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David Howellsda4458b2009-02-12 10:40:10 +00001/* 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
Fabian Frederickca9e5362014-08-08 14:22:59 -070059#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
60
David Howellsda4458b2009-02-12 10:40:10 +000061#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 "internal.h"
78
79static struct kmem_cache *romfs_inode_cachep;
80
81static const umode_t romfs_modemap[8] = {
82 0, /* hard link */
83 S_IFDIR | 0644, /* directory */
84 S_IFREG | 0644, /* regular file */
85 S_IFLNK | 0777, /* symlink */
86 S_IFBLK | 0600, /* blockdev */
87 S_IFCHR | 0600, /* chardev */
88 S_IFSOCK | 0644, /* socket */
89 S_IFIFO | 0644 /* FIFO */
90};
91
92static const unsigned char romfs_dtype_table[] = {
93 DT_UNKNOWN, DT_DIR, DT_REG, DT_LNK, DT_BLK, DT_CHR, DT_SOCK, DT_FIFO
94};
95
96static struct inode *romfs_iget(struct super_block *sb, unsigned long pos);
97
98/*
99 * read a page worth of data from the image
100 */
101static int romfs_readpage(struct file *file, struct page *page)
102{
103 struct inode *inode = page->mapping->host;
104 loff_t offset, size;
105 unsigned long fillsize, pos;
106 void *buf;
107 int ret;
108
109 buf = kmap(page);
110 if (!buf)
111 return -ENOMEM;
112
113 /* 32 bit warning -- but not for us :) */
114 offset = page_offset(page);
115 size = i_size_read(inode);
116 fillsize = 0;
117 ret = 0;
118 if (offset < size) {
119 size -= offset;
120 fillsize = size > PAGE_SIZE ? PAGE_SIZE : size;
121
122 pos = ROMFS_I(inode)->i_dataoffset + offset;
123
124 ret = romfs_dev_read(inode->i_sb, pos, buf, fillsize);
125 if (ret < 0) {
126 SetPageError(page);
127 fillsize = 0;
128 ret = -EIO;
129 }
130 }
131
132 if (fillsize < PAGE_SIZE)
133 memset(buf + fillsize, 0, PAGE_SIZE - fillsize);
134 if (ret == 0)
135 SetPageUptodate(page);
136
137 flush_dcache_page(page);
138 kunmap(page);
139 unlock_page(page);
140 return ret;
141}
142
143static const struct address_space_operations romfs_aops = {
144 .readpage = romfs_readpage
145};
146
147/*
148 * read the entries from a directory
149 */
Al Viro3903b382013-05-16 01:22:00 -0400150static int romfs_readdir(struct file *file, struct dir_context *ctx)
David Howellsda4458b2009-02-12 10:40:10 +0000151{
Al Viro3903b382013-05-16 01:22:00 -0400152 struct inode *i = file_inode(file);
David Howellsda4458b2009-02-12 10:40:10 +0000153 struct romfs_inode ri;
154 unsigned long offset, maxoff;
155 int j, ino, nextfh;
David Howellsda4458b2009-02-12 10:40:10 +0000156 char fsname[ROMFS_MAXFN]; /* XXX dynamic? */
157 int ret;
158
159 maxoff = romfs_maxsize(i->i_sb);
160
Al Viro3903b382013-05-16 01:22:00 -0400161 offset = ctx->pos;
David Howellsda4458b2009-02-12 10:40:10 +0000162 if (!offset) {
163 offset = i->i_ino & ROMFH_MASK;
164 ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
165 if (ret < 0)
166 goto out;
167 offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
168 }
169
170 /* Not really failsafe, but we are read-only... */
171 for (;;) {
172 if (!offset || offset >= maxoff) {
173 offset = maxoff;
Al Viro3903b382013-05-16 01:22:00 -0400174 ctx->pos = offset;
David Howellsda4458b2009-02-12 10:40:10 +0000175 goto out;
176 }
Al Viro3903b382013-05-16 01:22:00 -0400177 ctx->pos = offset;
David Howellsda4458b2009-02-12 10:40:10 +0000178
179 /* Fetch inode info */
180 ret = romfs_dev_read(i->i_sb, offset, &ri, ROMFH_SIZE);
181 if (ret < 0)
182 goto out;
183
184 j = romfs_dev_strnlen(i->i_sb, offset + ROMFH_SIZE,
185 sizeof(fsname) - 1);
186 if (j < 0)
187 goto out;
188
189 ret = romfs_dev_read(i->i_sb, offset + ROMFH_SIZE, fsname, j);
190 if (ret < 0)
191 goto out;
192 fsname[j] = '\0';
193
194 ino = offset;
195 nextfh = be32_to_cpu(ri.next);
196 if ((nextfh & ROMFH_TYPE) == ROMFH_HRD)
197 ino = be32_to_cpu(ri.spec);
Al Viro3903b382013-05-16 01:22:00 -0400198 if (!dir_emit(ctx, fsname, j, ino,
199 romfs_dtype_table[nextfh & ROMFH_TYPE]))
David Howellsda4458b2009-02-12 10:40:10 +0000200 goto out;
201
David Howellsda4458b2009-02-12 10:40:10 +0000202 offset = nextfh & ROMFH_MASK;
203 }
David Howellsda4458b2009-02-12 10:40:10 +0000204out:
Al Viro3903b382013-05-16 01:22:00 -0400205 return 0;
David Howellsda4458b2009-02-12 10:40:10 +0000206}
207
208/*
209 * look up an entry in a directory
210 */
211static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400212 unsigned int flags)
David Howellsda4458b2009-02-12 10:40:10 +0000213{
214 unsigned long offset, maxoff;
215 struct inode *inode;
216 struct romfs_inode ri;
217 const char *name; /* got from dentry */
218 int len, ret;
219
220 offset = dir->i_ino & ROMFH_MASK;
221 ret = romfs_dev_read(dir->i_sb, offset, &ri, ROMFH_SIZE);
222 if (ret < 0)
223 goto error;
224
225 /* search all the file entries in the list starting from the one
226 * pointed to by the directory's special data */
227 maxoff = romfs_maxsize(dir->i_sb);
228 offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
229
230 name = dentry->d_name.name;
231 len = dentry->d_name.len;
232
233 for (;;) {
234 if (!offset || offset >= maxoff)
235 goto out0;
236
237 ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri));
238 if (ret < 0)
239 goto error;
240
241 /* try to match the first 16 bytes of name */
David Howells84baf742009-04-23 16:41:13 +0100242 ret = romfs_dev_strcmp(dir->i_sb, offset + ROMFH_SIZE, name,
243 len);
David Howellsda4458b2009-02-12 10:40:10 +0000244 if (ret < 0)
245 goto error;
246 if (ret == 1)
247 break;
248
249 /* next entry */
250 offset = be32_to_cpu(ri.next) & ROMFH_MASK;
251 }
252
253 /* Hard link handling */
254 if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
255 offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
256
257 inode = romfs_iget(dir->i_sb, offset);
258 if (IS_ERR(inode)) {
259 ret = PTR_ERR(inode);
260 goto error;
261 }
262 goto outi;
263
264 /*
265 * it's a bit funky, _lookup needs to return an error code
266 * (negative) or a NULL, both as a dentry. ENOENT should not
267 * be returned, instead we need to create a negative dentry by
268 * d_add(dentry, NULL); and return 0 as no error.
269 * (Although as I see, it only matters on writable file
270 * systems).
271 */
272out0:
273 inode = NULL;
274outi:
275 d_add(dentry, inode);
276 ret = 0;
277error:
278 return ERR_PTR(ret);
279}
280
281static const struct file_operations romfs_dir_operations = {
282 .read = generic_read_dir,
Al Viro3903b382013-05-16 01:22:00 -0400283 .iterate = romfs_readdir,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200284 .llseek = default_llseek,
David Howellsda4458b2009-02-12 10:40:10 +0000285};
286
Alexey Dobriyan6e1d5dc2009-09-21 17:01:11 -0700287static const struct inode_operations romfs_dir_inode_operations = {
David Howellsda4458b2009-02-12 10:40:10 +0000288 .lookup = romfs_lookup,
289};
290
291/*
292 * get a romfs inode based on its position in the image (which doubles as the
293 * inode number)
294 */
295static struct inode *romfs_iget(struct super_block *sb, unsigned long pos)
296{
297 struct romfs_inode_info *inode;
298 struct romfs_inode ri;
299 struct inode *i;
300 unsigned long nlen;
Roel Kluin774e33e2009-04-26 14:51:17 +0200301 unsigned nextfh;
302 int ret;
David Howellsda4458b2009-02-12 10:40:10 +0000303 umode_t mode;
304
305 /* we might have to traverse a chain of "hard link" file entries to get
306 * to the actual file */
307 for (;;) {
308 ret = romfs_dev_read(sb, pos, &ri, sizeof(ri));
309 if (ret < 0)
310 goto error;
311
312 /* XXX: do romfs_checksum here too (with name) */
313
314 nextfh = be32_to_cpu(ri.next);
315 if ((nextfh & ROMFH_TYPE) != ROMFH_HRD)
316 break;
317
318 pos = be32_to_cpu(ri.spec) & ROMFH_MASK;
319 }
320
321 /* determine the length of the filename */
322 nlen = romfs_dev_strnlen(sb, pos + ROMFH_SIZE, ROMFS_MAXFN);
323 if (IS_ERR_VALUE(nlen))
324 goto eio;
325
326 /* get an inode for this image position */
327 i = iget_locked(sb, pos);
328 if (!i)
329 return ERR_PTR(-ENOMEM);
330
331 if (!(i->i_state & I_NEW))
332 return i;
333
334 /* precalculate the data offset */
335 inode = ROMFS_I(i);
336 inode->i_metasize = (ROMFH_SIZE + nlen + 1 + ROMFH_PAD) & ROMFH_MASK;
337 inode->i_dataoffset = pos + inode->i_metasize;
338
Miklos Szeredibfe86842011-10-28 14:13:29 +0200339 set_nlink(i, 1); /* Hard to decide.. */
David Howellsda4458b2009-02-12 10:40:10 +0000340 i->i_size = be32_to_cpu(ri.size);
341 i->i_mtime.tv_sec = i->i_atime.tv_sec = i->i_ctime.tv_sec = 0;
342 i->i_mtime.tv_nsec = i->i_atime.tv_nsec = i->i_ctime.tv_nsec = 0;
343
344 /* set up mode and ops */
345 mode = romfs_modemap[nextfh & ROMFH_TYPE];
346
347 switch (nextfh & ROMFH_TYPE) {
348 case ROMFH_DIR:
349 i->i_size = ROMFS_I(i)->i_metasize;
350 i->i_op = &romfs_dir_inode_operations;
351 i->i_fop = &romfs_dir_operations;
352 if (nextfh & ROMFH_EXEC)
353 mode |= S_IXUGO;
354 break;
355 case ROMFH_REG:
356 i->i_fop = &romfs_ro_fops;
357 i->i_data.a_ops = &romfs_aops;
358 if (i->i_sb->s_mtd)
359 i->i_data.backing_dev_info =
360 i->i_sb->s_mtd->backing_dev_info;
361 if (nextfh & ROMFH_EXEC)
362 mode |= S_IXUGO;
363 break;
364 case ROMFH_SYM:
365 i->i_op = &page_symlink_inode_operations;
366 i->i_data.a_ops = &romfs_aops;
367 mode |= S_IRWXUGO;
368 break;
369 default:
370 /* depending on MBZ for sock/fifos */
