[PATCH] knfsd: Avoid excess stack usage in svc_tcp_recvfrom

..  by allocating the array of 'kvec' in 'struct svc_rqst'.

As we plan to increase RPCSVC_MAXPAGES from 8 upto 256, we can no longer
allocate an array of this size on the stack.  So we allocate it in 'struct
svc_rqst'.

However svc_rqst contains (indirectly) an array of the same type and size
(actually several, but they are in a union).  So rather than waste space, we
move those arrays out of the separately allocated union and into svc_rqst to
share with the kvec moved out of svc_tcp_recvfrom (various arrays are used at
different times, so there is no conflict).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index f61142a..0c4fab0 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -180,7 +180,7 @@
 	fh_copy(&resp->fh, &argp->fh);
 	nfserr = nfsd_read(rqstp, &resp->fh, NULL,
 				  argp->offset,
-			   	  argp->vec, argp->vlen,
+			   	  rqstp->rq_vec, argp->vlen,
 				  &resp->count);
 	if (nfserr == 0) {
 		struct inode	*inode = resp->fh.fh_dentry->d_inode;
@@ -210,7 +210,7 @@
 	resp->committed = argp->stable;
 	nfserr = nfsd_write(rqstp, &resp->fh, NULL,
 				   argp->offset,
-				   argp->vec, argp->vlen,
+				   rqstp->rq_vec, argp->vlen,
 				   argp->len,
 				   &resp->committed);
 	resp->count = argp->count;