Hello, On Thu, Jan 08, 2015 at 06:45:25PM +0100, Christoph Hellwig wrote: > Since "bdi: reimplement bdev_inode_switch_bdi()" the block device code 018a17bdc865 ("bdi: reimplement bdev_inode_switch_bdi()") would be better. > 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. > @@ -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 disappaear, so flush all ^^^^^ typo > + * dirty data before. > */ > + bdev_write_inode(bdev->bd_inode); Is this an optimization or something necessary for the following changes? If latter, maybe it's a good idea to state why this is necessary in the description? Otherwise, Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html