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From:   trondmy@kernel.org
To:     linux-nfs@vger.kernel.org
Subject: [PATCH v7 06/21] NFS: If the cookie verifier changes, we must invalidate the page cache
Date:   Wed, 23 Feb 2022 16:12:50 -0500
Message-Id: <20220223211305.296816-7-trondmy@kernel.org>
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From: Trond Myklebust <trond.myklebust@hammerspace.com>

Ensure that if the cookie verifier changes when we use the zero-valued
cookie, then we invalidate any cached pages.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 5d9367d9b651..7932d474ce00 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -945,9 +945,14 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc)
 		/*
 		 * Set the cookie verifier if the page cache was empty
 		 */
-		if (desc->page_index == 0)
+		if (desc->last_cookie == 0 &&
+		    memcmp(nfsi->cookieverf, verf, sizeof(nfsi->cookieverf))) {
 			memcpy(nfsi->cookieverf, verf,
 			       sizeof(nfsi->cookieverf));
+			invalidate_inode_pages2_range(desc->file->f_mapping,
+						      desc->page_index_max + 1,
+						      -1);
+		}
 	}
 	res = nfs_readdir_search_array(desc);
 	if (res == 0)
-- 
2.35.1