blob: 1429f3ae1e868f2cb6f066542c3675d1d09134cd [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 - shared subroutines.
32 */
33#include <linux/fs.h>
34#include <linux/buffer_head.h>
35#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/pagemap.h>
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include "vxfs_extern.h"
39
40
41static int vxfs_readpage(struct file *, struct page *);
42static sector_t vxfs_bmap(struct address_space *, sector_t);
43
Christoph Hellwigf5e54d62006-06-28 04:26:44 -070044const struct address_space_operations vxfs_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 .readpage = vxfs_readpage,
46 .bmap = vxfs_bmap,
47 .sync_page = block_sync_page,
48};
49
50inline void
51vxfs_put_page(struct page *pp)
52{
53 kunmap(pp);
54 page_cache_release(pp);
55}
56
57/**
58 * vxfs_get_page - read a page into memory.
59 * @ip: inode to read from
60 * @n: page number
61 *
62 * Description:
63 * vxfs_get_page reads the @n th page of @ip into the pagecache.
64 *
65 * Returns:
66 * The wanted page on success, else a NULL pointer.
67 */
68struct page *
69vxfs_get_page(struct address_space *mapping, u_long n)
70{
71 struct page * pp;
72
Pekka Enberg090d2b12006-06-23 02:05:08 -070073 pp = read_mapping_page(mapping, n, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75 if (!IS_ERR(pp)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 kmap(pp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 /** if (!PageChecked(pp)) **/
78 /** vxfs_check_page(pp); **/
79 if (PageError(pp))
80 goto fail;
81 }
82
83 return (pp);
84
85fail:
86 vxfs_put_page(pp);
87 return ERR_PTR(-EIO);
88}
89
90/**
91 * vxfs_bread - read buffer for a give inode,block tuple
92 * @ip: inode
93 * @block: logical block
94 *
95 * Description:
96 * The vxfs_bread function reads block no @block of
97 * @ip into the buffercache.
98 *
99 * Returns:
100 * The resulting &struct buffer_head.
101 */
102struct buffer_head *
103vxfs_bread(struct inode *ip, int block)
104{
105 struct buffer_head *bp;
106 daddr_t pblock;
107
108 pblock = vxfs_bmap1(ip, block);
109 bp = sb_bread(ip->i_sb, pblock);
110
111 return (bp);
112}
113
114/**
115 * vxfs_get_block - locate buffer for given inode,block tuple
116 * @ip: inode
117 * @iblock: logical block
118 * @bp: buffer skeleton
119 * @create: %TRUE if blocks may be newly allocated.
120 *
121 * Description:
122 * The vxfs_get_block function fills @bp with the right physical
123 * block and device number to perform a lowlevel read/write on
124 * it.
125 *
126 * Returns:
127 * Zero on success, else a negativ error code (-EIO).
128 */
129static int
130vxfs_getblk(struct inode *ip, sector_t iblock,
131 struct buffer_head *bp, int create)
132{
133 daddr_t pblock;
134
135 pblock = vxfs_bmap1(ip, iblock);
136 if (pblock != 0) {
137 map_bh(bp, ip->i_sb, pblock);
138 return 0;
139 }
140
141 return -EIO;
142}
143
144/**
145 * vxfs_readpage - read one page synchronously into the pagecache
146 * @file: file context (unused)
147 * @page: page frame to fill in.
148 *
149 * Description:
150 * The vxfs_readpage routine reads @page synchronously into the
151 * pagecache.
152 *
153 * Returns:
154 * Zero on success, else a negative error code.
155 *
156 * Locking status:
157 * @page is locked and will be unlocked.
158 */
159static int
160vxfs_readpage(struct file *file, struct page *page)
161{
162 return block_read_full_page(page, vxfs_getblk);
163}
164
165/**
166 * vxfs_bmap - perform logical to physical block mapping
167 * @mapping: logical to physical mapping to use
168 * @block: logical block (relative to @mapping).
169 *
170 * Description:
171 * Vxfs_bmap find out the corresponding phsical block to the
172 * @mapping, @block pair.
173 *
174 * Returns:
175 * Physical block number on success, else Zero.
176 *
177 * Locking status:
178 * We are under the bkl.
179 */
180static sector_t
181vxfs_bmap(struct address_space *mapping, sector_t block)
182{
183 return generic_block_bmap(mapping, block, vxfs_getblk);
184}