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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/highmem.h>
9 #include <linux/mempool.h>
10 #include <linux/ioprio.h>
11 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
12 #include <linux/blk_types.h>
13 #include <linux/android_kabi.h>
14 
15 #define BIO_DEBUG
16 
17 #ifdef BIO_DEBUG
18 #define BIO_BUG_ON	BUG_ON
19 #else
20 #define BIO_BUG_ON
21 #endif
22 
23 #define BIO_MAX_PAGES		256
24 
25 #define bio_prio(bio)			(bio)->bi_ioprio
26 #define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
27 
28 #define bio_iter_iovec(bio, iter)				\
29 	bvec_iter_bvec((bio)->bi_io_vec, (iter))
30 
31 #define bio_iter_page(bio, iter)				\
32 	bvec_iter_page((bio)->bi_io_vec, (iter))
33 #define bio_iter_len(bio, iter)					\
34 	bvec_iter_len((bio)->bi_io_vec, (iter))
35 #define bio_iter_offset(bio, iter)				\
36 	bvec_iter_offset((bio)->bi_io_vec, (iter))
37 
38 #define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
39 #define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
40 #define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
41 
42 #define bvec_iter_sectors(iter)	((iter).bi_size >> 9)
43 #define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
44 
45 #define bio_sectors(bio)	bvec_iter_sectors((bio)->bi_iter)
46 #define bio_end_sector(bio)	bvec_iter_end_sector((bio)->bi_iter)
47 
48 /*
49  * Return the data direction, READ or WRITE.
50  */
51 #define bio_data_dir(bio) \
52 	(op_is_write(bio_op(bio)) ? WRITE : READ)
53 
54 /*
55  * Check whether this bio carries any data or not. A NULL bio is allowed.
56  */
bio_has_data(struct bio * bio)57 static inline bool bio_has_data(struct bio *bio)
58 {
59 	if (bio &&
60 	    bio->bi_iter.bi_size &&
61 	    bio_op(bio) != REQ_OP_DISCARD &&
62 	    bio_op(bio) != REQ_OP_SECURE_ERASE &&
63 	    bio_op(bio) != REQ_OP_WRITE_ZEROES)
64 		return true;
65 
66 	return false;
67 }
68 
bio_no_advance_iter(const struct bio * bio)69 static inline bool bio_no_advance_iter(const struct bio *bio)
70 {
71 	return bio_op(bio) == REQ_OP_DISCARD ||
72 	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
73 	       bio_op(bio) == REQ_OP_WRITE_SAME ||
74 	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
75 }
76 
bio_mergeable(struct bio * bio)77 static inline bool bio_mergeable(struct bio *bio)
78 {
79 	if (bio->bi_opf & REQ_NOMERGE_FLAGS)
80 		return false;
81 
82 	return true;
83 }
84 
bio_cur_bytes(struct bio * bio)85 static inline unsigned int bio_cur_bytes(struct bio *bio)
86 {
87 	if (bio_has_data(bio))
88 		return bio_iovec(bio).bv_len;
89 	else /* dataless requests such as discard */
90 		return bio->bi_iter.bi_size;
91 }
92 
bio_data(struct bio * bio)93 static inline void *bio_data(struct bio *bio)
94 {
95 	if (bio_has_data(bio))
96 		return page_address(bio_page(bio)) + bio_offset(bio);
97 
98 	return NULL;
99 }
100 
101 /**
102  * bio_full - check if the bio is full
103  * @bio:	bio to check
104  * @len:	length of one segment to be added
105  *
106  * Return true if @bio is full and one segment with @len bytes can't be
107  * added to the bio, otherwise return false
108  */
bio_full(struct bio * bio,unsigned len)109 static inline bool bio_full(struct bio *bio, unsigned len)
