From: Tao Ma <boyu.mt@taobao.com>
Date: Wed, 26 Oct 2011 15:08:39 +0000 (-0400)
Subject: ext4: don't check io->flag when setting EXT4_STATE_DIO_UNWRITTEN inode state
X-Git-Tag: v3.2-rc1~85^2~25
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3ff05690845911cc40387176f0bc5a7af9ef3ff;p=pandora-kernel.git

ext4: don't check io->flag when setting EXT4_STATE_DIO_UNWRITTEN inode state

When we want to convert the unitialized extent in direct write, we can
either do it in ext4_end_io_nolock(AIO case) or in
ext4_ext_direct_IO(non AIO case) and EXT4_I(inode)->cur_aio_dio is a
guard for ext4_ext_map_blocks to find the right case.  In e9e3bcecf,
we mistakenly change it by:

-			if (io)
+			if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
 				io->flag = EXT4_IO_END_UNWRITTEN;
-			else
+				atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
+			} else
 				ext4_set_inode_state(inode,
 						     EXT4_STATE_DIO_UNWRITTEN);

So now if we map 2 blocks, and the first one set the
EXT_IO_END_UNWRITTEN, the 2nd mapping will set inode state because of
the check for the flag. This is wrong.

Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

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