct inode *romfs_alloc_inode(struct super_block *sb)
374 {
375         struct romfs_inode_info *inode;
376 
377         inode = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL);
378         return inode ? &inode->vfs_inode : NULL;
379 }
380 
381 /*
382  * return a spent inode to the slab cache
383  */
384 static void romfs_i_callback(struct rcu_head *head)
385 {
386         struct inode *inode = container_of(head, struct inode, i_rcu);
387 
388         kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
389 }
390 
391 static void romfs_destroy_inode(struct inode *inode)
392 {
393         call_rcu(&inode->i_rcu, romfs_i_callback);
394 }
395 
396 /*
397  * get filesystem statistics
398  */
399 static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
400 {
401         struct super_block *sb = dentry->d_sb;
402         u64 id = 0;
403 
404         /* When calling huge_encode_dev(),
405          * use sb->s_bdev->bd_dev when,
406          *   - CONFIG_ROMFS_ON_BLOCK defined
407          * use sb->s_dev when,
408          *   - CONFIG_ROMFS_ON_BLOCK undefined and
409          *   - CONFIG_ROMFS_ON_MTD defined
410          * leave id as 0 when,
411          *   - CONFIG_ROMFS_ON_BLOCK undefined and
412          *   - CONFIG_ROMFS_ON_MTD undefined
413          */
414         if (sb->s_bdev)
415                 id = huge_encode_dev(sb->s_bdev->bd_dev);
416         else if (sb->s_dev)
417                 id = huge_encode_dev(sb->s_dev);
418 
419         buf->f_type = ROMFS_MAGIC;
420         buf->f_namelen = ROMFS_MAXFN;
421         buf->f_bsize = ROMBSIZE;
422         buf->f_bfree = buf->f_bavail = buf->f_ffree;
423         buf->f_blocks =
424                 (romfs_maxsize(dentry->d_sb) + ROMBSIZE - 1) >> ROMBSBITS;
425         buf->f_fsid.val[0] = (u32)id;
426         buf->f_fsid.val[1] = (u32)(id >> 32);
427         return 0;
428 }
429 
430 /*
431  * remounting must involve read-only
432  */
433 static int romfs_remount(struct super_block *sb, int *flags, char *data)
434 {
435         sync_filesystem(sb);
436         *flags |= SB_RDONLY;
437         return 0;
438 }
439 
440 static const struct super_operations romfs_super_ops = {
441         .alloc_inode    = romfs_alloc_inode,
442         .destroy_inode  = romfs_destroy_inode,
443         .statfs         = romfs_statfs,
444         .remount_fs     = romfs_remount,
445 };
446 
447 /*
448  * checksum check on part of a romfs filesystem
449  */
450 static __u32 romfs_checksum(const void *data, int size)
451 {
452         const __be32 *ptr = data;
453         __u32 sum;
454 
455         sum = 0;
456         size >>= 2;
457         while (size > 0) {
458                 sum += be32_to_cpu(*ptr++);
459                 size--;
460         }
461         return sum;
462 }
463 
464 /*
465  * fill in the superblock
466  */
467 static int romfs_fill_super(struct super_block *sb, void *data, int silent)
468 {
469         struct romfs_super_block *rsb;
470         struct inode *root;
471         unsigned long pos, img_size;
472         const char *storage;
473         size_t len;
474         int ret;
475 
476 #ifdef CONFIG_BLOCK
477         if (!sb->s_mtd) {
478                 sb_set_blocksize(sb, ROMBSIZE);
479         } else {
480                 sb->s_blocksize = ROMBSIZE;
481                 sb->s_blocksize_bits = blksize_bits(ROMBSIZE);
482         }
483 #endif
484 
485         sb->s_maxbytes = 0xFFFFFFFF;
486         sb->s_magic = ROMFS_MAGIC;
487         sb->s_flags |= SB_RDONLY | SB_NOATIME;
488         sb->s_op = &romfs_super_ops;
489 
490 #ifdef CONFIG_ROMFS_ON_MTD
491         /* Use same dev ID from the underlying mtdblock device */
492         if (sb->s_mtd)
493                 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, sb->s_mtd->index);
494 #endif
495         /* read the image superblock and check it */
496         rsb = kmalloc(512, GFP_KERNEL);
497         if (!rsb)
498                 return -ENOMEM;
499 
500         sb->s_fs_info = (void *) 512;
501         ret = romfs_dev_read(sb, 0, rsb, 512);
502         if (ret < 0)
503                 goto error_rsb;
504 
505         img_size = be32_to_cpu(rsb->size);
506 
507         if (sb->s_mtd && img_size > sb->s_mtd->size)
508                 goto error_rsb_inval;
509 
510         sb->s_fs_info = (void *) img_size;
511 
512         if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
513             img_size < ROMFH_SIZE) {
514                 if (!silent)
515                         pr_warn("VFS: Can't find a romfs filesystem on dev %s.\n",
