From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Tue, 22 Feb 2022 21:23:12 +0000 (-0500)
Subject: NFS: If the cookie verifier changes, we must invalidate the page cache
X-Git-Tag: v5.18-rc1~64^2~57
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c34f05b754622f473b546fd19ad3a89bd65bd89;p=thirdparty%2Fkernel%2Flinux.git

NFS: If the cookie verifier changes, we must invalidate the page cache

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>
---

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 520dc3ec4aefd..9998d7d173678 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -990,9 +990,14 @@ 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)