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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_IOMAP_H
#define LINUX_IOMAP_H 1
#include <linux/atomic.h>
#include <linux/bitmap.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/mm_types.h>
struct address_space;
struct fiemap_extent_info;
struct inode;
struct iov_iter;
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_BUFFER_HEAD 0x04 /* file system requires buffer heads */
/*
* 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 */
#define IOMAP_DIRECT (1 << 4) /* direct I/O */
#define IOMAP_NOWAIT (1 << 5) /* do not block */
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);
};
/*
* Structure allocate for each page when block size < PAGE_SIZE to track
* sub-page uptodate status and I/O completions.
*/
struct iomap_page {
atomic_t read_count;
atomic_t write_count;
DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);
};
static inline struct iomap_page *to_iomap_page(struct page *page)
{
if (page_has_private(page))
return (struct iomap_page *)page_private(page);
return NULL;
}
ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
const struct iomap_ops *ops);
int iomap_readpage(struct page *page, const struct iomap_ops *ops);
int iomap_readpages(struct address_space *mapping, struct list_head *pages,
unsigned nr_pages, const struct iomap_ops *ops);
int iomap_set_page_dirty(struct page *page);
int iomap_is_partially_uptodate(struct page *page, unsigned long from,
unsigned long count);
int iomap_releasepage(struct page *page, gfp_t gfp_mask);
void iomap_invalidatepage(struct page *page, unsigned int offset,
unsigned int len);
#ifdef CONFIG_MIGRATION
int iomap_migrate_page(struct address_space *mapping, struct page *newpage,
struct page *page, enum migrate_mode mode);
#else
#define iomap_migrate_page NULL
#endif
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);
vm_fault_t 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);
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);
sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
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);
int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
#ifdef CONFIG_SWAP
struct file;
struct swap_info_struct;
int iomap_swapfile_activate(struct swap_info_struct *sis,
struct file *swap_file, sector_t *pagespan,
const struct iomap_ops *ops);
#else
# define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO)
#endif /* CONFIG_SWAP */
#endif /* LINUX_IOMAP_H */
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