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Subject[PATCH 2.6.26 1/3] RDMA/cxgb3: Correctly serialize peer abort path.
Date

OpenMPI and other stress testing exposed a few bad bugs in handling
aborts in the middle of a normal close.

- serialize abort reply and peer abort processing with
disconnect processing

- warn (and ignore) if ep timer is stopped when it wasn't running

- cleaned up disconnect path to correctly deal with aborting and dead
endpoints

- in iwch_modify_qp(), add a ref to the ep before releasing the qp lock if
iwch_ep_disconnect() will be called. The dref after calling disconnect.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
---
drivers/infiniband/hw/cxgb3/iwch_cm.c | 98 ++++++++++++++++++++++-----------
drivers/infiniband/hw/cxgb3/iwch_cm.h | 1
drivers/infiniband/hw/cxgb3/iwch_qp.c | 6 ++
3 files changed, 71 insertions(+), 34 deletions(-)
diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.c b/drivers/infiniband/hw/cxgb3/iwch_cm.c
index 99f2f2a..1627bff 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.c
@@ -125,6 +125,12 @@ static void start_ep_timer(struct iwch_ep *ep)
static void stop_ep_timer(struct iwch_ep *ep)
{
PDBG("%s ep %p\n", __FUNCTION__, ep);
+ if (!timer_pending(&ep->timer)) {
+ printk(KERN_ERR "%s timer stopped when its not running! ep %p state %u\n",
+ __FUNCTION__, ep, ep->com.state);
+ WARN_ON(1);
+ return;
+ }
del_timer_sync(&ep->timer);
put_ep(&ep->com);
}
@@ -1083,8 +1089,11 @@ static int tx_ack(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
static int abort_rpl(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
{
struct iwch_ep *ep = ctx;
+ unsigned long flags;
+ int release = 0;

PDBG("%s ep %p\n", __FUNCTION__, ep);
+ BUG_ON(!ep);

/*
* We get 2 abort replies from the HW. The first one must
@@ -1095,9 +1104,22 @@ static int abort_rpl(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
return CPL_RET_BUF_DONE;
}

- close_complete_upcall(ep);
- state_set(&ep->com, DEAD);
- release_ep_resources(ep);
+ spin_lock_irqsave(&ep->com.lock, flags);
+ switch (ep->com.state) {
+ case ABORTING:
+ close_complete_upcall(ep);
+ __state_set(&ep->com, DEAD);
+ release = 1;
+ break;
+ default:
+ printk(KERN_ERR "%s ep %p state %d\n",
+ __FUNCTION__, ep, ep->com.state);
+ break;
+ }
+ spin_unlock_irqrestore(&ep->com.lock, flags);
+
+ if (release)
+ release_ep_resources(ep);
return CPL_RET_BUF_DONE;
}

@@ -1470,7 +1492,8 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
struct sk_buff *rpl_skb;
struct iwch_qp_attributes attrs;
int ret;
- int state;
+ int release = 0;
+ unsigned long flags;

if (is_neg_adv_abort(req->status)) {
PDBG("%s neg_adv_abort ep %p tid %d\n", __FUNCTION__, ep,
@@ -1488,9 +1511,9 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
return CPL_RET_BUF_DONE;
}

- state = state_read(&ep->com);
- PDBG("%s ep %p state %u\n", __FUNCTION__, ep, state);
- switch (state) {
+ spin_lock_irqsave(&ep->com.lock, flags);
+ PDBG("%s ep %p state %u\n", __FUNCTION__, ep, ep->com.state);
+ switch (ep->com.state) {
case CONNECTING:
break;
case MPA_REQ_WAIT:
@@ -1536,21 +1559,25 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
break;
case DEAD:
PDBG("%s PEER_ABORT IN DEAD STATE!!!!\n", __FUNCTION__);
+ spin_unlock_irqrestore(&ep->com.lock, flags);
return CPL_RET_BUF_DONE;
default:
BUG_ON(1);
break;
}
dst_confirm(ep->dst);
+ if (ep->com.state != ABORTING) {
+ __state_set(&ep->com, DEAD);
+ release = 1;
+ }
+ spin_unlock_irqrestore(&ep->com.lock, flags);

rpl_skb = get_skb(skb, sizeof(*rpl), GFP_KERNEL);
if (!rpl_skb) {
printk(KERN_ERR MOD "%s - cannot allocate skb!\n",
__FUNCTION__);
- dst_release(ep->dst);
- l2t_release(L2DATA(ep->com.tdev), ep->l2t);
- put_ep(&ep->com);
- return CPL_RET_BUF_DONE;
+ release = 1;
+ goto out;
}
rpl_skb->priority = CPL_PRIORITY_DATA;
rpl = (struct cpl_abort_rpl *) skb_put(rpl_skb, sizeof(*rpl));
@@ -1559,10 +1586,9 @@ static int peer_abort(struct t3cdev *tdev, struct sk_buff *skb, void *ctx)
OPCODE_TID(rpl) = htonl(MK_OPCODE_TID(CPL_ABORT_RPL, ep->hwtid));
rpl->cmd = CPL_ABORT_NO_RST;
cxgb3_ofld_send(ep->com.tdev, rpl_skb);
- if (state != ABORTING) {
- state_set(&ep->com, DEAD);
+out:
+ if (release)
release_ep_resources(ep);
- }
return CPL_RET_BUF_DONE;
}

