From 564f00f6c03a9339c259eb71a5b3aa8ef7ff1c2e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 14 Jan 2015 10:42:33 +0100 Subject: block_dev: only write bdev inode on close 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 Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/block_dev.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) (limited to 'fs/block_dev.c') diff --git a/fs/block_dev.c b/fs/block_dev.c index b48c41bf0f86..026ca7b8431c 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); } -- cgit v1.2.3