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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
7 struct fiemap_extent_info;
8 struct inode;
9 struct iov_iter;
10 struct kiocb;
11 struct vm_area_struct;
12 struct 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
44 struct 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
64 struct 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
83 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
84 const struct iomap_ops *ops);
85 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
86 const struct iomap_ops *ops);
87 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
88 bool *did_zero, const struct iomap_ops *ops);
89 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
90 const struct iomap_ops *ops);
91 int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops);
92 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
93 loff_t start, loff_t len, const struct iomap_ops *ops);
94 loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
95 const struct iomap_ops *ops);
96 loff_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) */
104 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
105 unsigned flags);
106 ssize_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 */