Patch "xprtrdma: Squelch kbuild sparse complaint" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

xprtrdma: Squelch kbuild sparse complaint

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
xprtrdma-squelch-kbuild-sparse-complaint.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Chuck Lever <[email protected]>
Date: Sat, 11 Mar 2017 15:52:47 -0500
Subject: xprtrdma: Squelch kbuild sparse complaint

From: Chuck Lever <[email protected]>

commit eed50879d64ab1b9f76445dbab822e43a098b309 upstream.

New complaint from kbuild for 4.9.y:

net/sunrpc/xprtrdma/verbs.c:489:19: sparse: incompatible types in
comparison expression (different type sizes)

verbs.c:
489 max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES);

I can't reproduce this running sparse here. Likewise, "make W=1 net/sunrpc/xprtrdma/verbs.o" never indicated any issue.

A little poking suggests that because the range of its values is small, gcc can make the actual width of RPCRDMA_MAX_SEND_SGES smaller than the width of an unsigned integer.

---
 net/sunrpc/xprtrdma/verbs.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -486,7 +486,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep,
 	struct ib_cq *sendcq, *recvcq;
 	int rc;
 
-	max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES);
+	max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
+			RPCRDMA_MAX_SEND_SGES);
 	if (max_sge < RPCRDMA_MIN_SEND_SGES) {
 		pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
 		return -ENOMEM;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/xprtrdma-squelch-kbuild-sparse-complaint.patch