md: port block device access to file

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-4-adbd023e19cc@kernel.orgReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

drivers/md/dm.c

@@ -726,7 +726,8 @@ static struct table_device *open_table_device(struct mapped_device *md,
 		dev_t dev, blk_mode_t mode)
 {
 	struct table_device *td;
-	struct bdev_handle *bdev_handle;
+	struct file *bdev_file;
+	struct block_device *bdev;
 	u64 part_off;
 	int r;
 
@@ -735,34 +736,36 @@ static struct table_device *open_table_device(struct mapped_device *md,
 		return ERR_PTR(-ENOMEM);
 	refcount_set(&td->count, 1);
 
-	bdev_handle = bdev_open_by_dev(dev, mode, _dm_claim_ptr, NULL);
-	if (IS_ERR(bdev_handle)) {
-		r = PTR_ERR(bdev_handle);
+	bdev_file = bdev_file_open_by_dev(dev, mode, _dm_claim_ptr, NULL);
+	if (IS_ERR(bdev_file)) {
+		r = PTR_ERR(bdev_file);
 		goto out_free_td;
 	}
 
+	bdev = file_bdev(bdev_file);
+
 	/*
 	 * We can be called before the dm disk is added.  In that case we can't
 	 * register the holder relation here.  It will be done once add_disk was
 	 * called.
 	 */
 	if (md->disk->slave_dir) {
-		r = bd_link_disk_holder(bdev_handle->bdev, md->disk);
+		r = bd_link_disk_holder(bdev, md->disk);
 		if (r)
 			goto out_blkdev_put;
 	}
 
 	td->dm_dev.mode = mode;
-	td->dm_dev.bdev = bdev_handle->bdev;
-	td->dm_dev.bdev_handle = bdev_handle;
-	td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev_handle->bdev, &part_off,
+	td->dm_dev.bdev = bdev;
+	td->dm_dev.bdev_file = bdev_file;
+	td->dm_dev.dax_dev = fs_dax_get_by_bdev(bdev, &part_off,
 						NULL, NULL);
 	format_dev_t(td->dm_dev.name, dev);
 	list_add(&td->list, &md->table_devices);
 	return td;
 
 out_blkdev_put:
-	bdev_release(bdev_handle);
+	fput(bdev_file);
 out_free_td:
 	kfree(td);
 	return ERR_PTR(r);
@@ -775,7 +778,7 @@ static void close_table_device(struct table_device *td, struct mapped_device *md
 {
 	if (md->disk->slave_dir)
 		bd_unlink_disk_holder(td->dm_dev.bdev, md->disk);
-	bdev_release(td->dm_dev.bdev_handle);
+	fput(td->dm_dev.bdev_file);
 	put_dax(td->dm_dev.dax_dev);
 	list_del(&td->list);
 	kfree(td);

drivers/md/md.c

@@ -2578,7 +2578,7 @@ static void export_rdev(struct md_rdev *rdev, struct mddev *mddev)
 	if (test_bit(AutoDetected, &rdev->flags))
 		md_autodetect_dev(rdev->bdev->bd_dev);
 #endif
-	bdev_release(rdev->bdev_handle);
+	fput(rdev->bdev_file);
 	rdev->bdev = NULL;
 	kobject_put(&rdev->kobj);
 }
@@ -3773,16 +3773,16 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 	if (err)
 		goto out_clear_rdev;
 
-	rdev->bdev_handle = bdev_open_by_dev(newdev,
+	rdev->bdev_file = bdev_file_open_by_dev(newdev,
 			BLK_OPEN_READ | BLK_OPEN_WRITE,
 			super_format == -2 ? &claim_rdev : rdev, NULL);
-	if (IS_ERR(rdev->bdev_handle)) {
+	if (IS_ERR(rdev->bdev_file)) {
 		pr_warn("md: could not open device unknown-block(%u,%u).\n",
 			MAJOR(newdev), MINOR(newdev));
-		err = PTR_ERR(rdev->bdev_handle);
+		err = PTR_ERR(rdev->bdev_file);
 		goto out_clear_rdev;
 	}
-	rdev->bdev = rdev->bdev_handle->bdev;
+	rdev->bdev = file_bdev(rdev->bdev_file);
 
 	kobject_init(&rdev->kobj, &rdev_ktype);
 
@@ -3813,7 +3813,7 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 	return rdev;
 
 out_blkdev_put:
-	bdev_release(rdev->bdev_handle);
+	fput(rdev->bdev_file);
 out_clear_rdev:
 	md_rdev_clear(rdev);
 out_free_rdev:

drivers/md/md.h

@@ -59,7 +59,7 @@ struct md_rdev {
 	 */
 	struct block_device *meta_bdev;
 	struct block_device *bdev;	/* block device handle */
-	struct bdev_handle *bdev_handle;	/* Handle from open for bdev */
+	struct file *bdev_file;		/* Handle from open for bdev */
 
 	struct page	*sb_page, *bb_page;
 	int		sb_loaded;

include/linux/device-mapper.h

@@ -165,7 +165,7 @@ void dm_error(const char *message);
 
 struct dm_dev {
 	struct block_device *bdev;
-	struct bdev_handle *bdev_handle;
+	struct file *bdev_file;
 	struct dax_device *dax_dev;
 	blk_mode_t mode;
 	char name[16];