The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3f015d89a47cd8855cd92f71fff770095bd885a1 Mon Sep 17 00:00:00 2001
From: Benjamin Coddington <bcodding@xxxxxxxxxx>
Date: Tue, 16 Nov 2021 10:48:13 -0500
Subject: [PATCH] NFSv42: Fix pagecache invalidation after COPY/CLONE
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>
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 08355b66e7cb..8b21ff1be717 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -289,7 +289,9 @@ static void nfs42_copy_dest_done(struct inode *inode, loff_t pos, loff_t len)
loff_t newsize = pos + len;
loff_t end = newsize - 1;
- truncate_pagecache_range(inode, pos, end);
+ WARN_ON_ONCE(invalidate_inode_pages2_range(inode->i_mapping,
+ pos >> PAGE_SHIFT, end >> PAGE_SHIFT));
+
spin_lock(&inode->i_lock);
if (newsize > i_size_read(inode))
i_size_write(inode, newsize);
