Return-Path: linux-nfs-owner@vger.kernel.org Received: from casper.infradead.org ([85.118.1.10]:57876 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751717AbbANJns (ORCPT ); Wed, 14 Jan 2015 04:43:48 -0500 From: Christoph Hellwig To: Jens Axboe Cc: David Howells , Tejun Heo , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org Subject: [PATCH 04/12] block_dev: only write bdev inode on close Date: Wed, 14 Jan 2015 10:42:33 +0100 Message-Id: <1421228561-16857-5-git-send-email-hch@lst.de> In-Reply-To: <1421228561-16857-1-git-send-email-hch@lst.de> References: <1421228561-16857-1-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: Since 018a17bdc865 ("bdi: reimplement bdev_inode_switch_bdi()") the block device code writes out all dirty data whenever switching the backing_dev_info for a block device inode. But a block device inode can only be dirtied when it is in use, which means we only have to write it out on the final blkdev_put, but not when doing a blkdev_get. Factoring out the write out from the bdi list switch prepares from removing the list switch later in the series. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo --- fs/block_dev.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index b48c41b..026ca7b 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -49,6 +49,17 @@ inline struct block_device *I_BDEV(struct inode *inode) } EXPORT_SYMBOL(I_BDEV); +static void bdev_write_inode(struct inode *inode) +{ + spin_lock(&inode->i_lock); + while (inode->i_state & I_DIRTY) { + spin_unlock(&inode->i_lock); + WARN_ON_ONCE(write_inode_now(inode, true)); + spin_lock(&inode->i_lock); + } + spin_unlock(&inode->i_lock); +} + /* * Move the inode from its current bdi to a new bdi. Make sure the inode * is clean before moving so that it doesn't linger on the old bdi. @@ -56,16 +67,10 @@ EXPORT_SYMBOL(I_BDEV); static void bdev_inode_switch_bdi(struct inode *inode, struct backing_dev_info *dst) { - while (true) { - spin_lock(&inode->i_lock); - if (!(inode->i_state & I_DIRTY)) { - inode->i_data.backing_dev_info = dst; - spin_unlock(&inode->i_lock); - return; - } - spin_unlock(&inode->i_lock); - WARN_ON_ONCE(write_inode_now(inode, true)); - } + spin_lock(&inode->i_lock); + WARN_ON_ONCE(inode->i_state & I_DIRTY); + inode->i_data.backing_dev_info = dst; + spin_unlock(&inode->i_lock); } /* Kill _all_ buffers and pagecache , dirty or not.. */ @@ -1464,9 +1469,11 @@ static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) WARN_ON_ONCE(bdev->bd_holders); sync_blockdev(bdev); kill_bdev(bdev); - /* ->release can cause the old bdi to disappear, - * so must switch it out first + /* + * ->release can cause the queue to disappear, so flush all + * dirty data before. */ + bdev_write_inode(bdev->bd_inode); bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); } -- 1.9.1