blob: 50aae77651b29c9c6558ee50f77ebe7ee6e55011 [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>
36#include <linux/slab.h>
37#include <linux/pagemap.h>
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include "vxfs_extern.h"
40
41
42static int vxfs_readpage(struct file *, struct page *);
43static sector_t vxfs_bmap(struct address_space *, sector_t);
44
45struct address_space_operations vxfs_aops = {
46 .readpage = vxfs_readpage,
47 .bmap = vxfs_bmap,
48 .sync_page = block_sync_page,
49};
50
51inline void
52vxfs_put_page(struct page *pp)
53{
54 kunmap(pp);
55 page_cache_release(pp);
56}
57
58/**
59 * vxfs_get_page - read a page into memory.
60 * @ip: inode to read from
61 * @n: page number
62 *
63 * Description:
64 * vxfs_get_page reads the @n th page of @ip into the pagecache.
65 *
66 * Returns:
67 * The wanted page on success, else a NULL pointer.
68 */
69struct page *
70vxfs_get_page(struct address_space *mapping, u_long n)
71{
72 struct page * pp;
73
74 pp = read_cache_page(mapping, n,
75 (filler_t*)mapping->a_ops->readpage, NULL);
76
77 if (!IS_ERR(pp)) {
78 wait_on_page_locked(pp);
79 kmap(pp);
80 if (!PageUptodate(pp))
81 goto fail;
82 /** if (!PageChecked(pp)) **/
83 /** vxfs_check_page(pp); **/
84 if (PageError(pp))
85 goto fail;
86 }
87
88 return (pp);
89
90fail:
91 vxfs_put_page(pp);
92 return ERR_PTR(-EIO);
93}
94
95/**
96 * vxfs_bread - read buffer for a give inode,block tuple
97 * @ip: inode
98 * @block: logical block
99 *
100 * Description:
101 * The vxfs_bread function reads block no @block of
102 * @ip into the buffercache.
103 *
104 * Returns:
105 * The resulting &struct buffer_head.
106 */
107struct buffer_head *
108vxfs_bread(struct inode *ip, int block)
109{
110 struct buffer_head *bp;
111 daddr_t pblock;
112
113 pblock = vxfs_bmap1(ip, block);
114 bp = sb_bread(ip->i_sb, pblock);
115
116 return (bp);
117}
118
119/**
120 * vxfs_get_block - locate buffer for given inode,block tuple
121 * @ip: inode
122 * @iblock: logical block
123 * @bp: buffer skeleton
124 * @create: %TRUE if blocks may be newly allocated.
125 *
126 * Description:
127 * The vxfs_get_block function fills @bp with the right physical
128 * block and device number to perform a lowlevel read/write on
129 * it.
130 *
131 * Returns:
132 * Zero on success, else a negativ error code (-EIO).
133 */
134static int
135vxfs_getblk(struct inode *ip, sector_t iblock,
136 struct buffer_head *bp, int create)
137{
138 daddr_t pblock;
139
140 pblock = vxfs_bmap1(ip, iblock);
141 if (pblock != 0) {
142 map_bh(bp, ip->i_sb, pblock);
143 return 0;
144 }
145
146 return -EIO;
147}
148
149/**
150 * vxfs_readpage - read one page synchronously into the pagecache
151 * @file: file context (unused)
152 * @page: page frame to fill in.
153 *
154 * Description:
155 * The vxfs_readpage routine reads @page synchronously into the
156 * pagecache.
157 *
158 * Returns:
159 * Zero on success, else a negative error code.
160 *
161 * Locking status:
162 * @page is locked and will be unlocked.
163 */
164static int
165vxfs_readpage(struct file *file, struct page *page)
166{
167 return block_read_full_page(page, vxfs_getblk);
168}
169
170/**
171 * vxfs_bmap - perform logical to physical block mapping
172 * @mapping: logical to physical mapping to use
173 * @block: logical block (relative to @mapping).
174 *
175 * Description:
176 * Vxfs_bmap find out the corresponding phsical block to the
177 * @mapping, @block pair.
178 *
179 * Returns:
180 * Physical block number on success, else Zero.
181 *
182 * Locking status:
183 * We are under the bkl.
184 */
185static sector_t
186vxfs_bmap(struct address_space *mapping, sector_t block)
187{
188 return generic_block_bmap(mapping, block, vxfs_getblk);
189}