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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 EB4CBC169C4 for ; Thu, 31 Jan 2019 22:14:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAB2F2087F for ; Thu, 31 Jan 2019 22:14:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="R6Ni4t6M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729601AbfAaWN7 (ORCPT ); Thu, 31 Jan 2019 17:13:59 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:35982 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726994AbfAaWN6 (ORCPT ); Thu, 31 Jan 2019 17:13:58 -0500 Received: by mail-pf1-f193.google.com with SMTP id b85so2129441pfc.3 for ; Thu, 31 Jan 2019 14:13:57 -0800 (PST) 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=6gcXthu6vb+ihTFEPQTW8BXATfR0X3APAkCL8SfFcdU=; b=R6Ni4t6MTpFAucDhvSxJfW+pJRURt8DS/lVpq1DQWhp5L5nA8lSUUWGVrgIqvH6dAD gW+CmiknE9tX1GhGspe0U2oOdk2GzUqkLQAxIMrrwjANiOCZpBBw6mUp9Xwf16fZh0Qx R4fpxhNg1NZWrubAYgSIZoEJ8L7gaD6lcPac8= 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=6gcXthu6vb+ihTFEPQTW8BXATfR0X3APAkCL8SfFcdU=; b=QuSNr9D/JlouH9suT/T/Zf8Pxeq7ofQwgpuVqE7muWZdvn++19O0XdCCb4LrZa+ylf O0HTp+D2xtCnYXPbJgS7VyrMjH24WWmLZUBOjDs8TEGCfmG+N4fXZxdwe4e4ics+piMu DFPFJXkJooU7L84mbCVkJ79GWw30cmqIiZWqqnRWUMnvkpGqaGyQkIhm5A1c46x9qyCo 9B31ThKipbXQ3mVCpW3saUTGEcXvkvJnoHBjtstpUTOAdNeYlziQZChAaGHUmmuDFnLP CA797pPjTOytQ6Tcl9uTAAmtXGjZLyu2h40RzQgGXPJLLCG0v9kf2On/O39uFZsCacvn KGRg== X-Gm-Message-State: AJcUukdsXT5ezIXDIxZ7yCtfHWNs59P3vxzYfiSRZhlXaQ1M77VOqfzF ntgtKxESb7ZFWNANb0rQZJdIWg== X-Google-Smtp-Source: ALg8bN6bjHJeyN+XaFsdg3hkLi0eQSTj5yP6QzAEqSOY1L3X931hxZna7uobS/gzxiJjUm0hhSo96Q== X-Received: by 2002:a65:5c4b:: with SMTP id v11mr33081093pgr.333.1548972837427; Thu, 31 Jan 2019 14:13:57 -0800 (PST) Received: from evgreen2.mtv.corp.google.com ([2620:15c:202:201:ffda:7716:9afc:1301]) by smtp.gmail.com with ESMTPSA id z10sm7961681pfg.120.2019.01.31.14.13.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 31 Jan 2019 14:13:56 -0800 (PST) From: Evan Green To: Jens Axboe Cc: Gwendal Grignou , Martin K Peterson , Alexis Savery , Ming Lei , Evan Green , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RESEND PATCH 2/2] loop: Better discard support for block devices Date: Thu, 31 Jan 2019 14:13:28 -0800 Message-Id: <20190131221328.85343-3-evgreen@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190131221328.85343-1-evgreen@chromium.org> References: <20190131221328.85343-1-evgreen@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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. 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 --- 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 a1ba555e3b92..8c2b6885db56 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; } @@ -602,8 +597,13 @@ 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); @@ -857,6 +857,25 @@ 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 @@ -864,22 +883,24 @@ 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) -- 2.20.1