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Commit 86b0624e authored by Jan Kara's avatar Jan Kara Committed by Vishal Verma
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ext2: Avoid DAX zeroing to corrupt data 



Currently ext2 zeroes any data blocks allocated for DAX inode however it
still returns them as BH_New. Thus DAX code zeroes them again in
dax_insert_mapping() which can possibly overwrite the data that has been
already stored to those blocks by a racing dax_io(). Avoid marking
pre-zeroed buffers as new.

Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
parent 9b6cd5f7

fs/ext2/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -745,11 +745,11 @@ static int ext2_get_blocks(struct inode *inode, 
			mutex_unlock(&ei->truncate_mutex);

			goto cleanup;

		}

	}

	} else

		set_buffer_new(bh_result);



	ext2_splice_branch(inode, iblock, partial, indirect_blks, count);

	mutex_unlock(&ei->truncate_mutex);

	set_buffer_new(bh_result);

got_it:

	map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));

	if (count > blocks_to_boundary)