blob: e141939080f0d6db65c525305cab5a74b9dd552c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Compressed rom filesystem for Linux.
3 *
4 * Copyright (C) 1999 Linus Torvalds.
5 *
6 * This file is released under the GPL.
7 */
8
9/*
10 * These are the VFS interfaces to the compressed rom filesystem.
11 * The actual compression is based on zlib, see the other files.
12 */
13
14#include <linux/module.h>
15#include <linux/fs.h>
16#include <linux/pagemap.h>
17#include <linux/init.h>
18#include <linux/string.h>
19#include <linux/blkdev.h>
20#include <linux/cramfs_fs.h>
21#include <linux/slab.h>
22#include <linux/cramfs_fs_sb.h>
23#include <linux/buffer_head.h>
24#include <linux/vfs.h>
Ingo Molnar353ab6e2006-03-26 01:37:12 -080025#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include <asm/uaccess.h>
28
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -080029static const struct super_operations cramfs_ops;
Arjan van de Ven754661f2007-02-12 00:55:38 -080030static const struct inode_operations cramfs_dir_inode_operations;
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080031static const struct file_operations cramfs_directory_operations;
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070032static const struct address_space_operations cramfs_aops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Ingo Molnar353ab6e2006-03-26 01:37:12 -080034static DEFINE_MUTEX(read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36
Stefani Seibold6f772fe2011-01-12 17:01:10 -080037/* These macros may change in future, to provide better st_ino semantics. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#define OFFSET(x) ((x)->i_ino)
39
Stefani Seibold6f772fe2011-01-12 17:01:10 -080040static unsigned long cramino(struct cramfs_inode *cino, unsigned int offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041{
Stefani Seibold6f772fe2011-01-12 17:01:10 -080042 if (!cino->offset)
43 return offset + 1;
44 if (!cino->size)
45 return offset + 1;
46
47 /*
48 * The file mode test fixes buggy mkcramfs implementations where
49 * cramfs_inode->offset is set to a non zero value for entries
50 * which did not contain data, like devices node and fifos.
51 */
52 switch (cino->mode & S_IFMT) {
53 case S_IFREG:
54 case S_IFDIR:
55 case S_IFLNK:
56 return cino->offset << 2;
57 default:
58 break;
59 }
60 return offset + 1;
61}
62
63static struct inode *get_cramfs_inode(struct super_block *sb,
64 struct cramfs_inode *cramfs_inode, unsigned int offset)
65{
66 struct inode *inode;
Al Viro77b8a752010-06-04 21:19:01 -040067 static struct timespec zerotime;
Stefani Seibold6f772fe2011-01-12 17:01:10 -080068
69 inode = iget_locked(sb, cramino(cramfs_inode, offset));
70 if (!inode)
71 return ERR_PTR(-ENOMEM);
72 if (!(inode->i_state & I_NEW))
73 return inode;
74
75 switch (cramfs_inode->mode & S_IFMT) {
76 case S_IFREG:
77 inode->i_fop = &generic_ro_fops;
78 inode->i_data.a_ops = &cramfs_aops;
79 break;
80 case S_IFDIR:
81 inode->i_op = &cramfs_dir_inode_operations;
82 inode->i_fop = &cramfs_directory_operations;
83 break;
84 case S_IFLNK:
85 inode->i_op = &page_symlink_inode_operations;
86 inode->i_data.a_ops = &cramfs_aops;
87 break;
88 default:
89 init_special_inode(inode, cramfs_inode->mode,
90 old_decode_dev(cramfs_inode->size));
91 }
92
Al Viro77b8a752010-06-04 21:19:01 -040093 inode->i_mode = cramfs_inode->mode;
94 inode->i_uid = cramfs_inode->uid;
Al Viro77b8a752010-06-04 21:19:01 -040095 inode->i_gid = cramfs_inode->gid;
Stefani Seibold6f772fe2011-01-12 17:01:10 -080096
97 /* if the lower 2 bits are zero, the inode contains data */
98 if (!(inode->i_ino & 3)) {
99 inode->i_size = cramfs_inode->size;
100 inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1;
101 }
102
Al Viro77b8a752010-06-04 21:19:01 -0400103 /* Struct copy intentional */
104 inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime;
105 /* inode->i_nlink is left 1 - arguably wrong for directories,
106 but it's the best we can do without reading the directory
107 contents. 1 yields the right result in GNU find, even
108 without -noleaf option. */
Dave Johnsona97c9bf2005-09-06 15:17:40 -0700109
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800110 unlock_new_inode(inode);
111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 return inode;
113}
114
115/*
116 * We have our own block cache: don't fill up the buffer cache
117 * with the rom-image, because the way the filesystem is set
118 * up the accesses should be fairly regular and cached in the
119 * page cache and dentry tree anyway..
