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/blk_types.h>
8 #include <linux/mm.h>
9 #include <linux/types.h>
10 #include <linux/mm_types.h>
11 #include <linux/blkdev.h>
12 #include <linux/pagevec.h>
13
14 struct address_space;
15 struct fiemap_extent_info;
16 struct inode;
17 struct iomap_iter;
18 struct iomap_dio;
19 struct iomap_writepage_ctx;
20 struct iomap_read_folio_ctx;
21 struct iov_iter;
22 struct kiocb;
23 struct page;
24 struct vm_area_struct;
25 struct vm_fault;
26
27 /*
28 * Types of block ranges for iomap mappings:
29 */
30 #define IOMAP_HOLE 0 /* no blocks allocated, need allocation */
31 #define IOMAP_DELALLOC 1 /* delayed allocation blocks */
32 #define IOMAP_MAPPED 2 /* blocks allocated at @addr */
33 #define IOMAP_UNWRITTEN 3 /* blocks allocated at @addr in unwritten state */
34 #define IOMAP_INLINE 4 /* data inline in the inode */
35
36 /*
37 * Flags reported by the file system from iomap_begin:
38 *
39 * IOMAP_F_NEW indicates that the blocks have been newly allocated and need
40 * zeroing for areas that no data is copied to.
41 *
42 * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
43 * written data and requires fdatasync to commit them to persistent storage.
44 * This needs to take into account metadata changes that *may* be made at IO
45 * completion, such as file size updates from direct IO.
46 *
47 * IOMAP_F_SHARED indicates that the blocks are shared, and will need to be
48 * unshared as part a write.
49 *
50 * IOMAP_F_MERGED indicates that the iomap contains the merge of multiple block
51 * mappings.
52 *
53 * IOMAP_F_BUFFER_HEAD indicates that the file system requires the use of
54 * buffer heads for this mapping.
55 *
56 * IOMAP_F_XATTR indicates that the iomap is for an extended attribute extent
57 * rather than a file data extent.
58 *
59 * IOMAP_F_BOUNDARY indicates that I/O and I/O completions for this iomap must
60 * never be merged with the mapping before it.
61 *
62 * IOMAP_F_ANON_WRITE indicates that (write) I/O does not have a target block
63 * assigned to it yet and the file system will do that in the bio submission
64 * handler, splitting the I/O as needed.
65 *
66 * IOMAP_F_ATOMIC_BIO indicates that (write) I/O will be issued as an atomic
67 * bio, i.e. set REQ_ATOMIC.
68 */
69 #define IOMAP_F_NEW (1U << 0)
70 #define IOMAP_F_DIRTY (1U << 1)
71 #define IOMAP_F_SHARED (1U << 2)
72 #define IOMAP_F_MERGED (1U << 3)
73 #ifdef CONFIG_BUFFER_HEAD
74 #define IOMAP_F_BUFFER_HEAD (1U << 4)
75 #else
76 #define IOMAP_F_BUFFER_HEAD 0
77 #endif /* CONFIG_BUFFER_HEAD */
78 #define IOMAP_F_XATTR (1U << 5)
79 #define IOMAP_F_BOUNDARY (1U << 6)
80 #define IOMAP_F_ANON_WRITE (1U << 7)
81 #define IOMAP_F_ATOMIC_BIO (1U << 8)
82
83 /*
84 * Flag reserved for file system specific usage
85 */
86 #define IOMAP_F_PRIVATE (1U << 12)
87
88 /*
89 * Flags set by the core iomap code during operations:
90 *
91 * IOMAP_F_FOLIO_BATCH indicates that the folio batch mechanism is active
92 * for this operation, set by iomap_fill_dirty_folios().
93 *
94 * IOMAP_F_SIZE_CHANGED indicates to the iomap_end method that the file size
95 * has changed as the result of this write operation.
96 *
97 * IOMAP_F_STALE indicates that the iomap is not valid any longer and the file
98 * range it covers needs to be remapped by the high level before the operation
99 * can proceed.
