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 #include <linux/blkdev.h> 11 12 struct address_space; 13 struct fiemap_extent_info; 14 struct inode; 15 struct iov_iter; 16 struct kiocb; 17 struct page; 18 struct vm_area_struct; 19 struct vm_fault; 20 21 /* 22 * Types of block ranges for iomap mappings: 23 */ 24 #define IOMAP_HOLE 0x01 /* no blocks allocated, need allocation */ 25 #define IOMAP_DELALLOC 0x02 /* delayed allocation blocks */ 26 #define IOMAP_MAPPED 0x03 /* blocks allocated at @addr */ 27 #define IOMAP_UNWRITTEN 0x04 /* blocks allocated at @addr in unwritten state */ 28 #define IOMAP_INLINE 0x05 /* data inline in the inode */ 29 30 /* 31 * Flags for all iomap mappings: 32 * 33 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access 34 * written data and requires fdatasync to commit them to persistent storage. 35 */ 36 #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ 37 #define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */ 38 #define IOMAP_F_BUFFER_HEAD 0x04 /* file system requires buffer heads */ 39 #define IOMAP_F_SIZE_CHANGED 0x08 /* file size has changed */ 40 41 /* 42 * Flags that only need to be reported for IOMAP_REPORT requests: 43 */ 44 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */ 45 #define IOMAP_F_SHARED 0x20 /* block shared with another file */ 46 47 /* 48 * Flags from 0x1000 up are for file system specific usage: 49 */ 50 #define IOMAP_F_PRIVATE 0x1000 51 52 53 /* 54 * Magic value for addr: 55 */ 56 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ 57 58 struct iomap_page_ops; 59 60 struct iomap { 61 u64 addr; /* disk offset of mapping, bytes */ 62 loff_t offset; /* file offset of mapping, bytes */ 63 u64 length; /* length of mapping, bytes */ 64 u16 type; /* type of mapping */ 65 u16 flags; /* flags for mapping */ 66 struct block_device *bdev; /* block device for I/O */ 67 struct dax_device *dax_dev; /* dax_dev for dax operations */ 68 void *inline_data; 69 void *private; /* filesystem private */ 70 const struct iomap_page_ops *page_ops; 71 }; 72 73 static inline sector_t 74 iomap_sector(struct iomap *iomap, loff_t pos) 75 { 76 return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT; 77 } 78 79 /* 80 * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare 81 * and page_done will be called for each page written to. This only applies to 82 * buffered writes as unbuffered writes will not typically have pages 83 * associated with them. 84 * 85 * When page_prepare succeeds, page_done will always be called to do any 86 * cleanup work necessary. In that page_done call, @page will be NULL if the 87 * associated page could not be obtained. 88 */ 89 struct iomap_page_ops { 90 int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, 91 struct iomap *iomap); 92 void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, 93 struct page *page, struct iomap *iomap); 94 }; 95 96 /* 97 * Flags for iomap_begin / iomap_end. No flag implies a read. 98 */ 99 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ 100 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ 101 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ 102 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ 103 #define IOMAP_DIRECT (1 << 4) /* direct I/O */ 104 #define IOMAP_NOWAIT (1 << 5) /* do not block */ 105 106 struct iomap_ops { 107 /* 108 * Return the existing mapping at pos, or reserve space starting at 109 * pos for up to length, as long as we can do it as a single mapping. 110 * The actual length is returned in iomap->length. 111 */ 112 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, 113 unsigned flags, struct iomap *iomap); 114 115 /* 116 * Commit and/or unreserve space previous allocated using iomap_begin. 117 * Written indicates the length of the successful write operation which 118 * needs to be commited, while the rest needs to be unreserved. 119 * Written might be zero if no data was written. 120 */ 121 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, 122 ssize_t written, unsigned flags, struct iomap *iomap); 123 }; 124 125 /* 126 * Main iomap iterator function. 127 */ 128 typedef loff_t (*iomap_actor_t)(struct inode *inode, loff_t pos, loff_t len, 129 void *data, struct iomap *iomap); 130 131 loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length, 132 unsigned flags, const struct iomap_ops *ops, void *data, 133 iomap_actor_t actor); 134 135 /* 136 * Structure allocate for each page when block size < PAGE_SIZE to track 137 * sub-page uptodate status and I/O completions. 138 */ 139 struct iomap_page { 140 atomic_t read_count; 141 atomic_t write_count; 142 DECLARE_BITMAP(uptodate, PAGE_SIZE / 512); 143 }; 144 145 static inline struct iomap_page *to_iomap_page(struct page *page) 146 { 147 if (page_has_private(page)) 148 return (struct iomap_page *)page_private(page); 149 return NULL; 150 } 151 152 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, 153 const struct iomap_ops *ops); 154 int iomap_readpage(struct page *page, const struct iomap_ops *ops); 155 int iomap_readpages(struct address_space *mapping, struct list_head *pages, 156 unsigned nr_pages, const struct iomap_ops *ops); 157 int iomap_set_page_dirty(struct page *page); 158 int iomap_is_partially_uptodate(struct page *page, unsigned long from, 159 unsigned long count); 160 int iomap_releasepage(struct page *page, gfp_t gfp_mask); 161 void iomap_invalidatepage(struct page *page, unsigned int offset, 162 unsigned int len); 163 #ifdef CONFIG_MIGRATION 164 int iomap_migrate_page(struct address_space *mapping, struct page *newpage, 165 struct page *page, enum migrate_mode mode); 166 #else 167 #define iomap_migrate_page NULL 168 #endif 169 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, 170 const struct iomap_ops *ops); 171 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, 172 bool *did_zero, const struct iomap_ops *ops); 173 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, 174 const struct iomap_ops *ops); 175 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, 176 const struct iomap_ops *ops); 177 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 178 loff_t start, loff_t len, const struct iomap_ops *ops); 179 loff_t iomap_seek_hole(struct inode *inode, loff_t offset, 180 const struct iomap_ops *ops); 181 loff_t iomap_seek_data(struct inode *inode, loff_t offset, 182 const struct iomap_ops *ops); 183 sector_t iomap_bmap(struct address_space *mapping, sector_t bno, 184 const struct iomap_ops *ops); 185 186 /* 187 * Flags for direct I/O ->end_io: 188 */ 189 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ 190 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ 191 192 struct iomap_dio_ops { 193 int (*end_io)(struct kiocb *iocb, ssize_t size, int error, 194 unsigned flags); 195 }; 196 197 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, 198 const struct iomap_ops *ops, const struct iomap_dio_ops *dops); 199 int iomap_dio_iopoll(struct kiocb *kiocb, bool spin); 200 201 #ifdef CONFIG_SWAP 202 struct file; 203 struct swap_info_struct; 204 205 int iomap_swapfile_activate(struct swap_info_struct *sis, 206 struct file *swap_file, sector_t *pagespan, 207 const struct iomap_ops *ops); 208 #else 209 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) 210 #endif /* CONFIG_SWAP */ 211 212 #endif /* LINUX_IOMAP_H */ 213