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
17 static int vxfs_read_folio(struct file *, struct folio *);
18 static sector_t vxfs_bmap(struct address_space *, sector_t);
19
20 const struct address_space_operations vxfs_aops = {
21 .read_folio = vxfs_read_folio,
22 .bmap = vxfs_bmap,
23 };
24
25 inline void
vxfs_put_page(struct page * pp)26 vxfs_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 */
43 struct page *
vxfs_get_page(struct address_space * mapping,u_long n)44 vxfs_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 */
71 struct buffer_head *
vxfs_bread(struct inode * ip,int block)72 vxfs_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 */
98 static int
vxfs_getblk(struct inode * ip,sector_t iblock,struct buffer_head * bp,int create)99 vxfs_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 */
vxfs_read_folio(struct file * file,struct folio * folio)128 static 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 */
148 static sector_t
vxfs_bmap(struct address_space * mapping,sector_t block)149 vxfs_bmap(struct address_space *mapping, sector_t block)
150 {
151 return generic_block_bmap(mapping, block, vxfs_getblk);
152 }
153