tree e3be38a3bc4fc628aacc35a361446da8694c1301
parent 98114659e0d467e2c0ee6f24f2429329328fc312
author Josef Bacik <jbacik@fusionio.com> 1347641960 -0400
committer Chris Mason <chris.mason@fusionio.com> 1349357998 -0400

Btrfs: do not hold the write_lock on the extent tree while logging

Dave Sterba pointed out a sleeping while atomic bug while doing fsync.  This
is because I'm an idiot and didn't realize that rwlock's were spin locks, so
we've been holding this thing while doing allocations and such which is not
good.  This patch fixes this by dropping the write lock before we do
anything heavy and re-acquire it when it is done.  We also need to take a
ref on the em's in case their corresponding pages are evicted and mark them
as being logged so that releasepage does not remove them and doesn't remove
them from our local list.  Thanks,

Reported-by: Dave Sterba <dave@jikos.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>