[mirror_ubuntu-bionic-kernel.git] / include / linux / iomap.h

#ifndef LINUX_IOMAP_H
#define LINUX_IOMAP_H 1

#include <linux/types.h>

struct inode;
struct iov_iter;
struct kiocb;
struct vm_area_struct;
struct vm_fault;

/*
 * Types of block ranges for iomap mappings:
 */
#define IOMAP_HOLE	0x01	/* no blocks allocated, need allocation */
#define IOMAP_DELALLOC	0x02	/* delayed allocation blocks */
#define IOMAP_MAPPED	0x03	/* blocks allocated @blkno */
#define IOMAP_UNWRITTEN	0x04	/* blocks allocated @blkno in unwritten state */

/*
 * Magic value for blkno:
 */
#define IOMAP_NULL_BLOCK -1LL	/* blkno is not valid */

struct iomap {
	sector_t		blkno;	/* 1st sector of mapping, 512b units */
	loff_t			offset;	/* file offset of mapping, bytes */
	u64			length;	/* length of mapping, bytes */
	int			type;	/* type of mapping */
	struct block_device	*bdev;	/* block device for I/O */
};

/*
 * Flags for iomap_begin / iomap_end.  No flag implies a read.
 */
#define IOMAP_WRITE		(1 << 0)
#define IOMAP_ZERO		(1 << 1)

struct iomap_ops {
	/*
	 * Return the existing mapping at pos, or reserve space starting at
	 * pos for up to length, as long as we can do it as a single mapping.
	 * The actual length is returned in iomap->length.
	 */
	int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
			unsigned flags, struct iomap *iomap);

	/*
	 * Commit and/or unreserve space previous allocated using iomap_begin.
	 * Written indicates the length of the successful write operation which
	 * needs to be commited, while the rest needs to be unreserved.
	 * Written might be zero if no data was written.
	 */
	int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
			ssize_t written, unsigned flags, struct iomap *iomap);
};

ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
		struct iomap_ops *ops);
int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
		bool *did_zero, struct iomap_ops *ops);
int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
		struct iomap_ops *ops);
int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
		struct iomap_ops *ops);

#endif /* LINUX_IOMAP_H */
Commit	Line	Data
199a31c6 CH	1	#ifndef LINUX_IOMAP_H
	2	#define LINUX_IOMAP_H 1
	3
	4	#include <linux/types.h>
	5
ae259a9c CH	6	struct inode;
	7	struct iov_iter;
	8	struct kiocb;
	9	struct vm_area_struct;
	10	struct vm_fault;
	11
	12	/*
	13	* Types of block ranges for iomap mappings:
	14	*/
199a31c6 CH	15	#define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */
	16	#define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */
	17	#define IOMAP_MAPPED 0x03 /* blocks allocated @blkno */
	18	#define IOMAP_UNWRITTEN 0x04 /* blocks allocated @blkno in unwritten state */
	19
ae259a9c CH	20	/*
	21	* Magic value for blkno:
	22	*/
199a31c6 CH	23	#define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */
	24
	25	struct iomap {
ae259a9c CH	26	sector_t blkno; /* 1st sector of mapping, 512b units */
	27	loff_t offset; /* file offset of mapping, bytes */
	28	u64 length; /* length of mapping, bytes */
	29	int type; /* type of mapping */
	30	struct block_device bdev; / block device for I/O */
	31	};
	32
	33	/*
	34	* Flags for iomap_begin / iomap_end. No flag implies a read.
	35	*/
	36	#define IOMAP_WRITE (1 << 0)
	37	#define IOMAP_ZERO (1 << 1)
	38
	39	struct iomap_ops {
	40	/*
	41	* Return the existing mapping at pos, or reserve space starting at
	42	* pos for up to length, as long as we can do it as a single mapping.
	43	* The actual length is returned in iomap->length.
	44	*/
	45	int (iomap_begin)(struct inode inode, loff_t pos, loff_t length,
	46	unsigned flags, struct iomap *iomap);
	47
	48	/*
	49	* Commit and/or unreserve space previous allocated using iomap_begin.
	50	* Written indicates the length of the successful write operation which
	51	* needs to be commited, while the rest needs to be unreserved.
	52	* Written might be zero if no data was written.
	53	*/
	54	int (iomap_end)(struct inode inode, loff_t pos, loff_t length,
	55	ssize_t written, unsigned flags, struct iomap *iomap);
199a31c6 CH	56	};
199a31c6 CH	57
ae259a9c CH	58	ssize_t iomap_file_buffered_write(struct kiocb iocb, struct iov_iter from,
	59	struct iomap_ops *ops);
	60	int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
	61	bool did_zero, struct iomap_ops ops);
	62	int iomap_truncate_page(struct inode inode, loff_t pos, bool did_zero,
	63	struct iomap_ops *ops);
	64	int iomap_page_mkwrite(struct vm_area_struct vma, struct vm_fault vmf,
	65	struct iomap_ops *ops);
	66
199a31c6	67	#endif /* LINUX_IOMAP_H */