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authorDan Williams <dan.j.williams@intel.com>2017-05-08 10:55:27 -0700
committerDan Williams <dan.j.williams@intel.com>2017-05-08 10:55:27 -0700
commitef51042472f55b325fd7f2b26a2e29fd89757234 (patch)
treead814d3a1537f69b6ca54c0417260324e8f1a6eb /fs/block_dev.c
parent74d71a01abef37f71d914f2105a4cb8712a2beb8 (diff)
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 <axboe@kernel.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r--fs/block_dev.c66
1 files changed, 0 insertions, 66 deletions
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
*/