120 *
121 * This also acts as a way to guarantee contiguous areas of up to
122 * BLKS_PER_BUF*PAGE_CACHE_SIZE, so that the caller doesn't need to
123 * worry about end-of-buffer issues even when decompressing a full
124 * page cache.
125 */
126#define READ_BUFFERS (2)
127/* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */
128#define NEXT_BUFFER(_ix) ((_ix) ^ 1)
129
130/*
131 * BLKS_PER_BUF_SHIFT should be at least 2 to allow for "compressed"
132 * data that takes up more space than the original and with unlucky
133 * alignment.
134 */
135#define BLKS_PER_BUF_SHIFT (2)
136#define BLKS_PER_BUF (1 << BLKS_PER_BUF_SHIFT)
137#define BUFFER_SIZE (BLKS_PER_BUF*PAGE_CACHE_SIZE)
138
139static unsigned char read_buffers[READ_BUFFERS][BUFFER_SIZE];
140static unsigned buffer_blocknr[READ_BUFFERS];
141static struct super_block * buffer_dev[READ_BUFFERS];
142static int next_buffer;
143
144/*
145 * Returns a pointer to a buffer containing at least LEN bytes of
146 * filesystem starting at byte offset OFFSET into the filesystem.
147 */
148static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned int len)
149{
150 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
151 struct page *pages[BLKS_PER_BUF];
Andi Drebes6bbfb072007-10-18 03:06:54 -0700152 unsigned i, blocknr, buffer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 unsigned long devsize;
154 char *data;
155
156 if (!len)
157 return NULL;
158 blocknr = offset >> PAGE_CACHE_SHIFT;
159 offset &= PAGE_CACHE_SIZE - 1;
160
161 /* Check if an existing buffer already has the data.. */
162 for (i = 0; i < READ_BUFFERS; i++) {
163 unsigned int blk_offset;
164
165 if (buffer_dev[i] != sb)
166 continue;
167 if (blocknr < buffer_blocknr[i])
168 continue;
169 blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_CACHE_SHIFT;
170 blk_offset += offset;
171 if (blk_offset + len > BUFFER_SIZE)
172 continue;
173 return read_buffers[i] + blk_offset;
174 }
175
176 devsize = mapping->host->i_size >> PAGE_CACHE_SHIFT;
177
178 /* Ok, read in BLKS_PER_BUF pages completely first. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 for (i = 0; i < BLKS_PER_BUF; i++) {
180 struct page *page = NULL;
181
182 if (blocknr + i < devsize) {
Nick Piggin6fe69002007-05-06 14:49:04 -0700183 page = read_mapping_page_async(mapping, blocknr + i,
184 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 /* synchronous error? */
186 if (IS_ERR(page))
187 page = NULL;
188 }
189 pages[i] = page;
190 }
191
192 for (i = 0; i < BLKS_PER_BUF; i++) {
193 struct page *page = pages[i];
194 if (page) {
195 wait_on_page_locked(page);
196 if (!PageUptodate(page)) {
197 /* asynchronous error */
198 page_cache_release(page);
199 pages[i] = NULL;
200 }
201 }
202 }
203
204 buffer = next_buffer;
205 next_buffer = NEXT_BUFFER(buffer);
206 buffer_blocknr[buffer] = blocknr;
207 buffer_dev[buffer] = sb;
208
209 data = read_buffers[buffer];
210 for (i = 0; i < BLKS_PER_BUF; i++) {
211 struct page *page = pages[i];
212 if (page) {
213 memcpy(data, kmap(page), PAGE_CACHE_SIZE);
214 kunmap(page);
215 page_cache_release(page);
216 } else
217 memset(data, 0, PAGE_CACHE_SIZE);
218 data += PAGE_CACHE_SIZE;
219 }
220 return read_buffers[buffer] + offset;
221}
222
223static void cramfs_put_super(struct super_block *sb)
224{
225 kfree(sb->s_fs_info);
226 sb->s_fs_info = NULL;
227}
228
229static int cramfs_remount(struct super_block *sb, int *flags, char *data)
230{
231 *flags |= MS_RDONLY;
232 return 0;
233}
234
235static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
236{
237 int i;
238 struct cramfs_super super;
239 unsigned long root_offset;
240 struct cramfs_sb_info *sbi;
241 struct inode *root;
242
243 sb->s_flags |= MS_RDONLY;
244
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700245 sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (!sbi)
247 return -ENOMEM;
248 sb->s_fs_info = sbi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250 /* Invalidate the read buffers on mount: think disk change.. */
