fs: allow per-device dax status checking for filesystems

Change bdev_dax_supported so it takes a bdev parameter.  This enables
multi-device filesystems like xfs to check that a dax device can work for
the particular filesystem.  Once that's in place, actually fix all the
parts of XFS where we need to be able to distinguish between datadev and
rtdev.

This patch fixes the problem where we screw up the dax support checking
in xfs if the datadev and rtdev have different dax capabilities.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[rez: Re-added __bdev_dax_supported() for !CONFIG_FS_DAX cases]
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>

1 files changed, 13 insertions, 13 deletions

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 2b2332b605e4..3943feb9a090 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -74,7 +74,7 @@ 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
+ * @bdev: block device to check
  * @blocksize: The block size of the device
  *
  * This is a library function for filesystems to check if the block device
@@ -82,33 +82,33 @@ EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
  *
  * Return: negative errno if unsupported, 0 if supported.
  */
-int __bdev_dax_supported(struct super_block *sb, int blocksize)
+int __bdev_dax_supported(struct block_device *bdev, 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;
+	char buf[BDEVNAME_SIZE];
 
 	if (blocksize != PAGE_SIZE) {
-		pr_debug("VFS (%s): error: unsupported blocksize for dax\n",
-				sb->s_id);
+		pr_debug("%s: error: unsupported blocksize for dax\n",
+				bdevname(bdev, buf));
 		return -EINVAL;
 	}
 
 	err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff);
 	if (err) {
-		pr_debug("VFS (%s): error: unaligned partition for dax\n",
-				sb->s_id);
+		pr_debug("%s: error: unaligned partition for dax\n",
+				bdevname(bdev, buf));
 		return err;
 	}
 
 	dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
 	if (!dax_dev) {
-		pr_debug("VFS (%s): error: device does not support dax\n",
-				sb->s_id);
+		pr_debug("%s: error: device does not support dax\n",
+				bdevname(bdev, buf));
 		return -EOPNOTSUPP;
 	}
 
@@ -119,8 +119,8 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 	put_dax(dax_dev);
 
 	if (len < 1) {
-		pr_debug("VFS (%s): error: dax access failed (%ld)\n",
-				sb->s_id, len);
+		pr_debug("%s: error: dax access failed (%ld)\n",
+				bdevname(bdev, buf), len);
 		return len < 0 ? len : -EIO;
 	}
 
@@ -137,8 +137,8 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 	} else if (pfn_t_devmap(pfn)) {
 		/* pass */;
 	} else {
-		pr_debug("VFS (%s): error: dax support not enabled\n",
-				sb->s_id);
+		pr_debug("%s: error: dax support not enabled\n",
+				bdevname(bdev, buf));
 		return -EOPNOTSUPP;
 	}