File: vxfs_subr.c

package info (click to toggle)
linux 3.16.7-ckt2-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 734,120 kB
  • ctags: 2,369,605
  • sloc: ansic: 12,212,866; asm: 277,256; perl: 53,999; xml: 47,771; makefile: 30,481; sh: 8,035; python: 6,583; cpp: 5,121; yacc: 4,254; lex: 2,215; awk: 741; pascal: 231; lisp: 218; sed: 30
file content (183 lines) | stat: -rw-r--r-- 4,669 bytes parent folder | download | duplicates (18)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Veritas filesystem driver - shared subroutines.
 */
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>

#include "vxfs_extern.h"


static int		vxfs_readpage(struct file *, struct page *);
static sector_t		vxfs_bmap(struct address_space *, sector_t);

const struct address_space_operations vxfs_aops = {
	.readpage =		vxfs_readpage,
	.bmap =			vxfs_bmap,
};

inline void
vxfs_put_page(struct page *pp)
{
	kunmap(pp);
	page_cache_release(pp);
}

/**
 * vxfs_get_page - read a page into memory.
 * @ip:		inode to read from
 * @n:		page number
 *
 * Description:
 *   vxfs_get_page reads the @n th page of @ip into the pagecache.
 *
 * Returns:
 *   The wanted page on success, else a NULL pointer.
 */
struct page *
vxfs_get_page(struct address_space *mapping, u_long n)
{
	struct page *			pp;

	pp = read_mapping_page(mapping, n, NULL);

	if (!IS_ERR(pp)) {
		kmap(pp);
		/** if (!PageChecked(pp)) **/
			/** vxfs_check_page(pp); **/
		if (PageError(pp))
			goto fail;
	}
	
	return (pp);
		 
fail:
	vxfs_put_page(pp);
	return ERR_PTR(-EIO);
}

/**
 * vxfs_bread - read buffer for a give inode,block tuple
 * @ip:		inode
 * @block:	logical block
 *
 * Description:
 *   The vxfs_bread function reads block no @block  of
 *   @ip into the buffercache.
 *
 * Returns:
 *   The resulting &struct buffer_head.
 */
struct buffer_head *
vxfs_bread(struct inode *ip, int block)
{
	struct buffer_head	*bp;
	daddr_t			pblock;

	pblock = vxfs_bmap1(ip, block);
	bp = sb_bread(ip->i_sb, pblock);

	return (bp);
}

/**
 * vxfs_get_block - locate buffer for given inode,block tuple 
 * @ip:		inode
 * @iblock:	logical block
 * @bp:		buffer skeleton
 * @create:	%TRUE if blocks may be newly allocated.
 *
 * Description:
 *   The vxfs_get_block function fills @bp with the right physical
 *   block and device number to perform a lowlevel read/write on
 *   it.
 *
 * Returns:
 *   Zero on success, else a negativ error code (-EIO).
 */
static int
vxfs_getblk(struct inode *ip, sector_t iblock,
	    struct buffer_head *bp, int create)
{
	daddr_t			pblock;

	pblock = vxfs_bmap1(ip, iblock);
	if (pblock != 0) {
		map_bh(bp, ip->i_sb, pblock);
		return 0;
	}

	return -EIO;
}

/**
 * vxfs_readpage - read one page synchronously into the pagecache
 * @file:	file context (unused)
 * @page:	page frame to fill in.
 *
 * Description:
 *   The vxfs_readpage routine reads @page synchronously into the
 *   pagecache.
 *
 * Returns:
 *   Zero on success, else a negative error code.
 *
 * Locking status:
 *   @page is locked and will be unlocked.
 */
static int
vxfs_readpage(struct file *file, struct page *page)
{
	return block_read_full_page(page, vxfs_getblk);
}
 
/**
 * vxfs_bmap - perform logical to physical block mapping
 * @mapping:	logical to physical mapping to use
 * @block:	logical block (relative to @mapping).
 *
 * Description:
 *   Vxfs_bmap find out the corresponding phsical block to the
 *   @mapping, @block pair.
 *
 * Returns:
 *   Physical block number on success, else Zero.
 *
 * Locking status:
 *   We are under the bkl.
 */
static sector_t
vxfs_bmap(struct address_space *mapping, sector_t block)
{
	return generic_block_bmap(mapping, block, vxfs_getblk);
}