| 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 | * Magic value for blkno: |
| 23 | */ |
| 24 | #define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */ |
| 25 | |
| 26 | struct iomap { |
| 27 | sector_t blkno; /* 1st sector of mapping, 512b units */ |
| 28 | loff_t offset; /* file offset of mapping, bytes */ |
| 29 | u64 length; /* length of mapping, bytes */ |
| 30 | int type; /* type of mapping */ |
| 31 | struct block_device *bdev; /* block device for I/O */ |
| 32 | }; |
| 33 | |
| 34 | /* |
| 35 | * Flags for iomap_begin / iomap_end. No flag implies a read. |
| 36 | */ |
| 37 | #define IOMAP_WRITE (1 << 0) |
| 38 | #define IOMAP_ZERO (1 << 1) |
| 39 | |
| 40 | struct iomap_ops { |
| 41 | /* |
| 42 | * Return the existing mapping at pos, or reserve space starting at |
| 43 | * pos for up to length, as long as we can do it as a single mapping. |
| 44 | * The actual length is returned in iomap->length. |
| 45 | */ |
| 46 | int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, |
| 47 | unsigned flags, struct iomap *iomap); |
| 48 | |
| 49 | /* |
| 50 | * Commit and/or unreserve space previous allocated using iomap_begin. |
| 51 | * Written indicates the length of the successful write operation which |
| 52 | * needs to be commited, while the rest needs to be unreserved. |
| 53 | * Written might be zero if no data was written. |
| 54 | */ |
| 55 | int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, |
| 56 | ssize_t written, unsigned flags, struct iomap *iomap); |
| 57 | }; |
| 58 | |
| 59 | ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, |
| 60 | struct iomap_ops *ops); |
| 61 | int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, |
| 62 | bool *did_zero, struct iomap_ops *ops); |
| 63 | int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, |
| 64 | struct iomap_ops *ops); |
| 65 | int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, |
| 66 | struct iomap_ops *ops); |
| 67 | int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
| 68 | loff_t start, loff_t len, struct iomap_ops *ops); |
| 69 | |
| 70 | #endif /* LINUX_IOMAP_H */ |