1 /* SPDX-License-Identifier: GPL-2.0 */
3 #define LINUX_IOMAP_H 1
5 #include <linux/atomic.h>
6 #include <linux/bitmap.h>
8 #include <linux/types.h>
9 #include <linux/mm_types.h>
12 struct fiemap_extent_info;
17 struct vm_area_struct;
21 * Types of block ranges for iomap mappings:
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 */
30 * Flags for all iomap mappings:
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.
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 #define IOMAP_F_SIZE_CHANGED 0x08 /* file size has changed */
41 * Flags that only need to be reported for IOMAP_REPORT requests:
43 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
44 #define IOMAP_F_SHARED 0x20 /* block shared with another file */
47 * Flags from 0x1000 up are for file system specific usage:
49 #define IOMAP_F_PRIVATE 0x1000
53 * Magic value for addr:
55 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
57 struct iomap_page_ops;
60 u64 addr; /* disk offset of mapping, bytes */
61 loff_t offset; /* file offset of mapping, bytes */
62 u64 length; /* length of mapping, bytes */
63 u16 type; /* type of mapping */
64 u16 flags; /* flags for mapping */
65 struct block_device *bdev; /* block device for I/O */
66 struct dax_device *dax_dev; /* dax_dev for dax operations */
68 void *private; /* filesystem private */
69 const struct iomap_page_ops *page_ops;
73 * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare
74 * and page_done will be called for each page written to. This only applies to
75 * buffered writes as unbuffered writes will not typically have pages
76 * associated with them.
78 * When page_prepare succeeds, page_done will always be called to do any
79 * cleanup work necessary. In that page_done call, @page will be NULL if the
80 * associated page could not be obtained.
82 struct iomap_page_ops {
83 int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len,
85 void (*page_done)(struct inode *inode, loff_t pos, unsigned copied,
86 struct page *page, struct iomap *iomap);
90 * Flags for iomap_begin / iomap_end. No flag implies a read.
92 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
93 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
94 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
95 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */
96 #define IOMAP_DIRECT (1 << 4) /* direct I/O */
97 #define IOMAP_NOWAIT (1 << 5) /* do not block */
101 * Return the existing mapping at pos, or reserve space starting at
102 * pos for up to length, as long as we can do it as a single mapping.
103 * The actual length is returned in iomap->length.
105 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
106 unsigned flags, struct iomap *iomap);
109 * Commit and/or unreserve space previous allocated using iomap_begin.
110 * Written indicates the length of the successful write operation which
111 * needs to be commited, while the rest needs to be unreserved.
112 * Written might be zero if no data was written.
114 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
115 ssize_t written, unsigned flags, struct iomap *iomap);
119 * Structure allocate for each page when block size < PAGE_SIZE to track
120 * sub-page uptodate status and I/O completions.
124 atomic_t write_count;
125 DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);
128 static inline struct iomap_page *to_iomap_page(struct page *page)
130 if (page_has_private(page))
131 return (struct iomap_page *)page_private(page);
135 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
136 const struct iomap_ops *ops);
137 int iomap_readpage(struct page *page, const struct iomap_ops *ops);
138 int iomap_readpages(struct address_space *mapping, struct list_head *pages,
139 unsigned nr_pages, const struct iomap_ops *ops);
140 int iomap_set_page_dirty(struct page *page);
141 int iomap_is_partially_uptodate(struct page *page, unsigned long from,
142 unsigned long count);
143 int iomap_releasepage(struct page *page, gfp_t gfp_mask);
144 void iomap_invalidatepage(struct page *page, unsigned int offset,
146 #ifdef CONFIG_MIGRATION
147 int iomap_migrate_page(struct address_space *mapping, struct page *newpage,
148 struct page *page, enum migrate_mode mode);
150 #define iomap_migrate_page NULL
152 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
153 const struct iomap_ops *ops);
154 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
155 bool *did_zero, const struct iomap_ops *ops);
156 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
157 const struct iomap_ops *ops);
158 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf,
159 const struct iomap_ops *ops);
160 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
161 loff_t start, loff_t len, const struct iomap_ops *ops);
162 loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
163 const struct iomap_ops *ops);
164 loff_t iomap_seek_data(struct inode *inode, loff_t offset,
165 const struct iomap_ops *ops);
166 sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
167 const struct iomap_ops *ops);
170 * Flags for direct I/O ->end_io:
172 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
173 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
174 typedef int (iomap_dio_end_io_t)(struct kiocb *iocb, ssize_t ret,
176 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
177 const struct iomap_ops *ops, iomap_dio_end_io_t end_io);
178 int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
182 struct swap_info_struct;
184 int iomap_swapfile_activate(struct swap_info_struct *sis,
185 struct file *swap_file, sector_t *pagespan,
186 const struct iomap_ops *ops);
188 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO)
189 #endif /* CONFIG_SWAP */
191 #endif /* LINUX_IOMAP_H */