IB/qib: Fix M_Key lease timeout handling

If a port has an M_Key lease set, the M_Key protect bits set to 1, and
a SubnSet arrives with an invalid M_Key, an M_Key mismatch trap is
generated, the lease timer begins as expected, and eventually the
M_Key protect bits will be set back to 0 as per the spec.  However, if
any other SMP with an invalid M_Key arrives, the lease timer is expired
and the M_Key protect bits remain in force.

This is not according to to spec.  In particular, C14-17 says that
a lease timer that is underway is not affected by protection level
checks (ie, at protection level 1, a SubnGet with a bad M_Key may be
successful, but does not stop the timer), and C14-19 says that the timer
shall stop when a valid M_Key has been received.  C14-19 is the only
compliance statement that specifies a stopping condition for the timer.

This behavior is magnified if the port's Master SM LID attribute
points at itself.  In that case, the M_Key mismatch trap is sufficient to
expire the timer, and the mkey lease attribute is rendered useless.

Reviewed-by: Ram Vepa <ram.vepa@qlogic.com>
Signed-off-by: Jim Foraker <foraker1@llnl.gov>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 29 insertions, 15 deletions

diff --git a/drivers/infiniband/hw/qib/qib_mad.c b/drivers/infiniband/hw/qib/qib_mad.c
index 9292c76380fd..ed611e8df64f 100644
--- a/drivers/infiniband/hw/qib/qib_mad.c
+++ b/drivers/infiniband/hw/qib/qib_mad.c
@@ -396,6 +396,7 @@ static int get_linkdowndefaultstate(struct qib_pportdata *ppd)
 
 static int check_mkey(struct qib_ibport *ibp, struct ib_smp *smp, int mad_flags)
 {
+        int valid_mkey = 0;
         int ret = 0;
 
         /* Is the mkey in the process of expiring? */
@@ -406,23 +407,36 @@ static int check_mkey(struct qib_ibport *ibp, struct ib_smp *smp, int mad_flags)
                 ibp->mkeyprot = 0;
         }
 
-        /* M_Key checking depends on Portinfo:M_Key_protect_bits */
-        if ((mad_flags & IB_MAD_IGNORE_MKEY) == 0 && ibp->mkey != 0 &&
-            ibp->mkey != smp->mkey &&
-            (smp->method == IB_MGMT_METHOD_SET ||
-             smp->method == IB_MGMT_METHOD_TRAP_REPRESS ||
-             (smp->method == IB_MGMT_METHOD_GET && ibp->mkeyprot >= 2))) {
-                if (ibp->mkey_violations != 0xFFFF)
-                        ++ibp->mkey_violations;
-                if (!ibp->mkey_lease_timeout && ibp->mkey_lease_period)
-                        ibp->mkey_lease_timeout = jiffies +
-                                ibp->mkey_lease_period * HZ;
-                /* Generate a trap notice. */
-                qib_bad_mkey(ibp, smp);
-                ret = IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
-        } else if (ibp->mkey_lease_timeout)
+        if ((mad_flags & IB_MAD_IGNORE_MKEY) ||  ibp->mkey == 0 ||
+            ibp->mkey == smp->mkey)
+                valid_mkey = 1;
+
+        /* Unset lease timeout on any valid Get/Set/TrapRepress */
+        if (valid_mkey && ibp->mkey_lease_timeout &&
+            (smp->method == IB_MGMT_METHOD_GET ||
+             smp->method == IB_MGMT_METHOD_SET ||
+             smp->method == IB_MGMT_METHOD_TRAP_REPRESS))
                 ibp->mkey_lease_timeout = 0;
 
+        if (!valid_mkey) {
+                switch (smp->method) {
+                case IB_MGMT_METHOD_GET:
+                        /* Bad mkey not a violation below level 2 */
+                        if (ibp->mkeyprot < 2)
+                                break;
+                case IB_MGMT_METHOD_SET:
+                case IB_MGMT_METHOD_TRAP_REPRESS:
+                        if (ibp->mkey_violations != 0xFFFF)
+                                ++ibp->mkey_violations;
+                        if (!ibp->mkey_lease_timeout && ibp->mkey_lease_period)
+                                ibp->mkey_lease_timeout = jiffies +
+                                        ibp->mkey_lease_period * HZ;
+                        /* Generate a trap notice. */
+                        qib_bad_mkey(ibp, smp);
+                        ret = IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED;
+                }
+        }
+
         return ret;
 }