--- /dev/null
+From 3f015d89a47cd8855cd92f71fff770095bd885a1 Mon Sep 17 00:00:00 2001
+From: Benjamin Coddington <bcodding@redhat.com>
+Date: Tue, 16 Nov 2021 10:48:13 -0500
+Subject: NFSv42: Fix pagecache invalidation after COPY/CLONE
+
+From: Benjamin Coddington <bcodding@redhat.com>
+
+commit 3f015d89a47cd8855cd92f71fff770095bd885a1 upstream.
+
+The mechanism in use to allow the client to see the results of COPY/CLONE
+is to drop those pages from the pagecache. This forces the client to read
+those pages once more from the server. However, truncate_pagecache_range()
+zeros out partial pages instead of dropping them. Let us instead use
+invalidate_inode_pages2_range() with full-page offsets to ensure the client
+properly sees the results of COPY/CLONE operations.
+
+Cc: <stable@vger.kernel.org> # v4.7+
+Fixes: 2e72448b07dc ("NFS: Add COPY nfs operation")
+Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
+Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/nfs/nfs42proc.c | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+--- a/fs/nfs/nfs42proc.c
++++ b/fs/nfs/nfs42proc.c
+@@ -186,8 +186,9 @@ static ssize_t _nfs42_proc_copy(struct f
+ goto out;
+ }
+
+- truncate_pagecache_range(dst_inode, pos_dst,
+- pos_dst + res->write_res.count);
++ WARN_ON_ONCE(invalidate_inode_pages2_range(dst_inode->i_mapping,
++ pos_dst >> PAGE_SHIFT,
++ (pos_dst + res->write_res.count - 1) >> PAGE_SHIFT));
+
+ status = res->write_res.count;
+ out: