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 all iomap mappings: 23 */ 24 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 25 26 /* 27 * Flags that only need to be reported for IOMAP_REPORT requests: 28 */ 29 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 30 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 31 32 /* 33 * Magic value for blkno: 34 */ 35 #define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */ 36 37 struct iomap { 38 sector_t blkno; /* 1st sector of mapping, 512b units */ 39 loff_t offset; /* file offset of mapping, bytes */ 40 u64 length; /* length of mapping, bytes */ 41 u16 type; /* type of mapping */ 42 u16 flags; /* flags for mapping */ 43 struct block_device *bdev; /* block device for I/O */ 44 struct dax_device *dax_dev; /* dax_dev for dax operations */ 45 }; 46 47 /* 48 * Flags for iomap_begin / iomap_end. No flag implies a read. 49 */ 50 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 51 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 52 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 53 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 54 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 55 56 struct iomap_ops { 57 /* 58 * Return the existing mapping at pos, or reserve space starting at 59 * pos for up to length, as long as we can do it as a single mapping. 60 * The actual length is returned in iomap->length. 61 */ 62 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 63 unsigned flags, struct iomap *iomap); 64 65 /* 66 * Commit and/or unreserve space previous allocated using iomap_begin. 67 * Written indicates the length of the successful write operation which 68 * needs to be commited, while the rest needs to be unreserved. 69 * Written might be zero if no data was written. 70 */ 71 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 72 ssize_t written, unsigned flags, struct iomap *iomap); 73 }; 74 75 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 76 const struct iomap_ops *ops); 77 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 78 const struct iomap_ops *ops); 79 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 80 bool *did_zero, const struct iomap_ops *ops); 81 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 82 const struct iomap_ops *ops); 83 int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); 84 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 85 loff_t start, loff_t len, const struct iomap_ops *ops); 86 87 /* 88 * Flags for direct I/O ->end_io: 89 */ 90 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 91 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 92 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, 93 unsigned flags); 94 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 95 const struct iomap_ops *ops, iomap_dio_end_io_t end_io); 96 97 #endif /* LINUX_IOMAP_H */ 98