Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here is the big staging and IIO driver pull request for 4.9-rc1.

  There are a lot of patches in here, the majority due to the
  drivers/staging/greybus/ subsystem being merged in with full
  development history that went back a few years, in order to preserve
  the work that those developers did over time.

  Lots and lots of tiny cleanups happened in the tree as well, due to
  the Outreachy application process and lots of other developers showing
  up for the first time to clean code up.  Along with those changes, we
  deleted a wireless driver, and added a raspberrypi driver (currently
  marked broken), and lots of new iio drivers.

  Overall the tree still shrunk with more lines removed than added,
  about 10 thousand lines removed in total. Full details are in the very
  long shortlog below.

  All of this has been in the linux-next tree with no issues. There will
  be some merge problems with other subsystem trees, but those are all
  minor problems and shouldn't be hard to work out when they happen
  (MAINTAINERS and some lustre build problems with the IB tree)"

And furter from me asking for clarification about greybus:
 "Right now there is a phone from Motorola shipping with this code (a
  slightly older version, but the same tree), so even though Ara is not
  alive in the same form, the functionality is happening. We are working
  with the developers of that phone to merge the newer stuff in with
  their fork so they can use the upstream version in future versions of
  their phone product line.

  Toshiba has at least one chip shipping in their catalog that
  needs/uses this protocol over a Unipro link, and rumor has it that
  there might be more in the future.

  There are also other users of the greybus protocols, there is a talk
  next week at ELC that shows how it is being used across a network
  connection to control a device, and previous ELC talks have showed the
  protocol stack being used over USB to drive embedded Linux boards.
  I've also talked to some people who are starting to work to add a host
  controller driver to control arduinos as the greybus PHY protocols are
  very useful to control a serial/i2c/spio/whatever device across a
  random physical link, as it is a way to have a self-describing device
  be attached to a host without needing manual configuration.

  So yes, people are using it, and there is still the chance that it
  will show up in a phone/laptop/tablet/whatever from Google in the
  future as well, the tech isn't dead, even if the original large phone
  project happens to be"

* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
  Staging: fbtft: Fix bug in fbtft-core
  staging: rtl8188eu: fix double unlock error in rtw_resume_process()
  staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
  staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
  staging:r8188eu: remove GEN_EVT_CODE macro
  staging:r8188eu: remove GEN_CMD_CODE macro
  staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
  staging:r8188eu: remove rtw_handle_dualmac declaration
  staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
  staging:r8188eu: change rtl8188e_process_phy_info function argument type
  Staging: fsl-mc: Remove blank lines
  Staging: fsl-mc: Fix unaligned * in block comments
  Staging: comedi: Align the * in block comments
  Staging : ks7010 : Fix block comments warninig
  Staging: vt6655: Remove explicit NULL comparison using Coccinelle
  staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
  staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
  staging: dgnc: Fix lines longer than 80 characters
  Staging: dgnc: constify attribute_group structures
  Staging: most: hdm-dim2: constify attribute_group structures
  ...

1 files changed, 109 insertions, 92 deletions

diff --git a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
index 596a697b9d39..b27de8888149 100644
--- a/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
+++ b/drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c
@@ -36,16 +36,19 @@
 
 #include "o2iblnd.h"
 
+#define MAX_CONN_RACES_BEFORE_ABORT 20
+
 static void kiblnd_peer_alive(struct kib_peer *peer);
 static void kiblnd_peer_connect_failed(struct kib_peer *peer, int active, int error);
-static void kiblnd_check_sends(struct kib_conn *conn);
 static void kiblnd_init_tx_msg(lnet_ni_t *ni, struct kib_tx *tx,
-				int type, int body_nob);
+			       int type, int body_nob);
 static int kiblnd_init_rdma(struct kib_conn *conn, struct kib_tx *tx, int type,
-			     int resid, struct kib_rdma_desc *dstrd, __u64 dstcookie);
+			    int resid, struct kib_rdma_desc *dstrd,
+			    __u64 dstcookie);
 static void kiblnd_queue_tx_locked(struct kib_tx *tx, struct kib_conn *conn);
 static void kiblnd_queue_tx(struct kib_tx *tx, struct kib_conn *conn);
 static void kiblnd_unmap_tx(lnet_ni_t *ni, struct kib_tx *tx);
+static void kiblnd_check_sends_locked(struct kib_conn *conn);
 
