linux/drivers/infiniband
Håkon Bugge a242c36951 RDMA/netlink: Do not always generate an ACK for some netlink operations
In rdma_nl_rcv_skb(), the local variable err is assigned the return value
of the supplied callback function, which could be one of
ib_nl_handle_resolve_resp(), ib_nl_handle_set_timeout(), or
ib_nl_handle_ip_res_resp(). These three functions all return skb->len on
success.

rdma_nl_rcv_skb() is merely a copy of netlink_rcv_skb(). The callback
functions used by the latter have the convention: "Returns 0 on success or
a negative error code".

In particular, the statement (equal for both functions):

   if (nlh->nlmsg_flags & NLM_F_ACK || err)

implies that rdma_nl_rcv_skb() always will ack a message, independent of
the NLM_F_ACK being set in nlmsg_flags or not.

The fix could be to change the above statement, but it is better to keep
the two *_rcv_skb() functions equal in this respect and instead change the
three callback functions in the rdma subsystem to the correct convention.

Fixes: 2ca546b92a ("IB/sa: Route SA pathrecord query through netlink")
Fixes: ae43f82867 ("IB/core: Add IP to GID netlink offload")
Link: https://lore.kernel.org/r/20191216120436.3204814-1-haakon.bugge@oracle.com
Suggested-by: Mark Haywood <mark.haywood@oracle.com>
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Tested-by: Mark Haywood <mark.haywood@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-03 16:02:32 -04:00
..
core RDMA/netlink: Do not always generate an ACK for some netlink operations 2020-01-03 16:02:32 -04:00
hw IB/mlx5: Fix outstanding_pi index for GSI qps 2020-01-03 15:56:41 -04:00
sw RDMA/siw: Simplify QP representation 2020-01-03 15:54:09 -04:00
ulp treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
Kconfig RDMA/iw_cxgb3: Remove the iw_cxgb3 module from kernel 2019-10-04 15:08:59 -03:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00