100 */
101 #define IOMAP_F_FOLIO_BATCH (1U << 13)
102 #define IOMAP_F_SIZE_CHANGED (1U << 14)
103 #define IOMAP_F_STALE (1U << 15)
104
105 /*
106 * Magic value for addr:
107 */
108 #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */
109
110 struct iomap {
111 u64 addr; /* disk offset of mapping, bytes */
112 loff_t offset; /* file offset of mapping, bytes */
113 u64 length; /* length of mapping, bytes */
114 u16 type; /* type of mapping */
115 u16 flags; /* flags for mapping */
116 struct block_device *bdev; /* block device for I/O */
117 struct dax_device *dax_dev; /* dax_dev for dax operations */
118 void *inline_data;
119 void *private; /* filesystem private */
120 u64 validity_cookie; /* used with .iomap_valid() */
121 };
122
iomap_sector(const struct iomap * iomap,loff_t pos)123 static inline sector_t iomap_sector(const struct iomap *iomap, loff_t pos)
124 {
125 if (iomap->flags & IOMAP_F_ANON_WRITE)
126 return U64_MAX; /* invalid */
127 return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;
128 }
129
130 /*
131 * Returns the inline data pointer for logical offset @pos.
132 */
iomap_inline_data(const struct iomap * iomap,loff_t pos)133 static inline void *iomap_inline_data(const struct iomap *iomap, loff_t pos)
134 {
135 return iomap->inline_data + pos - iomap->offset;
136 }
137
138 /*
139 * Check if the mapping's length is within the valid range for inline data.
140 * This is used to guard against accessing data beyond the page inline_data
141 * points at.
142 */
iomap_inline_data_valid(const struct iomap * iomap)143 static inline bool iomap_inline_data_valid(const struct iomap *iomap)
144 {
145 return iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data);
146 }
147
148 /*
149 * When get_folio succeeds, put_folio will always be called to do any
150 * cleanup work necessary. put_folio is responsible for unlocking and putting
151 * @folio.
152 */
153 struct iomap_write_ops {
154 struct folio *(*get_folio)(struct iomap_iter *iter, loff_t pos,
155 unsigned len);
156 void (*put_folio)(struct inode *inode, loff_t pos, unsigned copied,
157 struct folio *folio);
158
159 /*
160 * Check that the cached iomap still maps correctly to the filesystem's
161 * internal extent map. FS internal extent maps can change while iomap
162 * is iterating a cached iomap, so this hook allows iomap to detect that
163 * the iomap needs to be refreshed during a long running write
164 * operation.
165 *
166 * The filesystem can store internal state (e.g. a sequence number) in
167 * iomap->validity_cookie when the iomap is first mapped to be able to
168 * detect changes between mapping time and whenever .iomap_valid() is
169 * called.
170 *
171 * This is called with the folio over the specified file position held
172 * locked by the iomap code.
173 */
174 bool (*iomap_valid)(struct inode *inode, const struct iomap *iomap);
175
176 /*
177 * Optional if the filesystem wishes to provide a custom handler for
178 * reading in the contents of a folio, otherwise iomap will default to
179 * submitting a bio read request.
180 *
181 * The read must be done synchronously.
182 */
183 int (*read_folio_range)(const struct iomap_iter *iter,
184 struct folio *folio, loff_t pos, size_t len);
185 };
186
187 /*
188 * Flags for iomap_begin / iomap_end. No flag implies a read.
189 */
190 #define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
191 #define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
192 #define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
193 #define IOMAP_FAULT (1 << 3) /* mapping for page fault */
194 #define IOMAP_DIRECT (1 << 4) /* direct I/O */
195 #define IOMAP_NOWAIT (1 << 5) /* do not block */
196 #define IOMAP_OVERWRITE_ONLY (1 << 6) /* only pure overwrites allowed */
197 #define IOMAP_UNSHARE (1 << 7) /* unshare_file_range */
198 #ifdef CONFIG_FS_DAX
199 #define IOMAP_DAX (1 << 8) /* DAX mapping */
200 #else
201 #define IOMAP_DAX 0
202 #endif /* CONFIG_FS_DAX */
203 #define IOMAP_ATOMIC (1 << 9) /* torn-write protection */
204 #define IOMAP_DONTCACHE (1 << 10)
205
206 struct iomap_ops {
207 /*
208 * Return the existing mapping at pos, or reserve space starting at
209 * pos for up to length, as long as we can do it as a single mapping.
210 * The actual length is returned in iomap->length.
211 */
212 int (*iomap_begin)(struct inode *inode, loff_t pos, loff_t length,
213 unsigned flags, struct iomap *iomap,
214 struct iomap *srcmap);
215
216 /*
217 * Commit and/or unreserve space previous allocated using iomap_begin.
218 * Written indicates the length of the successful write operation which
219 * needs to be commited, while the rest needs to be unreserved.
220 * Written might be zero if no data was written.
221 */
222 int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
223 ssize_t written, unsigned flags, struct iomap *iomap);
224 };
225
226 /**
227 * struct iomap_iter - Iterate through a range of a file
228 * @inode: Set at the start of the iteration and should not change.
229 * @pos: The current file position we are operating on. It is updated by
230 * calls to iomap_iter(). Treat as read-only in the body.
231 * @len: The remaining length of the file segment we're operating on.
232 * It is updated at the same time as @pos.
233 * @iter_start_pos: The original start pos for the current iomap. Used for
234 * incremental iter advance.
235 * @status: Status of the most recent iteration. Zero on success or a negative
236 * errno on error.
237 * @flags: Zero or more of the iomap_begin flags above.
238 * @iomap: Map describing the I/O iteration
239 * @srcmap: Source map for COW operations
240 */
241 struct iomap_iter {
242 struct inode *inode;
243 loff_t pos;
244 u64 len;
245 loff_t iter_start_pos;
246 int status;
247 unsigned flags;
248 struct iomap iomap;
249 struct iomap srcmap;
250 struct folio_batch *fbatch;
251 void *private;
252 };
253
254 int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);
255 int iomap_iter_advance(struct iomap_iter *iter, u64 count);
256
257 /**
258 * iomap_length_trim - trimmed length of the current iomap iteration
259 * @iter: iteration structure
260 * @pos: File position to trim from.
261 * @len: Length of the mapping to trim to.
262 *
263 * Returns a trimmed length that the operation applies to for the current
264 * iteration.
265 */
iomap_length_trim(const struct iomap_iter * iter,loff_t pos,u64 len)266 static inline u64 iomap_length_trim(const struct iomap_iter *iter, loff_t pos,
267 u64 len)
268 {
269 u64 end = iter->iomap.offset + iter->iomap.length;
270
271 if (iter->srcmap.type != IOMAP_HOLE)
272 end = min(end, iter->srcmap.offset + iter->srcmap.length);
273 return min(len, end - pos);
274 }
275
276 /**
277 * iomap_length - length of the current iomap iteration
278 * @iter: iteration structure
279 *
280 * Returns the length that the operation applies to for the current iteration.
281 */
iomap_length(const struct iomap_iter * iter)282 static inline u64 iomap_length(const struct iomap_iter *iter)
283 {
284 return iomap_length_trim(iter, iter->pos, iter->len);
285 }
286
287 /**
288 * iomap_iter_advance_full - advance by the full length of current map
289 */
iomap_iter_advance_full(struct iomap_iter * iter)290 static inline int iomap_iter_advance_full(struct iomap_iter *iter)
291 {
292 return iomap_iter_advance(iter, iomap_length(iter));
293 }
294
295 /**
296 * iomap_iter_srcmap - return the source map for the current iomap iteration
297 * @i: iteration structure
298 *
299 * Write operations on file systems with reflink support might require a
300 * source and a destination map. This function retourns the source map
301 * for a given operation, which may or may no be identical to the destination
302 * map in &i->iomap.
303 */
iomap_iter_srcmap(const struct iomap_iter * i)304 static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i)
305 {
306 if (i->srcmap.type != IOMAP_HOLE)
307 return &i->srcmap;
308 return &i->iomap;
309 }
310
311 /*
312 * Return the file offset for the first unchanged block after a short write.
313 *
314 * If nothing was written, round @pos down to point at the first block in
315 * the range, else round up to include the partially written block.
316 */
iomap_last_written_block(struct inode * inode,loff_t pos,ssize_t written)317 static inline loff_t iomap_last_written_block(struct inode *inode, loff_t pos,
318 ssize_t written)
319 {
320 if (unlikely(!written))
321 return round_down(pos, i_blocksize(inode));
322 return round_up(pos + written, i_blocksize(inode));
323 }
324
325 /*
326 * Check if the range needs to be unshared for a FALLOC_FL_UNSHARE_RANGE
327 * operation.
328 *
329 * Don't bother with blocks that are not shared to start with; or mappings that
330 * cannot be shared, such as inline data, delalloc reservations, holes or
331 * unwritten extents.
332 *
333 * Note that we use srcmap directly instead of iomap_iter_srcmap as unsharing
334 * requires providing a separate source map, and the presence of one is a good
335 * indicator that unsharing is needed, unlike IOMAP_F_SHARED which can be set
336 * for any data that goes into the COW fork for XFS.
337 */
iomap_want_unshare_iter(const struct iomap_iter * iter)338 static inline bool iomap_want_unshare_iter(const struct iomap_iter *iter)
339 {
340 return (iter->iomap.flags & IOMAP_F_SHARED) &&
341 iter->srcmap.type == IOMAP_MAPPED;
342 }
343
344 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
345 const struct iomap_ops *ops,
346 const struct iomap_write_ops *write_ops, void *private);
347 void iomap_read_folio(const struct iomap_ops *ops,
348 struct iomap_read_folio_ctx *ctx);
349 void iomap_readahead(const struct iomap_ops *ops,
350 struct iomap_read_folio_ctx *ctx);
351 bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count);
352 struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos, size_t len);
353 bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags);
354 void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
355 bool iomap_dirty_folio(struct address_space *mapping, struct folio *folio);
356 int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
357 const struct iomap_ops *ops,
358 const struct iomap_write_ops *write_ops);
359 unsigned int iomap_fill_dirty_folios(struct iomap_iter *iter, loff_t *start,
360 loff_t end, unsigned int *iomap_flags);
361 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
362 bool *did_zero, const struct iomap_ops *ops,
363 const struct iomap_write_ops *write_ops, void *private);
364 int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
365 const struct iomap_ops *ops,
366 const struct iomap_write_ops *write_ops, void *private);
367 vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops,
368 void *private);
369 typedef void (*iomap_punch_t)(struct inode *inode, loff_t offset, loff_t length,
370 struct iomap *iomap);
371 void iomap_write_delalloc_release(struct inode *inode, loff_t start_byte,
372 loff_t end_byte, unsigned flags, struct iomap *iomap,
373 iomap_punch_t punch);
374
375 int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
376 u64 start, u64 len, const struct iomap_ops *ops);
377 loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
378 const struct iomap_ops *ops);
379 loff_t iomap_seek_data(struct inode *inode, loff_t offset,
380 const struct iomap_ops *ops);
381 sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
382 const struct iomap_ops *ops);
383
384 /*
385 * Flags for iomap_ioend->io_flags.
386 */
387 /* shared COW extent */
388 #define IOMAP_IOEND_SHARED (1U << 0)
389 /* unwritten extent */
390 #define IOMAP_IOEND_UNWRITTEN (1U << 1)
391 /* don't merge into previous ioend */
392 #define IOMAP_IOEND_BOUNDARY (1U << 2)
393 /* is direct I/O */
394 #define IOMAP_IOEND_DIRECT (1U << 3)
395 /* is DONTCACHE I/O */
396 #define IOMAP_IOEND_DONTCACHE (1U << 4)
397
398 /*
399 * Flags that if set on either ioend prevent the merge of two ioends.
400 * (IOMAP_IOEND_BOUNDARY also prevents merges, but only one-way)
401 */
402 #define IOMAP_IOEND_NOMERGE_FLAGS \
403 (IOMAP_IOEND_SHARED | IOMAP_IOEND_UNWRITTEN | IOMAP_IOEND_DIRECT | \
404 IOMAP_IOEND_DONTCACHE)
405
406 /*
407 * Structure for writeback I/O completions.
408 *
409 * File systems can split a bio generated by iomap. In that case the parent
410 * ioend it was split from is recorded in ioend->io_parent.
411 */
412 struct iomap_ioend {
413 struct list_head io_list; /* next ioend in chain */
414 u16 io_flags; /* IOMAP_IOEND_* */
415 struct inode *io_inode; /* file being written to */
416 size_t io_size; /* size of the extent */
417 atomic_t io_remaining; /* completetion defer count */
418 int io_error; /* stashed away status */
419 struct iomap_ioend *io_parent; /* parent for completions */
420 loff_t io_offset; /* offset in the file */
421 sector_t io_sector; /* start sector of ioend */
422 void *io_private; /* file system private data */
423 struct bio io_bio; /* MUST BE LAST! */
424 };
425
iomap_ioend_from_bio(struct bio * bio)426 static inline struct iomap_ioend *iomap_ioend_from_bio(struct bio *bio)
427 {
428 return container_of(bio, struct iomap_ioend, io_bio);
429 }
430
431 struct iomap_writeback_ops {
432 /*
433 * Performs writeback on the passed in range
434 *
435 * Can map arbitrarily large regions, but we need to call into it at
436 * least once per folio to allow the file systems to synchronize with
437 * the write path that could be invalidating mappings.
438 *
439 * An existing mapping from a previous call to this method can be reused
440 * by the file system if it is still valid.
441 *
442 * If this succeeds, iomap_finish_folio_write() must be called once
443 * writeback completes for the range, regardless of whether the
444 * writeback succeeded or failed.
445 *
446 * Returns the number of bytes processed or a negative errno.
447 */
448 ssize_t (*writeback_range)(struct iomap_writepage_ctx *wpc,
449 struct folio *folio, u64 pos, unsigned int len,
450 u64 end_pos);
451
452 /*
453 * Submit a writeback context previously build up by ->writeback_range.
454 *
455 * Returns 0 if the context was successfully submitted, or a negative
456 * error code if not. If @error is non-zero a failure occurred, and
457 * the writeback context should be completed with an error.
458 */
459 int (*writeback_submit)(struct iomap_writepage_ctx *wpc, int error);
460 };
461
462 struct iomap_writepage_ctx {
463 struct iomap iomap;
464 struct inode *inode;
465 struct writeback_control *wbc;
466 const struct iomap_writeback_ops *ops;
467 u32 nr_folios; /* folios added to the ioend */
468 void *wb_ctx; /* pending writeback context */
469 };
470
471 struct iomap_ioend *iomap_init_ioend(struct inode *inode, struct bio *bio,
472 loff_t file_offset, u16 ioend_flags);
473 struct iomap_ioend *iomap_split_ioend(struct iomap_ioend *ioend,
474 unsigned int max_len, bool is_append);
475 void iomap_finish_ioends(struct iomap_ioend *ioend, int error);
476 void iomap_ioend_try_merge(struct iomap_ioend *ioend,
477 struct list_head *more_ioends);
478 void iomap_sort_ioends(struct list_head *ioend_list);
479 ssize_t iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, struct folio *folio,
480 loff_t pos, loff_t end_pos, unsigned int dirty_len);
481 int iomap_ioend_writeback_submit(struct iomap_writepage_ctx *wpc, int error);
482
483 void iomap_finish_folio_read(struct folio *folio, size_t off, size_t len,
484 int error);
485 void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
486 size_t len);
487
488 int iomap_writeback_folio(struct iomap_writepage_ctx *wpc, struct folio *folio);
489 int iomap_writepages(struct iomap_writepage_ctx *wpc);
490
491 struct iomap_read_folio_ctx {
492 const struct iomap_read_ops *ops;
493 struct folio *cur_folio;
494 struct readahead_control *rac;
495 void *read_ctx;
496 };
497
498 struct iomap_read_ops {
499 /*
500 * Read in a folio range.
501 *
502 * If this succeeds, iomap_finish_folio_read() must be called after the
503 * range is read in, regardless of whether the read succeeded or failed.
504 *
505 * Returns 0 on success or a negative error on failure.
506 */
507 int (*read_folio_range)(const struct iomap_iter *iter,
508 struct iomap_read_folio_ctx *ctx, size_t len);
509
510 /*
511 * Submit any pending read requests.
512 *
513 * This is optional.
514 */
515 void (*submit_read)(struct iomap_read_folio_ctx *ctx);
516 };
517
518 /*
519 * Flags for direct I/O ->end_io:
520 */
521 #define IOMAP_DIO_UNWRITTEN (1 << 0) /* covers unwritten extent(s) */
522 #define IOMAP_DIO_COW (1 << 1) /* covers COW extent(s) */
523
524 struct iomap_dio_ops {
525 int (*end_io)(struct kiocb *iocb, ssize_t size, int error,
526 unsigned flags);
527 void (*submit_io)(const struct iomap_iter *iter, struct bio *bio,
528 loff_t file_offset);
529
530 /*
531 * Filesystems wishing to attach private information to a direct io bio
532 * must provide a ->submit_io method that attaches the additional
533 * information to the bio and changes the ->bi_end_io callback to a
534 * custom function. This function should, at a minimum, perform any
535 * relevant post-processing of the bio and end with a call to
536 * iomap_dio_bio_end_io.
537 */
538 struct bio_set *bio_set;
539 };
540
541 /*
542 * Wait for the I/O to complete in iomap_dio_rw even if the kiocb is not
543 * synchronous.
544 */
545 #define IOMAP_DIO_FORCE_WAIT (1 << 0)
546
547 /*
548 * Do not allocate blocks or zero partial blocks, but instead fall back to
549 * the caller by returning -EAGAIN. Used to optimize direct I/O writes that
550 * are not aligned to the file system block size.
551 */
552 #define IOMAP_DIO_OVERWRITE_ONLY (1 << 1)
553
554 /*
555 * When a page fault occurs, return a partial synchronous result and allow
556 * the caller to retry the rest of the operation after dealing with the page
557 * fault.
558 */
559 #define IOMAP_DIO_PARTIAL (1 << 2)
560
561 /*
562 * Ensure each bio is aligned to fs block size.
563 *
564 * For filesystems which need to calculate/verify the checksum of each fs
565 * block. Otherwise they may not be able to handle unaligned bios.
566 */
567 #define IOMAP_DIO_FSBLOCK_ALIGNED (1 << 3)
568
569 ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
570 const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
571 unsigned int dio_flags, void *private, size_t done_before);
572 struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
573 const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
574 unsigned int dio_flags, void *private, size_t done_before);
575 ssize_t iomap_dio_complete(struct iomap_dio *dio);
576 void iomap_dio_bio_end_io(struct bio *bio);
577
578 #ifdef CONFIG_SWAP
579 struct file;
580 struct swap_info_struct;
581
582 int iomap_swapfile_activate(struct swap_info_struct *sis,
583 struct file *swap_file, sector_t *pagespan,
584 const struct iomap_ops *ops);
585 #else
586 # define iomap_swapfile_activate(sis, swapfile, pagespan, ops) (-EIO)
587 #endif /* CONFIG_SWAP */
588
589 extern struct bio_set iomap_ioend_bioset;
590
591 #ifdef CONFIG_BLOCK
592 extern const struct iomap_read_ops iomap_bio_read_ops;
593
iomap_bio_read_folio(struct folio * folio,const struct iomap_ops * ops)594 static inline void iomap_bio_read_folio(struct folio *folio,
595 const struct iomap_ops *ops)
596 {
597 struct iomap_read_folio_ctx ctx = {
598 .ops = &iomap_bio_read_ops,
599 .cur_folio = folio,
600 };
601
602 iomap_read_folio(ops, &ctx);
603 }
604
iomap_bio_readahead(struct readahead_control * rac,const struct iomap_ops * ops)605 static inline void iomap_bio_readahead(struct readahead_control *rac,
606 const struct iomap_ops *ops)
607 {
608 struct iomap_read_folio_ctx ctx = {
609 .ops = &iomap_bio_read_ops,
610 .rac = rac,
611 };
612
613 iomap_readahead(ops, &ctx);
614 }
615 #endif /* CONFIG_BLOCK */
616
617 #endif /* LINUX_IOMAP_H */
618