From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5FBCC433DB for ; Wed, 10 Feb 2021 13:41:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9C9064E15 for ; Wed, 10 Feb 2021 13:41:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230192AbhBJNlr (ORCPT ); Wed, 10 Feb 2021 08:41:47 -0500 Received: from verein.lst.de ([213.95.11.211]:51214 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229710AbhBJNlp (ORCPT ); Wed, 10 Feb 2021 08:41:45 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 97BF768B02; Wed, 10 Feb 2021 14:41:00 +0100 (CET) Date: Wed, 10 Feb 2021 14:41:00 +0100 From: Christoph Hellwig To: Shiyang Ruan Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, dm-devel@redhat.com, darrick.wong@oracle.com, dan.j.williams@intel.com, david@fromorbit.com, hch@lst.de, agk@redhat.com, snitzer@redhat.com, rgoldwyn@suse.de, qi.fuli@fujitsu.com, y-goto@fujitsu.com Subject: Re: [PATCH v3 06/11] mm, pmem: Implement ->memory_failure() in pmem driver Message-ID: <20210210134100.GE30109@lst.de> References: <20210208105530.3072869-1-ruansy.fnst@cn.fujitsu.com> <20210208105530.3072869-7-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210208105530.3072869-7-ruansy.fnst@cn.fujitsu.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org > +static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap, > + unsigned long pfn, int flags) > +{ > + struct pmem_device *pdev; > + struct gendisk *disk; > + loff_t disk_offset; > + int rc = 0; > + unsigned long size = page_size(pfn_to_page(pfn)); > + > + pdev = container_of(pgmap, struct pmem_device, pgmap); > + disk = pdev->disk; Would be nice to initialize this at the time of declaration: struct pmem_device *pdev = container_of(pgmap, struct pmem_device, pgmap); struct gendisk *disk = pdev->disk unsigned long size = page_size(pfn_to_page(pfn)); > + if (!disk) > + return -ENXIO; > + > + disk_offset = PFN_PHYS(pfn) - pdev->phys_addr - pdev->data_offset; > + if (disk->fops->corrupted_range) { > + rc = disk->fops->corrupted_range(disk, NULL, disk_offset, > + size, &flags); > + if (rc == -ENODEV) > + rc = -ENXIO; > + } else > + rc = -EOPNOTSUPP; Why do we need the disk and fops check here? A pgmap registered by pmem.c should always have a disk with pmem_fops. And more importantly this has no business going through the block layer. Instead the file system should deposit a callback when starting to use the dax_device using fs_dax_get_by_bdev / dax_get_by_host and a private data (the superblock), and we avoid all the lookup problems. > +int mf_generic_kill_procs(unsigned long long pfn, int flags) This function seems to be only used inside of memory-failure.c, so it could be marked static. Also I'd name it dax_generic_memory_failure or something like that to match the naming of the ->memory_failure pgmap operation. Also maybe just splitting this out into a helper would be a nice prep patch.