 static void
 kiblnd_tx_done(lnet_ni_t *ni, struct kib_tx *tx)
@@ -211,9 +214,9 @@ kiblnd_post_rx(struct kib_rx *rx, int credit)
 		conn->ibc_outstanding_credits++;
 	else
 		conn->ibc_reserved_credits++;
+	kiblnd_check_sends_locked(conn);
 	spin_unlock(&conn->ibc_lock);
 
-	kiblnd_check_sends(conn);
 out:
 	kiblnd_conn_decref(conn);
 	return rc;
@@ -344,8 +347,8 @@ kiblnd_handle_rx(struct kib_rx *rx)
 		    !IBLND_OOB_CAPABLE(conn->ibc_version)) /* v1 only */
 			conn->ibc_outstanding_credits++;
 
+		kiblnd_check_sends_locked(conn);
 		spin_unlock(&conn->ibc_lock);
-		kiblnd_check_sends(conn);
 	}
 
 	switch (msg->ibm_type) {
@@ -648,7 +651,7 @@ static int kiblnd_map_tx(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc
 
 static int
 kiblnd_setup_rd_iov(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc *rd,
-		    unsigned int niov, struct kvec *iov, int offset, int nob)
+		    unsigned int niov, const struct kvec *iov, int offset, int nob)
 {
 	struct kib_net *net = ni->ni_data;
 	struct page *page;
@@ -705,7 +708,7 @@ kiblnd_setup_rd_iov(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc *rd,
 
 static int
 kiblnd_setup_rd_kiov(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc *rd,
-		     int nkiov, lnet_kiov_t *kiov, int offset, int nob)
+		     int nkiov, const lnet_kiov_t *kiov, int offset, int nob)
 {
 	struct kib_net *net = ni->ni_data;
 	struct scatterlist *sg;
@@ -717,8 +720,8 @@ kiblnd_setup_rd_kiov(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc *rd,
 	LASSERT(nkiov > 0);
 	LASSERT(net);
 
-	while (offset >= kiov->kiov_len) {
-		offset -= kiov->kiov_len;
+	while (offset >= kiov->bv_len) {
+		offset -= kiov->bv_len;
 		nkiov--;
 		kiov++;
 		LASSERT(nkiov > 0);
@@ -728,10 +731,10 @@ kiblnd_setup_rd_kiov(lnet_ni_t *ni, struct kib_tx *tx, struct kib_rdma_desc *rd,
 	do {
 		LASSERT(nkiov > 0);
 
-		fragnob = min((int)(kiov->kiov_len - offset), nob);
+		fragnob = min((int)(kiov->bv_len - offset), nob);
 
-		sg_set_page(sg, kiov->kiov_page, fragnob,
-			    kiov->kiov_offset + offset);
+		sg_set_page(sg, kiov->bv_page, fragnob,
+			    kiov->bv_offset + offset);
 		sg = sg_next(sg);
 		if (!sg) {
 			CERROR("lacking enough sg entries to map tx\n");
@@ -761,7 +764,6 @@ kiblnd_post_tx_locked(struct kib_conn *conn, struct kib_tx *tx, int credit)
 	LASSERT(tx->tx_queued);
 	/* We rely on this for QP sizing */
 	LASSERT(tx->tx_nwrq > 0);
-	LASSERT(tx->tx_nwrq <= 1 + conn->ibc_max_frags);
 
