From 78f35473508118df5ea04b9515ac3f1aaec0a980 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 30 Aug 2017 09:16:38 -0700 Subject: dax: introduce a fs_dax_get_by_bdev() helper Add a helper that can replace the following common pattern: if (blk_queue_dax(bdev->bd_queue)) fs_dax_get_by_host(bdev->bd_disk->disk_name); This will be used to move dax_device lookup from iomap-operation time to fs-mount time. Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Dan Williams --- drivers/dax/super.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/dax/super.c') diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 938eb4868f7f..b699aac268a6 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -46,6 +46,8 @@ void dax_read_unlock(int id) EXPORT_SYMBOL_GPL(dax_read_unlock); #ifdef CONFIG_BLOCK +#include + int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, pgoff_t *pgoff) { @@ -59,6 +61,14 @@ int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, } EXPORT_SYMBOL(bdev_dax_pgoff); +struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) +{ + if (!blk_queue_dax(bdev->bd_queue)) + return NULL; + return fs_dax_get_by_host(bdev->bd_disk->disk_name); +} +EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); + /** * __bdev_dax_supported() - Check if the device supports dax for filesystem * @sb: The superblock of the device -- cgit v1.2.3