xref: /openbmc/linux/fs/squashfs/file_cache.c (revision 5d331b7f)
1 /*
2  * Copyright (c) 2013
3  * Phillip Lougher <phillip@squashfs.org.uk>
4  *
5  * This work is licensed under the terms of the GNU GPL, version 2. See
6  * the COPYING file in the top-level directory.
7  */
8 
9 #include <linux/fs.h>
10 #include <linux/vfs.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/pagemap.h>
15 #include <linux/mutex.h>
16 
17 #include "squashfs_fs.h"
18 #include "squashfs_fs_sb.h"
19 #include "squashfs_fs_i.h"
20 #include "squashfs.h"
21 
22 /* Read separately compressed datablock and memcopy into page cache */
23 int squashfs_readpage_block(struct page *page, u64 block, int bsize, int expected)
24 {
25 	struct inode *i = page->mapping->host;
26 	struct squashfs_cache_entry *buffer = squashfs_get_datablock(i->i_sb,
27 		block, bsize);
28 	int res = buffer->error;
29 
30 	if (res)
31 		ERROR("Unable to read page, block %llx, size %x\n", block,
32 			bsize);
33 	else
34 		squashfs_copy_cache(page, buffer, expected, 0);
35 
36 	squashfs_cache_put(buffer);
37 	return res;
38 }
39