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 |
26 | vxfs_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 | */ |
43 | struct page * |
44 | vxfs_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 | */ |
71 | struct buffer_head * |
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(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 | */ |
98 | static int |
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(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 | */ |
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 |
149 | vxfs_bmap(struct address_space *mapping, sector_t block) |
150 | { |
151 | return generic_block_bmap(mapping, block, vxfs_getblk); |
152 | } |
153 | |