 	LASSERT(!credit || credit == 1);
 	LASSERT(conn->ibc_outstanding_credits >= 0);
@@ -800,7 +802,7 @@ kiblnd_post_tx_locked(struct kib_conn *conn, struct kib_tx *tx, int credit)
 	      conn->ibc_noops_posted == IBLND_OOB_MSGS(ver)))) {
 		/*
 		 * OK to drop when posted enough NOOPs, since
-		 * kiblnd_check_sends will queue NOOP again when
+		 * kiblnd_check_sends_locked will queue NOOP again when
 		 * posted NOOPs complete
 		 */
 		spin_unlock(&conn->ibc_lock);
@@ -905,7 +907,7 @@ kiblnd_post_tx_locked(struct kib_conn *conn, struct kib_tx *tx, int credit)
 }
 
 static void
-kiblnd_check_sends(struct kib_conn *conn)
+kiblnd_check_sends_locked(struct kib_conn *conn)
 {
 	int ver = conn->ibc_version;
 	lnet_ni_t *ni = conn->ibc_peer->ibp_ni;
@@ -918,8 +920,6 @@ kiblnd_check_sends(struct kib_conn *conn)
 		return;
 	}
 
-	spin_lock(&conn->ibc_lock);
-
 	LASSERT(conn->ibc_nsends_posted <= kiblnd_concurrent_sends(ver, ni));
 	LASSERT(!IBLND_OOB_CAPABLE(ver) ||
 		conn->ibc_noops_posted <= IBLND_OOB_MSGS(ver));
@@ -969,8 +969,6 @@ kiblnd_check_sends(struct kib_conn *conn)
 		if (kiblnd_post_tx_locked(conn, tx, credit))
 			break;
 	}
-
-	spin_unlock(&conn->ibc_lock);
 }
 
 static void
@@ -1016,16 +1014,11 @@ kiblnd_tx_complete(struct kib_tx *tx, int status)
 	if (idle)
 		list_del(&tx->tx_list);
 
-	kiblnd_conn_addref(conn);	       /* 1 ref for me.... */
-
+	kiblnd_check_sends_locked(conn);
 	spin_unlock(&conn->ibc_lock);
 
 	if (idle)
 		kiblnd_tx_done(conn->ibc_peer->ibp_ni, tx);
-
-	kiblnd_check_sends(conn);
-
-	kiblnd_conn_decref(conn);	       /* ...until here */
 }
 
 static void
@@ -1078,6 +1071,15 @@ kiblnd_init_rdma(struct kib_conn *conn, struct kib_tx *tx, int type,
 	LASSERT(type == IBLND_MSG_GET_DONE ||
 		type == IBLND_MSG_PUT_DONE);
 
+	if (kiblnd_rd_size(srcrd) > conn->ibc_max_frags << PAGE_SHIFT) {
+		CERROR("RDMA is too large for peer %s (%d), src size: %d dst size: %d\n",
+		       libcfs_nid2str(conn->ibc_peer->ibp_nid),
+		       conn->ibc_max_frags << PAGE_SHIFT,
+		       kiblnd_rd_size(srcrd), kiblnd_rd_size(dstrd));
+		rc = -EMSGSIZE;
+		goto too_big;
+	}
+
 	while (resid > 0) {
 		if (srcidx >= srcrd->rd_nfrags) {
 			CERROR("Src buffer exhausted: %d frags\n", srcidx);
@@ -1091,10 +1093,10 @@ kiblnd_init_rdma(struct kib_conn *conn, struct kib_tx *tx, int type,
 			break;
 		}
 
-		if (tx->tx_nwrq >= conn->ibc_max_frags) {
+		if (tx->tx_nwrq >= IBLND_MAX_RDMA_FRAGS) {
 			CERROR("RDMA has too many fragments for peer %s (%d), src idx/frags: %d/%d dst idx/frags: %d/%d\n",
 			       libcfs_nid2str(conn->ibc_peer->ibp_nid),
-			       conn->ibc_max_frags,
+			       IBLND_MAX_RDMA_FRAGS,
 			       srcidx, srcrd->rd_nfrags,
 			       dstidx, dstrd->rd_nfrags);
 			rc = -EMSGSIZE;
@@ -1132,7 +1134,7 @@ kiblnd_init_rdma(struct kib_conn *conn, struct kib_tx *tx, int type,
 		wrq++;
 		sge++;
 	}
-
+too_big:
 	if (rc < 0)			     /* no RDMA if completing with failure */
 		tx->tx_nwrq = 0;
 
