From 98d056603ce55ceb90631b3927151c190dfb1b27 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 15 Feb 2022 13:05:11 -0800 Subject: [PATCH] RDMA/ib_srp: Fix a deadlock [ Upstream commit 081bdc9fe05bb23248f5effb6f811da3da4b8252 ] Remove the flush_workqueue(system_long_wq) call since flushing system_long_wq is deadlock-prone and since that call is redundant with a preceding cancel_work_sync() Link: https://lore.kernel.org/r/20220215210511.28303-3-bvanassche@acm.org Fixes: ef6c49d87c34 ("IB/srp: Eliminate state SRP_TARGET_DEAD") Reported-by: syzbot+831661966588c802aae9@syzkaller.appspotmail.com Signed-off-by: Bart Van Assche Reviewed-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/ulp/srp/ib_srp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index e174e853f8a40..285b766e4e704 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -4047,9 +4047,11 @@ static void srp_remove_one(struct ib_device *device, void *client_data) spin_unlock(&host->target_lock); /* - * Wait for tl_err and target port removal tasks. + * srp_queue_remove_work() queues a call to + * srp_remove_target(). The latter function cancels + * target->tl_err_work so waiting for the remove works to + * finish is sufficient. */ - flush_workqueue(system_long_wq); flush_workqueue(srp_remove_wq); kfree(host);