fs/squashfs/file_cache.c

   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)
  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, buffer->length, 0);
  35
  36         squashfs_cache_put(buffer);
  37         return res;
  38 }