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 */
40 * Flags that only need to be reported for IOMAP_REPORT requests:
42 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
43 #define IOMAP_F_SHARED 0x20 /* block shared with another file */
46 * Flags from 0x1000 up are for file system specific usage:
48 #define IOMAP_F_PRIVATE 0x1000
52 * Magic value for addr:
54 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
56 struct iomap_page_ops
;
59 u64 addr
; /* disk offset of mapping, bytes */
60 loff_t offset
; /* file offset of mapping, bytes */
61 u64 length
; /* length of mapping, bytes */
62 u16 type
; /* type of mapping */
63 u16 flags
; /* flags for mapping */
64 struct block_device
*bdev
; /* block device for I/O */
65 struct dax_device
*dax_dev
; /* dax_dev for dax operations */
67 void *private; /* filesystem private */
68 const struct iomap_page_ops
*page_ops
;
72 * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare
73 * and page_done will be called for each page written to. This only applies to
74 * buffered writes as unbuffered writes will not typically have pages
75 * associated with them.
77 * When page_prepare succeeds, page_done will always be called to do any
78 * cleanup work necessary. In that page_done call, @page will be NULL if the
79 * associated page could not be obtained.
81 struct iomap_page_ops
{
82 int (*page_prepare
)(struct inode
*inode
, loff_t pos
, unsigned len
,
84 void (*page_done
)(struct inode
*inode
, loff_t pos
, unsigned copied
,
85 struct page
*page
, struct iomap
*iomap
);
89 * Flags for iomap_begin / iomap_end. No flag implies a read.
91 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
92 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
93 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
94 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */
95 #define IOMAP_DIRECT (1 << 4) /* direct I/O */
96 #define IOMAP_NOWAIT (1 << 5) /* do not block */
100 * Return the existing mapping at pos, or reserve space starting at
101 * pos for up to length, as long as we can do it as a single mapping.
102 * The actual length is returned in iomap->length.
104 int (*iomap_begin
)(struct inode
*inode
, loff_t pos
, loff_t length
,
105 unsigned flags
, struct iomap
*iomap
);
108 * Commit and/or unreserve space previous allocated using iomap_begin.
109 * Written indicates the length of the successful write operation which
110 * needs to be commited, while the rest needs to be unreserved.
111 * Written might be zero if no data was written.
113 int (*iomap_end
)(struct inode
*inode
, loff_t pos
, loff_t length
,
114 ssize_t written
, unsigned flags
, struct iomap
*iomap
);
118 * Structure allocate for each page when block size < PAGE_SIZE to track
119 * sub-page uptodate status and I/O completions.
123 atomic_t write_count
;
124 DECLARE_BITMAP(uptodate
, PAGE_SIZE
/ 512);
127 static inline struct iomap_page
*to_iomap_page(struct page
*page
)
129 if (page_has_private(page
))
130 return (struct iomap_page
*)page_private(page
);
134 ssize_t
iomap_file_buffered_write(struct kiocb
*iocb
, struct iov_iter
*from
,
135 const struct iomap_ops
*ops
);
136 int iomap_readpage(struct page
*page
, const struct iomap_ops
*ops
);
137 int iomap_readpages(struct address_space
*mapping
, struct list_head
*pages
,
138 unsigned nr_pages
, const struct iomap_ops
*ops
);
139 int iomap_set_page_dirty(struct page
*page
);
140 int iomap_is_partially_uptodate(struct page
*page
, unsigned long from
,
141 unsigned long count
);
142 int iomap_releasepage(struct page
*page
, gfp_t gfp_mask
);
143 void iomap_invalidatepage(struct page
*page
, unsigned int offset
,
145 #ifdef CONFIG_MIGRATION
146 int iomap_migrate_page(struct address_space
*mapping
, struct page
*newpage
,
147 struct page
*page
, enum migrate_mode mode
);
149 #define iomap_migrate_page NULL
151 int iomap_file_dirty(struct inode
*inode
, loff_t pos
, loff_t len
,
152 const struct iomap_ops
*ops
);
153 int iomap_zero_range(struct inode
*inode
, loff_t pos
, loff_t len
,
154 bool *did_zero
, const struct iomap_ops
*ops
);
155 int iomap_truncate_page(struct inode
*inode
, loff_t pos
, bool *did_zero
,
156 const struct iomap_ops
*ops
);
157 vm_fault_t
iomap_page_mkwrite(struct vm_fault
*vmf
,
158 const struct iomap_ops
*ops
);
159 int iomap_fiemap(struct inode
*inode
, struct fiemap_extent_info
*fieinfo
,
160 loff_t start
, loff_t len
, const struct iomap_ops
*ops
);
161 loff_t
iomap_seek_hole(struct inode
*inode
, loff_t offset
,
162 const struct iomap_ops
*ops
);
163 loff_t
iomap_seek_data(struct inode
*inode
, loff_t offset
,
164 const struct iomap_ops
*ops
);
165 sector_t
iomap_bmap(struct address_space
*mapping
, sector_t bno
,
166 const struct iomap_ops
*ops
);
169 * Flags for direct I/O ->end_io:
171 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
172 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
173 typedef int (iomap_dio_end_io_t
)(struct kiocb
*iocb
, ssize_t ret
,
175 ssize_t
iomap_dio_rw(struct kiocb
*iocb
, struct iov_iter
*iter
,
176 const struct iomap_ops
*ops
, iomap_dio_end_io_t end_io
);
177 int iomap_dio_iopoll(struct kiocb
*kiocb
, bool spin
);
181 struct swap_info_struct
;
183 int iomap_swapfile_activate(struct swap_info_struct
*sis
,
184 struct file
*swap_file
, sector_t
*pagespan
,
185 const struct iomap_ops
*ops
);
187 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO)
188 #endif /* CONFIG_SWAP */
190 #endif /* LINUX_IOMAP_H */