1/* 2 * Copyright (c) 2000-2001 Christoph Hellwig. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * Alternatively, this software may be distributed under the terms of the 15 * GNU General Public License ("GPL"). 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * Veritas filesystem driver - shared subroutines. 32 */ 33#include <linux/fs.h> 34#include <linux/buffer_head.h> 35#include <linux/kernel.h> 36#include <linux/pagemap.h> 37 38#include "vxfs_extern.h" 39 40 41static int vxfs_readpage(struct file *, struct page *); 42static sector_t vxfs_bmap(struct address_space *, sector_t); 43 44const struct address_space_operations vxfs_aops = { 45 .readpage = vxfs_readpage, 46 .bmap = vxfs_bmap, 47 .sync_page = block_sync_page, 48}; 49 50inline void 51vxfs_put_page(struct page *pp) 52{ 53 kunmap(pp); 54 page_cache_release(pp); 55} 56 57/** 58 * vxfs_get_page - read a page into memory. 59 * @ip: inode to read from 60 * @n: page number 61 * 62 * Description: 63 * vxfs_get_page reads the @n th page of @ip into the pagecache. 64 * 65 * Returns: 66 * The wanted page on success, else a NULL pointer. 67 */ 68struct page * 69vxfs_get_page(struct address_space *mapping, u_long n) 70{ 71 struct page * pp; 72 73 pp = read_mapping_page(mapping, n, NULL); 74 75 if (!IS_ERR(pp)) { 76 kmap(pp); 77 /** if (!PageChecked(pp)) **/ 78 /** vxfs_check_page(pp); **/ 79 if (PageError(pp)) 80 goto fail; 81 } 82 83 return (pp); 84 85fail: 86 vxfs_put_page(pp); 87 return ERR_PTR(-EIO); 88} 89 90/** 91 * vxfs_bread - read buffer for a give inode,block tuple 92 * @ip: inode 93 * @block: logical block 94 * 95 * Description: 96 * The vxfs_bread function reads block no @block of 97 * @ip into the buffercache. 98 * 99 * Returns: 100 * The resulting &struct buffer_head. 101 */ 102struct buffer_head * 103vxfs_bread(struct inode *ip, int block) 104{ 105 struct buffer_head *bp; 106 daddr_t pblock; 107 108 pblock = vxfs_bmap1(ip, block); 109 bp = sb_bread(ip->i_sb, pblock); 110 111 return (bp); 112} 113 114/** 115 * vxfs_get_block - locate buffer for given inode,block tuple 116 * @ip: inode 117 * @iblock: logical block 118 * @bp: buffer skeleton 119 * @create: %TRUE if blocks may be newly allocated. 120 * 121 * Description: 122 * The vxfs_get_block function fills @bp with the right physical 123 * block and device number to perform a lowlevel read/write on 124 * it. 125 * 126 * Returns: 127 * Zero on success, else a negativ error code (-EIO). 128 */ 129static int 130vxfs_getblk(struct inode *ip, sector_t iblock, 131 struct buffer_head *bp, int create) 132{ 133 daddr_t pblock; 134 135 pblock = vxfs_bmap1(ip, iblock); 136 if (pblock != 0) { 137 map_bh(bp, ip->i_sb, pblock); 138 return 0; 139 } 140 141 return -EIO; 142} 143 144/** 145 * vxfs_readpage - read one page synchronously into the pagecache 146 * @file: file context (unused) 147 * @page: page frame to fill in. 148 * 149 * Description: 150 * The vxfs_readpage routine reads @page synchronously into the 151 * pagecache. 152 * 153 * Returns: 154 * Zero on success, else a negative error code. 155 * 156 * Locking status: 157 * @page is locked and will be unlocked. 158 */ 159static int 160vxfs_readpage(struct file *file, struct page *page) 161{ 162 return block_read_full_page(page, vxfs_getblk); 163} 164 165/** 166 * vxfs_bmap - perform logical to physical block mapping 167 * @mapping: logical to physical mapping to use 168 * @block: logical block (relative to @mapping). 169 * 170 * Description: 171 * Vxfs_bmap find out the corresponding phsical block to the 172 * @mapping, @block pair. 173 * 174 * Returns: 175 * Physical block number on success, else Zero. 176 * 177 * Locking status: 178 * We are under the bkl. 179 */ 180static sector_t 181vxfs_bmap(struct address_space *mapping, sector_t block) 182{ 183 return generic_block_bmap(mapping, block, vxfs_getblk); 184} 185