tree d836230fe63ec680631c681f821c8a41d84dbe6b
parent 57b62d29ad5b384775974973087d47755a8c6fcc
author Jaegeuk Kim <jaegeuk@kernel.org> 1448929604 -0800
committer Jaegeuk Kim <jaegeuk@kernel.org> 1449258756 -0800

f2fs: avoid deadlock in f2fs_shrink_extent_tree

While handling extent trees, we can enter into a reclaiming path anytime.
If it tries to release some extent nodes in the same extent tree,
write_lock(&et->lock) would be hanged.
In order to avoid the deadlock, we can just skip it.

Note that, if it is an unreferenced tree, we should get write_lock(&et->lock)
successfully and release all of therein nodes.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>