1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
4  */
5 #ifndef __LINUX_BIO_H
6 #define __LINUX_BIO_H
7 
8 #include <linux/mempool.h>
9 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
10 #include <linux/blk_types.h>
11 #include <linux/uio.h>
12 
13 #define BIO_MAX_VECS		256U
14 
15 struct queue_limits;
16 
bio_max_segs(unsigned int nr_segs)17 static inline unsigned int bio_max_segs(unsigned int nr_segs)
18 {
19 	return min(nr_segs, BIO_MAX_VECS);
20 }
21 
22 #define bio_prio(bio)			(bio)->bi_ioprio
23 #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
24 
25 #define bio_iter_iovec(bio, iter)				\
26 	bvec_iter_bvec((bio)->bi_io_vec, (iter))
27 
28 #define bio_iter_page(bio, iter)				\
29 	bvec_iter_page((bio)->bi_io_vec, (iter))
30 #define bio_iter_len(bio, iter)					\
31 	bvec_iter_len((bio)->bi_io_vec, (iter))
32 #define bio_iter_offset(bio, iter)				\
33 	bvec_iter_offset((bio)->bi_io_vec, (iter))
34 
35 #define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
36 #define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
37 #define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
38 
39 #define bvec_iter_sectors(iter)	((iter).bi_size >> 9)
40 #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
41 
42 #define bio_sectors(bio)	bvec_iter_sectors((bio)->bi_iter)
43 #define bio_end_sector(bio)	bvec_iter_end_sector((bio)->bi_iter)
44 
45 /*
46  * Return the data direction, READ or WRITE.
47  */
48 #define bio_data_dir(bio) \
49 	(op_is_write(bio_op(bio)) ? WRITE : READ)
50 
51 /*
52  * Check whether this bio carries any data or not. A NULL bio is allowed.
53  */
bio_has_data(struct bio * bio)54 static inline bool bio_has_data(struct bio *bio)
55 {
56 	if (bio &&
57 	    bio->bi_iter.bi_size &&
58 	    bio_op(bio) != REQ_OP_DISCARD &&
59 	    bio_op(bio) != REQ_OP_SECURE_ERASE &&
60 	    bio_op(bio) != REQ_OP_WRITE_ZEROES)
61 		return true;
62 
63 	return false;
64 }
65 
bio_no_advance_iter(const struct bio * bio)66 static inline bool bio_no_advance_iter(const struct bio *bio)
67 {
68 	return bio_op(bio) == REQ_OP_DISCARD ||
69 	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
70 	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
71 }
72 
bio_data(struct bio * bio)73 static inline void *bio_data(struct bio *bio)
74 {
75 	if (bio_has_data(bio))
76 		return page_address(bio_page(bio)) + bio_offset(bio);
77 
78 	return NULL;
79 }
80 
bio_next_segment(const struct bio * bio,struct bvec_iter_all * iter)81 static inline bool bio_next_segment(const struct bio *bio,
82 				    struct bvec_iter_all *iter)
83 {
84 	if (iter->idx >= bio->bi_vcnt)
85 		return false;
86 
87 	bvec_advance(&bio->bi_io_vec[iter->idx], iter);
88 	return true;
89 }
90 
91 /*
92  * drivers should _never_ use the all version - the bio may have been split
93  * before it got to the driver and the driver won't own all of it
94  */
95 #define bio_for_each_segment_all(bvl, bio, iter) \
96 	for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
97 
bio_advance_iter(const struct bio * bio,struct bvec_iter * iter,unsigned int bytes)98 static inline void bio_advance_iter(const struct bio *bio,
99 				    struct bvec_iter *iter, unsigned int bytes)
100 {
101 	iter->bi_sector += bytes >> 9;
102 
103 	if (bio_no_advance_iter(bio))
104 		iter->bi_size -= bytes;
105 	else
106 		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
107 		/* TODO: It is reasonable to complete bio with error here. */
108 }
109 
110 /* @bytes should be less or equal to bvec[i->bi_idx].bv_len */
bio_advance_iter_single(const struct bio * bio,struct bvec_iter * iter,unsigned int bytes)111 static inline void bio_advance_iter_single(const struct bio *bio,
112 					   struct bvec_iter *iter,
113 					   unsigned int bytes)
114 {
115 	iter->bi_sector += bytes >> 9;
116 
117 	if (bio_no_advance_iter(bio))
118 		iter->bi_size -= bytes;
119 	else
120 		bvec_iter_advance_single(bio->bi_io_vec, iter, bytes);
121 }
122 
123 void __bio_advance(struct bio *, unsigned bytes);
124 
125 /**
126  * bio_advance - increment/complete a bio by some number of bytes
127  * @bio:	bio to advance
128  * @nbytes:	number of bytes to complete
129  *
130  * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
131  * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
132  * be updated on the last bvec as well.