371 nextfh = be32_to_cpu(ri.spec);
372 init_special_inode(i, mode, MKDEV(nextfh >> 16,
373 nextfh & 0xffff));
374 break;
375 }
376
377 i->i_mode = mode;
378
379 unlock_new_inode(i);
380 return i;
381
382eio:
383 ret = -EIO;
384error:
Fabian Frederickca9e5362014-08-08 14:22:59 -0700385 pr_err("read error for inode 0x%lx\n", pos);
David Howellsda4458b2009-02-12 10:40:10 +0000386 return ERR_PTR(ret);
387}
388
389/*
390 * allocate a new inode
391 */
392static struct inode *romfs_alloc_inode(struct super_block *sb)
393{
394 struct romfs_inode_info *inode;
Fabian Frederickb6d53b12014-08-08 14:23:01 -0700395
David Howellsda4458b2009-02-12 10:40:10 +0000396 inode = kmem_cache_alloc(romfs_inode_cachep, GFP_KERNEL);
397 return inode ? &inode->vfs_inode : NULL;
398}
399
400/*
401 * return a spent inode to the slab cache
402 */
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100403static void romfs_i_callback(struct rcu_head *head)
404{
405 struct inode *inode = container_of(head, struct inode, i_rcu);
Fabian Frederickb6d53b12014-08-08 14:23:01 -0700406
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100407 kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode));
408}
409
David Howellsda4458b2009-02-12 10:40:10 +0000410static void romfs_destroy_inode(struct inode *inode)
411{
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +1100412 call_rcu(&inode->i_rcu, romfs_i_callback);
David Howellsda4458b2009-02-12 10:40:10 +0000413}
414
415/*
416 * get filesystem statistics
417 */
418static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
419{
Coly Li8a59f5d2009-04-06 19:01:12 -0700420 struct super_block *sb = dentry->d_sb;
421 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
422
David Howellsda4458b2009-02-12 10:40:10 +0000423 buf->f_type = ROMFS_MAGIC;
424 buf->f_namelen = ROMFS_MAXFN;
425 buf->f_bsize = ROMBSIZE;
426 buf->f_bfree = buf->f_bavail = buf->f_ffree;
427 buf->f_blocks =
428 (romfs_maxsize(dentry->d_sb) + ROMBSIZE - 1) >> ROMBSBITS;
Coly Li8a59f5d2009-04-06 19:01:12 -0700429 buf->f_fsid.val[0] = (u32)id;
430 buf->f_fsid.val[1] = (u32)(id >> 32);
David Howellsda4458b2009-02-12 10:40:10 +0000431 return 0;
432}
433
434/*
435 * remounting must involve read-only
436 */
437static int romfs_remount(struct super_block *sb, int *flags, char *data)
438{
Theodore Ts'o02b99842014-03-13 10:14:33 -0400439 sync_filesystem(sb);
David Howellsda4458b2009-02-12 10:40:10 +0000440 *flags |= MS_RDONLY;
441 return 0;
442}
443
444static const struct super_operations romfs_super_ops = {
445 .alloc_inode = romfs_alloc_inode,
446 .destroy_inode = romfs_destroy_inode,
447 .statfs = romfs_statfs,
448 .remount_fs = romfs_remount,
449};
450
451/*
452 * checksum check on part of a romfs filesystem
453 */
454static __u32 romfs_checksum(const void *data, int size)
455{
456 const __be32 *ptr = data;
457 __u32 sum;
458
459 sum = 0;
460 size >>= 2;
461 while (size > 0) {
462 sum += be32_to_cpu(*ptr++);
463 size--;
464 }
465 return sum;
466}
467
468/*
469 * fill in the superblock
470 */
471static int romfs_fill_super(struct super_block *sb, void *data, int silent)
472{
473 struct romfs_super_block *rsb;
474 struct inode *root;
475 unsigned long pos, img_size;
476 const char *storage;
477 size_t len;
478 int ret;
479
480#ifdef CONFIG_BLOCK
481 if (!sb->s_mtd) {
482 sb_set_blocksize(sb, ROMBSIZE);
483 } else {
484 sb->s_blocksize = ROMBSIZE;
485 sb->s_blocksize_bits = blksize_bits(ROMBSIZE);
486 }
487#endif
488
489 sb->s_maxbytes = 0xFFFFFFFF;
490 sb->s_magic = ROMFS_MAGIC;
491 sb->s_flags |= MS_RDONLY | MS_NOATIME;
492 sb->s_op = &romfs_super_ops;
493
494 /* read the image superblock and check it */
495 rsb = kmalloc(512, GFP_KERNEL);
496 if (!rsb)
497 return -ENOMEM;
498
499 sb->s_fs_info = (void *) 512;
500 ret = romfs_dev_read(sb, 0, rsb, 512);
501 if (ret < 0)
502 goto error_rsb;
503
504 img_size = be32_to_cpu(rsb->size);
505
506 if (sb->s_mtd && img_size > sb->s_mtd->size)
507 goto error_rsb_inval;
508
509 sb->s_fs_info = (void *) img_size;
510
511 if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
512 img_size < ROMFH_SIZE) {
513 if (!silent)
Fabian Frederick3d79d312014-08-08 14:22:57 -0700514 pr_warn("VFS: Can't find a romfs filesystem on dev %s.\n",
David Howellsda4458b2009-02-12 10:40:10 +0000515 sb->s_id);
516 goto error_rsb_inval;
517 }
518
519 if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) {
Fabian Frederickca9e5362014-08-08 14:22:59 -0700520 pr_err("bad initial checksum on dev %s.\n", sb->s_id);
David Howellsda4458b2009-02-12 10:40:10 +0000521 goto error_rsb_inval;
522 }
523
524 storage = sb->s_mtd ? "MTD" : "the block layer";
525
526 len = strnlen(rsb->name, ROMFS_MAXFN);
527 if (!silent)
Fabian Frederickca9e5362014-08-08 14:22:59 -0700528 pr_notice("Mounting image '%*.*s' through %s\n",
529 (unsigned) len, (unsigned) len, rsb->name, storage);
David Howellsda4458b2009-02-12 10:40:10 +0000530
531 kfree(rsb);
532 rsb = NULL;
533
534 /* find the root directory */
535 pos = (ROMFH_SIZE + len + 1 + ROMFH_PAD) & ROMFH_MASK;
536
537 root = romfs_iget(sb, pos);
Julia Lawalla21f3c22009-09-23 15:57:35 -0700538 if (IS_ERR(root))
Rui Xiang40e2c712014-01-23 15:56:19 -0800539 return PTR_ERR(root);
David Howellsda4458b2009-02-12 10:40:10 +0000540
Al Viro48fde702012-01-08 22:15:13 -0500541 sb->s_root = d_make_root(root);
David Howellsda4458b2009-02-12 10:40:10 +0000542 if (!sb->s_root)
Rui Xiang40e2c712014-01-23 15:56:19 -0800543 return -ENOMEM;
David Howellsda4458b2009-02-12 10:40:10 +0000544
545 return 0;
546
David Howellsda4458b2009-02-12 10:40:10 +0000547error_rsb_inval:
548 ret = -EINVAL;
549error_rsb:
Al Viro7e32b7b2010-01-25 06:05:54 -0500550 kfree(rsb);
David Howellsda4458b2009-02-12 10:40:10 +0000551 return ret;
552}
553
554/*
555 * get a superblock for mounting
556 */
Al Viro848b83a2010-07-25 00:56:46 +0400557static struct dentry *romfs_mount(struct file_system_type *fs_type,
David Howellsda4458b2009-02-12 10:40:10 +0000558 int flags, const char *dev_name,
Al Viro848b83a2010-07-25 00:56:46 +0400559 void *data)
David Howellsda4458b2009-02-12 10:40:10 +0000560{
Al Viro848b83a2010-07-25 00:56:46 +0400561 struct dentry *ret = ERR_PTR(-EINVAL);
