From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 31 May 2016 09:17:56 +0200 Message-ID: Subject: Re: [fuse-devel] Changes in 4.7. From: Miklos Szeredi To: Stef Bon Cc: "fuse-devel@lists.sourceforge.net" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: On Tue, May 31, 2016 at 9:08 AM, Stef Bon wrote: > Hi, > > I've read some news about the 4.7 kernel : > > "And in particular, if > you're a low-level filesystem person, or involved in other ways in > path component lookup (security layer etc), go check that everything > looks ok, and if your filesystem isn't one that does parallel lookups > or readdirs yet (because locking issues), take a look at that too." > > https://lkml.org/lkml/2016/5/29/77 > > Does this have consequenses for fuse? > I know that with some filesystems I've written the readdir call locks > the directory exclusive. The problem would be if the fuse filesystem assumed serialized lookup/readdir and they don't do any locking themselves. We probably need to conditionally re-add the lookup/readdir serialization to the fuse kernel module, with an INIT flag to explicitly enable parallel readdir and lookup (i.e. disable the serialization). Thanks, Miklos