@@ -1204,9 +1206,8 @@ kiblnd_queue_tx(struct kib_tx *tx, struct kib_conn *conn)
 {
 	spin_lock(&conn->ibc_lock);
 	kiblnd_queue_tx_locked(tx, conn);
+	kiblnd_check_sends_locked(conn);
 	spin_unlock(&conn->ibc_lock);
-
-	kiblnd_check_sends(conn);
 }
 
 static int kiblnd_resolve_addr(struct rdma_cm_id *cmid,
@@ -1499,6 +1500,7 @@ kiblnd_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 	lnet_kiov_t *payload_kiov = lntmsg->msg_kiov;
 	unsigned int payload_offset = lntmsg->msg_offset;
 	unsigned int payload_nob = lntmsg->msg_len;
+	struct iov_iter from;
 	struct kib_msg *ibmsg;
 	struct kib_rdma_desc  *rd;
 	struct kib_tx *tx;
@@ -1518,6 +1520,17 @@ kiblnd_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 	/* payload is either all vaddrs or all pages */
 	LASSERT(!(payload_kiov && payload_iov));
 
+	if (payload_kiov)
+		iov_iter_bvec(&from, ITER_BVEC | WRITE,
+			      payload_kiov, payload_niov,
+			      payload_nob + payload_offset);
+	else
+		iov_iter_kvec(&from, ITER_KVEC | WRITE,
+			      payload_iov, payload_niov,
+			      payload_nob + payload_offset);
+
+	iov_iter_advance(&from, payload_offset);
+
 	switch (type) {
 	default:
 		LBUG();
@@ -1637,17 +1650,8 @@ kiblnd_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 	ibmsg = tx->tx_msg;
 	ibmsg->ibm_u.immediate.ibim_hdr = *hdr;
 
-	if (payload_kiov)
-		lnet_copy_kiov2flat(IBLND_MSG_SIZE, ibmsg,
-				    offsetof(struct kib_msg, ibm_u.immediate.ibim_payload),
-				    payload_niov, payload_kiov,
-				    payload_offset, payload_nob);
-	else
-		lnet_copy_iov2flat(IBLND_MSG_SIZE, ibmsg,
-				   offsetof(struct kib_msg, ibm_u.immediate.ibim_payload),
-				   payload_niov, payload_iov,
-				   payload_offset, payload_nob);
-
+	copy_from_iter(&ibmsg->ibm_u.immediate.ibim_payload, IBLND_MSG_SIZE,
+		       &from);
 	nob = offsetof(struct kib_immediate_msg, ibim_payload[payload_nob]);
 	kiblnd_init_tx_msg(ni, tx, IBLND_MSG_IMMEDIATE, nob);
 
@@ -1719,8 +1723,7 @@ kiblnd_reply(lnet_ni_t *ni, struct kib_rx *rx, lnet_msg_t *lntmsg)
 
 int
 kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
-	    unsigned int niov, struct kvec *iov, lnet_kiov_t *kiov,
-	    unsigned int offset, unsigned int mlen, unsigned int rlen)
+	    struct iov_iter *to, unsigned int rlen)
 {
 	struct kib_rx *rx = private;
 	struct kib_msg *rxmsg = rx->rx_msg;
@@ -1730,10 +1733,9 @@ kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
 	int post_credit = IBLND_POSTRX_PEER_CREDIT;
 	int rc = 0;
 
-	LASSERT(mlen <= rlen);
+	LASSERT(iov_iter_count(to) <= rlen);
 	LASSERT(!in_interrupt());
 	/* Either all pages or all vaddrs */
-	LASSERT(!(kiov && iov));
 
 	switch (rxmsg->ibm_type) {
 	default:
@@ -1749,16 +1751,8 @@ kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
 			break;
 		}
 
-		if (kiov)
-			lnet_copy_flat2kiov(niov, kiov, offset,
-					    IBLND_MSG_SIZE, rxmsg,
-					    offsetof(struct kib_msg, ibm_u.immediate.ibim_payload),
-					    mlen);
-		else
-			lnet_copy_flat2iov(niov, iov, offset,
-					   IBLND_MSG_SIZE, rxmsg,
-					   offsetof(struct kib_msg, ibm_u.immediate.ibim_payload),
-					   mlen);
+		copy_to_iter(&rxmsg->ibm_u.immediate.ibim_payload,
+			     IBLND_MSG_SIZE, to);
 		lnet_finalize(ni, lntmsg, 0);
 		break;
 
