aboutsummaryrefslogtreecommitdiffstats
path: root/fs/freevxfs/vxfs_subr.c
blob: c99282df7761a0e3f9732f76e9f7e2fbcedf4336 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 */

/*
 * 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_read_folio(struct file *, struct folio *);
static sector_t		vxfs_bmap(struct address_space *, sector_t);

const struct address_space_operations vxfs_aops = {
	.read_folio =		vxfs_read_folio,
	.bmap =			vxfs_bmap,
};

inline void
vxfs_put_page(struct page *pp)
{
	kunmap(pp);
	put_page(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); **/
	}
	
	return (pp);
}

/**
 * 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_read_folio - read one page synchronously into the pagecache
 * @file:	file context (unused)
 * @folio:	folio to fill in.
 *
 * Description:
 *   The vxfs_read_folio routine reads @folio synchronously into the
 *   pagecache.
 *
 * Returns:
 *   Zero on success, else a negative error code.
 *
 * Locking status:
 *   @folio is locked and will be unlocked.
 */
static int vxfs_read_folio(struct file *file, struct folio *folio)
{
	return block_read_full_folio(folio, 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);
}