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
41 static int vxfs_immed_readpage(struct file *, struct page *);
42
43 /*
44 * Address space operations for immed files and directories.
45 */
46 const 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 */
65 static int
66 vxfs_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 }