This is a note to let you know that I've just added the patch titled NFSv42: Fix pagecache invalidation after COPY/CLONE to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfsv42-fix-pagecache-invalidation-after-copy-clone.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3f015d89a47cd8855cd92f71fff770095bd885a1 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington <bcodding@xxxxxxxxxx> Date: Tue, 16 Nov 2021 10:48:13 -0500 Subject: NFSv42: Fix pagecache invalidation after COPY/CLONE From: Benjamin Coddington <bcodding@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx> # v4.7+ Fixes: 2e72448b07dc ("NFS: Add COPY nfs operation") Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/nfs/nfs42proc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/nfs/nfs42proc.c +++ b/fs/nfs/nfs42proc.c @@ -295,8 +295,9 @@ 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: Patches currently in stable-queue which might be from bcodding@xxxxxxxxxx are queue-5.4/nfsv42-fix-pagecache-invalidation-after-copy-clone.patch