From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:54125 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727356AbeLJRNd (ORCPT ); Mon, 10 Dec 2018 12:13:33 -0500 From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, sweil@redhat.com, swhiteho@redhat.com Subject: [PATCH 03/52] fuse: rely on mutex_unlock() barrier instead of fput() Date: Mon, 10 Dec 2018 12:12:29 -0500 Message-Id: <20181210171318.16998-4-vgoyal@redhat.com> In-Reply-To: <20181210171318.16998-1-vgoyal@redhat.com> References: <20181210171318.16998-1-vgoyal@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Stefan Hajnoczi fput() will be moved out of this function in a later patch, so we cannot rely on it as the memory barrier for ensuring file->private_data = fud is visible. Luckily there is a mutex_unlock() right before fput() which provides the same effect. Signed-off-by: Stefan Hajnoczi --- fs/fuse/inode.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 0b94b23b02d4..d08cd8bf7705 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1198,12 +1198,11 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) list_add_tail(&fc->entry, &fuse_conn_list); sb->s_root = root_dentry; file->private_data = fud; - mutex_unlock(&fuse_mutex); /* - * atomic_dec_and_test() in fput() provides the necessary - * memory barrier for file->private_data to be visible on all - * CPUs after this + * mutex_unlock() provides the necessary memory barrier for + * file->private_data to be visible on all CPUs after this */ + mutex_unlock(&fuse_mutex); fput(file); fuse_send_init(fc, init_req); -- 2.13.6