NFSv4.x: Enforce the ca_maxresponsesize_cached on the back channel
We have no duplicate reply cache, so we always set the back channel
ca_maxresponsesize_cached to zero when negotiating the session.
That means we should always error out as soon as we see the server
set args->csa_cachethis.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index e0844fd..345df63 100644
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -381,9 +381,8 @@
if (args->csa_cachethis == 0)
return htonl(NFS4ERR_RETRY_UNCACHED_REP);
- /* The ca_maxresponsesize_cached is 0 with no DRC */
- else if (args->csa_cachethis == 1)
- return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
+ /* Liar! We never allowed you to set csa_cachethis != 0 */
+ return htonl(NFS4ERR_SEQ_FALSE_RETRY);
}
/* Wraparound */
@@ -500,6 +499,10 @@
cps->slotid = args->csa_slotid;
+ /* The ca_maxresponsesize_cached is 0 with no DRC */
+ if (args->csa_cachethis != 0)
+ return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
+
/*
* Check for pending referring calls. If a match is found, a
* related callback was received before the response to the original