@@ -1766,7 +1760,7 @@ kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
 		struct kib_msg	*txmsg;
 		struct kib_rdma_desc *rd;
 
-		if (!mlen) {
+		if (!iov_iter_count(to)) {
 			lnet_finalize(ni, lntmsg, 0);
 			kiblnd_send_completion(rx->rx_conn, IBLND_MSG_PUT_NAK, 0,
 					       rxmsg->ibm_u.putreq.ibprm_cookie);
@@ -1784,12 +1778,16 @@ kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
 
 		txmsg = tx->tx_msg;
 		rd = &txmsg->ibm_u.putack.ibpam_rd;
-		if (!kiov)
+		if (!(to->type & ITER_BVEC))
 			rc = kiblnd_setup_rd_iov(ni, tx, rd,
-						 niov, iov, offset, mlen);
+						 to->nr_segs, to->kvec,
+						 to->iov_offset,
+						 iov_iter_count(to));
 		else
 			rc = kiblnd_setup_rd_kiov(ni, tx, rd,
-						  niov, kiov, offset, mlen);
+						  to->nr_segs, to->bvec,
+						  to->iov_offset,
+						  iov_iter_count(to));
 		if (rc) {
 			CERROR("Can't setup PUT sink for %s: %d\n",
 			       libcfs_nid2str(conn->ibc_peer->ibp_nid), rc);
@@ -2183,14 +2181,11 @@ kiblnd_connreq_done(struct kib_conn *conn, int status)
 		return;
 	}
 
-	/**
-	 * refcount taken by cmid is not reliable after I released the glock
-	 * because this connection is visible to other threads now, another
-	 * thread can find and close this connection right after I released
-	 * the glock, if kiblnd_cm_callback for RDMA_CM_EVENT_DISCONNECTED is
-	 * called, it can release the connection refcount taken by cmid.
-	 * It means the connection could be destroyed before I finish my
-	 * operations on it.
+	/*
+	 * +1 ref for myself, this connection is visible to other threads
+	 * now, refcount of peer:ibp_conns can be released by connection
+	 * close from either a different thread, or the calling of
+	 * kiblnd_check_sends_locked() below. See bz21911 for details.
 	 */
 	kiblnd_conn_addref(conn);
 	write_unlock_irqrestore(&kiblnd_data.kib_global_lock, flags);
@@ -2202,10 +2197,9 @@ kiblnd_connreq_done(struct kib_conn *conn, int status)
 
 		kiblnd_queue_tx_locked(tx, conn);
 	}
+	kiblnd_check_sends_locked(conn);
 	spin_unlock(&conn->ibc_lock);
 
-	kiblnd_check_sends(conn);
-
 	/* schedule blocked rxs */
 	kiblnd_handle_early_rxs(conn);
 
@@ -2240,6 +2234,7 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 	struct kib_rej rej;
 	int version = IBLND_MSG_VERSION;
 	unsigned long flags;
+	int max_frags;
 	int rc;
 	struct sockaddr_in *peer_addr;
 
@@ -2346,22 +2341,20 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 		goto failed;
 	}
 
-	if (reqmsg->ibm_u.connparams.ibcp_max_frags >
-	    kiblnd_rdma_frags(version, ni)) {
-		CWARN("Can't accept conn from %s (version %x): max_frags %d too large (%d wanted)\n",
-		      libcfs_nid2str(nid), version,
-		      reqmsg->ibm_u.connparams.ibcp_max_frags,
+	max_frags = reqmsg->ibm_u.connparams.ibcp_max_frags >> IBLND_FRAG_SHIFT;
+	if (max_frags > kiblnd_rdma_frags(version, ni)) {
+		CWARN("Can't accept conn from %s (version %x): max message size %d is too large (%d wanted)\n",
+		      libcfs_nid2str(nid), version, max_frags,
 		      kiblnd_rdma_frags(version, ni));
 
 		if (version >= IBLND_MSG_VERSION)
 			rej.ibr_why = IBLND_REJECT_RDMA_FRAGS;
 
 		goto failed;
-	} else if (reqmsg->ibm_u.connparams.ibcp_max_frags <
-		   kiblnd_rdma_frags(version, ni) && !net->ibn_fmr_ps) {
-		CWARN("Can't accept conn from %s (version %x): max_frags %d incompatible without FMR pool (%d wanted)\n",
-		      libcfs_nid2str(nid), version,
-		      reqmsg->ibm_u.connparams.ibcp_max_frags,
+	} else if (max_frags < kiblnd_rdma_frags(version, ni) &&
+		   !net->ibn_fmr_ps) {
+		CWARN("Can't accept conn from %s (version %x): max message size %d incompatible without FMR pool (%d wanted)\n",
+		      libcfs_nid2str(nid), version, max_frags,
 		      kiblnd_rdma_frags(version, ni));
 
 		if (version == IBLND_MSG_VERSION)
@@ -2387,7 +2380,7 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 	}
 
 	/* We have validated the peer's parameters so use those */
-	peer->ibp_max_frags = reqmsg->ibm_u.connparams.ibcp_max_frags;
+	peer->ibp_max_frags = max_frags;
 	peer->ibp_queue_depth = reqmsg->ibm_u.connparams.ibcp_queue_depth;
 
 	write_lock_irqsave(g_lock, flags);
@@ -2419,23 +2412,37 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 			goto failed;
 		}
 
-		/* tie-break connection race in favour of the higher NID */
+		/*
+		 * Tie-break connection race in favour of the higher NID.
+		 * If we keep running into a race condition multiple times,
+		 * we have to assume that the connection attempt with the
+		 * higher NID is stuck in a connecting state and will never
+		 * recover.  As such, we pass through this if-block and let
+		 * the lower NID connection win so we can move forward.
+		 */
 		if (peer2->ibp_connecting &&
-		    nid < ni->ni_nid) {
+		    nid < ni->ni_nid && peer2->ibp_races <
+		    MAX_CONN_RACES_BEFORE_ABORT) {
+			peer2->ibp_races++;
 			write_unlock_irqrestore(g_lock, flags);
 
-			CWARN("Conn race %s\n", libcfs_nid2str(peer2->ibp_nid));
+			CDEBUG(D_NET, "Conn race %s\n",
+			       libcfs_nid2str(peer2->ibp_nid));
 
 			kiblnd_peer_decref(peer);
 			rej.ibr_why = IBLND_REJECT_CONN_RACE;
 			goto failed;
 		}
-
+		if (peer2->ibp_races >= MAX_CONN_RACES_BEFORE_ABORT)
+			CNETERR("Conn race %s: unresolved after %d attempts, letting lower NID win\n",
+				libcfs_nid2str(peer2->ibp_nid),
+				MAX_CONN_RACES_BEFORE_ABORT);
 		/**
 		 * passive connection is allowed even this peer is waiting for
 		 * reconnection.
 		 */
 		peer2->ibp_reconnecting = 0;
+		peer2->ibp_races = 0;
 		peer2->ibp_accepting++;
 		kiblnd_peer_addref(peer2);
 
@@ -2494,7 +2501,7 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 	kiblnd_init_msg(ackmsg, IBLND_MSG_CONNACK,
 			sizeof(ackmsg->ibm_u.connparams));
 	ackmsg->ibm_u.connparams.ibcp_queue_depth = conn->ibc_queue_depth;
-	ackmsg->ibm_u.connparams.ibcp_max_frags = conn->ibc_max_frags;
+	ackmsg->ibm_u.connparams.ibcp_max_frags = conn->ibc_max_frags << IBLND_FRAG_SHIFT;
 	ackmsg->ibm_u.connparams.ibcp_max_msg_size = IBLND_MSG_SIZE;
 
 	kiblnd_pack_msg(ni, ackmsg, version, 0, nid, reqmsg->ibm_srcstamp);
@@ -2526,9 +2533,9 @@ kiblnd_passive_connect(struct rdma_cm_id *cmid, void *priv, int priv_nob)
 
  failed:
 	if (ni) {
-		lnet_ni_decref(ni);
 		rej.ibr_cp.ibcp_queue_depth = kiblnd_msg_queue_size(version, ni);
 		rej.ibr_cp.ibcp_max_frags = kiblnd_rdma_frags(version, ni);
+		lnet_ni_decref(ni);
 	}
 
 	rej.ibr_version             = version;
@@ -2556,7 +2563,7 @@ kiblnd_check_reconnect(struct kib_conn *conn, int version,
 
 	if (cp) {
 		msg_size = cp->ibcp_max_msg_size;
-		frag_num = cp->ibcp_max_frags;
+		frag_num	= cp->ibcp_max_frags << IBLND_FRAG_SHIFT;
 		queue_dep = cp->ibcp_queue_depth;
 	}
 