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800251 mutex_lock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 for (i = 0; i < READ_BUFFERS; i++)
253 buffer_blocknr[i] = -1;
254
255 /* Read the first block and get the superblock from it */
256 memcpy(&super, cramfs_read(sb, 0, sizeof(super)), sizeof(super));
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800257 mutex_unlock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
259 /* Do sanity checks on the superblock */
260 if (super.magic != CRAMFS_MAGIC) {
Andi Drebesac8d35c2007-10-16 23:27:12 -0700261 /* check for wrong endianess */
262 if (super.magic == CRAMFS_MAGIC_WEND) {
263 if (!silent)
264 printk(KERN_ERR "cramfs: wrong endianess\n");
265 goto out;
266 }
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 /* check at 512 byte offset */
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800269 mutex_lock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 memcpy(&super, cramfs_read(sb, 512, sizeof(super)), sizeof(super));
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800271 mutex_unlock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 if (super.magic != CRAMFS_MAGIC) {
Andi Drebesac8d35c2007-10-16 23:27:12 -0700273 if (super.magic == CRAMFS_MAGIC_WEND && !silent)
274 printk(KERN_ERR "cramfs: wrong endianess\n");
275 else if (!silent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 printk(KERN_ERR "cramfs: wrong magic\n");
277 goto out;
278 }
279 }
280
281 /* get feature flags first */
282 if (super.flags & ~CRAMFS_SUPPORTED_FLAGS) {
283 printk(KERN_ERR "cramfs: unsupported filesystem features\n");
284 goto out;
285 }
286
287 /* Check that the root inode is in a sane state */
288 if (!S_ISDIR(super.root.mode)) {
289 printk(KERN_ERR "cramfs: root is not a directory\n");
290 goto out;
291 }
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800292 /* correct strange, hard-coded permissions of mkcramfs */
293 super.root.mode |= (S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
294
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 root_offset = super.root.offset << 2;
296 if (super.flags & CRAMFS_FLAG_FSID_VERSION_2) {
297 sbi->size=super.size;
298 sbi->blocks=super.fsid.blocks;
299 sbi->files=super.fsid.files;
300 } else {
301 sbi->size=1<<28;
302 sbi->blocks=0;
303 sbi->files=0;
304 }
305 sbi->magic=super.magic;
306 sbi->flags=super.flags;
307 if (root_offset == 0)
308 printk(KERN_INFO "cramfs: empty filesystem");
309 else if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
310 ((root_offset != sizeof(struct cramfs_super)) &&
311 (root_offset != 512 + sizeof(struct cramfs_super))))
312 {
313 printk(KERN_ERR "cramfs: bad root offset %lu\n", root_offset);
314 goto out;
315 }
316
317 /* Set it all up.. */
318 sb->s_op = &cramfs_ops;
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800319 root = get_cramfs_inode(sb, &super.root, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 if (!root)
321 goto out;
322 sb->s_root = d_alloc_root(root);
323 if (!sb->s_root) {
324 iput(root);
325 goto out;
326 }
327 return 0;
328out:
329 kfree(sbi);
330 sb->s_fs_info = NULL;
331 return -EINVAL;
332}
333
David Howells726c3342006-06-23 02:02:58 -0700334static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335{
David Howells726c3342006-06-23 02:02:58 -0700336 struct super_block *sb = dentry->d_sb;
Coly Li94ea77a2009-04-02 16:59:33 -0700337 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
David Howells726c3342006-06-23 02:02:58 -0700338
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 buf->f_type = CRAMFS_MAGIC;
340 buf->f_bsize = PAGE_CACHE_SIZE;
341 buf->f_blocks = CRAMFS_SB(sb)->blocks;
342 buf->f_bfree = 0;
343 buf->f_bavail = 0;
344 buf->f_files = CRAMFS_SB(sb)->files;
345 buf->f_ffree = 0;
Coly Li94ea77a2009-04-02 16:59:33 -0700346 buf->f_fsid.val[0] = (u32)id;
347 buf->f_fsid.val[1] = (u32)(id >> 32);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 buf->f_namelen = CRAMFS_MAXPATHLEN;
349 return 0;
350}
351
352/*
353 * Read a cramfs directory entry.
354 */
355static int cramfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
356{
Josef Sipek352d8af2006-12-08 02:36:58 -0800357 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 struct super_block *sb = inode->i_sb;
359 char *buf;
360 unsigned int offset;
361 int copied;
362
363 /* Offset within the thing. */
364 offset = filp->f_pos;
365 if (offset >= inode->i_size)
366 return 0;
367 /* Directory entries are always 4-byte aligned */
368 if (offset & 3)
369 return -EINVAL;
370
Andi Drebes4176ed52007-10-18 03:06:55 -0700371 buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 if (!buf)
373 return -ENOMEM;
374
375 copied = 0;
376 while (offset < inode->i_size) {
377 struct cramfs_inode *de;
378 unsigned long nextoffset;
379 char *name;
380 ino_t ino;
381 mode_t mode;
382 int namelen, error;
383
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800384 mutex_lock(&read_mutex);
Andi Drebes4176ed52007-10-18 03:06:55 -0700385 de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 name = (char *)(de+1);
387
388 /*
389 * Namelengths on disk are shifted by two
390 * and the name padded out to 4-byte boundaries
391 * with zeroes.
392 */
393 namelen = de->namelen << 2;
394 memcpy(buf, name, namelen);
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800395 ino = cramino(de, OFFSET(inode) + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 mode = de->mode;
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800397 mutex_unlock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 nextoffset = offset + sizeof(*de) + namelen;
399 for (;;) {
400 if (!namelen) {
401 kfree(buf);
402 return -EIO;
403 }
404 if (buf[namelen-1])
405 break;
406 namelen--;
407 }
408 error = filldir(dirent, buf, namelen, offset, ino, mode >> 12);
409 if (error)
410 break;
411
412 offset = nextoffset;
413 filp->f_pos = offset;
414 copied++;
415 }
416 kfree(buf);
417 return 0;
418}
419
420/*
421 * Lookup and fill in the inode data..
422 */
423static struct dentry * cramfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
424{
425 unsigned int offset = 0;
426 int sorted;
427
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800428 mutex_lock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS;
430 while (offset < dir->i_size) {
431 struct cramfs_inode *de;
432 char *name;
433 int namelen, retval;
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800434 int dir_off = OFFSET(dir) + offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800436 de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 name = (char *)(de+1);
438
439 /* Try to take advantage of sorted directories */
440 if (sorted && (dentry->d_name.name[0] < name[0]))
441 break;
442
443 namelen = de->namelen << 2;
444 offset += sizeof(*de) + namelen;
445
446 /* Quick check that the name is roughly the right length */
447 if (((dentry->d_name.len + 3) & ~3) != namelen)
448 continue;
449
450 for (;;) {
451 if (!namelen) {
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800452 mutex_unlock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 return ERR_PTR(-EIO);
454 }
455 if (name[namelen-1])
456 break;
457 namelen--;
458 }
459 if (namelen != dentry->d_name.len)
460 continue;
461 retval = memcmp(dentry->d_name.name, name, namelen);
462 if (retval > 0)
463 continue;
464 if (!retval) {
465 struct cramfs_inode entry = *de;
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800466 mutex_unlock(&read_mutex);
Stefani Seibold6f772fe2011-01-12 17:01:10 -0800467 d_add(dentry, get_cramfs_inode(dir->i_sb, &entry, dir_off));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 return NULL;
469 }
470 /* else (retval < 0) */
471 if (sorted)
472 break;
473 }
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800474 mutex_unlock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 d_add(dentry, NULL);
476 return NULL;
477}
478
479static int cramfs_readpage(struct file *file, struct page * page)
480{
481 struct inode *inode = page->mapping->host;
David VomLehn98310e52009-04-02 16:59:15 -0700482 u32 maxblock;
483 int bytes_filled;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 void *pgdata;
485
486 maxblock = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
487 bytes_filled = 0;
David VomLehn98310e52009-04-02 16:59:15 -0700488 pgdata = kmap(page);
489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 if (page->index < maxblock) {
