From patchwork Wed Mar 27 22:28:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 10873979 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C250F139A for ; Wed, 27 Mar 2019 22:29:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC6E028C07 for ; Wed, 27 Mar 2019 22:29:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9C2E128857; Wed, 27 Mar 2019 22:29:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6ED1B28857 for ; Wed, 27 Mar 2019 22:29:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728158AbfC0W3E (ORCPT ); Wed, 27 Mar 2019 18:29:04 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:37338 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730802AbfC0W24 (ORCPT ); Wed, 27 Mar 2019 18:28:56 -0400 Received: by mail-pf1-f196.google.com with SMTP id 8so10368602pfr.4 for ; Wed, 27 Mar 2019 15:28:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=eYWuwfE/DeGo/A1CHMZZFvsRrpeE2/SycqG1x6uy3nw=; b=UuxxeyOmOFarpObTwkTeOFvi6Yr1E8o5qMwOWd7tt84GNSA08rUaTrCP4uGjLrAuPA N6GM4MD3hU1NczbHS0fklLSKVkUeOBFooMUJ1hIK38pP1pKiuWX9zzQhPjChhy+Xjvxr DeWixwsSy5NxR/T+ql2Ml7/4lgctS3M+H3irg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=eYWuwfE/DeGo/A1CHMZZFvsRrpeE2/SycqG1x6uy3nw=; b=nVbnFtMxR0rEJNFSvgRMqWNl2hzYCK4ogcYVAcdbHrvb7MC+ucQpodc1W9z5CdGC91 chQoAbRq10/L6paJhrofWpq8BjktgWK6xllZHgieBVniMgiup5oWKKH7RN5mEUXHtfZJ npaEZ1M+PZ9QeB4mpSWA+/QC8rYC94icWOcmbORq1F3vkIKlqU/Bri0dbDt4Lm551S4L ANLM3jGbynq/EsCXtiO2t22Z0mJg2efUH42tM7W3hpcPL2DH3oyzdLLffwZginSBj5st lv6+gTqxUvQivvJEhSu+2/jBDiveupu3sH9mnnnaygN91tp3FXk4YSDMSrOR6uyRYSIn 2lXw== X-Gm-Message-State: APjAAAV3VRE13BPW2ut7B0rXIL9ODn+l6T8aTo7/HsVlbOnq+HkhGIWj HymTYIKar06i2TYgc0wazZglvQ== X-Google-Smtp-Source: APXvYqxmqU8ek/cpCeFMpA9uEEBz/u+1kZBc6p+KdcKu3NW8LivYh8filJRJldSvP7R9v9RbLvblUg== X-Received: by 2002:a62:59cb:: with SMTP id k72mr38709411pfj.111.1553725736019; Wed, 27 Mar 2019 15:28:56 -0700 (PDT) Received: from evgreen2.mtv.corp.google.com ([2620:15c:202:201:ffda:7716:9afc:1301]) by smtp.gmail.com with ESMTPSA id p88sm36928347pfa.80.2019.03.27.15.28.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 27 Mar 2019 15:28:55 -0700 (PDT) From: Evan Green To: Jens Axboe , Martin K Petersen Cc: Bart Van Assche , Gwendal Grignou , Alexis Savery , Ming Lei , Evan Green , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] loop: Better discard support for block devices Date: Wed, 27 Mar 2019 15:28:41 -0700 Message-Id: <20190327222841.38650-3-evgreen@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190327222841.38650-1-evgreen@chromium.org> References: <20190327222841.38650-1-evgreen@chromium.org> MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If the backing device for a loop device is a block device, then mirror the discard properties of the underlying block device into the loop device. This new change only applies to loop devices backed directly by a block device, not loop devices backed by regular files. While in there, differentiate between REQ_OP_DISCARD and REQ_OP_WRITE_ZEROES, which are different for block devices, but which the loop device had just been lumping together, since they're largely the same for files. This change fixes blktest block/003, and removes an extraneous error print in block/013 when testing on a loop device backed by a block device that does not support discard. Signed-off-by: Evan Green --- Changes in v3: - Updated commit description Changes in v2: None drivers/block/loop.c | 61 +++++++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 20 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index bbf21ebeccd3..e1edd004298a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -417,19 +417,14 @@ static int lo_read_transfer(struct loop_device *lo, struct request *rq, return ret; } -static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos) +static int lo_discard(struct loop_device *lo, struct request *rq, + int mode, loff_t pos) { - /* - * We use punch hole to reclaim the free space used by the - * image a.k.a. discard. However we do not support discard if - * encryption is enabled, because it may give an attacker - * useful information. - */ struct file *file = lo->lo_backing_file; - int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; + struct request_queue *q = lo->lo_queue; int ret; - if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) { + if (!blk_queue_discard(q)) { ret = -EOPNOTSUPP; goto out; } @@ -599,8 +594,13 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) case REQ_OP_FLUSH: return lo_req_flush(lo, rq); case REQ_OP_DISCARD: + return lo_discard(lo, rq, + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, pos); + case REQ_OP_WRITE_ZEROES: - return lo_discard(lo, rq, pos); + return lo_discard(lo, rq, + FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE, pos); + case REQ_OP_WRITE: if (lo->transfer) return lo_write_transfer(lo, rq, pos); @@ -854,6 +854,25 @@ static void loop_config_discard(struct loop_device *lo) struct file *file = lo->lo_backing_file; struct inode *inode = file->f_mapping->host; struct request_queue *q = lo->lo_queue; + struct request_queue *backingq; + + /* + * If the backing device is a block device, mirror its discard + * capabilities. + */ + if (S_ISBLK(inode->i_mode)) { + backingq = bdev_get_queue(inode->i_bdev); + blk_queue_max_discard_sectors(q, + backingq->limits.max_discard_sectors); + + blk_queue_max_write_zeroes_sectors(q, + backingq->limits.max_write_zeroes_sectors); + + q->limits.discard_granularity = + backingq->limits.discard_granularity; + + q->limits.discard_alignment = + backingq->limits.discard_alignment; /* * We use punch hole to reclaim the free space used by the @@ -861,22 +880,24 @@ static void loop_config_discard(struct loop_device *lo) * encryption is enabled, because it may give an attacker * useful information. */ - if ((!file->f_op->fallocate) || - lo->lo_encrypt_key_size) { + } else if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) { q->limits.discard_granularity = 0; q->limits.discard_alignment = 0; blk_queue_max_discard_sectors(q, 0); blk_queue_max_write_zeroes_sectors(q, 0); - blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); - return; - } - q->limits.discard_granularity = inode->i_sb->s_blocksize; - q->limits.discard_alignment = 0; + } else { + q->limits.discard_granularity = inode->i_sb->s_blocksize; + q->limits.discard_alignment = 0; + + blk_queue_max_discard_sectors(q, UINT_MAX >> 9); + blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9); + } - blk_queue_max_discard_sectors(q, UINT_MAX >> 9); - blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9); - blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); + if (q->limits.max_discard_sectors || q->limits.max_write_zeroes_sectors) + blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); + else + blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); } static void loop_unprepare_queue(struct loop_device *lo)