Commit | Line | Data |
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da4458bd DH |
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 | ||
ca9e5368 FF |
59 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
60 | ||
da4458bd DH |
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> | |
f598f82e | 77 | #include <linux/major.h> |
da4458bd DH |
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 | */ | |
3903b38c | 151 | static int romfs_readdir(struct file *file, struct dir_context *ctx) |
da4458bd | 152 | { |
3903b38c | 153 | struct inode *i = file_inode(file); |
da4458bd DH |
154 | struct romfs_inode ri; |
155 | unsigned long offset, maxoff; | |
156 | int j, ino, nextfh; | |
da4458bd DH |
157 | char fsname[ROMFS_MAXFN]; /* XXX dynamic? */ |
158 | int ret; | |
159 | ||
160 | maxoff = romfs_maxsize(i->i_sb); | |
161 | ||
3903b38c | 162 | offset = ctx->pos; |
da4458bd DH |
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; | |
3903b38c | 175 | ctx->pos = offset; |
da4458bd DH |
176 | goto out; |
177 | } | |
3903b38c | 178 | ctx->pos = offset; |
da4458bd DH |
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); | |
3903b38c AV |
199 | if (!dir_emit(ctx, fsname, j, ino, |
200 | romfs_dtype_table[nextfh & ROMFH_TYPE])) | |
da4458bd DH |
201 | goto out; |
202 | ||
da4458bd DH |
203 | offset = nextfh & ROMFH_MASK; |
204 | } | |
da4458bd | 205 | out: |
3903b38c | 206 | return 0; |
da4458bd DH |
207 | } |
208 | ||
209 | /* | |
210 | * look up an entry in a directory | |
211 | */ | |
212 | static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry, | |
00cd8dd3 | 213 | unsigned int flags) |
da4458bd DH |
214 | { |
215 | unsigned long offset, maxoff; | |
8130c151 | 216 | struct inode *inode = NULL; |
da4458bd DH |
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) | |
8130c151 | 236 | break; |
da4458bd DH |
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 */ | |
84baf74b DH |
243 | ret = romfs_dev_strcmp(dir->i_sb, offset + ROMFH_SIZE, name, |
244 | len); | |
da4458bd DH |
245 | if (ret < 0) |
246 | goto error; | |
8130c151 AV |
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); | |
da4458bd | 252 | break; |
8130c151 | 253 | } |
da4458bd DH |
254 | |
255 | /* next entry */ | |
256 | offset = be32_to_cpu(ri.next) & ROMFH_MASK; | |
257 | } | |
258 | ||
8130c151 | 259 | return d_splice_alias(inode, dentry); |
da4458bd DH |
260 | error: |
261 | return ERR_PTR(ret); | |
262 | } | |
263 | ||
264 | static const struct file_operations romfs_dir_operations = { | |
265 | .read = generic_read_dir, | |
d375570f AV |
266 | .iterate_shared = romfs_readdir, |
267 | .llseek = generic_file_llseek, | |
da4458bd DH |
268 | }; |
269 | ||
6e1d5dcc | 270 | static const struct inode_operations romfs_dir_inode_operations = { |
da4458bd DH |
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; | |
774e33e7 RK |
284 | unsigned nextfh; |
285 | int ret; | |
da4458bd DH |
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 | ||
bfe86848 | 322 | set_nlink(i, 1); /* Hard to decide.. */ |
da4458bd DH |
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; | |
da4458bd DH |
341 | if (nextfh & ROMFH_EXEC) |
342 | mode |= S_IXUGO; | |
343 | break; | |
344 | case ROMFH_SYM: | |
345 | i->i_op = &page_symlink_inode_operations; | |
21fc61c7 | 346 | inode_nohighmem(i); |
da4458bd DH |
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: | |
ca9e5368 | 366 | pr_err("read error for inode 0x%lx\n", pos); |
da4458bd DH |
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; | |
b6d53b1b | 376 | |
da4458bd DH |
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 | */ | |
fa0d7e3d | 384 | static void romfs_i_callback(struct rcu_head *head) |
da4458bd | 385 | { |
fa0d7e3d | 386 | struct inode *inode = container_of(head, struct inode, i_rcu); |
b6d53b1b | 387 | |
da4458bd DH |
388 | kmem_cache_free(romfs_inode_cachep, ROMFS_I(inode)); |
389 | } | |
390 | ||
fa0d7e3d NP |
391 | static void romfs_destroy_inode(struct inode *inode) |
392 | { | |
