Branch data Line data Source code
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 : 0 : 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 [ # # # # : 0 : if (page_has_private(page))
# # # # #
# ]
148 : 0 : 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 */
|