133  *
134  * @bio will then represent the remaining, uncompleted portion of the io.
135  */
bio_advance(struct bio * bio,unsigned int nbytes)136 static inline void bio_advance(struct bio *bio, unsigned int nbytes)
137 {
138 	if (nbytes == bio->bi_iter.bi_size) {
139 		bio->bi_iter.bi_size = 0;
140 		return;
141 	}
142 	__bio_advance(bio, nbytes);
143 }
144 
145 #define __bio_for_each_segment(bvl, bio, iter, start)			\
146 	for (iter = (start);						\
147 	     (iter).bi_size &&						\
148 		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
149 	     bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
150 
151 #define bio_for_each_segment(bvl, bio, iter)				\
152 	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
153 
154 #define __bio_for_each_bvec(bvl, bio, iter, start)		\
155 	for (iter = (start);						\
156 	     (iter).bi_size &&						\
157 		((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
158 	     bio_advance_iter_single((bio), &(iter), (bvl).bv_len))
159 
160 /* iterate over multi-page bvec */
161 #define bio_for_each_bvec(bvl, bio, iter)			\
162 	__bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
163 
164 /*
165  * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
166  * same reasons as bio_for_each_segment_all().
167  */
168 #define bio_for_each_bvec_all(bvl, bio, i)		\
169 	for (i = 0, bvl = bio_first_bvec_all(bio);	\
170 	     i < (bio)->bi_vcnt; i++, bvl++)
171 
172 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
173 
bio_segments(struct bio * bio)174 static inline unsigned bio_segments(struct bio *bio)
175 {
176 	unsigned segs = 0;
177 	struct bio_vec bv;
178 	struct bvec_iter iter;
179 
180 	/*
181 	 * We special case discard/write same/write zeroes, because they
182 	 * interpret bi_size differently:
183 	 */
184 
185 	switch (bio_op(bio)) {
186 	case REQ_OP_DISCARD:
187 	case REQ_OP_SECURE_ERASE:
188 	case REQ_OP_WRITE_ZEROES:
189 		return 0;
190 	default:
191 		break;
192 	}
193 
194 	bio_for_each_segment(bv, bio, iter)
195 		segs++;
196 
197 	return segs;
198 }
199 
200 /*
201  * get a reference to a bio, so it won't disappear. the intended use is
202  * something like:
203  *
204  * bio_get(bio);
205  * submit_bio(rw, bio);
206  * if (bio->bi_flags ...)
