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authorKaike Wan <kaike.wan@intel.com>2019-03-18 09:55:19 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-20 09:17:05 +0200
commitb59d92ac8a328d9b0212ba5fcd3318cdf8a69409 (patch)
tree3dacc5d835369a2c9dccd2f3fba9e055314ce43e
parentb05baa9f19d070674dc6863f8341c5207c18c0e2 (diff)
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IB/hfi1: Failed to drain send queue when QP is put into error state
commit 662d66466637862ef955f7f6e78a286d8cf0ebef upstream. When a QP is put into error state, all pending requests in the send work queue should be drained. The following sequence of events could lead to a failure, causing a request to hang: (1) The QP builds a packet and tries to send through SDMA engine. However, PIO engine is still busy. Consequently, this packet is put on the QP's tx list and the QP is put on the PIO waiting list. The field qp->s_flags is set with HFI1_S_WAIT_PIO_DRAIN; (2) The QP is put into error state by the user application and notify_error_qp() is called, which removes the QP from the PIO waiting list and the packet from the QP's tx list. In addition, qp->s_flags is cleared of RVT_S_ANY_WAIT_IO bits, which does not include HFI1_S_WAIT_PIO_DRAIN bit; (3) The hfi1_schdule_send() function is called to drain the QP's send queue. Subsequently, hfi1_do_send() is called. Since the flag bit HFI1_S_WAIT_PIO_DRAIN is set in qp->s_flags, hfi1_send_ok() fails. As a result, hfi1_do_send() bails out without draining any request from the send queue; (4) The PIO engine completes the sending and tries to wake up any QP on its waiting list. But the QP has been removed from the PIO waiting list and therefore is kept in sleep forever. The fix is to clear qp->s_flags of HFI1_S_ANY_WAIT_IO bits in step (2). HFI1_S_ANY_WAIT_IO includes RVT_S_ANY_WAIT_IO and HFI1_S_WAIT_PIO_DRAIN. Fixes: 2e2ba09e48b7 ("IB/rdmavt, IB/hfi1: Create device dependent s_flags") Cc: <stable@vger.kernel.org> # 4.19.x+ Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Reviewed-by: Alex Estrin <alex.estrin@intel.com> Signed-off-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/infiniband/hw/hfi1/qp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/hw/hfi1/qp.c b/drivers/infiniband/hw/hfi1/qp.c
index 5344e8993b28..5866f358ea04 100644
--- a/drivers/infiniband/hw/hfi1/qp.c
+++ b/drivers/infiniband/hw/hfi1/qp.c
@@ -833,7 +833,7 @@ void notify_error_qp(struct rvt_qp *qp)
write_seqlock(lock);
if (!list_empty(&priv->s_iowait.list) &&
!(qp->s_flags & RVT_S_BUSY)) {
- qp->s_flags &= ~RVT_S_ANY_WAIT_IO;
+ qp->s_flags &= ~HFI1_S_ANY_WAIT_IO;
list_del_init(&priv->s_iowait.list);
priv->s_iowait.lock = NULL;
rvt_put_qp(qp);