From: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Date: Wed, 4 Dec 2013 13:16:53 +0000 (+0800)
Subject: Btrfs: wrap repeated code into scrub_blocked_if_needed()
X-Git-Tag: v3.14-rc1~29^2~97
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb7ab02156e4;p=pandora-kernel.git

Btrfs: wrap repeated code into scrub_blocked_if_needed()

Just wrap same code into one function scrub_blocked_if_needed().

This make a change that we will move waiting (@workers_pending = 0)
before we can wake up commiting transaction(atomic_inc(@scrub_paused)),
we must take carefully to not deadlock here.

Thread 1			Thread 2
				|->btrfs_commit_transaction()
					|->set trans type(COMMIT_DOING)
					|->btrfs_scrub_paused()(blocked)
|->join_transaction(blocked)

Move btrfs_scrub_paused() before setting trans type which means we can
still join a transaction when commiting_transaction is blocked.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Suggested-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
---

Reading git-diff-tree failed