81 lines
1.8 KiB
C
81 lines
1.8 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, unsigned long *data) {
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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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int
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ext2_clear_xip_target(struct inode *inode, int block) {
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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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return rc;
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clear_page((void*)data);
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return 0;
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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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if ((sb->s_bdev == NULL) ||
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sb->s_bdev->bd_disk == NULL ||
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sb->s_bdev->bd_disk->fops == NULL ||
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sb->s_bdev->bd_disk->fops->direct_access == NULL) {
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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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}
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struct page*
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ext2_get_xip_page(struct address_space *mapping, sector_t blockno,
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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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struct buffer_head tmp;
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tmp.b_state = 0;
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tmp.b_blocknr = 0;
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rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp,
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create);
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if (rc)
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return ERR_PTR(rc);
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if (tmp.b_blocknr == 0) {
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/* SPARSE block */
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BUG_ON(create);
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return ERR_PTR(-ENODATA);
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}
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rc = __inode_direct_access
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(mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data);
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if (rc)
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return ERR_PTR(rc);
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SetPageUptodate(virt_to_page(data));
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return virt_to_page(data);
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}
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