516                                sb->s_id);
517                 goto error_rsb_inval;
518         }
519 
520         if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) {
521                 pr_err("bad initial checksum on dev %s.\n", sb->s_id);
522                 goto error_rsb_inval;
523         }
524 
525         storage = sb->s_mtd ? "MTD" : "the block layer";
526 
527         len = strnlen(rsb->name, ROMFS_MAXFN);
528         if (!silent)
529                 pr_notice("Mounting image '%*.*s' through %s\n",
530                           (unsigned) len, (unsigned) len, rsb->name, storage);
531 
532         kfree(rsb);
533         rsb = NULL;
534 
535         /* find the root directory */
536         pos = (ROMFH_SIZE + len + 1 + ROMFH_PAD) & ROMFH_MASK;
537 
538         root = romfs_iget(sb, pos);
539         if (IS_ERR(root))
540                 return PTR_ERR(root);
541 
542         sb->s_root = d_make_root(root);
543         if (!sb->s_root)
544                 return -ENOMEM;
545 
546         return 0;
547 
548 error_rsb_inval:
549         ret = -EINVAL;
550 error_rsb:
551         kfree(rsb);
552         return ret;
553 }
554 
555 /*
556  * get a superblock for mounting
557  */
558 static struct dentry *romfs_mount(struct file_system_type *fs_type,
559                         int flags, const char *dev_name,
560                         void *data)
561 {
562         struct dentry *ret = ERR_PTR(-EINVAL);
563 
564 #ifdef CONFIG_ROMFS_ON_MTD
565         ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super);
566 #endif
567 #ifdef CONFIG_ROMFS_ON_BLOCK
568         if (ret == ERR_PTR(-EINVAL))
569                 ret = mount_bdev(fs_type, flags, dev_name, data,
570                                   romfs_fill_super);
571 #endif
572         return ret;
573 }
574 
575 /*
576  * destroy a romfs superblock in the appropriate manner
577  */
578 static void romfs_kill_sb(struct super_block *sb)
579 {
580 #ifdef CONFIG_ROMFS_ON_MTD
581         if (sb->s_mtd) {
582                 kill_mtd_super(sb);
583                 return;
584         }
585 #endif
586 #ifdef CONFIG_ROMFS_ON_BLOCK
587         if (sb->s_bdev) {
588                 kill_block_super(sb);
589                 return;
590         }
591 #endif
592 }
593 
594 static struct file_system_type romfs_fs_type = {
595         .owner          = THIS_MODULE,
596         .name           = "romfs",
597         .mount          = romfs_mount,
598         .kill_sb        = romfs_kill_sb,
599         .fs_flags       = FS_REQUIRES_DEV,
600 };
601 MODULE_ALIAS_FS("romfs");
602 
603 /*
604  * inode storage initialiser
605  */
606 static void romfs_i_init_once(void *_inode)
607 {
608         struct romfs_inode_info *inode = _inode;
609 
610         inode_init_once(&inode->vfs_inode);
611 }
612 
613 /*
614  * romfs module initialisation
615  */
616 static int __init init_romfs_fs(void)
617 {
618         int ret;
619 
620         pr_info("ROMFS MTD (C) 2007 Red Hat, Inc.\n");
621 
622         romfs_inode_cachep =
623                 kmem_cache_create("romfs_i",
624                                   sizeof(struct romfs_inode_info), 0,
625                                   SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD |
626                                   SLAB_ACCOUNT, romfs_i_init_once);
627 
628         if (!romfs_inode_cachep) {
629                 pr_err("Failed to initialise inode cache\n");
630                 return -ENOMEM;
631         }
632         ret = register_filesystem(&romfs_fs_type);
633         if (ret) {
634                 pr_err("Failed to register filesystem\n");
635                 goto error_register;
636         }
637         return 0;
638 
639 error_register:
640         kmem_cache_destroy(romfs_inode_cachep);
641         return ret;
642 }
643 
644 /*
645  * romfs module removal
646  */
647 static void __exit exit_romfs_fs(void)
648 {
649         unregister_filesystem(&romfs_fs_type);
650         /*
651          * Make sure all delayed rcu free inodes are flushed before we
652          * destroy cache.
653          */
654         rcu_barrier();
655         kmem_cache_destroy(romfs_inode_cachep);
656 }
657 
658 module_init(init_romfs_fs);
659 module_exit(exit_romfs_fs);
660 
661 MODULE_DESCRIPTION("Direct-MTD Capable RomFS");
662 MODULE_AUTHOR("Red Hat, Inc.");
663 MODULE_LICENSE("GPL"); /* Actually dual-licensed, but it doesn't matter for */
664 

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