110 {
111 	if (bio->bi_vcnt >= bio->bi_max_vecs)
112 		return true;
113 
114 	if (bio->bi_iter.bi_size > UINT_MAX - len)
115 		return true;
116 
117 	return false;
118 }
119 
bio_next_segment(const struct bio * bio,struct bvec_iter_all * iter)120 static inline bool bio_next_segment(const struct bio *bio,
121 				    struct bvec_iter_all *iter)
122 {
123 	if (iter->idx >= bio->bi_vcnt)
124 		return false;
125 
126 	bvec_advance(&bio->bi_io_vec[iter->idx], iter);
127 	return true;
128 }
129 
130 /*
131  * drivers should _never_ use the all version - the bio may have been split
132  * before it got to the driver and the driver won't own all of it
133  */
134 #define bio_for_each_segment_all(bvl, bio, iter) \
135 	for (bvl = bvec_init_iter_all(&iter); bio_next_segment((bio), &iter); )
136 
bio_advance_iter(const struct bio * bio,struct bvec_iter * iter,unsigned int bytes)137 static inline void bio_advance_iter(const struct bio *bio,
138 				    struct bvec_iter *iter, unsigned int bytes)
139 {
140 	iter->bi_sector += bytes >> 9;
141 
142 	if (bio_no_advance_iter(bio))
143 		iter->bi_size -= bytes;
144 	else
145 		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
146 		/* TODO: It is reasonable to complete bio with error here. */
147 }
148 
149 #define __bio_for_each_segment(bvl, bio, iter, start)			\
150 	for (iter = (start);						\
151 	     (iter).bi_size &&						\
152 		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
153 	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
154 
155 #define bio_for_each_segment(bvl, bio, iter)				\
156 	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
157 
158 #define __bio_for_each_bvec(bvl, bio, iter, start)		\
159 	for (iter = (start);						\
160 	     (iter).bi_size &&						\
161 		((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \
162 	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
163 
164 /* iterate over multi-page bvec */
165 #define bio_for_each_bvec(bvl, bio, iter)			\
166 	__bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter)
167 
168 /*
169  * Iterate over all multi-page bvecs. Drivers shouldn't use this version for the
170  * same reasons as bio_for_each_segment_all().
171  */
172 #define bio_for_each_bvec_all(bvl, bio, i)		\
173 	for (i = 0, bvl = bio_first_bvec_all(bio);	\
174 	     i < (bio)->bi_vcnt; i++, bvl++)		\
175 
176 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
177 
bio_segments(struct bio * bio)178 static inline unsigned bio_segments(struct bio *bio)
179 {
180 	unsigned segs = 0;
181 	struct bio_vec bv;
182 	struct bvec_iter iter;
183 
184 	/*
185 	 * We special case discard/write same/write zeroes, because they
186 	 * interpret bi_size differently:
187 	 */
188 
189 	switch (bio_op(bio)) {
190 	case REQ_OP_DISCARD:
191 	case REQ_OP_SECURE_ERASE:
192 	case REQ_OP_WRITE_ZEROES:
193 		return 0;
194 	case REQ_OP_WRITE_SAME:
195 		return 1;
196 	default:
197 		break;
198 	}
199 
200 	bio_for_each_segment(bv, bio, iter)
201 		segs++;
202 
203 	return segs;
204 }
205 
206 /*
207  * get a reference to a bio, so it won't disappear. the intended use is
208  * something like:
209  *
210  * bio_get(bio);
211  * submit_bio(rw, bio);
212  * if (bio->bi_flags ...)
