tree fc2b1d1e9555f2f9de847ba4134d827613c66e73
parent 5e71b5d5ec07e4b3fb4c78c4e4b108ff667f123f
author Li Zefan <lizf@cn.fujitsu.com> 1289285810 +0800
committer Li Zefan <lizf@cn.fujitsu.com> 1296061490 +0800

btrfs: Add a helper try_merge_free_space()

When adding a new extent, we'll firstly see if we can merge
this extent to the left or/and right extent. Extract this as
a helper try_merge_free_space().

As a side effect, we fix a small bug that if the new extent
has non-bitmap left entry but is unmergeble, we'll directly
link the extent without trying to drop it into bitmap.

This also prepares for the next patch.

Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>