@@ -2821,11 +2828,11 @@ kiblnd_check_connreply(struct kib_conn *conn, void *priv, int priv_nob)
 		goto failed;
 	}
 
-	if (msg->ibm_u.connparams.ibcp_max_frags >
+	if ((msg->ibm_u.connparams.ibcp_max_frags >> IBLND_FRAG_SHIFT) >
 	    conn->ibc_max_frags) {
 		CERROR("%s has incompatible max_frags %d (<=%d wanted)\n",
 		       libcfs_nid2str(peer->ibp_nid),
-		       msg->ibm_u.connparams.ibcp_max_frags,
+		       msg->ibm_u.connparams.ibcp_max_frags >> IBLND_FRAG_SHIFT,
 		       conn->ibc_max_frags);
 		rc = -EPROTO;
 		goto failed;
@@ -2859,7 +2866,7 @@ kiblnd_check_connreply(struct kib_conn *conn, void *priv, int priv_nob)
 	conn->ibc_credits = msg->ibm_u.connparams.ibcp_queue_depth;
 	conn->ibc_reserved_credits = msg->ibm_u.connparams.ibcp_queue_depth;
 	conn->ibc_queue_depth = msg->ibm_u.connparams.ibcp_queue_depth;
-	conn->ibc_max_frags = msg->ibm_u.connparams.ibcp_max_frags;
+	conn->ibc_max_frags = msg->ibm_u.connparams.ibcp_max_frags >> IBLND_FRAG_SHIFT;
 	LASSERT(conn->ibc_credits + conn->ibc_reserved_credits +
 		IBLND_OOB_MSGS(ver) <= IBLND_RX_MSGS(conn));
 
@@ -2916,7 +2923,7 @@ kiblnd_active_connect(struct rdma_cm_id *cmid)
 	memset(msg, 0, sizeof(*msg));
 	kiblnd_init_msg(msg, IBLND_MSG_CONNREQ, sizeof(msg->ibm_u.connparams));
 	msg->ibm_u.connparams.ibcp_queue_depth = conn->ibc_queue_depth;
-	msg->ibm_u.connparams.ibcp_max_frags = conn->ibc_max_frags;
+	msg->ibm_u.connparams.ibcp_max_frags = conn->ibc_max_frags << IBLND_FRAG_SHIFT;
 	msg->ibm_u.connparams.ibcp_max_msg_size = IBLND_MSG_SIZE;
 
 	kiblnd_pack_msg(peer->ibp_ni, msg, version,
@@ -3233,7 +3240,11 @@ kiblnd_check_conns(int idx)
 	 */
 	list_for_each_entry_safe(conn, temp, &checksends, ibc_connd_list) {
 		list_del(&conn->ibc_connd_list);
-		kiblnd_check_sends(conn);
+
+		spin_lock(&conn->ibc_lock);
+		kiblnd_check_sends_locked(conn);
+		spin_unlock(&conn->ibc_lock);
+
 		kiblnd_conn_decref(conn);
 	}
 }
@@ -3419,6 +3430,12 @@ kiblnd_qp_event(struct ib_event *event, void *arg)
 	case IB_EVENT_COMM_EST:
 		CDEBUG(D_NET, "%s established\n",
 		       libcfs_nid2str(conn->ibc_peer->ibp_nid));
+		/*
+		 * We received a packet but connection isn't established
+		 * probably handshake packet was lost, so free to
+		 * force make connection established
+		 */
+		rdma_notify(conn->ibc_cmid, IB_EVENT_COMM_EST);
 		return;
 
 	default: