Commit | Line | Data |
---|---|---|
1da177e4 LT |
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_kcompat.h" | |
40 | #include "vxfs_extern.h" | |
41 | ||
42 | ||
43 | static int vxfs_readpage(struct file *, struct page *); | |
44 | static sector_t vxfs_bmap(struct address_space *, sector_t); | |
45 | ||
46 | struct address_space_operations vxfs_aops = { | |
47 | .readpage = vxfs_readpage, | |
48 | .bmap = vxfs_bmap, | |
49 | .sync_page = block_sync_page, | |
50 | }; | |
51 | ||
52 | inline void | |
53 | vxfs_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 | */ | |
70 | struct page * | |
71 | vxfs_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 | ||
91 | fail: | |
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 | */ | |
108 | struct buffer_head * | |
109 | vxfs_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 | */ | |
135 | static int | |
136 | vxfs_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 | */ | |
165 | static int | |
166 | vxfs_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 | */ | |
186 | static sector_t | |
187 | vxfs_bmap(struct address_space *mapping, sector_t block) | |
188 | { | |
189 | return generic_block_bmap(mapping, block, vxfs_getblk); | |
190 | } |