blob: 5e305612054a5519ab4f34efa92f372a686bc17c [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
39#include "vxfs_kcompat.h"
40#include "vxfs_extern.h"
41
42
43static int vxfs_readpage(struct file *, struct page *);
44static sector_t vxfs_bmap(struct address_space *, sector_t);
45
46struct address_space_operations vxfs_aops = {
47 .readpage = vxfs_readpage,
48 .bmap = vxfs_bmap,
49 .sync_page = block_sync_page,
50};
51
52inline void
53vxfs_put_page(struct page *pp)
54{
55 kunmap(pp);
56 page_cache_release(pp);
57}
58
59/**
60 * vxfs_get_page - read a page into memory.
61 * @ip: inode to read from
62 * @n: page number
63 *
64 * Description:
65 * vxfs_get_page reads the @n th page of @ip into the pagecache.
66 *
67 * Returns:
68 * The wanted page on success, else a NULL pointer.
69 */
70struct page *
71vxfs_get_page(struct address_space *mapping, u_long n)
72{
73 struct page * pp;
74
75 pp = read_cache_page(mapping, n,
76 (filler_t*)mapping->a_ops->readpage, NULL);
77
78 if (!IS_ERR(pp)) {
79 wait_on_page_locked(pp);
80 kmap(pp);
81 if (!PageUptodate(pp))
82 goto fail;
83 /** if (!PageChecked(pp)) **/
84 /** vxfs_check_page(pp); **/
85 if (PageError(pp))
86 goto fail;
87 }
88
89 return (pp);
90
91fail:
92 vxfs_put_page(pp);
93 return ERR_PTR(-EIO);
94}
95
96/**
97 * vxfs_bread - read buffer for a give inode,block tuple
98 * @ip: inode
99 * @block: logical block
100 *
101 * Description:
102 * The vxfs_bread function reads block no @block of
103 * @ip into the buffercache.
104 *
105 * Returns:
106 * The resulting &struct buffer_head.
107 */
108struct buffer_head *
109vxfs_bread(struct inode *ip, int block)
110{
111 struct buffer_head *bp;
112 daddr_t pblock;
113
114 pblock = vxfs_bmap1(ip, block);
115 bp = sb_bread(ip->i_sb, pblock);
116
117 return (bp);
118}
119
120/**
121 * vxfs_get_block - locate buffer for given inode,block tuple
122 * @ip: inode
123 * @iblock: logical block
124 * @bp: buffer skeleton
125 * @create: %TRUE if blocks may be newly allocated.
126 *
127 * Description:
128 * The vxfs_get_block function fills @bp with the right physical
129 * block and device number to perform a lowlevel read/write on
130 * it.
131 *
132 * Returns:
133 * Zero on success, else a negativ error code (-EIO).
134 */
135static int
136vxfs_getblk(struct inode *ip, sector_t iblock,
137 struct buffer_head *bp, int create)
138{
139 daddr_t pblock;
140
141 pblock = vxfs_bmap1(ip, iblock);
142 if (pblock != 0) {
143 map_bh(bp, ip->i_sb, pblock);
144 return 0;
145 }
146
147 return -EIO;
148}
149
150/**
151 * vxfs_readpage - read one page synchronously into the pagecache
152 * @file: file context (unused)
153 * @page: page frame to fill in.
154 *
155 * Description:
156 * The vxfs_readpage routine reads @page synchronously into the
157 * pagecache.
158 *
159 * Returns:
160 * Zero on success, else a negative error code.
161 *
162 * Locking status:
163 * @page is locked and will be unlocked.
164 */
165static int
166vxfs_readpage(struct file *file, struct page *page)
167{
168 return block_read_full_page(page, vxfs_getblk);
169}
170
171/**
172 * vxfs_bmap - perform logical to physical block mapping
173 * @mapping: logical to physical mapping to use
174 * @block: logical block (relative to @mapping).
175 *
176 * Description:
177 * Vxfs_bmap find out the corresponding phsical block to the
178 * @mapping, @block pair.
179 *
180 * Returns:
181 * Physical block number on success, else Zero.
182 *
183 * Locking status:
184 * We are under the bkl.
185 */
186static sector_t
187vxfs_bmap(struct address_space *mapping, sector_t block)
188{
189 return generic_block_bmap(mapping, block, vxfs_getblk);
190}