Our QE team during automated API testing hit deadlock in ZFS, caused
by lock order reversal. From one side dsl_sync_task_sync() locks
dp_config_rwlock as writer and calls spa_sync_props(), which waits
for spa_props_lock. From another spa_prop_get() locks spa_props_lock
and then calls dsl_pool_config_enter(), trying to lock dp_config_rwlock
as reader.
This patch makes spa_prop_get() lock dp_config_rwlock before
spa_props_lock, making the order consistent.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Closes#10553
1743c737f5