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* [PATCH for-next] IB/core: Fix mgid key handling in SA agent multicast data-base
@ 2014-11-19  9:08 Or Gerlitz
       [not found] ` <1416388138-25669-1-git-send-email-ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
  0 siblings, 1 reply; 4+ messages in thread
From: Or Gerlitz @ 2014-11-19  9:08 UTC (permalink / raw)
  To: Sean Hefty
  Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA, Roland Dreier,
	Jack Morgenstein, Or Gerlitz

From: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>

Applications can request that the SM assign an mgid, by passing a mcast
member request containing an mgid = 0. When the SM responds by sending
the allocated mgid, this mgid replaces the 0-mgid in the multicast group.

However, the mgid field in the group is also the key field in the IB core
multicast code red-black tree containing the multicast groups for the port.

Since this is a key field, correct handling requires that the group entry
be deleted from the rb table, and then re-inserted with the new key,
so that the table structure is properly maintained.

The current code does not do this correctly. Correct operation
requires that if the key-field gid has changed at all, it should
be deleted and re-inserted, fix that.

Note that when inserting, if the new mgid is zero (not the case here
but the code should handle this correctly), we allow duplicate entries
for 0-mgids.

Signed-off-by: Jack Morgenstein <jackm-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
Signed-off-by: Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
 drivers/infiniband/core/multicast.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c
index d2360a8..fa17b55 100644
--- a/drivers/infiniband/core/multicast.c
+++ b/drivers/infiniband/core/multicast.c
@@ -525,17 +525,22 @@ static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
 	if (status)
 		process_join_error(group, status);
 	else {
+		int mgids_changed, is_mgid0;
 		ib_find_pkey(group->port->dev->device, group->port->port_num,
 			     be16_to_cpu(rec->pkey), &pkey_index);
 
 		spin_lock_irq(&group->port->lock);
-		group->rec = *rec;
 		if (group->state == MCAST_BUSY &&
 		    group->pkey_index == MCAST_INVALID_PKEY_INDEX)
 			group->pkey_index = pkey_index;
-		if (!memcmp(&mgid0, &group->rec.mgid, sizeof mgid0)) {
+		mgids_changed = memcmp(&rec->mgid, &group->rec.mgid,
+				       sizeof(group->rec.mgid));
+		group->rec = *rec;
+		if (mgids_changed) {
 			rb_erase(&group->node, &group->port->table);
-			mcast_insert(group->port, group, 1);
+			is_mgid0 = !memcmp(&mgid0, &group->rec.mgid,
+					   sizeof(mgid0));
+			mcast_insert(group->port, group, is_mgid0);
 		}
 		spin_unlock_irq(&group->port->lock);
 	}
-- 
1.7.1

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^ permalink raw reply related	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-12-02  0:59 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-11-19  9:08 [PATCH for-next] IB/core: Fix mgid key handling in SA agent multicast data-base Or Gerlitz
     [not found] ` <1416388138-25669-1-git-send-email-ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2014-11-19  9:13   ` Or Gerlitz
2014-11-25  7:20   ` Or Gerlitz
2014-12-02  0:59   ` Hefty, Sean

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