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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, "Paulo Alcantara (SUSE)" <pc@cjr.nz>,
        Ronnie Sahlberg <lsahlber@redhat.com>,
        Steve French <stfrench@microsoft.com>
Subject: [PATCH 5.15 17/45] cifs: revalidate mapping when doing direct writes
Date:   Wed, 21 Sep 2022 17:46:07 +0200
Message-Id: <20220921153647.454450096@linuxfoundation.org>
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From: Ronnie Sahlberg <lsahlber@redhat.com>

commit 7500a99281dfed2d4a84771c933bcb9e17af279b upstream.

Kernel bugzilla: 216301

When doing direct writes we need to also invalidate the mapping in case
we have a cached copy of the affected page(s) in memory or else
subsequent reads of the data might return the old/stale content
before we wrote an update to the server.

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/cifs/file.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3318,6 +3318,9 @@ static ssize_t __cifs_writev(
 
 ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from)
 {
+	struct file *file = iocb->ki_filp;
+
+	cifs_revalidate_mapping(file->f_inode);
 	return __cifs_writev(iocb, from, true);
 }