[PATCH 25/27] staging: lustre: check wr_id returned by ib_poll_cq

James Simmons
2016-03-02T22:03:47Z

From: Liang Zhen <liang.zhen@intel.com>

If ib_poll_cq returned +ve without initialising ib_wc::wr_id (bug
in driver), then o2iblnd will run into unpredictable situation
because ib_wc::wr_id may refer to stale tx/rx pointer in stack.

It indicates bug in HCA driver if this happened, ko2iblnd should
output console error then close current connection.

This patch could also be helpful for LU-5271

Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-519
Reviewed-on: http://review.whamcloud.com/12747
Reviewed-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---
.../staging/lustre/lnet/klnds/o2iblnd/o2iblnd.h | 9 ++++---
.../staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c | 21 ++++++++++++++++++-
2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.h b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.h
index 3db1413..6a4c4ac 100644
--- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.h
+++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd.h
@@ -762,10 +762,11 @@ kiblnd_queue2str(kib_conn_t *conn, struct list_head *q)
/* CAVEAT EMPTOR: We rely on descriptor alignment to allow us to use the */
/* lowest bits of the work request id to stash the work item type. */

-#define IBLND_WID_TX 0
-#define IBLND_WID_RDMA 1
-#define IBLND_WID_RX 2
-#define IBLND_WID_MASK 3UL
+#define IBLND_WID_INVAL 0
+#define IBLND_WID_TX 1
+#define IBLND_WID_RX 2
+#define IBLND_WID_RDMA 3
+#define IBLND_WID_MASK 3UL

static inline __u64
kiblnd_ptr2wreqid(void *ptr, int type)
diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
index 9428166..1c62875 100644
--- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
+++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
@@ -768,7 +768,6 @@ kiblnd_post_tx_locked(kib_conn_t *conn, kib_tx_t *tx, int credit)
int ver = conn->ibc_version;
int rc;
int done;
- struct ib_send_wr *bad_wrq;

LASSERT(tx->tx_queued);
/* We rely on this for QP sizing */
@@ -852,7 +851,14 @@ kiblnd_post_tx_locked(kib_conn_t *conn, kib_tx_t *tx, int credit)
/* close_conn will launch failover */
rc = -ENETDOWN;
} else {
- rc = ib_post_send(conn->ibc_cmid->qp, &tx->tx_wrq->wr, &bad_wrq);
+ struct ib_send_wr *wrq = &tx->tx_wrq[tx->tx_nwrq - 1].wr;
+
+ LASSERTF(wrq->wr_id == kiblnd_ptr2wreqid(tx, IBLND_WID_TX),
+ "bad wr_id %llx, opc %d, flags %d, peer: %s\n",
+ wrq->wr_id, wrq->opcode, wrq->send_flags,
+ libcfs_nid2str(conn->ibc_peer->ibp_nid));
+ wrq = NULL;
+ rc = ib_post_send(conn->ibc_cmid->qp, &tx->tx_wrq->wr, &wrq);
}

conn->ibc_last_send = jiffies;
@@ -3421,6 +3427,8 @@ kiblnd_scheduler(void *arg)

spin_unlock_irqrestore(&sched->ibs_lock, flags);

+ wc.wr_id = IBLND_WID_INVAL;
+
rc = ib_poll_cq(conn->ibc_cq, 1, &wc);
if (!rc) {
rc = ib_req_notify_cq(conn->ibc_cq,
@@ -3438,6 +3446,15 @@ kiblnd_scheduler(void *arg)
rc = ib_poll_cq(conn->ibc_cq, 1, &wc);
}

+ if (unlikely(rc > 0 && wc.wr_id == IBLND_WID_INVAL)) {
+ LCONSOLE_ERROR("ib_poll_cq (rc: %d) returned invalid wr_id, opcode %d, status: %d, vendor_err: %d, conn: %s status: %d\nplease upgrade firmware and OFED or contact vendor.\n",
+ rc, wc.opcode, wc.status,
+ wc.vendor_err,
+ libcfs_nid2str(conn->ibc_peer->ibp_nid),
+ conn->ibc_state);
+ rc = -EINVAL;
+ }
+
if (rc < 0) {
CWARN("%s: ib_poll_cq failed: %d, closing connection\n",
libcfs_nid2str(conn->ibc_peer->ibp_nid),
--
1.7.1