1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef LINUX_IOMAP_H 3 #define LINUX_IOMAP_H 1 4 5 #include <linux/types.h> 6 7 struct fiemap_extent_info; 8 struct inode; 9 struct iov_iter; 10 struct kiocb; 11 struct vm_area_struct; 12 struct vm_fault; 13 14 /* 15 * Types of block ranges for iomap mappings: 16 */ 17 #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */ 18 #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */ 19 #define IOMAP_MAPPED 0x03 /* blocks allocated @blkno */ 20 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated @blkno in unwritten state */ 21 22 /* 23 * Flags for all iomap mappings: 24 */ 25 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 26 27 /* 28 * Flags that only need to be reported for IOMAP_REPORT requests: 29 */ 30 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 31 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 32 33 /* 34 * Magic value for blkno: 35 */ 36 #define IOMAP_NULL_BLOCK -1LL /* blkno is not valid */ 37 38 struct iomap { 39 sector_t blkno; /* 1st sector of mapping, 512b units */ 40 loff_t offset; /* file offset of mapping, bytes */ 41 u64 length; /* length of mapping, bytes */ 42 u16 type; /* type of mapping */ 43 u16 flags; /* flags for mapping */ 44 struct block_device *bdev; /* block device for I/O */ 45 struct dax_device *dax_dev; /* dax_dev for dax operations */ 46 }; 47 48 /* 49 * Flags for iomap_begin / iomap_end. No flag implies a read. 50 */ 51 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 52 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 53 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 54 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 55 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 56 #define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */ 57 58 struct iomap_ops { 59 /* 60 * Return the existing mapping at pos, or reserve space starting at 61 * pos for up to length, as long as we can do it as a single mapping. 62 * The actual length is returned in iomap->length. 63 */ 64 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 65 unsigned flags, struct iomap *iomap); 66 67 /* 68 * Commit and/or unreserve space previous allocated using iomap_begin. 69 * Written indicates the length of the successful write operation which 70 * needs to be commited, while the rest needs to be unreserved. 71 * Written might be zero if no data was written. 72 */ 73 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 74 ssize_t written, unsigned flags, struct iomap *iomap); 75 }; 76 77 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 78 const struct iomap_ops *ops); 79 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 80 const struct iomap_ops *ops); 81 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 82 bool *did_zero, const struct iomap_ops *ops); 83 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 84 const struct iomap_ops *ops); 85 int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); 86 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 87 loff_t start, loff_t len, const struct iomap_ops *ops); 88 loff_t iomap_seek_hole(struct inode *inode, loff_t offset, 89 const struct iomap_ops *ops); 90 loff_t iomap_seek_data(struct inode *inode, loff_t offset, 91 const struct iomap_ops *ops); 92 93 /* 94 * Flags for direct I/O ->end_io: 95 */ 96 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 97 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 98 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, 99 unsigned flags); 100 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 101 const struct iomap_ops *ops, iomap_dio_end_io_t end_io); 102 103 #endif /* LINUX_IOMAP_H */ 104