iscsi-target: Fix potential deadlock on lock taken in timer
We need to disable BHs when taking sess_idr_lock because the
iscsit_handle_time2retain_timeout() timer function takes
se_tpg->session_lock, and iscsit_close_session() nests sess_idr_lock
inside se_tpg->session_lock. So if the timer can run inside
sess_idr_lock, we have a potential AB-BA deadlock.
Fix this by disabling BHs when taking sess_idr_lock. This was found
because of a lockdep warning, but it looks like a real (if highly
theoretical) deadlock. In any case avoiding lockdep spew so that we can
find other issues is a worthy cause.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
1 file changed