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 at @addr */ 20 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */ 21 22 /* 23 * Flags for all iomap mappings: 24 * 25 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access 26 * written data and requires fdatasync to commit them to persistent storage. 27 */ 28 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 29 #define IOMAP_F_BOUNDARY 0x02 /* mapping ends at metadata boundary */ 30 #define IOMAP_F_DIRTY 0x04 /* uncommitted metadata */ 31 32 /* 33 * Flags that only need to be reported for IOMAP_REPORT requests: 34 */ 35 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 36 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 37 #define IOMAP_F_DATA_INLINE 0x40 /* data inline in the inode */ 38 39 /* 40 * Magic value for addr: 41 */ 42 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ 43 44 struct iomap { 45 u64 addr; /* disk offset of mapping, bytes */ 46 loff_t offset; /* file offset of mapping, bytes */ 47 u64 length; /* length of mapping, bytes */ 48 u16 type; /* type of mapping */ 49 u16 flags; /* flags for mapping */ 50 struct block_device *bdev; /* block device for I/O */ 51 struct dax_device *dax_dev; /* dax_dev for dax operations */ 52 }; 53 54 /* 55 * Flags for iomap_begin / iomap_end. No flag implies a read. 56 */ 57 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 58 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 59 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 60 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 61 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 62 #define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */ 63 64 struct iomap_ops { 65 /* 66 * Return the existing mapping at pos, or reserve space starting at 67 * pos for up to length, as long as we can do it as a single mapping. 68 * The actual length is returned in iomap->length. 69 */ 70 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 71 unsigned flags, struct iomap *iomap); 72 73 /* 74 * Commit and/or unreserve space previous allocated using iomap_begin. 75 * Written indicates the length of the successful write operation which 76 * needs to be commited, while the rest needs to be unreserved. 77 * Written might be zero if no data was written. 78 */ 79 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 80 ssize_t written, unsigned flags, struct iomap *iomap); 81 }; 82 83 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 84 const struct iomap_ops *ops); 85 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 86 const struct iomap_ops *ops); 87 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 88 bool *did_zero, const struct iomap_ops *ops); 89 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 90 const struct iomap_ops *ops); 91 int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); 92 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 93 loff_t start, loff_t len, const struct iomap_ops *ops); 94 loff_t iomap_seek_hole(struct inode *inode, loff_t offset, 95 const struct iomap_ops *ops); 96 loff_t iomap_seek_data(struct inode *inode, loff_t offset, 97 const struct iomap_ops *ops); 98 99 /* 100 * Flags for direct I/O ->end_io: 101 */ 102 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 103 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 104 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, 105 unsigned flags); 106 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 107 const struct iomap_ops *ops, iomap_dio_end_io_t end_io); 108 109 #endif /* LINUX_IOMAP_H */ 110