From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id A53422095B9C6 for ; Thu, 24 Aug 2017 05:28:52 -0700 (PDT) Date: Thu, 24 Aug 2017 05:31:26 -0700 From: Christoph Hellwig Subject: Re: [PATCH 13/13] ext4: Support for synchronous DAX faults Message-ID: <20170824123126.GA21282@infradead.org> References: <20170817160815.30466-1-jack@suse.cz> <20170817160815.30466-14-jack@suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170817160815.30466-14-jack@suse.cz> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Jan Kara Cc: Christoph Hellwig , Boaz Harrosh , linux-nvdimm@lists.01.org, linux-xfs@vger.kernel.org, Andy Lutomirski , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org List-ID: On Thu, Aug 17, 2017 at 06:08:15PM +0200, Jan Kara wrote: > We return IOMAP_F_NEEDDSYNC flag from ext4_iomap_begin() for a > synchronous write fault when inode has some uncommitted metadata > changes. In the fault handler ext4_dax_fault() we then detect this case, > call vfs_fsync_range() to make sure all metadata is committed, and call > dax_pfn_mkwrite() to mark PTE as writeable. Note that this will also > dirty corresponding radix tree entry which is what we want - fsync(2) > will still provide data integrity guarantees for applications not using > userspace flushing. And applications using userspace flushing can avoid > calling fsync(2) and thus avoid the performance overhead. Why is this only wiered up for the huge_fault handler and not the regular? _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm