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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
199a31c6 CH |
2 | #ifndef LINUX_IOMAP_H |
3 | #define LINUX_IOMAP_H 1 | |
4 | ||
9dc55f13 CH |
5 | #include <linux/atomic.h> |
6 | #include <linux/bitmap.h> | |
598ecfba | 7 | #include <linux/blk_types.h> |
9dc55f13 | 8 | #include <linux/mm.h> |
199a31c6 | 9 | #include <linux/types.h> |
5780a02f | 10 | #include <linux/mm_types.h> |
db074436 | 11 | #include <linux/blkdev.h> |
199a31c6 | 12 | |
89eb1906 | 13 | struct address_space; |
8be9f564 | 14 | struct fiemap_extent_info; |
ae259a9c | 15 | struct inode; |
c3d4ed1a | 16 | struct iomap_dio; |
598ecfba | 17 | struct iomap_writepage_ctx; |
ae259a9c CH |
18 | struct iov_iter; |
19 | struct kiocb; | |
63899c6f | 20 | struct page; |
ae259a9c CH |
21 | struct vm_area_struct; |
22 | struct vm_fault; | |
23 | ||
24 | /* | |
25 | * Types of block ranges for iomap mappings: | |
26 | */ | |
eb81cf9d CH |
27 | #define IOMAP_HOLE 0 /* no blocks allocated, need allocation */ |
28 | #define IOMAP_DELALLOC 1 /* delayed allocation blocks */ | |
29 | #define IOMAP_MAPPED 2 /* blocks allocated at @addr */ | |
30 | #define IOMAP_UNWRITTEN 3 /* blocks allocated at @addr in unwritten state */ | |
31 | #define IOMAP_INLINE 4 /* data inline in the inode */ | |
199a31c6 | 32 | |
17de0a9f | 33 | /* |
65a60e86 CH |
34 | * Flags reported by the file system from iomap_begin: |
35 | * | |
36 | * IOMAP_F_NEW indicates that the blocks have been newly allocated and need | |
37 | * zeroing for areas that no data is copied to. | |
a3841f94 | 38 | * |
caa51d26 JK |
39 | * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access |
40 | * written data and requires fdatasync to commit them to persistent storage. | |
7684e2c4 DC |
41 | * This needs to take into account metadata changes that *may* be made at IO |
42 | * completion, such as file size updates from direct IO. | |
65a60e86 CH |
43 | * |
44 | * IOMAP_F_SHARED indicates that the blocks are shared, and will need to be | |
45 | * unshared as part a write. | |
46 | * | |
47 | * IOMAP_F_MERGED indicates that the iomap contains the merge of multiple block | |
48 | * mappings. | |
49 | * | |
50 | * IOMAP_F_BUFFER_HEAD indicates that the file system requires the use of | |
51 | * buffer heads for this mapping. | |
17de0a9f | 52 | */ |
65a60e86 CH |
53 | #define IOMAP_F_NEW 0x01 |
54 | #define IOMAP_F_DIRTY 0x02 | |
55 | #define IOMAP_F_SHARED 0x04 | |
56 | #define IOMAP_F_MERGED 0x08 | |
57 | #define IOMAP_F_BUFFER_HEAD 0x10 | |
c3b0e880 | 58 | #define IOMAP_F_ZONE_APPEND 0x20 |
d33fd776 CH |
59 | |
60 | /* | |
65a60e86 CH |
61 | * Flags set by the core iomap code during operations: |
62 | * | |
63 | * IOMAP_F_SIZE_CHANGED indicates to the iomap_end method that the file size | |
64 | * has changed as the result of this write operation. | |
d33fd776 | 65 | */ |
65a60e86 | 66 | #define IOMAP_F_SIZE_CHANGED 0x100 |
17de0a9f | 67 | |
7ee66c03 CH |
68 | /* |
69 | * Flags from 0x1000 up are for file system specific usage: | |
70 | */ | |
71 | #define IOMAP_F_PRIVATE 0x1000 | |
72 | ||
73 | ||
ae259a9c | 74 | /* |
19fe5f64 | 75 | * Magic value for addr: |
ae259a9c | 76 | */ |
19fe5f64 | 77 | #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ |
199a31c6 | 78 | |
df0db3ec AG |
79 | struct iomap_page_ops; |
80 | ||
199a31c6 | 81 | struct iomap { |
19fe5f64 | 82 | u64 addr; /* disk offset of mapping, bytes */ |
ae259a9c CH |
83 | loff_t offset; /* file offset of mapping, bytes */ |
84 | u64 length; /* length of mapping, bytes */ | |
17de0a9f CH |
85 | u16 type; /* type of mapping */ |
86 | u16 flags; /* flags for mapping */ | |
ae259a9c | 87 | struct block_device *bdev; /* block device for I/O */ |
fa5d932c | 88 | struct dax_device *dax_dev; /* dax_dev for dax operations */ |
19e0c58f | 89 | void *inline_data; |
e184fde6 | 90 | void *private; /* filesystem private */ |
df0db3ec AG |
91 | const struct iomap_page_ops *page_ops; |
92 | }; | |
63899c6f | 93 | |
66b8165e | 94 | static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos) |
db074436 DW |
95 | { |
96 | return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT; | |
97 | } | |
98 | ||
69f4a26c GX |
99 | /* |
100 | * Returns the inline data pointer for logical offset @pos. | |
101 | */ | |
4495c33e | 102 | static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos) |
69f4a26c GX |
103 | { |
104 | return iomap->inline_data + pos - iomap->offset; | |
105 | } | |
106 | ||
107 | /* | |
108 | * Check if the mapping's length is within the valid range for inline data. | |
109 | * This is used to guard against accessing data beyond the page inline_data | |
110 | * points at. | |
111 | */ | |
e3c4ffb0 | 112 | static inline bool iomap_inline_data_valid(const struct iomap *iomap) |
69f4a26c GX |
113 | { |
114 | return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data); | |
115 | } | |
116 | ||
df0db3ec AG |
117 | /* |
118 | * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare | |
119 | * and page_done will be called for each page written to. This only applies to | |
120 | * buffered writes as unbuffered writes will not typically have pages | |
121 | * associated with them. | |
122 | * | |
123 | * When page_prepare succeeds, page_done will always be called to do any | |
124 | * cleanup work necessary. In that page_done call, @page will be NULL if the | |
125 | * associated page could not be obtained. | |
126 | */ | |
127 | struct iomap_page_ops { | |
1d25d0ae | 128 | int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len); |
63899c6f | 129 | void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, |
1d25d0ae | 130 | struct page *page); |
ae259a9c CH |
131 | }; |
132 | ||
133 | /* | |
134 | * Flags for iomap_begin / iomap_end. No flag implies a read. | |
135 | */ | |
d33fd776 CH |
136 | #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */ |
137 | #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */ | |
138 | #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */ | |
9484ab1b | 139 | #define IOMAP_FAULT (1 << 3) /* mapping for page fault */ |
ff6a9292 | 140 | #define IOMAP_DIRECT (1 << 4) /* direct I/O */ |
9ecac0ef | 141 | #define IOMAP_NOWAIT (1 << 5) /* do not block */ |
213f6271 | 142 | #define IOMAP_OVERWRITE_ONLY (1 << 6) /* only pure overwrites allowed */ |
b74b1293 | 143 | #define IOMAP_UNSHARE (1 << 7) /* unshare_file_range */ |
952da063 CH |
144 | #ifdef CONFIG_FS_DAX |
145 | #define IOMAP_DAX (1 << 8) /* DAX mapping */ | |
146 | #else | |
147 | #define IOMAP_DAX 0 | |
148 | #endif /* CONFIG_FS_DAX */ | |
ae259a9c CH |
149 | |
150 | struct iomap_ops { | |
151 | /* | |
152 | * Return the existing mapping at pos, or reserve space starting at | |
153 | * pos for up to length, as long as we can do it as a single mapping. | |
154 | * The actual length is returned in iomap->length. | |
155 | */ | |
156 | int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length, | |
c039b997 GR |
157 | unsigned flags, struct iomap *iomap, |
158 | struct iomap *srcmap); | |
ae259a9c CH |
159 | |
160 | /* | |
161 | * Commit and/or unreserve space previous allocated using iomap_begin. | |
162 | * Written indicates the length of the successful write operation which | |
163 | * needs to be commited, while the rest needs to be unreserved. | |
164 | * Written might be zero if no data was written. | |
165 | */ | |
166 | int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length, | |
167 | ssize_t written, unsigned flags, struct iomap *iomap); | |
199a31c6 CH |
168 | }; |
169 | ||
f4b896c2 CH |
170 | /** |
171 | * struct iomap_iter - Iterate through a range of a file | |
172 | * @inode: Set at the start of the iteration and should not change. | |
173 | * @pos: The current file position we are operating on. It is updated by | |
174 | * calls to iomap_iter(). Treat as read-only in the body. | |
175 | * @len: The remaining length of the file segment we're operating on. | |
176 | * It is updated at the same time as @pos. | |
177 | * @processed: The number of bytes processed by the body in the most recent | |
178 | * iteration, or a negative errno. 0 causes the iteration to stop. | |
179 | * @flags: Zero or more of the iomap_begin flags above. | |
180 | * @iomap: Map describing the I/O iteration | |
181 | * @srcmap: Source map for COW operations | |
182 | */ | |
183 | struct iomap_iter { | |
184 | struct inode *inode; | |
185 | loff_t pos; | |
186 | u64 len; | |
187 | s64 processed; | |
188 | unsigned flags; | |
189 | struct iomap iomap; | |
