afa597ba20
This patch includes feedback from Andrew and Christoph. Thanks for taking time to review. Use of empty_zero_page was eliminated to fix compilation for architectures that don't have it. This patch removes setting pages up-to-date in ext2_get_xip_page and all bug checks to verify that the page is indeed up to date. Setting the page state on mapping to userland is bogus. None of the code patchs involved with these pages in mm cares about the page state. still on my ToDo list: identify a place outside second extended where __inode_direct_access should reside Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
94 lines
2.0 KiB
C
94 lines
2.0 KiB
C
/*
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* linux/fs/ext2/xip.c
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*
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* Copyright (C) 2005 IBM Corporation
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* Author: Carsten Otte (cotte@de.ibm.com)
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*/
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/genhd.h>
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#include <linux/buffer_head.h>
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#include <linux/ext2_fs_sb.h>
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#include <linux/ext2_fs.h>
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#include "ext2.h"
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#include "xip.h"
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static inline int
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__inode_direct_access(struct inode *inode, sector_t sector,
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unsigned long *data)
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{
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BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access);
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return inode->i_sb->s_bdev->bd_disk->fops
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->direct_access(inode->i_sb->s_bdev,sector,data);
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}
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static inline int
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__ext2_get_sector(struct inode *inode, sector_t offset, int create,
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sector_t *result)
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{
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struct buffer_head tmp;
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int rc;
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memset(&tmp, 0, sizeof(struct buffer_head));
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rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &tmp,
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create);
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*result = tmp.b_blocknr;
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/* did we get a sparse block (hole in the file)? */
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if (!(*result)) {
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BUG_ON(create);
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rc = -ENODATA;
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}
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return rc;
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}
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int
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ext2_clear_xip_target(struct inode *inode, int block)
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{
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sector_t sector = block * (PAGE_SIZE/512);
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unsigned long data;
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int rc;
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rc = __inode_direct_access(inode, sector, &data);
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if (!rc)
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clear_page((void*)data);
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return rc;
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}
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void ext2_xip_verify_sb(struct super_block *sb)
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{
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struct ext2_sb_info *sbi = EXT2_SB(sb);
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if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) &&
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!sb->s_bdev->bd_disk->fops->direct_access) {
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sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
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ext2_warning(sb, __FUNCTION__,
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"ignoring xip option - not supported by bdev");
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}
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}
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struct page *
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ext2_get_xip_page(struct address_space *mapping, sector_t offset,
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int create)
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{
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int rc;
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unsigned long data;
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sector_t sector;
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/* first, retrieve the sector number */
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rc = __ext2_get_sector(mapping->host, offset, create, §or);
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if (rc)
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goto error;
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/* retrieve address of the target data */
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rc = __inode_direct_access
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(mapping->host, sector * (PAGE_SIZE/512), &data);
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if (!rc)
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return virt_to_page(data);
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error:
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return ERR_PTR(rc);
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}
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