From ef51042472f55b325fd7f2b26a2e29fd89757234 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 8 May 2017 10:55:27 -0700 Subject: block, dax: move "select DAX" from BLOCK to FS_DAX For configurations that do not enable DAX filesystems or drivers, do not require the DAX core to be built. Given that the 'direct_access' method has been removed from 'block_device_operations', we can also go ahead and remove the block-related dax helper functions from fs/block_dev.c to drivers/dax/super.c. This keeps dax details out of the block layer and lets the DAX core be built as a module in the FS_DAX=n case. Filesystems need to include dax.h to call bdev_dax_supported(). Cc: linux-xfs@vger.kernel.org Cc: Jens Axboe Cc: "Theodore Ts'o" Cc: Matthew Wilcox Cc: Alexander Viro Cc: "Darrick J. Wong" Cc: Ross Zwisler Reviewed-by: Jan Kara Reported-by: Geert Uytterhoeven Signed-off-by: Dan Williams --- fs/block_dev.c | 66 ---------------------------------------------------------- 1 file changed, 66 deletions(-) (limited to 'fs/block_dev.c') diff --git a/fs/block_dev.c b/fs/block_dev.c index 666367e13711..3096ecd48304 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -718,72 +718,6 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL_GPL(bdev_write_page); -int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, - pgoff_t *pgoff) -{ - phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; - - if (pgoff) - *pgoff = PHYS_PFN(phys_off); - if (phys_off % PAGE_SIZE || size % PAGE_SIZE) - return -EINVAL; - return 0; -} -EXPORT_SYMBOL(bdev_dax_pgoff); - -/** - * bdev_dax_supported() - Check if the device supports dax for filesystem - * @sb: The superblock of the device - * @blocksize: The block size of the device - * - * This is a library function for filesystems to check if the block device - * can be mounted with dax option. - * - * Return: negative errno if unsupported, 0 if supported. - */ -int bdev_dax_supported(struct super_block *sb, int blocksize) -{ - struct block_device *bdev = sb->s_bdev; - struct dax_device *dax_dev; - pgoff_t pgoff; - int err, id; - void *kaddr; - pfn_t pfn; - long len; - - if (blocksize != PAGE_SIZE) { - vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); - return -EINVAL; - } - - err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); - if (err) { - vfs_msg(sb, KERN_ERR, "error: unaligned partition for dax"); - return err; - } - - dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); - if (!dax_dev) { - vfs_msg(sb, KERN_ERR, "error: device does not support dax"); - return -EOPNOTSUPP; - } - - id = dax_read_lock(); - len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); - dax_read_unlock(id); - - put_dax(dax_dev); - - if (len < 1) { - vfs_msg(sb, KERN_ERR, - "error: dax access failed (%ld)", len); - return len < 0 ? len : -EIO; - } - - return 0; -} -EXPORT_SYMBOL_GPL(bdev_dax_supported); - /* * pseudo-fs */ -- cgit v1.2.3