Commit c70f019a authored Sep 17, 2015 by Theodore Ts'o Committed by Mohamad Ayyash Sep 02, 2016

ext4: disable zeroout optimization when encryption is enabled



When we are manipulate a sparse file's extent tree, there is an
optimization where we will explicitly zero out some data blocks instead
of making the extent tree overly bushy.  Unfortunately, this can
sometimes lead to the file system's extent tree getting corrupted.

Disabling the optimization works around this bug, but we don't have a
completely understood root cause yet.  So this should be understood as
only a (hopefully!) temporary workaround.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: "Theodore Ts'o" <tytso@google.com>
Change-Id: Ie237434603ad1e36351b3e42954ffecbd5c0f035

parent 88ae994c

fs/ext4/extents.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -3542,7 +3542,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
		*/
		split_flag \|= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;

		if (EXT4_EXT_MAY_ZEROOUT & split_flag)
		if ((EXT4_EXT_MAY_ZEROOUT & split_flag) &&
		!ext4_encrypted_inode(inode))
		max_zeroout = sbi->s_extent_max_zeroout_kb >>
		(inode->i_sb->s_blocksize_bits - 10);