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(pp);
29	put_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, n, NULL);
49
50	if (!IS_ERR(pp)) {
51		kmap(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(ip->i_sb, 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(bp, ip->i_sb, 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