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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 5AAE8C4321A for ; Tue, 11 Jun 2019 13:11:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C24C20673 for ; Tue, 11 Jun 2019 13:11:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729078AbfFKNLf (ORCPT ); Tue, 11 Jun 2019 09:11:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41482 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726713AbfFKNLf (ORCPT ); Tue, 11 Jun 2019 09:11:35 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 875513082E6A; Tue, 11 Jun 2019 13:11:19 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 374A45D704; Tue, 11 Jun 2019 13:11:08 +0000 (UTC) Received: from zmail21.collab.prod.int.phx2.redhat.com (zmail21.collab.prod.int.phx2.redhat.com [10.5.83.24]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 4A3B74EBC9; Tue, 11 Jun 2019 13:10:59 +0000 (UTC) Date: Tue, 11 Jun 2019 09:10:58 -0400 (EDT) From: Pankaj Gupta To: Mike Snitzer Cc: cohuck@redhat.com, jack@suse.cz, kvm@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, david@fromorbit.com, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, dm-devel@redhat.com, adilger kernel , zwisler@kernel.org, aarcange@redhat.com, dave jiang , jstaron@google.com, linux-nvdimm@lists.01.org, vishal l verma , david@redhat.com, willy@infradead.org, hch@infradead.org, linux-acpi@vger.kernel.org, jmoyer@redhat.com, linux-ext4@vger.kernel.org, lenb@kernel.org, kilobyte@angband.pl, rdunlap@infradead.org, riel@surriel.com, yuval shaia , stefanha@redhat.com, pbonzini@redhat.com, dan j williams , lcapitulino@redhat.com, kwolf@redhat.com, nilal@redhat.com, tytso@mit.edu, xiaoguangrong eric , darrick wong , rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, imammedo@redhat.com Message-ID: <1206355816.34396746.1560258658768.JavaMail.zimbra@redhat.com> In-Reply-To: <20190610192803.GA29002@redhat.com> References: <20190610090730.8589-1-pagupta@redhat.com> <20190610090730.8589-5-pagupta@redhat.com> <20190610192803.GA29002@redhat.com> Subject: Re: [Qemu-devel] [PATCH v11 4/7] dm: enable synchronous dax MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.116.33, 10.4.195.27] Thread-Topic: enable synchronous dax Thread-Index: 9TyGIIOSkuHn9exFInDwoSOU8/oLjA== X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 11 Jun 2019 13:11:34 +0000 (UTC) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Hi Mike, Thanks for the review Please find my reply inline. > > dm_table_supports_dax() is called multiple times (from > dm_table_set_restrictions and dm_table_determine_type). It is strange > to have a getter have a side-effect of being a setter too. Overloading > like this could get you in trouble in the future. > > Are you certain this is what you want? I agree with you. > > Or would it be better to refactor dm_table_supports_dax() to take an > iterate_devices_fn arg and have callers pass the appropriate function? > Then have dm_table_set_restrictions() caller do: > > if (dm_table_supports_dax(t, device_synchronous, NULL)) > set_dax_synchronous(t->md->dax_dev); > > (NULL arg implies dm_table_supports_dax() refactoring would take a int > *data pointer rather than int type). > > Mike > I am sending below patch as per your suggestion. Does it look near to what you have in mind? Thank you, Pankaj =============== diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 350cf0451456..8d89acc8b8c2 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -881,7 +881,7 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type) EXPORT_SYMBOL_GPL(dm_table_set_type); /* validate the dax capability of the target device span */ -static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, +int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { int blocksize = *(int *) data; @@ -890,7 +890,15 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, start, len); } -bool dm_table_supports_dax(struct dm_table *t, int blocksize) +/* Check devices support synchronous DAX */ +static int device_synchronous(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + return dax_synchronous(dev->dax_dev); +} + +bool dm_table_supports_dax(struct dm_table *t, + iterate_devices_callout_fn iterate_fn, int *blocksize) { struct dm_target *ti; unsigned i; @@ -903,8 +911,7 @@ bool dm_table_supports_dax(struct dm_table *t, int blocksize) return false; if (!ti->type->iterate_devices || - !ti->type->iterate_devices(ti, device_supports_dax, - &blocksize)) + !ti->type->iterate_devices(ti, iterate_fn, blocksize)) return false; } @@ -940,6 +947,7 @@ static int dm_table_determine_type(struct dm_table *t) struct dm_target *tgt; struct list_head *devices = dm_table_get_devices(t); enum dm_queue_mode live_md_type = dm_get_md_type(t->md); + int page_size = PAGE_SIZE; if (t->type != DM_TYPE_NONE) { /* target already set the table's type */ @@ -984,7 +992,7 @@ static int dm_table_determine_type(struct dm_table *t) verify_bio_based: /* We must use this table as bio-based */ t->type = DM_TYPE_BIO_BASED; - if (dm_table_supports_dax(t, PAGE_SIZE) || + if (dm_table_supports_dax(t, device_supports_dax, &page_size) || (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) { t->type = DM_TYPE_DAX_BIO_BASED; } else { @@ -1883,6 +1891,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { bool wc = false, fua = false; + int page_size = PAGE_SIZE; /* * Copy table's limits to the DM device's request_queue @@ -1910,8 +1919,13 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_write_cache(q, wc, fua); - if (dm_table_supports_dax(t, PAGE_SIZE)) + if (dm_table_supports_dax(t, device_supports_dax, &page_size)) { + blk_queue_flag_set(QUEUE_FLAG_DAX, q); + if (dm_table_supports_dax(t, device_synchronous, NULL)) + set_dax_synchronous(t->md->dax_dev); + } else blk_queue_flag_clear(QUEUE_FLAG_DAX, q); diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b1caa7188209..b92c42a72ad4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1119,7 +1119,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd if (!map) return false; - ret = dm_table_supports_dax(map, blocksize); + ret = dm_table_supports_dax(map, device_supports_dax, &blocksize); dm_put_live_table(md, srcu_idx); diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 17e3db54404c..0475673337f3 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -72,7 +72,10 @@ bool dm_table_bio_based(struct dm_table *t); bool dm_table_request_based(struct dm_table *t); void dm_table_free_md_mempools(struct dm_table *t); struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t); -bool dm_table_supports_dax(struct dm_table *t, int blocksize); +bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn, + int *blocksize); +int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data); void dm_lock_md_type(struct mapped_device *md); void dm_unlock_md_type(struct mapped_device *md); -- 2.20.1