cregit-Linux how code gets into the kernel

Release 4.12 include/linux/iomap.h

Directory: include/linux

#define LINUX_IOMAP_H 1

#include <linux/types.h>

struct fiemap_extent_info;
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 */

 * Flags for all iomap mappings:

#define IOMAP_F_NEW	0x01	
/* blocks have been newly allocated */

 * Flags that only need to be reported for IOMAP_REPORT requests:

#define IOMAP_F_MERGED	0x10	
/* contains multiple blocks/extents */

#define IOMAP_F_SHARED	0x20	
/* block shared with another file */

 * Magic value for blkno:

/* 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 */
u16			type;	/* type of mapping */
u16			flags;	/* flags for mapping */
struct block_device	*bdev;	/* block device for I/O */
struct dax_device	*dax_dev; /* dax_dev for dax operations */

 * Flags for iomap_begin / iomap_end.  No flag implies a read.

#define IOMAP_WRITE		(1 << 0) 
/* writing, must allocate blocks */

#define IOMAP_ZERO		(1 << 1) 
/* zeroing operation, may skip holes */

#define IOMAP_REPORT		(1 << 2) 
/* report extent status, e.g. FIEMAP */

#define IOMAP_FAULT		(1 << 3) 
/* mapping for page fault */

#define IOMAP_DIRECT		(1 << 4) 
/* direct I/O */

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,
		const struct iomap_ops *ops);
int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
		const struct iomap_ops *ops);
int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
		bool *did_zero, const struct iomap_ops *ops);
int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
		const struct iomap_ops *ops);
int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops);
int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		loff_t start, loff_t len, const struct iomap_ops *ops);

 * Flags for direct I/O ->end_io:

#define IOMAP_DIO_UNWRITTEN	(1 << 0)	
/* covers unwritten extent(s) */

#define IOMAP_DIO_COW		(1 << 1)	
/* covers COW extent(s) */

typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
		unsigned flags);
ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
		const struct iomap_ops *ops, iomap_dio_end_io_t end_io);

#endif /* LINUX_IOMAP_H */

Overall Contributors

Christoph Hellwig36896.59%975.00%
Dan J Williams61.57%18.33%
Jan Kara51.31%18.33%
Darrick J. Wong20.52%18.33%
Directory: include/linux
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.