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 #define IOMAP_F_SHARED 0x02 /* block shared with another file */ 26 #define IOMAP_F_NEW 0x04 /* blocks have been newly allocated */ 27 28 /* 29 * Magic value for blkno: 30 */ 31 #define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */ 32 33 struct iomap { 34 sector_t blkno; /* 1st sector of mapping, 512b units */ 35 loff_t offset; /* file offset of mapping, bytes */ 36 u64 length; /* length of mapping, bytes */ 37 u16 type; /* type of mapping */ 38 u16 flags; /* flags for mapping */ 39 struct block_device *bdev; /* block device for I/O */ 40 }; 41 42 /* 43 * Flags for iomap_begin / iomap_end. No flag implies a read. 44 */ 45 #define IOMAP_WRITE (1 << 0) 46 #define IOMAP_ZERO (1 << 1) 47 48 struct iomap_ops { 49 /* 50 * Return the existing mapping at pos, or reserve space starting at 51 * pos for up to length, as long as we can do it as a single mapping. 52 * The actual length is returned in iomap->length. 53 */ 54 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 55 unsigned flags, struct iomap *iomap); 56 57 /* 58 * Commit and/or unreserve space previous allocated using iomap_begin. 59 * Written indicates the length of the successful write operation which 60 * needs to be commited, while the rest needs to be unreserved. 61 * Written might be zero if no data was written. 62 */ 63 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 64 ssize_t written, unsigned flags, struct iomap *iomap); 65 }; 66 67 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 68 struct iomap_ops *ops); 69 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 70 struct iomap_ops *ops); 71 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 72 bool *did_zero, struct iomap_ops *ops); 73 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 74 struct iomap_ops *ops); 75 int iomap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, 76 struct iomap_ops *ops); 77 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 78 loff_t start, loff_t len, struct iomap_ops *ops); 79 80 #endif /* LINUX_IOMAP_H */ 81