190 | struct iomap srcmap; | |
786f847f | 191 | void *private; |
f4b896c2 CH |
192 | }; |
193 | ||
194 | int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops); | |
195 | ||
196 | /** | |
197 | * iomap_length - length of the current iomap iteration | |
198 | * @iter: iteration structure | |
199 | * | |
200 | * Returns the length that the operation applies to for the current iteration. | |
201 | */ | |
202 | static inline u64 iomap_length(const struct iomap_iter *iter) | |
203 | { | |
204 | u64 end = iter->iomap.offset + iter->iomap.length; | |
205 | ||
206 | if (iter->srcmap.type != IOMAP_HOLE) | |
207 | end = min(end, iter->srcmap.offset + iter->srcmap.length); | |
208 | return min(iter->len, end - iter->pos); | |
209 | } | |
210 | ||
211 | /** | |
212 | * iomap_iter_srcmap - return the source map for the current iomap iteration | |
213 | * @i: iteration structure | |
214 | * | |
215 | * Write operations on file systems with reflink support might require a | |
216 | * source and a destination map. This function retourns the source map | |
217 | * for a given operation, which may or may no be identical to the destination | |
218 | * map in &i->iomap. | |
219 | */ | |
fad0a1ab | 220 | static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i) |
f4b896c2 CH |
221 | { |
222 | if (i->srcmap.type != IOMAP_HOLE) | |
223 | return &i->srcmap; | |
224 | return &i->iomap; | |
225 | } | |
226 | ||
ae259a9c | 227 | ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, |
8ff6daa1 | 228 | const struct iomap_ops *ops); |
7479c505 | 229 | int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops); |
9d24a13a | 230 | void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops); |
2e7e80f7 | 231 | bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count); |
8597447d | 232 | bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags); |
8306a5f5 | 233 | void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len); |
3590c4d8 | 234 | int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len, |
8ff6daa1 | 235 | const struct iomap_ops *ops); |
ae259a9c | 236 | int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, |
8ff6daa1 | 237 | bool *did_zero, const struct iomap_ops *ops); |
ae259a9c | 238 | int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero, |
8ff6daa1 | 239 | const struct iomap_ops *ops); |
5780a02f SJ |
240 | vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, |
241 | const struct iomap_ops *ops); | |
8be9f564 | 242 | int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
27328818 | 243 | u64 start, u64 len, const struct iomap_ops *ops); |
0ed3b0d4 AG |
244 | loff_t iomap_seek_hole(struct inode *inode, loff_t offset, |
245 | const struct iomap_ops *ops); | |
246 | loff_t iomap_seek_data(struct inode *inode, loff_t offset, | |
247 | const struct iomap_ops *ops); | |
89eb1906 CH |
248 | sector_t iomap_bmap(struct address_space *mapping, sector_t bno, |
249 | const struct iomap_ops *ops); | |
ae259a9c | 250 | |
598ecfba CH |
251 | /* |
252 | * Structure for writeback I/O completions. | |
253 | */ | |
254 | struct iomap_ioend { | |
255 | struct list_head io_list; /* next ioend in chain */ | |
256 | u16 io_type; | |
257 | u16 io_flags; /* IOMAP_F_* */ | |
ebb7fb15 | 258 | u32 io_folios; /* folios added to ioend */ |
598ecfba CH |
259 | struct inode *io_inode; /* file being written to */ |
260 | size_t io_size; /* size of the extent */ | |
261 | loff_t io_offset; /* offset in the file */ | |
ebb7fb15 | 262 | sector_t io_sector; /* start sector of ioend */ |
598ecfba CH |
263 | struct bio *io_bio; /* bio being built */ |
264 | struct bio io_inline_bio; /* MUST BE LAST! */ | |
265 | }; | |
266 | ||
267 | struct iomap_writeback_ops { | |
268 | /* | |
269 | * Required, maps the blocks so that writeback can be performed on | |
270 | * the range starting at offset. | |
271 | */ | |
272 | int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode, | |
273 | loff_t offset); | |
274 | ||
275 | /* | |
276 | * Optional, allows the file systems to perform actions just before | |
277 | * submitting the bio and/or override the bio end_io handler for complex | |
278 | * operations like copy on write extent manipulation or unwritten extent | |
279 | * conversions. | |
280 | */ | |
