1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef LINUX_IOMAP_H 3 #define LINUX_IOMAP_H 1 4 5 #include <linux/atomic.h> 6 #include <linux/bitmap.h> 7 #include <linux/mm.h> 8 #include <linux/types.h> 9 #include <linux/mm_types.h> 10 11 struct address_space; 12 struct fiemap_extent_info; 13 struct inode; 14 struct iov_iter; 15 struct kiocb; 16 struct page; 17 struct vm_area_struct; 18 struct vm_fault; 19 20 /* 21 * Types of block ranges for iomap mappings: 22 */ 23 #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */ 24 #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */ 25 #define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */ 26 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */ 27 #define IOMAP_INLINE 0x05 /* data inline in the inode */ 28 29 /* 30 * Flags for all iomap mappings: 31 * 32 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access 33 * written data and requires fdatasync to commit them to persistent storage. 34 */ 35 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 36 #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ 37 #define IOMAP_F_BUFFER_HEAD 0x04 /* file system requires buffer heads */ 38 39 /* 40 * Flags that only need to be reported for IOMAP_REPORT requests: 41 */ 42 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 43 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 44 45 /* 46 * Flags from 0x1000 up are for file system specific usage: 47 */ 48 #define IOMAP_F_PRIVATE 0x1000 49 50 51 /* 52 * Magic value for addr: 53 */ 54 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ 55 56 struct iomap { 57 u64 addr; /* disk offset of mapping, bytes */ 58 loff_t offset; /* file offset of mapping, bytes */ 59 u64 length; /* length of mapping, bytes */ 60 u16 type; /* type of mapping */ 61 u16 flags; /* flags for mapping */ 62 struct block_device *bdev; /* block device for I/O */ 63 struct dax_device *dax_dev; /* dax_dev for dax operations */ 64 void *inline_data; 65 void *private; /* filesystem private */ 66 67 /* 68 * Called when finished processing a page in the mapping returned in 69 * this iomap. At least for now this is only supported in the buffered 70 * write path. 71 */ 72 void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, 73 struct page *page, struct iomap *iomap); 74 }; 75 76 /* 77 * Flags for iomap_begin / iomap_end. No flag implies a read. 78 */ 79 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 80 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 81 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 82 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 83 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 84 #define IOMAP_NOWAIT (1 << 5) /* do not block */ 85 86 struct iomap_ops { 87 /* 88 * Return the existing mapping at pos, or reserve space starting at 89 * pos for up to length, as long as we can do it as a single mapping. 90 * The actual length is returned in iomap->length. 91 */ 92 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 93 unsigned flags, struct iomap *iomap); 94 95 /* 96 * Commit and/or unreserve space previous allocated using iomap_begin. 97 * Written indicates the length of the successful write operation which 98 * needs to be commited, while the rest needs to be unreserved. 99 * Written might be zero if no data was written. 100 */ 101 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 102 ssize_t written, unsigned flags, struct iomap *iomap); 103 }; 104 105 /* 106 * Structure allocate for each page when block size < PAGE_SIZE to track 107 * sub-page uptodate status and I/O completions. 108 */ 109 struct iomap_page { 110 atomic_t read_count; 111 atomic_t write_count; 112 DECLARE_BITMAP(uptodate, PAGE_SIZE / 512); 113 }; 114 115 static inline struct iomap_page *to_iomap_page(struct page *page) 116 { 117 if (page_has_private(page)) 118 return (struct iomap_page *)page_private(page); 119 return NULL; 120 } 121 122 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 123 const struct iomap_ops *ops); 124 int iomap_readpage(struct page *page, const struct iomap_ops *ops); 125 int iomap_readpages(struct address_space *mapping, struct list_head *pages, 126 unsigned nr_pages, const struct iomap_ops *ops); 127 int iomap_set_page_dirty(struct page *page); 128 int iomap_is_partially_uptodate(struct page *page, unsigned long from, 129 unsigned long count); 130 int iomap_releasepage(struct page *page, gfp_t gfp_mask); 131 void iomap_invalidatepage(struct page *page, unsigned int offset, 132 unsigned int len); 133 #ifdef CONFIG_MIGRATION 134 int iomap_migrate_page(struct address_space *mapping, struct page *newpage, 135 struct page *page, enum migrate_mode mode); 136 #else 137 #define iomap_migrate_page NULL 138 #endif 139 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 140 const struct iomap_ops *ops); 141 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 142 bool *did_zero, const struct iomap_ops *ops); 143 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 144 const struct iomap_ops *ops); 145 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, 146 const struct iomap_ops *ops); 147 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 148 loff_t start, loff_t len, const struct iomap_ops *ops); 149 loff_t iomap_seek_hole(struct inode *inode, loff_t offset, 150 const struct iomap_ops *ops); 151 loff_t iomap_seek_data(struct inode *inode, loff_t offset, 152 const struct iomap_ops *ops); 153 sector_t iomap_bmap(struct address_space *mapping, sector_t bno, 154 const struct iomap_ops *ops); 155 156 /* 157 * Flags for direct I/O ->end_io: 158 */ 159 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 160 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 161 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret, 162 unsigned flags); 163 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 164 const struct iomap_ops *ops, iomap_dio_end_io_t end_io); 165 166 #ifdef CONFIG_SWAP 167 struct file; 168 struct swap_info_struct; 169 170 int iomap_swapfile_activate(struct swap_info_struct *sis, 171 struct file *swap_file, sector_t *pagespan, 172 const struct iomap_ops *ops); 173 #else 174 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) 175 #endif /* CONFIG_SWAP */ 176 177 #endif /* LINUX_IOMAP_H */ 178