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	Follow the lead of xfs_break_dax_layouts() and add synchronization between operations in ext4 which remove blocks from an inode (hole punch, truncate down, etc.) and pages which are pinned due to DAX DMA operations. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
		
			
				
	
	
		
			50 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			50 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * linux/fs/ext4/truncate.h
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 *
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 * Common inline functions needed for truncate support
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 */
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/*
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 * Truncate blocks that were not used by write. We have to truncate the
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 * pagecache as well so that corresponding buffers get properly unmapped.
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 */
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static inline void ext4_truncate_failed_write(struct inode *inode)
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{
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	/*
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	 * We don't need to call ext4_break_layouts() because the blocks we
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	 * are truncating were never visible to userspace.
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	 */
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	down_write(&EXT4_I(inode)->i_mmap_sem);
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	truncate_inode_pages(inode->i_mapping, inode->i_size);
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	ext4_truncate(inode);
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	up_write(&EXT4_I(inode)->i_mmap_sem);
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}
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/*
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 * Work out how many blocks we need to proceed with the next chunk of a
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 * truncate transaction.
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 */
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static inline unsigned long ext4_blocks_for_truncate(struct inode *inode)
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{
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	ext4_lblk_t needed;
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	needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
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	/* Give ourselves just enough room to cope with inodes in which
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	 * i_blocks is corrupt: we've seen disk corruptions in the past
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	 * which resulted in random data in an inode which looked enough
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	 * like a regular file for ext4 to try to delete it.  Things
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	 * will go a bit crazy if that happens, but at least we should
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	 * try not to panic the whole kernel. */
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	if (needed < 2)
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		needed = 2;
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	/* But we need to bound the transaction so we don't overflow the
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	 * journal. */
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	if (needed > EXT4_MAX_TRANS_DATA)
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		needed = EXT4_MAX_TRANS_DATA;
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	return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
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}
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