From patchwork Tue Nov 24 13:27:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11928833 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 8F25BC56201 for ; Tue, 24 Nov 2020 13:28:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E7A162087D for ; Tue, 24 Nov 2020 13:28:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y1N/2HD3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7A162087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C10C96B00D6; Tue, 24 Nov 2020 08:28:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BBABA6B00D7; Tue, 24 Nov 2020 08:28:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A0FE46B00D8; Tue, 24 Nov 2020 08:28:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0178.hostedemail.com [216.40.44.178]) by kanga.kvack.org (Postfix) with ESMTP id 844D56B00D6 for ; Tue, 24 Nov 2020 08:28:32 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4A5791EE6 for ; Tue, 24 Nov 2020 13:28:32 +0000 (UTC) X-FDA: 77519391264.14.sofa17_3e005ce2736e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id 1BA9A18229835 for ; Tue, 24 Nov 2020 13:28:32 +0000 (UTC) X-HE-Tag: sofa17_3e005ce2736e X-Filterd-Recvd-Size: 9733 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf31.hostedemail.com (Postfix) with ESMTP for ; Tue, 24 Nov 2020 13:28:31 +0000 (UTC) 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=/wu2CSHeB3Gl/t7r+Aw3SS2grYZ13bhBv8r8IW86TqI=; b=Y1N/2HD33Uav08FYSVkGnaVSHI WPlSFEuXLyQhBcuSLeIqr73yqS6AW4O7CCXgYlwLqk7PRnfEAxOgc5ebT2zGe/Q4jDKj1TZml5KW6 zxuduAnEcRYNXRLJfNfoVEqB7dvLowMzijO8QeIjl6QFuGAlKHuyv25WN4tJ8QUrAbMO9TBEVtuQZ BjmoIXu0ikoriwKuMSaI9W6uv3yCs3/9OxRgQnCKwZGoy0qYl1OR9rpx0/icb21Cc4JuTljr3xVK/ lAjKL1pMZ8mwxFgvHH2tqEwyW4bK8qHE278Pz0q8BuTy3VF1zNvkF7La7YPUW8Bcc35jmJRRWkLo3 3nOUSf4A==; Received: from [2001:4bb8:180:5443:c70:4a89:bc61:3] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1khYMS-0006UY-Of; Tue, 24 Nov 2020 13:28:01 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Tejun Heo , Josef Bacik , Konrad Rzeszutek Wilk , Coly Li , Mike Snitzer , Greg Kroah-Hartman , Jan Kara , Johannes Thumshirn , dm-devel@redhat.com, Richard Weinberger , Jan Kara , linux-block@vger.kernel.org, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 04/45] fs: simplify freeze_bdev/thaw_bdev Date: Tue, 24 Nov 2020 14:27:10 +0100 Message-Id: <20201124132751.3747337-5-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201124132751.3747337-1-hch@lst.de> References: <20201124132751.3747337-1-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-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Store the frozen superblock in struct block_device to avoid the awkward interface that can return a sb only used a cookie, an ERR_PTR or NULL. Signed-off-by: Christoph Hellwig Acked-by: Chao Yu --- drivers/md/dm-core.h | 5 ----- drivers/md/dm.c | 20 ++++++-------------- fs/block_dev.c | 39 ++++++++++++++++----------------------- fs/buffer.c | 2 +- fs/ext4/ioctl.c | 2 +- fs/f2fs/file.c | 14 +++++--------- fs/xfs/xfs_fsops.c | 7 ++----- include/linux/blk_types.h | 1 + include/linux/blkdev.h | 4 ++-- 9 files changed, 34 insertions(+), 60 deletions(-) diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index d522093cb39dda..aace147effcacb 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -96,11 +96,6 @@ struct mapped_device { */ struct workqueue_struct *wq; - /* - * freeze/thaw support require holding onto a super block - */ - struct super_block *frozen_sb; - /* forced geometry settings */ struct hd_geometry geometry; diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 54739f1b579bc8..50541d336c719b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2392,27 +2392,19 @@ static int lock_fs(struct mapped_device *md) { int r; - WARN_ON(md->frozen_sb); + WARN_ON(test_bit(DMF_FROZEN, &md->flags)); - md->frozen_sb = freeze_bdev(md->bdev); - if (IS_ERR(md->frozen_sb)) { - r = PTR_ERR(md->frozen_sb); - md->frozen_sb = NULL; - return r; - } - - set_bit(DMF_FROZEN, &md->flags); - - return 0; + r = freeze_bdev(md->bdev); + if (!r) + set_bit(DMF_FROZEN, &md->flags); + return r; } static void unlock_fs(struct mapped_device *md) { if (!test_bit(DMF_FROZEN, &md->flags)) return; - - thaw_bdev(md->bdev, md->frozen_sb); - md->frozen_sb = NULL; + thaw_bdev(md->bdev); clear_bit(DMF_FROZEN, &md->flags); } diff --git a/fs/block_dev.c b/fs/block_dev.c index d8664f5c1ff669..60492620d51866 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -548,55 +548,47 @@ EXPORT_SYMBOL(fsync_bdev); * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze * actually. */ -struct super_block *freeze_bdev(struct block_device *bdev) +int freeze_bdev(struct block_device *bdev) { struct super_block *sb; int error = 0; mutex_lock(&bdev->bd_fsfreeze_mutex); - if (++bdev->bd_fsfreeze_count > 1) { - /* - * We don't even need to grab a reference - the first call - * to freeze_bdev grab an active reference and only the last - * thaw_bdev drops it. - */ - sb = get_super(bdev); - if (sb) - drop_super(sb); - mutex_unlock(&bdev->bd_fsfreeze_mutex); - return sb; - } + if (++bdev->bd_fsfreeze_count > 1) + goto done; sb = get_active_super(bdev); if (!sb) - goto out; + goto sync; if (sb->s_op->freeze_super) error = sb->s_op->freeze_super(sb); else error = freeze_super(sb); + deactivate_super(sb); + if (error) { - deactivate_super(sb); bdev->bd_fsfreeze_count--; - mutex_unlock(&bdev->bd_fsfreeze_mutex); - return ERR_PTR(error); + goto done; } - deactivate_super(sb); - out: + bdev->bd_fsfreeze_sb = sb; + +sync: sync_blockdev(bdev); +done: mutex_unlock(&bdev->bd_fsfreeze_mutex); - return sb; /* thaw_bdev releases s->s_umount */ + return error; /* thaw_bdev releases s->s_umount */ } EXPORT_SYMBOL(freeze_bdev); /** * thaw_bdev -- unlock filesystem * @bdev: blockdevice to unlock - * @sb: associated superblock * * Unlocks the filesystem and marks it writeable again after freeze_bdev(). */ -int thaw_bdev(struct block_device *bdev, struct super_block *sb) +int thaw_bdev(struct block_device *bdev) { + struct super_block *sb; int error = -EINVAL; mutex_lock(&bdev->bd_fsfreeze_mutex); @@ -607,6 +599,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) if (--bdev->bd_fsfreeze_count > 0) goto out; + sb = bdev->bd_fsfreeze_sb; if (!sb) goto out; @@ -618,7 +611,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb) bdev->bd_fsfreeze_count++; out: mutex_unlock(&bdev->bd_fsfreeze_mutex); - return error; + return 0; } EXPORT_SYMBOL(thaw_bdev); diff --git a/fs/buffer.c b/fs/buffer.c index 23f645657488ba..a7595ada9400ff 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -523,7 +523,7 @@ static int osync_buffers_list(spinlock_t *lock, struct list_head *list) void emergency_thaw_bdev(struct super_block *sb) { - while (sb->s_bdev && !thaw_bdev(sb->s_bdev, sb)) + while (sb->s_bdev && !thaw_bdev(sb->s_bdev)) printk(KERN_WARNING "Emergency Thaw on %pg\n", sb->s_bdev); } diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index f0381876a7e5b0..524e134324475e 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -624,7 +624,7 @@ static int ext4_shutdown(struct super_block *sb, unsigned long arg) case EXT4_GOING_FLAGS_DEFAULT: freeze_bdev(sb->s_bdev); set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags); - thaw_bdev(sb->s_bdev, sb); + thaw_bdev(sb->s_bdev); break; case EXT4_GOING_FLAGS_LOGFLUSH: set_bit(EXT4_FLAGS_SHUTDOWN, &sbi->s_ext4_flags); diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index ee861c6d9ff026..a9fc482a0e60a5 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2230,16 +2230,12 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg) switch (in) { case F2FS_GOING_DOWN_FULLSYNC: - sb = freeze_bdev(sb->s_bdev); - if (IS_ERR(sb)) { - ret = PTR_ERR(sb); + ret = freeze_bdev(sb->s_bdev); + if (ret) goto out; - } - if (sb) { - f2fs_stop_checkpoint(sbi, false); - set_sbi_flag(sbi, SBI_IS_SHUTDOWN); - thaw_bdev(sb->s_bdev, sb); - } + f2fs_stop_checkpoint(sbi, false); + set_sbi_flag(sbi, SBI_IS_SHUTDOWN); + thaw_bdev(sb->s_bdev); break; case F2FS_GOING_DOWN_METASYNC: /* do checkpoint only */ diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index ef1d5bb88b93ab..b7c5783a031c69 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -433,13 +433,10 @@ xfs_fs_goingdown( { switch (inflags) { case XFS_FSOP_GOING_FLAGS_DEFAULT: { - struct super_block *sb = freeze_bdev(mp->m_super->s_bdev); - - if (sb && !IS_ERR(sb)) { + if (!freeze_bdev(mp->m_super->s_bdev)) { xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT); - thaw_bdev(sb->s_bdev, sb); + thaw_bdev(mp->m_super->s_bdev); } - break; } case XFS_FSOP_GOING_FLAGS_LOGFLUSH: diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index d9b69bbde5cc54..ebfb4e7c1fd125 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -46,6 +46,7 @@ struct block_device { int bd_fsfreeze_count; /* Mutex for freeze */ struct mutex bd_fsfreeze_mutex; + struct super_block *bd_fsfreeze_sb; } __randomize_layout; /* diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 05b346a68c2eee..12810a19edebc4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -2020,7 +2020,7 @@ static inline int sync_blockdev(struct block_device *bdev) #endif int fsync_bdev(struct block_device *bdev); -struct super_block *freeze_bdev(struct block_device *bdev); -int thaw_bdev(struct block_device *bdev, struct super_block *sb); +int freeze_bdev(struct block_device *bdev); +int thaw_bdev(struct block_device *bdev); #endif /* _LINUX_BLKDEV_H */