207  *	do_something
208  * bio_put(bio);
209  *
210  * without the bio_get(), it could potentially complete I/O before submit_bio
211  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
212  * runs
213  */
bio_get(struct bio * bio)214 static inline void bio_get(struct bio *bio)
215 {
216 	bio->bi_flags |= (1 << BIO_REFFED);
217 	smp_mb__before_atomic();
218 	atomic_inc(&bio->__bi_cnt);
219 }
220 
bio_cnt_set(struct bio * bio,unsigned int count)221 static inline void bio_cnt_set(struct bio *bio, unsigned int count)
222 {
223 	if (count != 1) {
224 		bio->bi_flags |= (1 << BIO_REFFED);
225 		smp_mb();
226 	}
227 	atomic_set(&bio->__bi_cnt, count);
228 }
229 
bio_flagged(struct bio * bio,unsigned int bit)230 static inline bool bio_flagged(struct bio *bio, unsigned int bit)
231 {
232 	return (bio->bi_flags & (1U << bit)) != 0;
233 }
234 
bio_set_flag(struct bio * bio,unsigned int bit)235 static inline void bio_set_flag(struct bio *bio, unsigned int bit)
236 {
237 	bio->bi_flags |= (1U << bit);
238 }
239 
bio_clear_flag(struct bio * bio,unsigned int bit)240 static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
241 {
242 	bio->bi_flags &= ~(1U << bit);
243 }
244 
bio_first_bvec_all(struct bio * bio)245 static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
246 {
247 	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
248 	return bio->bi_io_vec;
249 }
250 
bio_first_page_all(struct bio * bio)251 static inline struct page *bio_first_page_all(struct bio *bio)
252 {
253 	return bio_first_bvec_all(bio)->bv_page;
254 }
255 
bio_last_bvec_all(struct bio * bio)256 static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
257 {
258 	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
259 	return &bio->bi_io_vec[bio->bi_vcnt - 1];
260 }
261 
262 /**
263  * struct folio_iter - State for iterating all folios in a bio.
264  * @folio: The current folio we're iterating.  NULL after the last folio.
265  * @offset: The byte offset within the current folio.
266  * @length: The number of bytes in this iteration (will not cross folio
267  *	boundary).
268  */
269 struct folio_iter {
270 	struct folio *folio;
271 	size_t offset;
272 	size_t length;
273 	/* private: for use by the iterator */
274 	struct folio *_next;
275 	size_t _seg_count;
276 	int _i;
277 };
278 
bio_first_folio(struct folio_iter * fi,struct bio * bio,int i)279 static inline void bio_first_folio(struct folio_iter *fi, struct bio *bio,
280 				   int i)
281 {
282 	struct bio_vec *bvec = bio_first_bvec_all(bio) + i;
283 
284 	fi->folio = page_folio(bvec->bv_page);
285 	fi->offset = bvec->bv_offset +
286 			PAGE_SIZE * (bvec->bv_page - &fi->folio->page);
287 	fi->_seg_count = bvec->bv_len;
288 	fi->length = min(folio_size(fi->folio) - fi->offset, fi->_seg_count);
289 	fi->_next = folio_next(fi->folio);
290 	fi->_i = i;
291 }
292 
bio_next_folio(struct folio_iter * fi,struct bio * bio)293 static inline void bio_next_folio(struct folio_iter *fi, struct bio *bio)
294 {
295 	fi->_seg_count -= fi->length;
296 	if (fi->_seg_count) {
297 		fi->folio = fi->_next;
298 		fi->offset = 0;
299 		fi->length = min(folio_size(fi->folio), fi->_seg_count);
300 		fi->_next = folio_next(fi->folio);
301 	} else if (fi->_i + 1 < bio->bi_vcnt) {
302 		bio_first_folio(fi, bio, fi->_i + 1);
303 	} else {
304 		fi->folio = NULL;
305 	}
306 }
307 
308 /**
309  * bio_for_each_folio_all - Iterate over each folio in a bio.
310  * @fi: struct folio_iter which is updated for each folio.
311  * @bio: struct bio to iterate over.
312  */
313 #define bio_for_each_folio_all(fi, bio)				\
314 	for (bio_first_folio(&fi, bio, 0); fi.folio; bio_next_folio(&fi, bio))
315 
316 enum bip_flags {
317 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
318 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
319 	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
320 	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
321 	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
322 };
323 
324 /*
325  * bio integrity payload
326  */
327 struct bio_integrity_payload {
328 	struct bio		*bip_bio;	/* parent bio */
329 
330 	struct bvec_iter	bip_iter;
331 
332 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
333 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
334 	unsigned short		bip_flags;	/* control flags */
335 
336 	struct bvec_iter	bio_iter;	/* for rewinding parent bio */
337 
338 	struct work_struct	bip_work;	/* I/O completion */
339 
340 	struct bio_vec		*bip_vec;
341 	struct bio_vec		bip_inline_vecs[];/* embedded bvec array */
342 };
343 
344 #if defined(CONFIG_BLK_DEV_INTEGRITY)
345 
bio_integrity(struct bio * bio)346 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
347 {
348 	if (bio->bi_opf & REQ_INTEGRITY)
349 		return bio->bi_integrity;
350 
351 	return NULL;
352 }
353 
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)354 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
355 {
356 	struct bio_integrity_payload *bip = bio_integrity(bio);
357 
358 	if (bip)
359 		return bip->bip_flags & flag;
360 
361 	return false;
362 }
363 
bip_get_seed(struct bio_integrity_payload * bip)364 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
365 {
366 	return bip->bip_iter.bi_sector;
367 }
368 
bip_set_seed(struct bio_integrity_payload * bip,sector_t seed)369 static inline void bip_set_seed(struct bio_integrity_payload *bip,
370 				sector_t seed)
371 {
372 	bip->bip_iter.bi_sector = seed;
373 }
374 
375 #endif /* CONFIG_BLK_DEV_INTEGRITY */
376 
377 void bio_trim(struct bio *bio, sector_t offset, sector_t size);
378 extern struct bio *bio_split(struct bio *bio, int sectors,
379 			     gfp_t gfp, struct bio_set *bs);
380 struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
381 		unsigned *segs, struct bio_set *bs, unsigned max_bytes);
382 
383 /**
384  * bio_next_split - get next @sectors from a bio, splitting if necessary
385  * @bio:	bio to split
386  * @sectors:	number of sectors to split from the front of @bio
387  * @gfp:	gfp mask
388  * @bs:		bio set to allocate from
389  *
390  * Return: a bio representing the next @sectors of @bio - if the bio is smaller
391  * than @sectors, returns the original bio unchanged.
392  */
bio_next_split(struct bio * bio,int sectors,gfp_t gfp,struct bio_set * bs)393 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
394 					 gfp_t gfp, struct bio_set *bs)
395 {
396 	if (sectors >= bio_sectors(bio))
397 		return bio;
398 
399 	return bio_split(bio, sectors, gfp, bs);
400 }
401 
402 enum {
403 	BIOSET_NEED_BVECS = BIT(0),
404 	BIOSET_NEED_RESCUER = BIT(1),
405 	BIOSET_PERCPU_CACHE = BIT(2),
406 };
407 extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
408 extern void bioset_exit(struct bio_set *);
409 extern int biovec_init_pool(mempool_t *pool, int pool_entries);
410 
411 struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
412 			     blk_opf_t opf, gfp_t gfp_mask,
413 			     struct bio_set *bs);
414 struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask);
415 extern void bio_put(struct bio *);
416 
417 struct bio *bio_alloc_clone(struct block_device *bdev, struct bio *bio_src,
418 		gfp_t gfp, struct bio_set *bs);
419 int bio_init_clone(struct block_device *bdev, struct bio *bio,
420 		struct bio *bio_src, gfp_t gfp);
421 
422 extern struct bio_set fs_bio_set;
423 
bio_alloc(struct block_device * bdev,unsigned short nr_vecs,blk_opf_t opf,gfp_t gfp_mask)424 static inline struct bio *bio_alloc(struct block_device *bdev,
425 		unsigned short nr_vecs, blk_opf_t opf, gfp_t gfp_mask)
426 {
427 	return bio_alloc_bioset(bdev, nr_vecs, opf, gfp_mask, &fs_bio_set);
428 }
429 
430 void submit_bio(struct bio *bio);
431 
432 extern void bio_endio(struct bio *);
433 
bio_io_error(struct bio * bio)434 static inline void bio_io_error(struct bio *bio)
435 {
436 	bio->bi_status = BLK_STS_IOERR;
437 	bio_endio(bio);
438 }
439 
bio_wouldblock_error(struct bio * bio)440 static inline void bio_wouldblock_error(struct bio *bio)
441 {
442 	bio_set_flag(bio, BIO_QUIET);
443 	bio->bi_status = BLK_STS_AGAIN;
444 	bio_endio(bio);
445 }
446 
447 /*
448  * Calculate number of bvec segments that should be allocated to fit data
449  * pointed by @iter. If @iter is backed by bvec it's going to be reused
450  * instead of allocating a new one.
