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