281 | int (*prepare_ioend)(struct iomap_ioend *ioend, int status); | |
282 | ||
283 | /* | |
284 | * Optional, allows the file system to discard state on a page where | |
285 | * we failed to submit any I/O. | |
286 | */ | |
6e478521 | 287 | void (*discard_folio)(struct folio *folio, loff_t pos); |
598ecfba CH |
288 | }; |
289 | ||
290 | struct iomap_writepage_ctx { | |
291 | struct iomap iomap; | |
292 | struct iomap_ioend *ioend; | |
293 | const struct iomap_writeback_ops *ops; | |
294 | }; | |
295 | ||
296 | void iomap_finish_ioends(struct iomap_ioend *ioend, int error); | |
297 | void iomap_ioend_try_merge(struct iomap_ioend *ioend, | |
6e552494 | 298 | struct list_head *more_ioends); |
598ecfba CH |
299 | void iomap_sort_ioends(struct list_head *ioend_list); |
300 | int iomap_writepage(struct page *page, struct writeback_control *wbc, | |
301 | struct iomap_writepage_ctx *wpc, | |
302 | const struct iomap_writeback_ops *ops); | |
303 | int iomap_writepages(struct address_space *mapping, | |
304 | struct writeback_control *wbc, struct iomap_writepage_ctx *wpc, | |
305 | const struct iomap_writeback_ops *ops); | |
306 | ||
ff6a9292 CH |
307 | /* |
308 | * Flags for direct I/O ->end_io: | |
309 | */ | |
310 | #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */ | |
311 | #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */ | |
838c4f3d CH |
312 | |
313 | struct iomap_dio_ops { | |
314 | int (*end_io)(struct kiocb *iocb, ssize_t size, int error, | |
315 | unsigned flags); | |
3e08773c CH |
316 | void (*submit_io)(const struct iomap_iter *iter, struct bio *bio, |
317 | loff_t file_offset); | |
908c5490 CH |
318 | |
319 | /* | |
320 | * Filesystems wishing to attach private information to a direct io bio | |
321 | * must provide a ->submit_io method that attaches the additional | |
322 | * information to the bio and changes the ->bi_end_io callback to a | |
323 | * custom function. This function should, at a minimum, perform any | |
324 | * relevant post-processing of the bio and end with a call to | |
325 | * iomap_dio_bio_end_io. | |
326 | */ | |
327 | struct bio_set *bio_set; | |
838c4f3d CH |
328 | }; |
329 | ||
2f632965 CH |
330 | /* |
331 | * Wait for the I/O to complete in iomap_dio_rw even if the kiocb is not | |
332 | * synchronous. | |
333 | */ | |
334 | #define IOMAP_DIO_FORCE_WAIT (1 << 0) | |
335 | ||
213f6271 CH |
336 | /* |
337 | * Do not allocate blocks or zero partial blocks, but instead fall back to | |
338 | * the caller by returning -EAGAIN. Used to optimize direct I/O writes that | |
339 | * are not aligned to the file system block size. | |
340 | */ | |
341 | #define IOMAP_DIO_OVERWRITE_ONLY (1 << 1) | |
342 | ||
97308f8b AG |
343 | /* |
344 | * When a page fault occurs, return a partial synchronous result and allow | |
345 | * the caller to retry the rest of the operation after dealing with the page | |
346 | * fault. | |
347 | */ | |
348 | #define IOMAP_DIO_PARTIAL (1 << 2) | |
349 | ||
36518b6b AV |
350 | /* |
351 | * The caller will sync the write if needed; do not sync it within | |
352 | * iomap_dio_rw. Overrides IOMAP_DIO_FORCE_WAIT. | |
353 | */ | |
354 | #define IOMAP_DIO_NOSYNC (1 << 3) | |
355 | ||
ff6a9292 | 356 | ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, |
13ef9544 | 357 | const struct iomap_ops *ops, const struct iomap_dio_ops *dops, |
786f847f | 358 | unsigned int dio_flags, void *private, size_t done_before); |
c3d4ed1a CH |
359 | struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, |
360 | const struct iomap_ops *ops, const struct iomap_dio_ops *dops, | |
786f847f | 361 | unsigned int dio_flags, void *private, size_t done_before); |
c3d4ed1a | 362 | ssize_t iomap_dio_complete(struct iomap_dio *dio); |
908c5490 | 363 | void iomap_dio_bio_end_io(struct bio *bio); |
ff6a9292 | 364 | |
67482129 DW |
365 | #ifdef CONFIG_SWAP |
366 | struct file; | |
367 | struct swap_info_struct; | |
368 | ||
369 | int iomap_swapfile_activate(struct swap_info_struct *sis, | |
370 | struct file *swap_file, sector_t *pagespan, | |
371 | const struct iomap_ops *ops); | |
372 | #else | |
373 | # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO) | |
374 | #endif /* CONFIG_SWAP */ | |
375 | ||
199a31c6 | 376 | #endif /* LINUX_IOMAP_H */ |