[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>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 4e06810b6104..ca4973150218 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -159,7 +159,7 @@ nfsd_proc_read(struct svc_rqst *rqstp, struct nfsd_readargs *argp,
         resp->count = argp->count;
         nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
                                   argp->offset,
-                                  argp->vec, argp->vlen,
+                                  rqstp->rq_vec, argp->vlen,
                                   &resp->count);
 
         if (nfserr) return nfserr;
@@ -185,7 +185,7 @@ nfsd_proc_write(struct svc_rqst *rqstp, struct nfsd_writeargs *argp,
 
         nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh), NULL,
                                    argp->offset,
-                                   argp->vec, argp->vlen,
+                                   rqstp->rq_vec, argp->vlen,
                                    argp->len,
                                    &stable);
         return nfsd_return_attrs(nfserr, resp);