@@ -1661,15 +1687,18 @@ static void ep_timeout(unsigned long arg)
struct iwch_ep *ep = (struct iwch_ep *)arg;
struct iwch_qp_attributes attrs;
unsigned long flags;
+ int abort=1;

spin_lock_irqsave(&ep->com.lock, flags);
PDBG("%s ep %p tid %u state %d\n", __FUNCTION__, ep, ep->hwtid,
ep->com.state);
switch (ep->com.state) {
case MPA_REQ_SENT:
+ __state_set(&ep->com, ABORTING);
connect_reply_upcall(ep, -ETIMEDOUT);
break;
case MPA_REQ_WAIT:
+ __state_set(&ep->com, ABORTING);
break;
case CLOSING:
case MORIBUND:
@@ -1679,13 +1708,17 @@ static void ep_timeout(unsigned long arg)
ep->com.qp, IWCH_QP_ATTR_NEXT_STATE,
&attrs, 1);
}
+ __state_set(&ep->com, ABORTING);
break;
default:
- BUG();
+ printk(KERN_ERR "%s unexpected state ep %p state %u\n",
+ __FUNCTION__, ep, ep->com.state);
+ WARN_ON(1);
+ abort=0;
}
- __state_set(&ep->com, CLOSING);
spin_unlock_irqrestore(&ep->com.lock, flags);
- abort_connection(ep, NULL, GFP_ATOMIC);
+ if (abort)
+ abort_connection(ep, NULL, GFP_ATOMIC);
put_ep(&ep->com);
}

@@ -1968,34 +2001,33 @@ int iwch_ep_disconnect(struct iwch_ep *ep, int abrupt, gfp_t gfp)
PDBG("%s ep %p state %s, abrupt %d\n", __FUNCTION__, ep,
states[ep->com.state], abrupt);

- if (ep->com.state == DEAD) {
- PDBG("%s already dead ep %p\n", __FUNCTION__, ep);
- goto out;
- }
-
- if (abrupt) {
- if (ep->com.state != ABORTING) {
- ep->com.state = ABORTING;
- close = 1;
- }
- goto out;
- }
-
switch (ep->com.state) {
case MPA_REQ_WAIT:
case MPA_REQ_SENT:
case MPA_REQ_RCVD:
case MPA_REP_SENT:
case FPDU_MODE:
- start_ep_timer(ep);
- ep->com.state = CLOSING;
close = 1;
+ if (abrupt)
+ ep->com.state = ABORTING;
+ else {
+ ep->com.state = CLOSING;
+ start_ep_timer(ep);
+ }
break;
case CLOSING:
- ep->com.state = MORIBUND;
close = 1;
+ if (abrupt) {
+ stop_ep_timer(ep);
+ ep->com.state = ABORTING;
+ } else
+ ep->com.state = MORIBUND;
break;
case MORIBUND:
+ case ABORTING:
+ case DEAD:
+ PDBG("%s ignoring disconnect ep %p state %u\n",
+ __FUNCTION__, ep, ep->com.state);
break;
default:
BUG();
diff --git a/drivers/infiniband/hw/cxgb3/iwch_cm.h b/drivers/infiniband/hw/cxgb3/iwch_cm.h
index 6107e7c..a3fb959 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_cm.h
+++ b/drivers/infiniband/hw/cxgb3/iwch_cm.h
@@ -56,6 +56,7 @@
#define put_ep(ep) { \
PDBG("put_ep (via %s:%u) ep %p refcnt %d\n", __FUNCTION__, __LINE__, \
ep, atomic_read(&((ep)->kref.refcount))); \
+ WARN_ON(atomic_read(&((ep)->kref.refcount)) < 1); \
kref_put(&((ep)->kref), __free_ep); \
}

diff --git a/drivers/infiniband/hw/cxgb3/iwch_qp.c b/drivers/infiniband/hw/cxgb3/iwch_qp.c
index ea2cdd7..c02bb94 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_qp.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_qp.c
@@ -832,6 +832,7 @@ int iwch_modify_qp(struct iwch_dev *rhp, struct iwch_qp *qhp,
abort=0;
disconnect = 1;
ep = qhp->ep;
+ get_ep(&ep->com);
}
flush_qp(qhp, &flag);
break;
@@ -848,6 +849,7 @@ int iwch_modify_qp(struct iwch_dev *rhp, struct iwch_qp *qhp,
abort=1;
disconnect = 1;
ep = qhp->ep;
+ get_ep(&ep->com);
}
goto err;
break;
@@ -929,8 +931,10 @@ out:
* on the EP. This can be a normal close (RTS->CLOSING) or
* an abnormal close (RTS/CLOSING->ERROR).
*/
- if (disconnect)
+ if (disconnect) {
iwch_ep_disconnect(ep, abort, GFP_KERNEL);
+ put_ep(&ep->com);
+ }

/*
* If free is 1, then we've disassociated the EP from the QP

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