491 struct super_block *sb = inode->i_sb;
492 u32 blkptr_offset = OFFSET(inode) + page->index*4;
493 u32 start_offset, compr_len;
494
495 start_offset = OFFSET(inode) + maxblock*4;
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800496 mutex_lock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 if (page->index)
David VomLehn98310e52009-04-02 16:59:15 -0700498 start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4,
499 4);
500 compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) -
501 start_offset);
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800502 mutex_unlock(&read_mutex);
David VomLehn98310e52009-04-02 16:59:15 -0700503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (compr_len == 0)
505 ; /* hole */
David VomLehn98310e52009-04-02 16:59:15 -0700506 else if (unlikely(compr_len > (PAGE_CACHE_SIZE << 1))) {
507 pr_err("cramfs: bad compressed blocksize %u\n",
508 compr_len);
509 goto err;
510 } else {
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800511 mutex_lock(&read_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 bytes_filled = cramfs_uncompress_block(pgdata,
513 PAGE_CACHE_SIZE,
514 cramfs_read(sb, start_offset, compr_len),
515 compr_len);
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800516 mutex_unlock(&read_mutex);
David VomLehn98310e52009-04-02 16:59:15 -0700517 if (unlikely(bytes_filled < 0))
518 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
David VomLehn98310e52009-04-02 16:59:15 -0700520 }
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 memset(pgdata + bytes_filled, 0, PAGE_CACHE_SIZE - bytes_filled);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 flush_dcache_page(page);
David VomLehn98310e52009-04-02 16:59:15 -0700524 kunmap(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 SetPageUptodate(page);
526 unlock_page(page);
527 return 0;
David VomLehn98310e52009-04-02 16:59:15 -0700528
529err:
530 kunmap(page);
531 ClearPageUptodate(page);
532 SetPageError(page);
533 unlock_page(page);
534 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535}
536
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700537static const struct address_space_operations cramfs_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 .readpage = cramfs_readpage
539};
540
541/*
542 * Our operations:
543 */
544
545/*
546 * A directory can only readdir
547 */
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800548static const struct file_operations cramfs_directory_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 .llseek = generic_file_llseek,
550 .read = generic_read_dir,
551 .readdir = cramfs_readdir,
552};
553
Arjan van de Ven754661f2007-02-12 00:55:38 -0800554static const struct inode_operations cramfs_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 .lookup = cramfs_lookup,
556};
557
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800558static const struct super_operations cramfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 .put_super = cramfs_put_super,
560 .remount_fs = cramfs_remount,
561 .statfs = cramfs_statfs,
562};
563
Al Viro152a0832010-07-25 00:46:55 +0400564static struct dentry *cramfs_mount(struct file_system_type *fs_type,
565 int flags, const char *dev_name, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566{
Al Viro152a0832010-07-25 00:46:55 +0400567 return mount_bdev(fs_type, flags, dev_name, data, cramfs_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568}
569
570static struct file_system_type cramfs_fs_type = {
571 .owner = THIS_MODULE,
572 .name = "cramfs",
Al Viro152a0832010-07-25 00:46:55 +0400573 .mount = cramfs_mount,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 .kill_sb = kill_block_super,
575 .fs_flags = FS_REQUIRES_DEV,
576};
577
578static int __init init_cramfs_fs(void)
579{
Alexey Dobriyan50d44ed2006-09-29 02:01:04 -0700580 int rv;
581
582 rv = cramfs_uncompress_init();
583 if (rv < 0)
584 return rv;
585 rv = register_filesystem(&cramfs_fs_type);
586 if (rv < 0)
587 cramfs_uncompress_exit();
588 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589}
590
591static void __exit exit_cramfs_fs(void)
592{
593 cramfs_uncompress_exit();
594 unregister_filesystem(&cramfs_fs_type);
595}
596
597module_init(init_cramfs_fs)
598module_exit(exit_cramfs_fs)
599MODULE_LICENSE("GPL");