cifs: Fix missing fscache invalidation

A network filesystem needs to implement a netfslib hook to invalidate
fscache if it's to be able to use the cache.

Fix cifs to implement the cache invalidation hook.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 3ee1a1f ("cifs: Cut over to using netfslib")
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: dhowells

fs/smb/client/file.c

@@ -133,6 +133,11 @@ static void cifs_issue_write(struct netfs_io_subrequest *subreq)
 	goto out;
 }
 
+static void cifs_netfs_invalidate_cache(struct netfs_io_request *wreq)
+{
+	cifs_invalidate_cache(wreq->inode, 0);
+}
+
 /*
  * Split the read up according to how many credits we can get for each piece.
  * It's okay to sleep here if we need to wait for more credit to become
@@ -337,6 +342,7 @@ const struct netfs_request_ops cifs_req_ops = {
 	.begin_writeback	= cifs_begin_writeback,
 	.prepare_write		= cifs_prepare_write,
 	.issue_write		= cifs_issue_write,
+	.invalidate_cache	= cifs_netfs_invalidate_cache,
 };
 
 /*