Current File : //usr/src/kernels/3.10.0-1160.81.1.el7.centos.plus.x86_64/include/linux/iomap.h
#ifndef LINUX_IOMAP_H
#define LINUX_IOMAP_H 1
#include <linux/types.h>
#ifndef __GENKSYMS__
#include <linux/aio.h>
#endif
struct fiemap_extent_info;
struct inode;
struct kiocb;
struct page;
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 at @addr */
#define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */
#define IOMAP_INLINE 0x05 /* data inline in the inode */
/*
* Flags for all iomap mappings:
*
* IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
* written data and requires fdatasync to commit them to persistent storage.
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
#define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */
#define IOMAP_F_SIZE_CHANGED 0x08 /* file size has changed */
/*
* 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 */
/*
* Flags from 0x1000 up are for file system specific usage:
*/
#define IOMAP_F_PRIVATE 0x1000
/*
* Magic value for addr:
*/
#define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
struct iomap_page_ops;
struct iomap {
u64 addr; /* disk offset of mapping, bytes */
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 */
void *inline_data;
void *private; /* filesystem private */
const struct iomap_page_ops *page_ops;
};
/*
* When a filesystem sets page_ops in an iomap mapping it returns, page_prepare
* and page_done will be called for each page written to. This only applies to
* buffered writes as unbuffered writes will not typically have pages
* associated with them.
*
* When page_prepare succeeds, page_done will always be called to do any
* cleanup work necessary. In that page_done call, @page will be NULL if the
* associated page could not be obtained.
*/
struct iomap_page_ops {
int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len,
struct iomap *iomap);
void (*page_done)(struct inode *inode, loff_t pos, unsigned copied,
struct page *page, struct iomap *iomap);
};
/*
* 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 */
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, const struct iovec *iov,
unsigned long nr_segs, loff_t pos, loff_t *ppos,
size_t ocount, 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_area_struct *vma, 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);
loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
const struct iomap_ops *ops);
loff_t iomap_seek_data(struct inode *inode, loff_t offset,
const struct iomap_ops *ops);
#endif /* LINUX_IOMAP_H */
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