1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2000-2001 Christoph Hellwig.
4 */
5
6/*
7 * Veritas filesystem driver - shared subroutines.
8 */
9#include <linux/fs.h>
10#include <linux/buffer_head.h>
11#include <linux/kernel.h>
12#include <linux/pagemap.h>
13
14#include "vxfs_extern.h"
15
16
17static int vxfs_read_folio(struct file *, struct folio *);
18static sector_t vxfs_bmap(struct address_space *, sector_t);
19
20const struct address_space_operations vxfs_aops = {
21 .read_folio = vxfs_read_folio,
22 .bmap = vxfs_bmap,
23};
24
25inline void
26vxfs_put_page(struct page *pp)
27{
28 kunmap(page: pp);
29 put_page(page: pp);
30}
31
32/**
33 * vxfs_get_page - read a page into memory.
34 * @mapping: mapping to read from
35 * @n: page number
36 *
37 * Description:
38 * vxfs_get_page reads the @n th page of @ip into the pagecache.
39 *
40 * Returns:
41 * The wanted page on success, else a NULL pointer.
42 */
43struct page *
44vxfs_get_page(struct address_space *mapping, u_long n)
45{
46 struct page * pp;
47
48 pp = read_mapping_page(mapping, index: n, NULL);
49
50 if (!IS_ERR(ptr: pp)) {
51 kmap(page: pp);
52 /** if (!PageChecked(pp)) **/
53 /** vxfs_check_page(pp); **/
54 }
55
56 return (pp);
57}
58
59/**
60 * vxfs_bread - read buffer for a give inode,block tuple
61 * @ip: inode
62 * @block: logical block
63 *
64 * Description:
65 * The vxfs_bread function reads block no @block of
66 * @ip into the buffercache.
67 *
68 * Returns:
69 * The resulting &struct buffer_head.
70 */
71struct buffer_head *
72vxfs_bread(struct inode *ip, int block)
73{
74 struct buffer_head *bp;
75 daddr_t pblock;
76
77 pblock = vxfs_bmap1(ip, block);
78 bp = sb_bread(sb: ip->i_sb, block: pblock);
79
80 return (bp);
81}
82
83/**
84 * vxfs_getblk - locate buffer for given inode,block tuple
85 * @ip: inode
86 * @iblock: logical block
87 * @bp: buffer skeleton
88 * @create: %TRUE if blocks may be newly allocated.
89 *
90 * Description:
91 * The vxfs_getblk function fills @bp with the right physical
92 * block and device number to perform a lowlevel read/write on
93 * it.
94 *
95 * Returns:
96 * Zero on success, else a negativ error code (-EIO).
97 */
98static int
99vxfs_getblk(struct inode *ip, sector_t iblock,
100 struct buffer_head *bp, int create)
101{
102 daddr_t pblock;
103
104 pblock = vxfs_bmap1(ip, iblock);
105 if (pblock != 0) {
106 map_bh(bh: bp, sb: ip->i_sb, block: pblock);
107 return 0;
108 }
109
110 return -EIO;
111}
112
113/**
114 * vxfs_read_folio - read one page synchronously into the pagecache
115 * @file: file context (unused)
116 * @folio: folio to fill in.
117 *
118 * Description:
119 * The vxfs_read_folio routine reads @folio synchronously into the
120 * pagecache.
121 *
122 * Returns:
123 * Zero on success, else a negative error code.
124 *
125 * Locking status:
126 * @folio is locked and will be unlocked.
127 */
128static int vxfs_read_folio(struct file *file, struct folio *folio)
129{
130 return block_read_full_folio(folio, vxfs_getblk);
131}
132
133/**
134 * vxfs_bmap - perform logical to physical block mapping
135 * @mapping: logical to physical mapping to use
136 * @block: logical block (relative to @mapping).
137 *
138 * Description:
139 * Vxfs_bmap find out the corresponding phsical block to the
140 * @mapping, @block pair.
141 *
142 * Returns:
143 * Physical block number on success, else Zero.
144 *
145 * Locking status:
146 * We are under the bkl.
147 */
148static sector_t
149vxfs_bmap(struct address_space *mapping, sector_t block)
150{
151 return generic_block_bmap(mapping, block, vxfs_getblk);
152}
153

source code of linux/fs/freevxfs/vxfs_subr.c