Commit f9586abf authored Oct 09, 2017 by Alex Estrin Committed by Doug Ledford Oct 18, 2017

IB/rdmavt: Don't wait for resources in QP reset



Per the IBTA spec, QP destroy shall fail if the QP is attached
to multicast groups, although the spec is silent on modify_qp
to reset state. It implies that ULP must deregister QP from
all mcast groups for destroy to succeed.
The faulty patch "IB/ipoib: Update broadcast object if PKey value
was changed in index 0" exposed two issues in rdmavt:
1. Rvt QP reset waits for qp references to go to zero.
This will hang if QP is attached to multicast groups.
2. The mcast group detach will fail for a QP in reset state
therefore preventing ULP from correcting the issue.
This patch moves the reference count wait to the the destroy QP
path and allows a QP mcast detach to work in the reset state.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Alex Estrin <alex.estrin@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

parent a8979cc5

drivers/infiniband/sw/rdmavt/mcast.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -351,7 +351,7 @@ int rvt_detach_mcast(struct ib_qp ibqp, union ib_gid gid, u16 lid)
		int last = 0;
		int ret = 0;

		if (ibqp->qp_num <= 1 \|\| qp->state == IB_QPS_RESET)
		if (ibqp->qp_num <= 1)
		return -EINVAL;

		spin_lock_irq(&ibp->lock);

drivers/infiniband/sw/rdmavt/qp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -717,7 +717,6 @@ static void rvt_reset_qp(struct rvt_dev_info rdi, struct rvt_qp qp,

		/* take qp out the hash and wait for it to be unused */
		rvt_remove_qp(rdi, qp);
		wait_event(qp->wait, !atomic_read(&qp->refcount));

		/* grab the lock b/c it was locked at call time */
		spin_lock_irq(&qp->r_lock);
		@@ -1443,6 +1442,7 @@ int rvt_destroy_qp(struct ib_qp *ibqp)
		spin_unlock(&qp->s_hlock);
		spin_unlock_irq(&qp->r_lock);

		wait_event(qp->wait, !atomic_read(&qp->refcount));
		/* qpn is now available for use again */
		rvt_free_qpn(&rdi->qp_dev->qpn_table, qp->ibqp.qp_num);

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