[PATCH v2 01/10] sunrpc: Remove backchannel check in svc_init_buffer()

[cel@kernel.org]

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

A backchannel service might use forechannel send and receive
buffers, but svc_recv() still calls svc_alloc_arg() on backchannel
svc_rqsts, so it will populate the svc_rqst's rq_pages[] array
anyway. The "is backchannel" check in svc_init_buffer() saves us
nothing.

In a moment, I plan to replace the rq_pages[] array with a
dynamically-allocated piece of memory, and svc_init_buffer() is
where that memory will get allocated. Backchannel requests actually
do use that array, so it has to be available to handle those
requests without a segfault.

XXX: Or, make svc_alloc_arg() ignore backchannel requests too?
     Could set rqstp->rq_maxpages to zero.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/svc.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index e7f9c295d13c..8ce3e6b3df6a 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -640,10 +640,6 @@ svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
 {
 	unsigned long pages, ret;
 
-	/* bc_xprt uses fore channel allocated buffers */
-	if (svc_is_backchannel(rqstp))
-		return true;
-
 	pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 				       * We assume one is at most one page
 				       */
-- 
2.49.0