1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
new file mode 100644
index 000000000..af75a5ee4
--- /dev/null
+++ b/drivers/block/loop.h
@@ -0,0 +1,94 @@
+/*
+ * loop.h
+ *
+ * Written by Theodore Ts'o, 3/29/93.
+ *
+ * Copyright 1993 by Theodore Ts'o.  Redistribution of this file is
+ * permitted under the GNU General Public License.
+ */
+#ifndef _LINUX_LOOP_H
+#define _LINUX_LOOP_H
+
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/kthread.h>
+#include <uapi/linux/loop.h>
+
+/* Possible states of device */
+enum {
+	Lo_unbound,
+	Lo_bound,
+	Lo_rundown,
+};
+
+struct loop_func_table;
+
+struct loop_device {
+	int		lo_number;
+	atomic_t	lo_refcnt;
+	loff_t		lo_offset;
+	loff_t		lo_sizelimit;
+	int		lo_flags;
+	int		(*transfer)(struct loop_device *, int cmd,
+				    struct page *raw_page, unsigned raw_off,
+				    struct page *loop_page, unsigned loop_off,
+				    int size, sector_t real_block);
+	char		lo_file_name[LO_NAME_SIZE];
+	char		lo_crypt_name[LO_NAME_SIZE];
+	char		lo_encrypt_key[LO_KEY_SIZE];
+	int		lo_encrypt_key_size;
+	struct loop_func_table *lo_encryption;
+	__u32           lo_init[2];
+	kuid_t		lo_key_owner;	/* Who set the key */
+	int		(*ioctl)(struct loop_device *, int cmd, 
+				 unsigned long arg); 
+
+	struct file *	lo_backing_file;
+	struct block_device *lo_device;
+	void		*key_data; 
+
+	gfp_t		old_gfp_mask;
+
+	spinlock_t		lo_lock;
+	int			lo_state;
+	struct kthread_worker	worker;
+	struct task_struct	*worker_task;
+	bool			use_dio;
+	bool			sysfs_inited;
+
+	struct request_queue	*lo_queue;
+	struct blk_mq_tag_set	tag_set;
+	struct gendisk		*lo_disk;
+};
+
+struct loop_cmd {
+	struct kthread_work work;
+	bool use_aio; /* use AIO interface to handle I/O */
+	atomic_t ref; /* only for aio */
+	long ret;
+	struct kiocb iocb;
+	struct bio_vec *bvec;
+	struct cgroup_subsys_state *css;
+};
+
+/* Support for loadable transfer modules */
+struct loop_func_table {
+	int number;	/* filter type */ 
+	int (*transfer)(struct loop_device *lo, int cmd,
+			struct page *raw_page, unsigned raw_off,
+			struct page *loop_page, unsigned loop_off,
+			int size, sector_t real_block);
+	int (*init)(struct loop_device *, const struct loop_info64 *); 
+	/* release is called from loop_unregister_transfer or clr_fd */
+	int (*release)(struct loop_device *); 
+	int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
+	struct module *owner;
+}; 
+
+int loop_register_transfer(struct loop_func_table *funcs);
+int loop_unregister_transfer(int number); 
+
+#endif