[PATCH for v4.9 LTS 34/87] Btrfs: use down_read_nested to make lockdep silent

2017-07-14 Thread Levin, Alexander (Sasha Levin)
From: Liu Bo [ Upstream commit e321f8a801d7b4c40da8005257b05b9c2b51b072 ] If @block_group is not @used_bg, it'll try to get @used_bg's lock without droping @block_group 's lock and lockdep has throwed a scary deadlock warning about it. Fix it by using down_read_nested.

[PATCH for v4.9 LTS 34/87] Btrfs: use down_read_nested to make lockdep silent

2017-07-14 Thread Levin, Alexander (Sasha Levin)
From: Liu Bo [ Upstream commit e321f8a801d7b4c40da8005257b05b9c2b51b072 ] If @block_group is not @used_bg, it'll try to get @used_bg's lock without droping @block_group 's lock and lockdep has throwed a scary deadlock warning about it. Fix it by using down_read_nested. Signed-off-by: Liu Bo