[PATCH 5.19 22/38] cifs: revalidate mapping when doing direct writes

Greg Kroah-Hartman
2022-09-21T15:51:27Z

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
@@ -3327,6 +3327,9 @@ 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);
}