From: Dan Williams Subject: [PATCH v3 1/4] dax: introduce a fs_dax_get_by_bdev() helper Date: Wed, 30 Aug 2017 12:43:52 -0700 Message-ID: <150412223265.10177.11004612169458058274.stgit@dwillia2-desk3.amr.corp.intel.com> References: <150412222686.10177.8031279869867070772.stgit@dwillia2-desk3.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jan Kara , Christoph Hellwig , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org To: linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <150412222686.10177.8031279869867070772.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org 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. Cc: Jan Kara Cc: Christoph Hellwig Signed-off-by: Dan Williams --- drivers/dax/super.c | 10 ++++++++++ include/linux/dax.h | 6 ++++++ 2 files changed, 16 insertions(+) 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 diff --git a/include/linux/dax.h b/include/linux/dax.h index df97b7af7e2c..ac8afa18f707 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -57,6 +57,7 @@ static inline void fs_put_dax(struct dax_device *dax_dev) put_dax(dax_dev); } +struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); #else static inline int bdev_dax_supported(struct super_block *sb, int blocksize) { @@ -71,6 +72,11 @@ static inline struct dax_device *fs_dax_get_by_host(const char *host) static inline void fs_put_dax(struct dax_device *dax_dev) { } + +static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) +{ + return NULL; +} #endif int dax_read_lock(void);