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 address_space; 8 struct fiemap_extent_info; 9 struct inode; 10 struct iov_iter; 11 struct kiocb; 12 struct vm_area_struct; 13 struct vm_fault; 14 15 /* 16 * Types of block ranges for iomap mappings: 17 */ 18 #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */ 19 #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */ 20 #define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */ 21 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */ 22 #define IOMAP_INLINE 0x05 /* data inline in the inode */ 23 24 /* 25 * Flags for all iomap mappings: 26 * 27 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access 28 * written data and requires fdatasync to commit them to persistent storage. 29 */ 30 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 31 #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ 32 33 /* 34 * Flags that only need to be reported for IOMAP_REPORT requests: 35 */ 36 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 37 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 38 39 /* 40 * Flags from 0x1000 up are for file system specific usage: 41 */ 42 #define IOMAP_F_PRIVATE 0x1000 43 44 45 /* 46 * Magic value for addr: 47 */ 48 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ 49 50 struct iomap { 51 u64 addr; /* disk offset of mapping, bytes */ 52 loff_t offset; /* file offset of mapping, bytes */ 53 u64 length; /* length of mapping, bytes */ 54 u16 type; /* type of mapping */ 55 u16 flags; /* flags for mapping */ 56 struct block_device *bdev; /* block device for I/O */ 57 struct dax_device *dax_dev; /* dax_dev for dax operations */ 58 }; 59 60 /* 61 * Flags for iomap_begin / iomap_end. No flag implies a read. 62 */ 63 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 64 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 65 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 66 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 67 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 68 #define IOMAP_NOWAIT (1 << 5) /* do not block */ 69 70 struct iomap_ops { 71 /* 72 * Return the existing mapping at pos, or reserve space starting at 73 * pos for up to length, as long as we can do it as a single mapping. 74 * The actual length is returned in iomap->length. 75 */ 76 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 77 unsigned flags, struct iomap *iomap); 78 79 /* 80 * Commit and/or unreserve space previous allocated using iomap_begin. 81 * Written indicates the length of the successful write operation which 82 * needs to be commited, while the rest needs to be unreserved. 83 * Written might be zero if no data was written. 84 */ 85 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 86 ssize_t written, unsigned flags, struct iomap *iomap); 87 }; 88 89 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 90 const struct iomap_ops *ops); 91 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 92 const struct iomap_ops *ops); 93 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 94 bool *did_zero, const struct iomap_ops *ops); 95 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 96 const struct iomap_ops *ops); 97 int iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops); 98 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 99 loff_t start, loff_t len, const struct iomap_ops *ops); 100 loff_t iomap_seek_hole(struct inode *inode, loff_t offset, 101 const struct iomap_ops *ops); 102 loff_t iomap_seek_data(struct inode *inode, loff_t offset, 103 const struct iomap_ops *ops); 104 sector_t iomap_bmap(struct address_space *mapping, sector_t bno, 105 const struct iomap_ops *ops); 106 107 /* 108 * Flags for direct I/O ->end_io: 109 */ 110 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 111 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 112 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, 113 unsigned flags); 114 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 115 const struct iomap_ops *ops, iomap_dio_end_io_t end_io); 116 117 #ifdef CONFIG_SWAP 118 struct file; 119 struct swap_info_struct; 120 121 int iomap_swapfile_activate(struct swap_info_struct *sis, 122 struct file *swap_file, sector_t *pagespan, 123 const struct iomap_ops *ops); 124 #else 125 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) 126 #endif /* CONFIG_SWAP */ 127 128 #endif /* LINUX_IOMAP_H */ 129