From patchwork Thu Aug 10 10:10:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 13349208 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B723C001B0 for ; Thu, 10 Aug 2023 10:11:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233024AbjHJKLC (ORCPT ); Thu, 10 Aug 2023 06:11:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232030AbjHJKLB (ORCPT ); Thu, 10 Aug 2023 06:11:01 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90ABE128 for ; Thu, 10 Aug 2023 03:10:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691662215; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=kZSPj5/CzHhTNACKP6Hil6EI3Kv631Cd5foB+TFz2IM=; b=eLUviX68S0dwOj3XdxNy5j11TuFIwH1SNCn3LdJd11n57Igwh+75KFOMa6RwIC8/XaFIyz D1mijD5qG1gpt2x/M6tJu1jovnyYSAgPzyDOX9nv7FApVsEvde4AdeHN0AIEPqj4dcH5QE wnTfFZEncrCSLlYwpKPdEbgNtzo784Y= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-497-_w7CmM8GPw-HxTCVzK6t7A-1; Thu, 10 Aug 2023 06:10:12 -0400 X-MC-Unique: _w7CmM8GPw-HxTCVzK6t7A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B8CB91C31C50; Thu, 10 Aug 2023 10:10:11 +0000 (UTC) Received: from file1-rdu.file-001.prod.rdu2.dc.redhat.com (unknown [10.11.5.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A92C940C6F4E; Thu, 10 Aug 2023 10:10:11 +0000 (UTC) Received: by file1-rdu.file-001.prod.rdu2.dc.redhat.com (Postfix, from userid 12668) id F0E7930B9C07; Thu, 10 Aug 2023 10:10:10 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by file1-rdu.file-001.prod.rdu2.dc.redhat.com (Postfix) with ESMTP id AD8B53F7CF; Thu, 10 Aug 2023 12:10:10 +0200 (CEST) Date: Thu, 10 Aug 2023 12:10:09 +0200 (CEST) From: Mikulas Patocka To: Jens Axboe cc: Li Nan , Zdenek Kabelac , Christoph Hellwig , Chaitanya Kulkarni , linux-block@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v3 4/4] brd: implement write zeroes In-Reply-To: <2dacc73-854-e71c-1746-99b017401c9a@redhat.com> Message-ID: <19a1a124-cc21-9123-1ba1-2d7cadb9cdbe@redhat.com> References: <2dacc73-854-e71c-1746-99b017401c9a@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This patch implements REQ_OP_WRITE_ZEROES on brd. Write zeroes will free the pages just like discard, but the difference is that it writes zeroes to the preceding and following page if the range is not aligned on page boundary. Signed-off-by: Mikulas Patocka --- drivers/block/brd.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) Index: linux-2.6/drivers/block/brd.c =================================================================== --- linux-2.6.orig/drivers/block/brd.c +++ linux-2.6/drivers/block/brd.c @@ -301,7 +301,8 @@ out: void brd_do_discard(struct brd_device *brd, struct bio *bio) { struct free_page_batch *batch = NULL; - sector_t sector, len, front_pad; + bool zero_padding = bio_op(bio) == REQ_OP_WRITE_ZEROES; + sector_t sector, len, front_pad, end_pad; if (unlikely(!discard)) { bio->bi_status = BLK_STS_NOTSUPP; @@ -311,11 +312,22 @@ void brd_do_discard(struct brd_device *b sector = bio->bi_iter.bi_sector; len = bio_sectors(bio); front_pad = -sector & (PAGE_SECTORS - 1); + + if (zero_padding && unlikely(front_pad != 0)) + copy_to_brd(brd, page_address(ZERO_PAGE(0)), + sector, min(len, front_pad) << SECTOR_SHIFT); + sector += front_pad; if (unlikely(len <= front_pad)) return; len -= front_pad; - len = round_down(len, PAGE_SECTORS); + + end_pad = len & (PAGE_SECTORS - 1); + if (zero_padding && unlikely(end_pad != 0)) + copy_to_brd(brd, page_address(ZERO_PAGE(0)), + sector + len - end_pad, end_pad << SECTOR_SHIFT); + len -= end_pad; + while (len) { brd_free_page(brd, sector, &batch); sector += PAGE_SECTORS; @@ -359,6 +371,7 @@ static void brd_submit_bio(struct bio *b } break; case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: brd_do_discard(brd, bio); break; default: @@ -383,9 +396,11 @@ static void brd_set_discard_limits(struc if (discard) { queue->limits.discard_granularity = PAGE_SIZE; blk_queue_max_discard_sectors(queue, round_down(UINT_MAX, PAGE_SECTORS)); + blk_queue_max_write_zeroes_sectors(queue, round_down(UINT_MAX, PAGE_SECTORS)); } else { queue->limits.discard_granularity = 0; blk_queue_max_discard_sectors(queue, 0); + blk_queue_max_write_zeroes_sectors(queue, 0); } } @@ -425,7 +440,7 @@ MODULE_PARM_DESC(max_part, "Num Minors t static bool discard = false; module_param_cb(discard, &discard_ops, &discard, 0644); -MODULE_PARM_DESC(discard, "Support discard"); +MODULE_PARM_DESC(discard, "Support discard and write zeroes"); MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);