393 | call_rcu(&inode->i_rcu, romfs_i_callback); | |
394 | } | |
395 | ||
da4458bd DH |
396 | /* |
397 | * get filesystem statistics | |
398 | */ | |
399 | static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf) | |
400 | { | |
8a59f5d2 | 401 | struct super_block *sb = dentry->d_sb; |
f598f82e CL |
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); | |
8a59f5d2 | 418 | |
da4458bd DH |
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; | |
8a59f5d2 CL |
425 | buf->f_fsid.val[0] = (u32)id; |
426 | buf->f_fsid.val[1] = (u32)(id >> 32); | |
da4458bd DH |
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 | { | |
02b9984d | 435 | sync_filesystem(sb); |
1751e8a6 | 436 | *flags |= SB_RDONLY; |
da4458bd DH |
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; | |
1751e8a6 | 487 | sb->s_flags |= SB_RDONLY | SB_NOATIME; |
da4458bd DH |
488 | sb->s_op = &romfs_super_ops; |
489 | ||
f598f82e CL |
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 | |
da4458bd DH |
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) | |
3d79d314 | 515 | pr_warn("VFS: Can't find a romfs filesystem on dev %s.\n", |
da4458bd DH |
516 | sb->s_id); |
517 | goto error_rsb_inval; | |
518 | } | |
519 | ||
520 | if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) { | |
ca9e5368 | 521 | pr_err("bad initial checksum on dev %s.\n", sb->s_id); |
da4458bd DH |
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) | |
ca9e5368 FF |
529 | pr_notice("Mounting image '%*.*s' through %s\n", |
530 | (unsigned) len, (unsigned) len, rsb->name, storage); | |
da4458bd DH |
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); | |
a21f3c2a | 539 | if (IS_ERR(root)) |
40e2c71d | 540 | return PTR_ERR(root); |
da4458bd | 541 | |
48fde701 | 542 | sb->s_root = d_make_root(root); |
da4458bd | 543 | if (!sb->s_root) |
40e2c71d | 544 | return -ENOMEM; |
da4458bd DH |
545 | |
546 | return 0; | |
547 | ||
da4458bd DH |
548 | error_rsb_inval: |
549 | ret = -EINVAL; | |
550 | error_rsb: | |
7e32b7bb | 551 | kfree(rsb); |
da4458bd DH |
552 | return ret; |
553 | } | |
554 | ||
555 | /* | |
556 | * get a superblock for mounting | |
557 | */ | |
848b83a5 | 558 | static struct dentry *romfs_mount(struct file_system_type *fs_type, |
da4458bd | 559 | int flags, const char *dev_name, |
848b83a5 | 560 | void *data) |
da4458bd | 561 | { |
848b83a5 | 562 | struct dentry *ret = ERR_PTR(-EINVAL); |
da4458bd DH |
563 | |
564 | #ifdef CONFIG_ROMFS_ON_MTD | |
848b83a5 | 565 | ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super); |
da4458bd DH |
566 | #endif |
567 | #ifdef CONFIG_ROMFS_ON_BLOCK | |
848b83a5 AV |
568 | if (ret == ERR_PTR(-EINVAL)) |
569 | ret = mount_bdev(fs_type, flags, dev_name, data, | |
570 | romfs_fill_super); | |
da4458bd DH |
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", | |
848b83a5 | 597 | .mount = romfs_mount, |
da4458bd DH |
598 | .kill_sb = romfs_kill_sb, |
599 | .fs_flags = FS_REQUIRES_DEV, | |
600 | }; | |
7f78e035 | 601 | MODULE_ALIAS_FS("romfs"); |
da4458bd DH |
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 | ||
3d79d314 | 620 | pr_info("ROMFS MTD (C) 2007 Red Hat, Inc.\n"); |
da4458bd DH |
621 | |
622 | romfs_inode_cachep = | |
623 | kmem_cache_create("romfs_i", | |
624 | sizeof(struct romfs_inode_info), 0, | |
5d097056 VD |
625 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | |
626 | SLAB_ACCOUNT, romfs_i_init_once); | |
da4458bd DH |
627 | |
628 | if (!romfs_inode_cachep) { | |
ca9e5368 | 629 | pr_err("Failed to initialise inode cache\n"); |
da4458bd DH |
630 | return -ENOMEM; |
631 | } | |
632 | ret = register_filesystem(&romfs_fs_type); | |
633 | if (ret) { | |
ca9e5368 | 634 | pr_err("Failed to register filesystem\n"); |
da4458bd DH |
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); | |
8c0a8537 KS |
650 | /* |
651 | * Make sure all delayed rcu free inodes are flushed before we | |
652 | * destroy cache. | |
653 | */ | |
654 | rcu_barrier(); | |
da4458bd DH |
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 */ |