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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>
10 #include <linux/blkdev.h>
13 struct fiemap_extent_info
;
18 struct vm_area_struct
;
22 * Types of block ranges for iomap mappings:
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 */
31 * Flags for all iomap mappings:
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.
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 */
42 * Flags that only need to be reported for IOMAP_REPORT requests:
44 #define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
45 #define IOMAP_F_SHARED 0x20 /* block shared with another file */
48 * Flags from 0x1000 up are for file system specific usage:
50 #define IOMAP_F_PRIVATE 0x1000
54 * Magic value for addr:
56 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
58 struct iomap_page_ops
;
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 */
69 void *private; /* filesystem private */
70 const struct iomap_page_ops
*page_ops
;
73 static inline sector_t
74 iomap_sector(struct iomap
*iomap
, loff_t pos
)
76 return (iomap
->addr
+ pos
- iomap
->offset
) >> SECTOR_SHIFT
;
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.
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.
89 struct iomap_page_ops
{
90 int (*page_prepare
)(struct inode
*inode
, loff_t pos
, unsigned len
,
92 void (*page_done
)(struct inode
*inode
, loff_t pos
, unsigned copied
,
93 struct page
*page
, struct iomap
*iomap
);
97 * Flags for iomap_begin / iomap_end. No flag implies a read.
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 */
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.
112 int (*iomap_begin
)(struct inode
*inode
, loff_t pos
, loff_t length
,
113 unsigned flags
, struct iomap
*iomap
);
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.
121 int (*iomap_end
)(struct inode
*inode
, loff_t pos
, loff_t length
,
122 ssize_t written
, unsigned flags
, struct iomap
*iomap
);
126 * Main iomap iterator function.
128 typedef loff_t (*iomap_actor_t
)(struct inode
*inode
, loff_t pos
, loff_t len
,
129 void *data
, struct iomap
*iomap
);
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
);
136 * Structure allocate for each page when block size < PAGE_SIZE to track
137 * sub-page uptodate status and I/O completions.
141 atomic_t write_count
;
142 DECLARE_BITMAP(uptodate
, PAGE_SIZE
/ 512);
145 static inline struct iomap_page
*to_iomap_page(struct page
*page
)
147 if (page_has_private(page
))
148 return (struct iomap_page
*)page_private(page
);
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
,
163 #ifdef CONFIG_MIGRATION
164 int iomap_migrate_page(struct address_space
*mapping
, struct page
*newpage
,
165 struct page
*page
, enum migrate_mode mode
);
167 #define iomap_migrate_page NULL
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
);
187 * Flags for direct I/O ->end_io:
189 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
190 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
192 struct iomap_dio_ops
{
193 int (*end_io
)(struct kiocb
*iocb
, ssize_t size
, int error
,
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
);
203 struct swap_info_struct
;
205 int iomap_swapfile_activate(struct swap_info_struct
*sis
,
206 struct file
*swap_file
, sector_t
*pagespan
,
207 const struct iomap_ops
*ops
);
209 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO)
210 #endif /* CONFIG_SWAP */
212 #endif /* LINUX_IOMAP_H */