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90 lines
2.0 KiB
90 lines
2.0 KiB
/* |
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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/blkdev.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 block, |
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void **kaddr, unsigned long *pfn) |
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{ |
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struct block_device *bdev = inode->i_sb->s_bdev; |
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const struct block_device_operations *ops = bdev->bd_disk->fops; |
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sector_t sector; |
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sector = block * (PAGE_SIZE / 512); /* ext2 block to bdev sector */ |
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BUG_ON(!ops->direct_access); |
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return ops->direct_access(bdev, sector, kaddr, pfn); |
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} |
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static inline int |
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__ext2_get_block(struct inode *inode, pgoff_t pgoff, 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, pgoff, &tmp, 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 (!tmp.b_blocknr && !rc) { |
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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, sector_t block) |
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{ |
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void *kaddr; |
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unsigned long pfn; |
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int rc; |
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rc = __inode_direct_access(inode, block, &kaddr, &pfn); |
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if (!rc) |
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clear_page(kaddr); |
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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_msg(sb, KERN_WARNING, |
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"warning: ignoring xip option - " |
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"not supported by bdev"); |
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} |
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} |
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int ext2_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create, |
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void **kmem, unsigned long *pfn) |
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{ |
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int rc; |
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sector_t block; |
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/* first, retrieve the sector number */ |
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rc = __ext2_get_block(mapping->host, pgoff, create, &block); |
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if (rc) |
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return rc; |
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/* retrieve address of the target data */ |
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rc = __inode_direct_access(mapping->host, block, kmem, pfn); |
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return rc; |
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}
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