NFSv4: Fix range checking in __nfs4_get_acl_uncached and __nfs4_proc_set_acl

commit 21f498c2f73bd6150d82931f09965826dca0b5f2 upstream.

Ensure that the user supplied buffer size doesn't cause us to overflow
the 'pages' array.

Also fix up some confusion between the use of PAGE_SIZE and
PAGE_CACHE_SIZE when calculating buffer sizes. We're not using
the page cache for anything here.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc fs/nfs/nfs4proc.c
Simple merge