451  */
bio_iov_vecs_to_alloc(struct iov_iter * iter,int max_segs)452 static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs)
453 {
454 	if (iov_iter_is_bvec(iter))
455 		return 0;
456 	return iov_iter_npages(iter, max_segs);
457 }
458 
459 struct request_queue;
460 
461 extern int submit_bio_wait(struct bio *bio);
462 void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
463 	      unsigned short max_vecs, blk_opf_t opf);
464 extern void bio_uninit(struct bio *);
465 void bio_reset(struct bio *bio, struct block_device *bdev, blk_opf_t opf);
466 void bio_chain(struct bio *, struct bio *);
467 
468 int bio_add_page(struct bio *, struct page *, unsigned len, unsigned off);
469 bool bio_add_folio(struct bio *, struct folio *, size_t len, size_t off);
470 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
471 			   unsigned int, unsigned int);
472 int bio_add_zone_append_page(struct bio *bio, struct page *page,
473 			     unsigned int len, unsigned int offset);
474 void __bio_add_page(struct bio *bio, struct page *page,
475 		unsigned int len, unsigned int off);
476 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
477 void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter);
478 void __bio_release_pages(struct bio *bio, bool mark_dirty);
479 extern void bio_set_pages_dirty(struct bio *bio);
480 extern void bio_check_pages_dirty(struct bio *bio);
481 
482 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
483 			       struct bio *src, struct bvec_iter *src_iter);
484 extern void bio_copy_data(struct bio *dst, struct bio *src);
485 extern void bio_free_pages(struct bio *bio);
486 void guard_bio_eod(struct bio *bio);
487 void zero_fill_bio(struct bio *bio);
488 
bio_release_pages(struct bio * bio,bool mark_dirty)489 static inline void bio_release_pages(struct bio *bio, bool mark_dirty)
490 {
491 	if (!bio_flagged(bio, BIO_NO_PAGE_REF))
492 		__bio_release_pages(bio, mark_dirty);
493 }
494 
495 #define bio_dev(bio) \
496 	disk_devt((bio)->bi_bdev->bd_disk)
497 
498 #ifdef CONFIG_BLK_CGROUP
499 void bio_associate_blkg(struct bio *bio);
500 void bio_associate_blkg_from_css(struct bio *bio,
501 				 struct cgroup_subsys_state *css);
502 void bio_clone_blkg_association(struct bio *dst, struct bio *src);
503 #else	/* CONFIG_BLK_CGROUP */
bio_associate_blkg(struct bio * bio)504 static inline void bio_associate_blkg(struct bio *bio) { }
bio_associate_blkg_from_css(struct bio * bio,struct cgroup_subsys_state * css)505 static inline void bio_associate_blkg_from_css(struct bio *bio,
506 					       struct cgroup_subsys_state *css)
507 { }
bio_clone_blkg_association(struct bio * dst,struct bio * src)508 static inline void bio_clone_blkg_association(struct bio *dst,
509 					      struct bio *src) { }
510 #endif	/* CONFIG_BLK_CGROUP */
511 
bio_set_dev(struct bio * bio,struct block_device * bdev)512 static inline void bio_set_dev(struct bio *bio, struct block_device *bdev)
513 {
514 	bio_clear_flag(bio, BIO_REMAPPED);
515 	if (bio->bi_bdev != bdev)
516 		bio_clear_flag(bio, BIO_BPS_THROTTLED);
517 	bio->bi_bdev = bdev;
518 	bio_associate_blkg(bio);
519 }
520 
521 /*
522  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
523  *
524  * A bio_list anchors a singly-linked list of bios chained through the bi_next
525  * member of the bio.  The bio_list also caches the last list member to allow
526  * fast access to the tail.
527  */
528 struct bio_list {
529 	struct bio *head;
530 	struct bio *tail;
531 };
532 
bio_list_empty(const struct bio_list * bl)533 static inline int bio_list_empty(const struct bio_list *bl)
534 {
535 	return bl->head == NULL;
536 }
537 
bio_list_init(struct bio_list * bl)538 static inline void bio_list_init(struct bio_list *bl)
539 {
540 	bl->head = bl->tail = NULL;
541 }
542 
543 #define BIO_EMPTY_LIST	{ NULL, NULL }
544 
545 #define bio_list_for_each(bio, bl) \
546 	for (bio = (bl)->head; bio; bio = bio->bi_next)
547 
bio_list_size(const struct bio_list * bl)548 static inline unsigned bio_list_size(const struct bio_list *bl)
549 {
550 	unsigned sz = 0;
551 	struct bio *bio;
552 
553 	bio_list_for_each(bio, bl)
554 		sz++;
555 
556 	return sz;
557 }
558 
bio_list_add(struct bio_list * bl,struct bio * bio)559 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
560 {
561 	bio->bi_next = NULL;
562 
563 	if (bl->tail)
564 		bl->tail->bi_next = bio;
565 	else
566 		bl->head = bio;
567 
568 	bl->tail = bio;
569 }
570 
bio_list_add_head(struct bio_list * bl,struct bio * bio)571 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
572 {
573 	bio->bi_next = bl->head;
574 
575 	bl->head = bio;
576 
577 	if (!bl->tail)
578 		bl->tail = bio;
579 }
580 
bio_list_merge(struct bio_list * bl,struct bio_list * bl2)581 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
582 {
583 	if (!bl2->head)
584 		return;
585 
586 	if (bl->tail)
587 		bl->tail->bi_next = bl2->head;
588 	else
589 		bl->head = bl2->head;
590 
591 	bl->tail = bl2->tail;
592 }
593 
bio_list_merge_head(struct bio_list * bl,struct bio_list * bl2)594 static inline void bio_list_merge_head(struct bio_list *bl,
595 				       struct bio_list *bl2)
596 {
597 	if (!bl2->head)
598 		return;
599 
600 	if (bl->head)
601 		bl2->tail->bi_next = bl->head;
602 	else
603 		bl->tail = bl2->tail;
604 
605 	bl->head = bl2->head;
606 }
607 
bio_list_peek(struct bio_list * bl)608 static inline struct bio *bio_list_peek(struct bio_list *bl)
609 {
610 	return bl->head;
611 }
612 
bio_list_pop(struct bio_list * bl)613 static inline struct bio *bio_list_pop(struct bio_list *bl)
614 {
615 	struct bio *bio = bl->head;
616 
617 	if (bio) {
618 		bl->head = bl->head->bi_next;
619 		if (!bl->head)
620 			bl->tail = NULL;
621 
622 		bio->bi_next = NULL;
623 	}
624 
625 	return bio;
626 }
627 
bio_list_get(struct bio_list * bl)628 static inline struct bio *bio_list_get(struct bio_list *bl)
629 {
630 	struct bio *bio = bl->head;
631 
632 	bl->head = bl->tail = NULL;
633 
634 	return bio;
635 }
636 
637 /*
638  * Increment chain count for the bio. Make sure the CHAIN flag update
639  * is visible before the raised count.
640  */
bio_inc_remaining(struct bio * bio)641 static inline void bio_inc_remaining(struct bio *bio)
642 {
643 	bio_set_flag(bio, BIO_CHAIN);
644 	smp_mb__before_atomic();
645 	atomic_inc(&bio->__bi_remaining);
646 }
647 
648 /*
649  * bio_set is used to allow other portions of the IO system to
650  * allocate their own private memory pools for bio and iovec structures.
651  * These memory pools in turn all allocate from the bio_slab
652  * and the bvec_slabs[].
653  */
654 #define BIO_POOL_SIZE 2
655 
656 struct bio_set {
657 	struct kmem_cache *bio_slab;
658 	unsigned int front_pad;
659 
660 	/*
661 	 * per-cpu bio alloc cache
662 	 */
663 	struct bio_alloc_cache __percpu *cache;
664 
665 	mempool_t bio_pool;
666 	mempool_t bvec_pool;
667 #if defined(CONFIG_BLK_DEV_INTEGRITY)
668 	mempool_t bio_integrity_pool;
669 	mempool_t bvec_integrity_pool;
670 #endif
671 
672 	unsigned int back_pad;
673 	/*
674 	 * Deadlock avoidance for stacking block drivers: see comments in
675 	 * bio_alloc_bioset() for details
676 	 */
677 	spinlock_t		rescue_lock;
678 	struct bio_list		rescue_list;
679 	struct work_struct	rescue_work;
680 	struct workqueue_struct	*rescue_workqueue;
681 
682 	/*
683 	 * Hot un-plug notifier for the per-cpu cache, if used
684 	 */
685 	struct hlist_node cpuhp_dead;
686 };
687 
bioset_initialized(struct bio_set * bs)688 static inline bool bioset_initialized(struct bio_set *bs)
689 {
690 	return bs->bio_slab != NULL;
691 }
692 
693 #if defined(CONFIG_BLK_DEV_INTEGRITY)
694 
695 #define bip_for_each_vec(bvl, bip, iter)				\
696 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
697 
698 #define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
699 	for_each_bio(_bio)						\
700 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
701 
702 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
703 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
704 extern bool bio_integrity_prep(struct bio *);
705 extern void bio_integrity_advance(struct bio *, unsigned int);
706 extern void bio_integrity_trim(struct bio *);
707 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
708 extern int bioset_integrity_create(struct bio_set *, int);
709 extern void bioset_integrity_free(struct bio_set *);
710 extern void bio_integrity_init(void);
711 
712 #else /* CONFIG_BLK_DEV_INTEGRITY */
713 
bio_integrity(struct bio * bio)714 static inline void *bio_integrity(struct bio *bio)
715 {
716 	return NULL;
717 }
718 
bioset_integrity_create(struct bio_set * bs,int pool_size)719 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
720 {
721 	return 0;
722 }
723 
bioset_integrity_free(struct bio_set * bs)724 static inline void bioset_integrity_free (struct bio_set *bs)
725 {
726 	return;
727 }
728 
bio_integrity_prep(struct bio * bio)729 static inline bool bio_integrity_prep(struct bio *bio)
730 {
731 	return true;
732 }
733 
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)734 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
735 				      gfp_t gfp_mask)
736 {
737 	return 0;
738 }
739 
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)740 static inline void bio_integrity_advance(struct bio *bio,
741 					 unsigned int bytes_done)
742 {
743 	return;
744 }
745 
bio_integrity_trim(struct bio * bio)746 static inline void bio_integrity_trim(struct bio *bio)
747 {
748 	return;
749 }
750 
bio_integrity_init(void)751 static inline void bio_integrity_init(void)
752 {
753 	return;
754 }
755 
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)756 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
757 {
758 	return false;
759 }
760 
bio_integrity_alloc(struct bio * bio,gfp_t gfp,unsigned int nr)761 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
762 								unsigned int nr)
763 {
764 	return ERR_PTR(-EINVAL);
765 }
766 
bio_integrity_add_page(struct bio * bio,struct page * page,unsigned int len,unsigned int offset)767 static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
768 					unsigned int len, unsigned int offset)
769 {
770 	return 0;
771 }
772 
773 #endif /* CONFIG_BLK_DEV_INTEGRITY */
774 
775 /*
776  * Mark a bio as polled. Note that for async polled IO, the caller must
777  * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
778  * We cannot block waiting for requests on polled IO, as those completions
779  * must be found by the caller. This is different than IRQ driven IO, where
780  * it's safe to wait for IO to complete.
781  */
bio_set_polled(struct bio * bio,struct kiocb * kiocb)782 static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
783 {
784 	bio->bi_opf |= REQ_POLLED;
785 	if (!is_sync_kiocb(kiocb))
786 		bio->bi_opf |= REQ_NOWAIT;
787 }
788 
bio_clear_polled(struct bio * bio)789 static inline void bio_clear_polled(struct bio *bio)
790 {
791 	bio->bi_opf &= ~REQ_POLLED;
792 }
793 
794 struct bio *blk_next_bio(struct bio *bio, struct block_device *bdev,
795 		unsigned int nr_pages, blk_opf_t opf, gfp_t gfp);
796 
797 #endif /* __LINUX_BIO_H */
798