[PATCH 4.9 10/24] xprtrdma: Squelch kbuild sparse complaint

Greg Kroah-Hartman
2017-03-24T18:23:46Z

From: Chuck Lever <chuck.lever@oracle.com>

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.

Fixes: 16f906d66cd7 ("xprtrdma: Reduce required number of send SGEs")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -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;