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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 5F962C5519F for ; Mon, 16 Nov 2020 15:11:56 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F0DA9204FD for ; Mon, 16 Nov 2020 15:11:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="tb9itT34"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="um2QX1aP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0DA9204FD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=g42kKyp+EsuIPhlxgir6w2+bSRL7pZilb8DNGiQjL+g=; b=tb9itT34E5z3IbE7ZQsmxrFOX 2bgTCz+IcnIO54RA1dBYlxZcVCCN58FJVaMvnujuxe9QEpml83UC8mwnTShDBUBcpKGUmoqihvIvy +g+zS8tPtpB0IQfyMM7W4WF1GTZtwCi7lG3QuiUAzrjTWuFi6b5nEASwEdNfB3+rXBgkRiUaxSvsY IpLZ6D0QCHX5YZbJlDLY8kh28+A1xqn7+mn0c2xDcMdJ6NWrTpPhg8+m1BD75h++kCr8yzz5ttA9W qEzpEmIxOZFEOKAYj3CmJjaqQDH2xTZVJ99nQcoQ85hIvdgu8vXAF5pTBUimuPfpwQXYl/q/gLV19 ADAicL0DQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kegAV-0002fV-Of; Mon, 16 Nov 2020 15:11:47 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kefyl-0003zg-Bx for linux-nvme@merlin.infradead.org; Mon, 16 Nov 2020 14:59:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=MmPwn4ttbQT6DHYheoE0UJGEFNI8kA6nAc7IEYdL0K0=; b=um2QX1aPNEBrXGLXtU6YvAtfko SUJQ/zrYAfsNYMAKdZ3tINvi3zqorS3Hcvwis/lRWwGYc/D4a1i+axMJb3c9L3kCaZuM/YpRBYYYl XLZ6DdJ1Y/xHMe+0KQ4YHMrkyZmtkiCaiO6dicUKCBonmuuw50C1TKzUDzndp/SXSYZ/wTEjCmw8k AIxOkUDjtUH52YVU8pqQr/5UXUu1+KzSvrDq39iKullr+3CXYrM5D1wNrkUadnpJVHhZ7zw3XpmrF j8SHOcAIOQu8AyneX2JJ5GEkPZOzCGTSxW+MHMHVW+E/mdPaslbb69OAjiZZeO+aj/n9AezJ3u1Wq K2n33VVw==; Received: from [2001:4bb8:180:6600:255b:7def:a93:4a09] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kefyi-0004Ad-Px; Mon, 16 Nov 2020 14:59:37 +0000 From: Christoph Hellwig To: Jens Axboe Subject: [PATCH 60/78] zram: remove the claim mechanism Date: Mon, 16 Nov 2020 15:57:51 +0100 Message-Id: <20201116145809.410558-61-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201116145809.410558-1-hch@lst.de> References: <20201116145809.410558-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Justin Sanders , Mike Snitzer , "Michael S. Tsirkin" , Jason Wang , linux-nvme@lists.infradead.org, Song Liu , dm-devel@redhat.com, drbd-dev@lists.linbit.com, linux-scsi@vger.kernel.org, xen-devel@lists.xenproject.org, Ilya Dryomov , Jack Wang , Konrad Rzeszutek Wilk , Josef Bacik , nbd@other.debian.org, linux-raid@vger.kernel.org, Stefan Hajnoczi , ceph-devel@vger.kernel.org, linux-block@vger.kernel.org, "Martin K. Petersen" , Minchan Kim , linux-fsdevel@vger.kernel.org, Paolo Bonzini , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org The zram claim mechanism was added to ensure no new opens come in during teardown. But the proper way to archive that is to call del_gendisk first, which takes care of all that. Once del_gendisk is called in the right place, the reset side can also be simplified as no I/O can be outstanding on a block device that is not open. Signed-off-by: Christoph Hellwig --- drivers/block/zram/zram_drv.c | 76 ++++++++++------------------------- 1 file changed, 21 insertions(+), 55 deletions(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 6d15d51cee2b7e..3641434a9b154d 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1756,64 +1756,33 @@ static ssize_t disksize_store(struct device *dev, static ssize_t reset_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { - int ret; - unsigned short do_reset; - struct zram *zram; + struct zram *zram = dev_to_zram(dev); struct block_device *bdev; + unsigned short do_reset; + int ret = 0; ret = kstrtou16(buf, 10, &do_reset); if (ret) return ret; - if (!do_reset) return -EINVAL; - zram = dev_to_zram(dev); bdev = bdget_disk(zram->disk, 0); if (!bdev) return -ENOMEM; mutex_lock(&bdev->bd_mutex); - /* Do not reset an active device or claimed device */ - if (bdev->bd_openers || zram->claim) { - mutex_unlock(&bdev->bd_mutex); - bdput(bdev); - return -EBUSY; - } - - /* From now on, anyone can't open /dev/zram[0-9] */ - zram->claim = true; + if (bdev->bd_openers) + ret = -EBUSY; + else + zram_reset_device(zram); mutex_unlock(&bdev->bd_mutex); - - /* Make sure all the pending I/O are finished */ - fsync_bdev(bdev); - zram_reset_device(zram); bdput(bdev); - mutex_lock(&bdev->bd_mutex); - zram->claim = false; - mutex_unlock(&bdev->bd_mutex); - - return len; -} - -static int zram_open(struct block_device *bdev, fmode_t mode) -{ - int ret = 0; - struct zram *zram; - - WARN_ON(!mutex_is_locked(&bdev->bd_mutex)); - - zram = bdev->bd_disk->private_data; - /* zram was claimed to reset so open request fails */ - if (zram->claim) - ret = -EBUSY; - - return ret; + return ret ? ret : len; } static const struct block_device_operations zram_devops = { - .open = zram_open, .submit_bio = zram_submit_bio, .swap_slot_free_notify = zram_slot_free_notify, .rw_page = zram_rw_page, @@ -1821,7 +1790,6 @@ static const struct block_device_operations zram_devops = { }; static const struct block_device_operations zram_wb_devops = { - .open = zram_open, .submit_bio = zram_submit_bio, .swap_slot_free_notify = zram_slot_free_notify, .owner = THIS_MODULE @@ -1972,34 +1940,32 @@ static int zram_add(void) return ret; } -static int zram_remove(struct zram *zram) +static bool zram_busy(struct zram *zram) { struct block_device *bdev; + bool busy = false; bdev = bdget_disk(zram->disk, 0); - if (!bdev) - return -ENOMEM; - - mutex_lock(&bdev->bd_mutex); - if (bdev->bd_openers || zram->claim) { - mutex_unlock(&bdev->bd_mutex); + if (bdev) { + if (bdev->bd_openers) + busy = true; bdput(bdev); - return -EBUSY; } - zram->claim = true; - mutex_unlock(&bdev->bd_mutex); + return busy; +} - zram_debugfs_unregister(zram); +static int zram_remove(struct zram *zram) +{ + if (zram_busy(zram)) + return -EBUSY; - /* Make sure all the pending I/O are finished */ - fsync_bdev(bdev); + del_gendisk(zram->disk); + zram_debugfs_unregister(zram); zram_reset_device(zram); - bdput(bdev); pr_info("Removed device: %s\n", zram->disk->disk_name); - del_gendisk(zram->disk); blk_cleanup_queue(zram->disk->queue); put_disk(zram->disk); kfree(zram); -- 2.29.2 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme