From patchwork Thu Nov 26 13:04:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11933627 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=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 9477AC71155 for ; Thu, 26 Nov 2020 13:07:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4068021D7E for ; Thu, 26 Nov 2020 13:07:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NMV1mshq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389960AbgKZNHU (ORCPT ); Thu, 26 Nov 2020 08:07:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389943AbgKZNHT (ORCPT ); Thu, 26 Nov 2020 08:07:19 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E1BDC0613D4; Thu, 26 Nov 2020 05:07:19 -0800 (PST) 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=yfOmHITfcmrnqqH2mTFIs2gex5rvDz6ddqSrV3AiET0=; b=NMV1mshqul/Oud+p60vEs+VE0p o7Qst0ZFTy6wPe6H5OvWgcxVgVScZ1iZUi8ckr3mSDgDpONWHd7vNCqRrGh2ZmvUjtu9YrFRWnEfb DIACGJCnZB5f1zWW0B9/+snJ2nNXMdIcPeAJf0p8I8ibdF1HSWAlDT1na8+hKIrd2Uvz1zVzHCTN9 Fqs4h9iuwKNPX+dDYVDVDw/3MxdbwiObHwTqY0DM1Q2ZEb/eQnGQP3+qD4Cj3AjWYXZuRKAA4sttg fUwulEoxgHx5kI4IgGfc7V18741CIxeX137t1b3lnD+FP8dT5dQ1JsNc4lHyQ4lPtAXXcLCQ8Q2hK yTj8uIkw==; Received: from [2001:4bb8:18c:1dd6:27b8:b8a1:c13e:ceb1] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kiGzN-00043l-V4; Thu, 26 Nov 2020 13:07:10 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Tejun Heo , Josef Bacik , Coly Li , Mike Snitzer , Greg Kroah-Hartman , Jan Kara , Johannes Thumshirn , dm-devel@redhat.com, Jan Kara , linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 26/44] block: simplify the block device claiming interface Date: Thu, 26 Nov 2020 14:04:04 +0100 Message-Id: <20201126130422.92945-27-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201126130422.92945-1-hch@lst.de> References: <20201126130422.92945-1-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 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Stop passing the whole device as a separate argument given that it can be trivially deducted and cleanup the !holder debug check. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jan Kara Acked-by: Tejun Heo --- drivers/block/loop.c | 12 +++++----- fs/block_dev.c | 51 +++++++++++++++--------------------------- include/linux/blkdev.h | 6 ++--- 3 files changed, 25 insertions(+), 44 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index c0df88b3300c41..d643c67be6acea 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1069,7 +1069,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, struct file *file; struct inode *inode; struct address_space *mapping; - struct block_device *claimed_bdev = NULL; int error; loff_t size; bool partscan; @@ -1088,8 +1087,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, * here to avoid changing device under exclusive owner. */ if (!(mode & FMODE_EXCL)) { - claimed_bdev = bdev_whole(bdev); - error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure); + error = bd_prepare_to_claim(bdev, loop_configure); if (error) goto out_putf; } @@ -1176,15 +1174,15 @@ static int loop_configure(struct loop_device *lo, fmode_t mode, mutex_unlock(&loop_ctl_mutex); if (partscan) loop_reread_partitions(lo, bdev); - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, loop_configure); + if (!(mode & FMODE_EXCL)) + bd_abort_claiming(bdev, loop_configure); return 0; out_unlock: mutex_unlock(&loop_ctl_mutex); out_bdev: - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, loop_configure); + if (!(mode & FMODE_EXCL)) + bd_abort_claiming(bdev, loop_configure); out_putf: fput(file); out: diff --git a/fs/block_dev.c b/fs/block_dev.c index 73f45ae1d3d50c..f180ac0e87844f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -110,24 +110,20 @@ EXPORT_SYMBOL(invalidate_bdev); int truncate_bdev_range(struct block_device *bdev, fmode_t mode, loff_t lstart, loff_t lend) { - struct block_device *claimed_bdev = NULL; - int err; - /* * If we don't hold exclusive handle for the device, upgrade to it * while we discard the buffer cache to avoid discarding buffers * under live filesystem. */ if (!(mode & FMODE_EXCL)) { - claimed_bdev = bdev_whole(bdev); - err = bd_prepare_to_claim(bdev, claimed_bdev, - truncate_bdev_range); + int err = bd_prepare_to_claim(bdev, truncate_bdev_range); if (err) return err; } + truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); - if (claimed_bdev) - bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range); + if (!(mode & FMODE_EXCL)) + bd_abort_claiming(bdev, truncate_bdev_range); return 0; } EXPORT_SYMBOL(truncate_bdev_range); @@ -974,7 +970,6 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, /** * bd_prepare_to_claim - claim a block device * @bdev: block device of interest - * @whole: the whole device containing @bdev, may equal @bdev * @holder: holder trying to claim @bdev * * Claim @bdev. This function fails if @bdev is already claimed by another @@ -984,9 +979,12 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, * RETURNS: * 0 if @bdev can be claimed, -EBUSY otherwise. */ -int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, - void *holder) +int bd_prepare_to_claim(struct block_device *bdev, void *holder) { + struct block_device *whole = bdev_whole(bdev); + + if (WARN_ON_ONCE(!holder)) + return -EINVAL; retry: spin_lock(&bdev_lock); /* if someone else claimed, fail */ @@ -1026,15 +1024,15 @@ static void bd_clear_claiming(struct block_device *whole, void *holder) /** * bd_finish_claiming - finish claiming of a block device * @bdev: block device of interest - * @whole: whole block device * @holder: holder that has claimed @bdev * * Finish exclusive open of a block device. Mark the device as exlusively * open by the holder and wake up all waiters for exclusive open to finish. */ -static void bd_finish_claiming(struct block_device *bdev, - struct block_device *whole, void *holder) +static void bd_finish_claiming(struct block_device *bdev, void *holder) { + struct block_device *whole = bdev_whole(bdev); + spin_lock(&bdev_lock); BUG_ON(!bd_may_claim(bdev, whole, holder)); /* @@ -1059,11 +1057,10 @@ static void bd_finish_claiming(struct block_device *bdev, * also used when exclusive open is not actually desired and we just needed * to block other exclusive openers for a while. */ -void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, - void *holder) +void bd_abort_claiming(struct block_device *bdev, void *holder) { spin_lock(&bdev_lock); - bd_clear_claiming(whole, holder); + bd_clear_claiming(bdev_whole(bdev), holder); spin_unlock(&bdev_lock); } EXPORT_SYMBOL(bd_abort_claiming); @@ -1480,7 +1477,6 @@ void blkdev_put_no_open(struct block_device *bdev) */ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) { - struct block_device *claiming; bool unblock_events = true; struct block_device *bdev; struct gendisk *disk; @@ -1503,15 +1499,9 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) disk = bdev->bd_disk; if (mode & FMODE_EXCL) { - WARN_ON_ONCE(!holder); - - ret = -ENOMEM; - claiming = bdget_disk(disk, 0); - if (!claiming) - goto put_blkdev; - ret = bd_prepare_to_claim(bdev, claiming, holder); + ret = bd_prepare_to_claim(bdev, holder); if (ret) - goto put_claiming; + goto put_blkdev; } disk_block_events(disk); @@ -1521,7 +1511,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) if (ret) goto abort_claiming; if (mode & FMODE_EXCL) { - bd_finish_claiming(bdev, claiming, holder); + bd_finish_claiming(bdev, holder); /* * Block event polling for write claims if requested. Any write @@ -1540,18 +1530,13 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) if (unblock_events) disk_unblock_events(disk); - if (mode & FMODE_EXCL) - bdput(claiming); return bdev; abort_claiming: if (mode & FMODE_EXCL) - bd_abort_claiming(bdev, claiming, holder); + bd_abort_claiming(bdev, holder); mutex_unlock(&bdev->bd_mutex); disk_unblock_events(disk); -put_claiming: - if (mode & FMODE_EXCL) - bdput(claiming); put_blkdev: blkdev_put_no_open(bdev); if (ret == -ERESTARTSYS) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5d48b92f5e4348..43a25d855e049a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1988,10 +1988,8 @@ void blkdev_show(struct seq_file *seqf, off_t offset); struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, void *holder); struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder); -int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, - void *holder); -void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, - void *holder); +int bd_prepare_to_claim(struct block_device *bdev, void *holder); +void bd_abort_claiming(struct block_device *bdev, void *holder); void blkdev_put(struct block_device *bdev, fmode_t mode); /* just for blk-cgroup, don't use elsewhere */