LXR linux/fs/freevxfs/vxfs

   1/*
   2 * Copyright (c) 2000-2001 Christoph Hellwig.
   3 * All rights reserved.
   4 *
   5 * Redistribution and use in source and binary forms, with or without
   6 * modification, are permitted provided that the following conditions
   7 * are met:
   8 * 1. Redistributions of source code must retain the above copyright
   9 *    notice, this list of conditions, and the following disclaimer,
  10 *    without modification.
  11 * 2. The name of the author may not be used to endorse or promote products
  12 *    derived from this software without specific prior written permission.
  13 *
  14 * Alternatively, this software may be distributed under the terms of the
  15 * GNU General Public License ("GPL").
  16 *
  17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27 * SUCH DAMAGE.
  28 */
  29
  30/*
  31 * Veritas filesystem driver - support for 'immed' inodes.
  32 */
  33#include <linux/fs.h>
  34#include <linux/pagemap.h>
  35
  36#include "vxfs.h"
  37#include "vxfs_extern.h"
  38#include "vxfs_inode.h"
  39
  40
  41static int      vxfs_immed_readpage(struct file *, struct page *);
  42
  43/*
  44 * Address space operations for immed files and directories.
  45 */
  46const struct address_space_operations vxfs_immed_aops = {
  47        .readpage =             vxfs_immed_readpage,
  48};
  49
  50/**
  51 * vxfs_immed_readpage - read part of an immed inode into pagecache
  52 * @file:       file context (unused)
  53 * @page:       page frame to fill in.
  54 *
  55 * Description:
  56 *   vxfs_immed_readpage reads a part of the immed area of the
  57 *   file that hosts @pp into the pagecache.
  58 *
  59 * Returns:
  60 *   Zero on success, else a negative error code.
  61 *
  62 * Locking status:
  63 *   @page is locked and will be unlocked.
  64 */
  65static int
  66vxfs_immed_readpage(struct file *fp, struct page *pp)
  67{
  68        struct vxfs_inode_info  *vip = VXFS_INO(pp->mapping->host);
  69        u_int64_t       offset = (u_int64_t)pp->index << PAGE_SHIFT;
  70        caddr_t         kaddr;
  71
  72        kaddr = kmap(pp);
  73        memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_SIZE);
  74        kunmap(pp);
  75        
  76        flush_dcache_page(pp);
  77        SetPageUptodate(pp);
  78        unlock_page(pp);
  79
  80        return 0;
  81}
  82