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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_IOMAP_H
3#define LINUX_IOMAP_H 1
4
5#include <linux/types.h>
6
7struct fiemap_extent_info;
8struct inode;
9struct iov_iter;
10struct kiocb;
11struct vm_area_struct;
12struct vm_fault;
13
14/*
15 * Types of block ranges for iomap mappings:
16 */
17#define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */
18#define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */
19#define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */
20#define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */
21
22/*
23 * Flags for all iomap mappings:
24 *
25 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
26 * written data and requires fdatasync to commit them to persistent storage.
27 */
28#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
29#define IOMAP_F_BOUNDARY 0x02 /* mapping ends at metadata boundary */
30#define IOMAP_F_DIRTY 0x04 /* uncommitted metadata */
31
32/*
33 * Flags that only need to be reported for IOMAP_REPORT requests:
34 */
35#define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
36#define IOMAP_F_SHARED 0x20 /* block shared with another file */
37#define IOMAP_F_DATA_INLINE 0x40 /* data inline in the inode */
38
39/*
40 * Magic value for addr:
41 */
42#define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
43
44struct iomap {
45 u64 addr; /* disk offset of mapping, bytes */
46 loff_t offset; /* file offset of mapping, bytes */
47 u64 length; /* length of mapping, bytes */
48 u16 type; /* type of mapping */
49 u16 flags; /* flags for mapping */
50 struct block_device *bdev; /* block device for I/O */
51 struct dax_device *dax_dev; /* dax_dev for dax operations */
52};
53
54/*
55 * Flags for iomap_begin / iomap_end. No flag implies a read.
56 */
57#define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
58#define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
59#define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
60#define IOMAP_FAULT (1 << 3) /* mapping for page fault */
61#define IOMAP_DIRECT (1 << 4) /* direct I/O */
62#define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */
63
64struct iomap_ops {
65 /*
66 * Return the existing mapping at pos, or reserve space starting at
67 * pos for up to length, as long as we can do it as a single mapping.
68 * The actual length is returned in iomap->length.
69 */
70 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
71 unsigned flags, struct iomap *iomap);
72
73 /*
74 * Commit and/or unreserve space previous allocated using iomap_begin.
75 * Written indicates the length of the successful write operation which
76 * needs to be commited, while the rest needs to be unreserved.
77 * Written might be zero if no data was written.
78 */
79 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
80 ssize_t written, unsigned flags, struct iomap *iomap);
81};
82
83ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
84 const struct iomap_ops *ops);
85int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
86 const struct iomap_ops *ops);
87int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
88 bool *did_zero, const struct iomap_ops *ops);
89int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
90 const struct iomap_ops *ops);
91int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops);
92int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
93 loff_t start, loff_t len, const struct iomap_ops *ops);
94loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
95 const struct iomap_ops *ops);
96loff_t iomap_seek_data(struct inode *inode, loff_t offset,
97 const struct iomap_ops *ops);
98
99/*
100 * Flags for direct I/O ->end_io:
101 */
102#define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
103#define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
104typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
105 unsigned flags);
106ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
107 const struct iomap_ops *ops, iomap_dio_end_io_t end_io);
108
109#endif /* LINUX_IOMAP_H */