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 */ 71