On Thu, Nov 09, 2017 at 01:37:43PM +0200, Sagi Grimberg wrote: > >> To allow lockless path lookup the list of nvme_ns structures per >> nvme_ns_head is protected by SRCU, which requires freeing the nvme_ns >> structure through call_srcu. > > Can you remind me why isn't rcu sufficient? Can looking up a > path (ns from head->list) block? blk_mq_make_request can block.
