Merge remote-tracking branch 'omap_dss2/for-next'
[deliverable/linux.git] / include / linux / iomap.h
1 #ifndef LINUX_IOMAP_H
2 #define LINUX_IOMAP_H 1
3
4 #include <linux/types.h>
5
6 struct fiemap_extent_info;
7 struct inode;
8 struct iov_iter;
9 struct kiocb;
10 struct vm_area_struct;
11 struct vm_fault;
12
13 /*
14 * Types of block ranges for iomap mappings:
15 */
16 #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */
17 #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */
18 #define IOMAP_MAPPED 0x03 /* blocks allocated @blkno */
19 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated @blkno in unwritten state */
20
21 /*
22 * Flags for iomap mappings:
23 */
24 #define IOMAP_F_MERGED 0x01 /* contains multiple blocks/extents */
25
26 /*
27 * Magic value for blkno:
28 */
29 #define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */
30
31 struct iomap {
32 sector_t blkno; /* 1st sector of mapping, 512b units */
33 loff_t offset; /* file offset of mapping, bytes */
34 u64 length; /* length of mapping, bytes */
35 u16 type; /* type of mapping */
36 u16 flags; /* flags for mapping */
37 struct block_device *bdev; /* block device for I/O */
38 };
39
40 /*
41 * Flags for iomap_begin / iomap_end. No flag implies a read.
42 */
43 #define IOMAP_WRITE (1 << 0)
44 #define IOMAP_ZERO (1 << 1)
45
46 struct iomap_ops {
47 /*
48 * Return the existing mapping at pos, or reserve space starting at
49 * pos for up to length, as long as we can do it as a single mapping.
50 * The actual length is returned in iomap->length.
51 */
52 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
53 unsigned flags, struct iomap *iomap);
54
55 /*
56 * Commit and/or unreserve space previous allocated using iomap_begin.
57 * Written indicates the length of the successful write operation which
58 * needs to be commited, while the rest needs to be unreserved.
59 * Written might be zero if no data was written.
60 */
61 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
62 ssize_t written, unsigned flags, struct iomap *iomap);
63 };
64
65 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
66 struct iomap_ops *ops);
67 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
68 bool *did_zero, struct iomap_ops *ops);
69 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
70 struct iomap_ops *ops);
71 int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
72 struct iomap_ops *ops);
73 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
74 loff_t start, loff_t len, struct iomap_ops *ops);
75
76 #endif /* LINUX_IOMAP_H */
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