[3.11.y.z extended stable] Patch "Btrfs: fix hole check in log_one_extent" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    Btrfs: fix hole check in log_one_extent

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e48620f693ddeef37c1f6a10fcb2c7b8456946ef Mon Sep 17 00:00:00 2001
From: Josef Bacik <jbacik at fusionio.com>
Date: Mon, 14 Oct 2013 17:23:08 -0400
Subject: Btrfs: fix hole check in log_one_extent

commit ed9e8af88e2551aaa6bf51d8063a2493e2d71597 upstream.

I added an assert to make sure we were looking up aligned offsets for csums and
I tripped it when running xfstests.  This is because log_one_extent was checking
if block_start == 0 for a hole instead of EXTENT_MAP_HOLE.  This worked out fine
in practice it seems, but it adds a lot of extra work that is uneeded.  With
this fix I'm no longer tripping my assert.  Thanks,

Signed-off-by: Josef Bacik <jbacik at fusionio.com>
Signed-off-by: Chris Mason <chris.mason at fusionio.com>
Cc: David Sterba <dsterba at suse.cz>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/btrfs/tree-log.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index ff60d89..e535185 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3332,7 +3332,7 @@ static int log_one_extent(struct btrfs_trans_handle *trans,
 		btrfs_set_token_file_extent_type(leaf, fi,
 						 BTRFS_FILE_EXTENT_REG,
 						 &token);
-		if (em->block_start == 0)
+		if (em->block_start == EXTENT_MAP_HOLE)
 			skip_csum = true;
 	}

--
1.8.3.2