153 строки
3.2 KiB
C
153 строки
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2000-2001 Christoph Hellwig.
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*/
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/*
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* Veritas filesystem driver - shared subroutines.
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*/
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#include <linux/fs.h>
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#include <linux/buffer_head.h>
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#include <linux/kernel.h>
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#include <linux/pagemap.h>
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#include "vxfs_extern.h"
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static int vxfs_read_folio(struct file *, struct folio *);
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static sector_t vxfs_bmap(struct address_space *, sector_t);
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const struct address_space_operations vxfs_aops = {
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.read_folio = vxfs_read_folio,
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.bmap = vxfs_bmap,
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};
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inline void
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vxfs_put_page(struct page *pp)
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{
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kunmap(pp);
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put_page(pp);
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}
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/**
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* vxfs_get_page - read a page into memory.
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* @ip: inode to read from
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* @n: page number
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*
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* Description:
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* vxfs_get_page reads the @n th page of @ip into the pagecache.
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*
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* Returns:
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* The wanted page on success, else a NULL pointer.
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*/
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struct page *
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vxfs_get_page(struct address_space *mapping, u_long n)
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{
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struct page * pp;
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pp = read_mapping_page(mapping, n, NULL);
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if (!IS_ERR(pp)) {
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kmap(pp);
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/** if (!PageChecked(pp)) **/
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/** vxfs_check_page(pp); **/
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}
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return (pp);
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}
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/**
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* vxfs_bread - read buffer for a give inode,block tuple
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* @ip: inode
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* @block: logical block
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*
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* Description:
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* The vxfs_bread function reads block no @block of
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* @ip into the buffercache.
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*
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* Returns:
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* The resulting &struct buffer_head.
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*/
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struct buffer_head *
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vxfs_bread(struct inode *ip, int block)
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{
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struct buffer_head *bp;
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daddr_t pblock;
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pblock = vxfs_bmap1(ip, block);
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bp = sb_bread(ip->i_sb, pblock);
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return (bp);
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}
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/**
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* vxfs_get_block - locate buffer for given inode,block tuple
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* @ip: inode
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* @iblock: logical block
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* @bp: buffer skeleton
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* @create: %TRUE if blocks may be newly allocated.
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*
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* Description:
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* The vxfs_get_block function fills @bp with the right physical
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* block and device number to perform a lowlevel read/write on
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* it.
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*
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* Returns:
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* Zero on success, else a negativ error code (-EIO).
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*/
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static int
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vxfs_getblk(struct inode *ip, sector_t iblock,
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struct buffer_head *bp, int create)
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{
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daddr_t pblock;
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pblock = vxfs_bmap1(ip, iblock);
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if (pblock != 0) {
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map_bh(bp, ip->i_sb, pblock);
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return 0;
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}
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return -EIO;
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}
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/**
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* vxfs_read_folio - read one page synchronously into the pagecache
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* @file: file context (unused)
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* @folio: folio to fill in.
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*
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* Description:
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* The vxfs_read_folio routine reads @folio synchronously into the
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* pagecache.
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*
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* Returns:
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* Zero on success, else a negative error code.
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*
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* Locking status:
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* @folio is locked and will be unlocked.
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*/
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static int vxfs_read_folio(struct file *file, struct folio *folio)
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{
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return block_read_full_folio(folio, vxfs_getblk);
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}
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/**
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* vxfs_bmap - perform logical to physical block mapping
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* @mapping: logical to physical mapping to use
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* @block: logical block (relative to @mapping).
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*
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* Description:
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* Vxfs_bmap find out the corresponding phsical block to the
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* @mapping, @block pair.
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*
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* Returns:
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* Physical block number on success, else Zero.
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*
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* Locking status:
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* We are under the bkl.
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*/
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static sector_t
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vxfs_bmap(struct address_space *mapping, sector_t block)
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{
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return generic_block_bmap(mapping, block, vxfs_getblk);
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}
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