From patchwork Mon May 6 18:27:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 10931791 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 EBCC01575 for ; Mon, 6 May 2019 18:30:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE7E0288A9 for ; Mon, 6 May 2019 18:30:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D2F51288B9; Mon, 6 May 2019 18:30:33 +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 7D597288A6 for ; Mon, 6 May 2019 18:30:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726566AbfEFSaX (ORCPT ); Mon, 6 May 2019 14:30:23 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:35673 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbfEFSaW (ORCPT ); Mon, 6 May 2019 14:30:22 -0400 Received: by mail-pl1-f196.google.com with SMTP id w24so6794599plp.2 for ; Mon, 06 May 2019 11:30:22 -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=h4fAKuH/byVNhylCS+A6U39gO11PXacps3u7CzHGthA=; b=dNSKDUXF2oZSIiYLphUbNUQDSbjx83YCVELTwCDErbC7zdeU0NBLzprYH4IWfSBwRc 58wL4Yzryf+zRobhFJ//WBRL7i0WJ+HTgQZbdJk50dWzazix94IbKZyQbCvBjp7yQ+jB ueO4NgyjTDCmL1u4yaMpujTc3Wqy63pV8WkNw= 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=h4fAKuH/byVNhylCS+A6U39gO11PXacps3u7CzHGthA=; b=fyShq4iqEtaW5OGy9VZbwfOoQUzdtSWETEstAyokzm7UD2gaVxVIS2nivW3CJ060Kv iev2sqTPIBvOJ+bn7PFyYkMAM+4enhDUNseriSvnjwa6bHXGd9ZOdt8oQT5Usd9T+HLJ hb3cb4h8anPAHiz4tA4Amudwt7YZMSYOREthlZv5HnbEi93ON1SVX2kkXspIefFyvAGo yUnxwOaTgfz7JEkuNVo7yvmXgv1023Ba4/bXQ75A6Q1UsZXBML4pSY+xH/Cc5K/kKSF2 03B1tOVUQqOPdRxW9avn0tEd6dChzQgQQWKb3V7BSFH4uS7TY1DnsKWFiV8y3ul3v0TQ CjWA== X-Gm-Message-State: APjAAAWmj1DqexgCudCrg3U/KZLohxZofpB6oyUgUzknn3oMgD4qv4oC j9A2cJJfPHgEG09is715tbOy/g== X-Google-Smtp-Source: APXvYqxZOm72vl0eWsFna1xWIPu80i8z2lHBi28o1Kv41r+YVXTalThuFqrYphk6KLaVhUsaytlrGA== X-Received: by 2002:a17:902:12f:: with SMTP id 44mr34438223plb.193.1557167421854; Mon, 06 May 2019 11:30:21 -0700 (PDT) Received: from evgreen2.mtv.corp.google.com ([2620:15c:202:201:ffda:7716:9afc:1301]) by smtp.gmail.com with ESMTPSA id o81sm18858033pfa.156.2019.05.06.11.30.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 06 May 2019 11:30:21 -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 v5 1/2] loop: Report EOPNOTSUPP properly Date: Mon, 6 May 2019 11:27:35 -0700 Message-Id: <20190506182736.21064-2-evgreen@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190506182736.21064-1-evgreen@chromium.org> References: <20190506182736.21064-1-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 Properly plumb out EOPNOTSUPP from loop driver operations, which may get returned when for instance a discard operation is attempted but not supported by the underlying block device. Before this change, everything was reported in the log as an I/O error, which is scary and not helpful in debugging. Signed-off-by: Evan Green Reviewed-by: Ming Lei Reviewed-by: Bart Van Assche Reviewed-by: Martin K. Petersen Reviewed-by: Gwendal Grignou Reviewed-by: Chaitanya Kulkarni --- Changes in v5: None Changes in v4: None Changes in v3: - Updated tags Changes in v2: - Unnested error if statement (Bart) drivers/block/loop.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index bf1c61cab8eb..bbf21ebeccd3 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -458,7 +458,9 @@ static void lo_complete_rq(struct request *rq) if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || req_op(rq) != REQ_OP_READ) { - if (cmd->ret < 0) + if (cmd->ret == -EOPNOTSUPP) + ret = BLK_STS_NOTSUPP; + else if (cmd->ret < 0) ret = BLK_STS_IOERR; goto end_io; } @@ -1892,7 +1894,10 @@ static void loop_handle_cmd(struct loop_cmd *cmd) failed: /* complete non-aio request */ if (!cmd->use_aio || ret) { - cmd->ret = ret ? -EIO : 0; + if (ret == -EOPNOTSUPP) + cmd->ret = ret; + else + cmd->ret = ret ? -EIO : 0; blk_mq_complete_request(rq); } } From patchwork Mon May 6 18:27:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Green X-Patchwork-Id: 10931789 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 7D823924 for ; Mon, 6 May 2019 18:30:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C56228831 for ; Mon, 6 May 2019 18:30:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6077B288B9; Mon, 6 May 2019 18:30:33 +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 B9793288BA for ; 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bh=75ImqmVpanW8AKh7C/kPiDhvEBpTWl1hHz0h9oahWdQ=; b=BQChH2iU7QtQY5bpDkJ/D89f8fyi2CFYNxC4H+R+H2vIDiWY66J94qZkpJ/saU3fX9 1lT796I2jc2Y80zhLVK1YafLVrI/LugYn4htpFrkCtNTmSQjU3Ksi5iVcF/MwsxRba0H PL+Yf38/rLP8ekkN2UEYsfhLvBPa0/mFFPVesDJx/YE62IAEsF6rSLc9D922XN6sS/Oe 0ra4dwb2ytNOHl4AgsUEMeq9EDi9WFvzTo4+ugZHfhe9u14pT6LDDflpd5eLlariu+b5 174Z9/w1KkQT60Rt2glemmfZKEY2pFHhGSuu+gp4JvydlN8yGzFep2E3jSpMg+RIsFnN nrHw== X-Gm-Message-State: APjAAAXfv8NhAZAEiEgL06x7/Dxrf+yfVXmXkBjtc5ErP2zYUJ1Gs289 iWZhfZKfqlNSLdpf112Mddwlhg== X-Google-Smtp-Source: APXvYqxMWTOAHjugYuVOigsWKSgA7rZBZkfNZ/VPfc8SAuWHM1L3BxZ3JoAB7ZjXo/Q0rTzygXIphQ== X-Received: by 2002:a65:64ca:: with SMTP id t10mr34037891pgv.177.1557167425364; Mon, 06 May 2019 11:30:25 -0700 (PDT) Received: from evgreen2.mtv.corp.google.com ([2620:15c:202:201:ffda:7716:9afc:1301]) by smtp.gmail.com with ESMTPSA id o81sm18858033pfa.156.2019.05.06.11.30.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 06 May 2019 11:30:24 -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 v5 2/2] loop: Better discard support for block devices Date: Mon, 6 May 2019 11:27:36 -0700 Message-Id: <20190506182736.21064-3-evgreen@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190506182736.21064-1-evgreen@chromium.org> References: <20190506182736.21064-1-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 "write zeroes" capabilities of the underlying block device into the loop device. Copy this capability into both max_write_zeroes_sectors and max_discard_sectors of the loop device. The reason for this is that REQ_OP_DISCARD on a loop device translates into blkdev_issue_zeroout(), rather than blkdev_issue_discard(). This presents a consistent interface for loop devices (that discarded data is zeroed), regardless of the backing device type of the loop device. There should be no behavior change for 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 Reviewed-by: Gwendal Grignou Reviewed-by: Chaitanya Kulkarni --- Changes in v5: - Don't mirror discard if lo_encrypt_key_size is non-zero (Gwendal) Changes in v4: - Mirror blkdev's write_zeroes into loopdev's discard_sectors. Changes in v3: - Updated commit description Changes in v2: None drivers/block/loop.c | 57 ++++++++++++++++++++++++++++---------------- 1 file changed, 37 insertions(+), 20 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index bbf21ebeccd3..a147210ed009 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 +854,21 @@ 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 zeroing + * capability. REQ_OP_DISCARD translates to a zero-out even when backed + * by block devices to keep consistent behavior with file-backed loop + * devices. + */ + if (S_ISBLK(inode->i_mode) && !lo->lo_encrypt_key_size) { + backingq = bdev_get_queue(inode->i_bdev); + blk_queue_max_discard_sectors(q, + backingq->limits.max_write_zeroes_sectors); + + blk_queue_max_write_zeroes_sectors(q, + backingq->limits.max_write_zeroes_sectors); /* * We use punch hole to reclaim the free space used by the @@ -861,22 +876,24 @@ 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_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)