From: Theodore Ts'o Subject: Re: [PATCH v2 3/4] ext4: Add iomap support for inline data Date: Thu, 28 Sep 2017 13:57:48 -0400 Message-ID: <20170928175748.23b7wkjiqavpunvj@thunk.org> References: <20170914095047.23935-1-agruenba@redhat.com> <20170914095047.23935-4-agruenba@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, Jan Kara , Christoph Hellwig To: Andreas Gruenbacher Return-path: Received: from imap.thunk.org ([74.207.234.97]:43328 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752467AbdI1R5z (ORCPT ); Thu, 28 Sep 2017 13:57:55 -0400 Content-Disposition: inline In-Reply-To: <20170914095047.23935-4-agruenba@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Sep 14, 2017 at 11:50:46AM +0200, Andreas Gruenbacher wrote: > +int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap) > +{ > + __u64 addr; > + int error = -EAGAIN; > + struct ext4_iloc iloc; > + > + down_read(&EXT4_I(inode)->xattr_sem); > + if (!ext4_has_inline_data(inode)) > + goto out; .... > +out: > + up_read(&EXT4_I(inode)->xattr_sem); > + return error; > +} If we race with the inline data flag getting cleared, ext4_iomap_begin() will return with -EAGAIN. As near as I can tell, this will get reflected all the way up to userspace, instead of having the retry happen in the kernel. Is this intentional? It looks like a user visible change, no? - Ted