linux/drivers/infiniband
Mike Marciniszyn bcc9b67a5b IB/qib: Fix QP locate/remove race
remove_qp() can execute concurrently with a qib_lookup_qpn() on
another CPU, which in of itself, is ok, given the RCU locking.

The issue is that remove_qp() NULLs out the qp->next field so that a
qib_lookup_qpn() might fail to find a qp if it occurs after the one
that is being deleted.  This is a momentary issue and subsequent
qib_lookup_qpn() calls would find the qp's since the search restarts
from the bucket head.  At scale, the issue might causes dropped
packets and unnecessary retransmissions.

The fix just deletes the qp->next NULL assignment to prevent the
remove_qp() from hiding qp's from qib_lookup_qpn().

Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-02-14 17:04:18 -08:00
..
core RDMA/cm: Change return value from find_gid_port() 2012-11-29 12:16:29 -08:00
hw IB/qib: Fix QP locate/remove race 2013-02-14 17:04:18 -08:00
ulp IPoIB: Fix crash due to skb double destruct 2013-02-05 09:35:06 -08:00
Kconfig RDMA/ocrdma: Add driver for Emulex OneConnect IBoE RDMA adapter 2012-05-08 11:17:47 -07:00
Makefile RDMA/ocrdma: Add driver for Emulex OneConnect IBoE RDMA adapter 2012-05-08 11:17:47 -07:00