David Howellsda4458b2009-02-12 10:40:10 +0000562
563#ifdef CONFIG_ROMFS_ON_MTD
Al Viro848b83a2010-07-25 00:56:46 +0400564 ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super);
David Howellsda4458b2009-02-12 10:40:10 +0000565#endif
566#ifdef CONFIG_ROMFS_ON_BLOCK
Al Viro848b83a2010-07-25 00:56:46 +0400567 if (ret == ERR_PTR(-EINVAL))
568 ret = mount_bdev(fs_type, flags, dev_name, data,
569 romfs_fill_super);
David Howellsda4458b2009-02-12 10:40:10 +0000570#endif
571 return ret;
572}
573
574/*
575 * destroy a romfs superblock in the appropriate manner
576 */
577static void romfs_kill_sb(struct super_block *sb)
578{
579#ifdef CONFIG_ROMFS_ON_MTD
580 if (sb->s_mtd) {
581 kill_mtd_super(sb);
582 return;
583 }
584#endif
585#ifdef CONFIG_ROMFS_ON_BLOCK
586 if (sb->s_bdev) {
587 kill_block_super(sb);
588 return;
589 }
590#endif
591}
592
593static struct file_system_type romfs_fs_type = {
594 .owner = THIS_MODULE,
595 .name = "romfs",
Al Viro848b83a2010-07-25 00:56:46 +0400596 .mount = romfs_mount,
David Howellsda4458b2009-02-12 10:40:10 +0000597 .kill_sb = romfs_kill_sb,
598 .fs_flags = FS_REQUIRES_DEV,
599};
Eric W. Biederman7f78e032013-03-02 19:39:14 -0800600MODULE_ALIAS_FS("romfs");
David Howellsda4458b2009-02-12 10:40:10 +0000601
602/*
603 * inode storage initialiser
604 */
605static void romfs_i_init_once(void *_inode)
606{
607 struct romfs_inode_info *inode = _inode;
608
609 inode_init_once(&inode->vfs_inode);
610}
611
612/*
613 * romfs module initialisation
614 */
615static int __init init_romfs_fs(void)
616{
617 int ret;
618
Fabian Frederick3d79d312014-08-08 14:22:57 -0700619 pr_info("ROMFS MTD (C) 2007 Red Hat, Inc.\n");
David Howellsda4458b2009-02-12 10:40:10 +0000620
621 romfs_inode_cachep =
622 kmem_cache_create("romfs_i",
623 sizeof(struct romfs_inode_info), 0,
624 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
625 romfs_i_init_once);
626
627 if (!romfs_inode_cachep) {
Fabian Frederickca9e5362014-08-08 14:22:59 -0700628 pr_err("Failed to initialise inode cache\n");
David Howellsda4458b2009-02-12 10:40:10 +0000629 return -ENOMEM;
630 }
631 ret = register_filesystem(&romfs_fs_type);
632 if (ret) {
Fabian Frederickca9e5362014-08-08 14:22:59 -0700633 pr_err("Failed to register filesystem\n");
David Howellsda4458b2009-02-12 10:40:10 +0000634 goto error_register;
635 }
636 return 0;
637
638error_register:
639 kmem_cache_destroy(romfs_inode_cachep);
640 return ret;
641}
642
643/*
644 * romfs module removal
645 */
646static void __exit exit_romfs_fs(void)
647{
648 unregister_filesystem(&romfs_fs_type);
Kirill A. Shutemov8c0a8532012-09-26 11:33:07 +1000649 /*
650 * Make sure all delayed rcu free inodes are flushed before we
651 * destroy cache.
652 */
653 rcu_barrier();
David Howellsda4458b2009-02-12 10:40:10 +0000654 kmem_cache_destroy(romfs_inode_cachep);
655}
656
657module_init(init_romfs_fs);
658module_exit(exit_romfs_fs);
659
660MODULE_DESCRIPTION("Direct-MTD Capable RomFS");
661MODULE_AUTHOR("Red Hat, Inc.");
662MODULE_LICENSE("GPL"); /* Actually dual-licensed, but it doesn't matter for */