213  *	do_something
214  * bio_put(bio);
215  *
216  * without the bio_get(), it could potentially complete I/O before submit_bio
217  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
218  * runs
219  */
bio_get(struct bio * bio)220 static inline void bio_get(struct bio *bio)
221 {
222 	bio->bi_flags |= (1 << BIO_REFFED);
223 	smp_mb__before_atomic();
224 	atomic_inc(&bio->__bi_cnt);
225 }
226 
bio_cnt_set(struct bio * bio,unsigned int count)227 static inline void bio_cnt_set(struct bio *bio, unsigned int count)
228 {
229 	if (count != 1) {
230 		bio->bi_flags |= (1 << BIO_REFFED);
231 		smp_mb();
232 	}
233 	atomic_set(&bio->__bi_cnt, count);
234 }
235 
bio_flagged(struct bio * bio,unsigned int bit)236 static inline bool bio_flagged(struct bio *bio, unsigned int bit)
237 {
238 	return (bio->bi_flags & (1U << bit)) != 0;
239 }
240 
bio_set_flag(struct bio * bio,unsigned int bit)241 static inline void bio_set_flag(struct bio *bio, unsigned int bit)
242 {
243 	bio->bi_flags |= (1U << bit);
244 }
245 
bio_clear_flag(struct bio * bio,unsigned int bit)246 static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
247 {
248 	bio->bi_flags &= ~(1U << bit);
249 }
250 
bio_get_first_bvec(struct bio * bio,struct bio_vec * bv)251 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
252 {
253 	*bv = mp_bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
254 }
255 
bio_get_last_bvec(struct bio * bio,struct bio_vec * bv)256 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
257 {
258 	struct bvec_iter iter = bio->bi_iter;
259 	int idx;
260 
261 	bio_get_first_bvec(bio, bv);
262 	if (bv->bv_len == bio->bi_iter.bi_size)
263 		return;		/* this bio only has a single bvec */
264 
265 	bio_advance_iter(bio, &iter, iter.bi_size);
266 
267 	if (!iter.bi_bvec_done)
268 		idx = iter.bi_idx - 1;
269 	else	/* in the middle of bvec */
270 		idx = iter.bi_idx;
271 
272 	*bv = bio->bi_io_vec[idx];
273 
274 	/*
275 	 * iter.bi_bvec_done records actual length of the last bvec
276 	 * if this bio ends in the middle of one io vector
277 	 */
278 	if (iter.bi_bvec_done)
279 		bv->bv_len = iter.bi_bvec_done;
280 }
281 
bio_first_bvec_all(struct bio * bio)282 static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
283 {
284 	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
285 	return bio->bi_io_vec;
286 }
287 
bio_first_page_all(struct bio * bio)288 static inline struct page *bio_first_page_all(struct bio *bio)
289 {
290 	return bio_first_bvec_all(bio)->bv_page;
291 }
292 
bio_last_bvec_all(struct bio * bio)293 static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
294 {
295 	WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
296 	return &bio->bi_io_vec[bio->bi_vcnt - 1];
297 }
298 
299 enum bip_flags {
300 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
301 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
302 	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
303 	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
304 	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
305 };
306 
307 /*
308  * bio integrity payload
309  */
310 struct bio_integrity_payload {
311 	struct bio		*bip_bio;	/* parent bio */
312 
313 	struct bvec_iter	bip_iter;
314 
315 	unsigned short		bip_slab;	/* slab the bip came from */
316 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
317 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
318 	unsigned short		bip_flags;	/* control flags */
319 
320 	struct bvec_iter	bio_iter;	/* for rewinding parent bio */
321 
322 	struct work_struct	bip_work;	/* I/O completion */
323 
324 	struct bio_vec		*bip_vec;
325 
326 	ANDROID_KABI_RESERVE(1);
327 	ANDROID_KABI_RESERVE(2);
328 
329 	struct bio_vec		bip_inline_vecs[];/* embedded bvec array */
330 };
331 
332 #if defined(CONFIG_BLK_DEV_INTEGRITY)
333 
bio_integrity(struct bio * bio)334 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
335 {
336 	if (bio->bi_opf & REQ_INTEGRITY)
337 		return bio->bi_integrity;
338 
339 	return NULL;
340 }
341 
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)342 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
343 {
344 	struct bio_integrity_payload *bip = bio_integrity(bio);
345 
346 	if (bip)
347 		return bip->bip_flags & flag;
348 
349 	return false;
350 }
351 
bip_get_seed(struct bio_integrity_payload * bip)352 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
353 {
354 	return bip->bip_iter.bi_sector;
355 }
356 
bip_set_seed(struct bio_integrity_payload * bip,sector_t seed)357 static inline void bip_set_seed(struct bio_integrity_payload *bip,
358 				sector_t seed)
359 {
360 	bip->bip_iter.bi_sector = seed;
361 }
362 
363 #endif /* CONFIG_BLK_DEV_INTEGRITY */
364 
365 extern void bio_trim(struct bio *bio, int offset, int size);
366 extern struct bio *bio_split(struct bio *bio, int sectors,
367 			     gfp_t gfp, struct bio_set *bs);
368 
369 /**
370  * bio_next_split - get next @sectors from a bio, splitting if necessary
371  * @bio:	bio to split
372  * @sectors:	number of sectors to split from the front of @bio
373  * @gfp:	gfp mask
374  * @bs:		bio set to allocate from
375  *
376  * Returns a bio representing the next @sectors of @bio - if the bio is smaller
377  * than @sectors, returns the original bio unchanged.
378  */
bio_next_split(struct bio * bio,int sectors,gfp_t gfp,struct bio_set * bs)379 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
380 					 gfp_t gfp, struct bio_set *bs)
381 {
382 	if (sectors >= bio_sectors(bio))
383 		return bio;
384 
385 	return bio_split(bio, sectors, gfp, bs);
386 }
387 
388 enum {
389 	BIOSET_NEED_BVECS = BIT(0),
390 	BIOSET_NEED_RESCUER = BIT(1),
391 };
392 extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
393 extern void bioset_exit(struct bio_set *);
394 extern int biovec_init_pool(mempool_t *pool, int pool_entries);
395 extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
396 
397 extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
398 extern void bio_put(struct bio *);
399 
400 extern void __bio_clone_fast(struct bio *, struct bio *);
401 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
402 
403 extern struct bio_set fs_bio_set;
404 
bio_alloc(gfp_t gfp_mask,unsigned int nr_iovecs)405 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
406 {
407 	return bio_alloc_bioset(gfp_mask, nr_iovecs, &fs_bio_set);
408 }
409 
bio_kmalloc(gfp_t gfp_mask,unsigned int nr_iovecs)410 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
411 {
412 	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
413 }
414 
415 extern blk_qc_t submit_bio(struct bio *);
416 
417 extern void bio_endio(struct bio *);
418 
bio_io_error(struct bio * bio)419 static inline void bio_io_error(struct bio *bio)
420 {
421 	bio->bi_status = BLK_STS_IOERR;
422 	bio_endio(bio);
423 }
424 
bio_wouldblock_error(struct bio * bio)425 static inline void bio_wouldblock_error(struct bio *bio)
426 {
427 	bio_set_flag(bio, BIO_QUIET);
428 	bio->bi_status = BLK_STS_AGAIN;
429 	bio_endio(bio);
430 }
431 
432 struct request_queue;
433 
434 extern int submit_bio_wait(struct bio *bio);
435 extern void bio_advance(struct bio *, unsigned);
436 
437 extern void bio_init(struct bio *bio, struct bio_vec *table,
438 		     unsigned short max_vecs);
439 extern void bio_uninit(struct bio *);
440 extern void bio_reset(struct bio *);
441 void bio_chain(struct bio *, struct bio *);
442 
443 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
444 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
445 			   unsigned int, unsigned int);
446 bool __bio_try_merge_page(struct bio *bio, struct page *page,
447 		unsigned int len, unsigned int off, bool *same_page);
448 void __bio_add_page(struct bio *bio, struct page *page,
449 		unsigned int len, unsigned int off);
450 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
451 void bio_release_pages(struct bio *bio, bool mark_dirty);
452 extern void bio_set_pages_dirty(struct bio *bio);
453 extern void bio_check_pages_dirty(struct bio *bio);
454 
455 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
456 			       struct bio *src, struct bvec_iter *src_iter);
457 extern void bio_copy_data(struct bio *dst, struct bio *src);
458 extern void bio_list_copy_data(struct bio *dst, struct bio *src);
459 extern void bio_free_pages(struct bio *bio);
460 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
461 void bio_truncate(struct bio *bio, unsigned new_size);
462 void guard_bio_eod(struct bio *bio);
463 
zero_fill_bio(struct bio * bio)464 static inline void zero_fill_bio(struct bio *bio)
465 {
466 	zero_fill_bio_iter(bio, bio->bi_iter);
467 }
468 
469 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
470 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
471 extern unsigned int bvec_nr_vecs(unsigned short idx);
472 extern const char *bio_devname(struct bio *bio, char *buffer);
473 
474 #define bio_set_dev(bio, bdev) 			\
475 do {						\
476 	if ((bio)->bi_disk != (bdev)->bd_disk)	\
477 		bio_clear_flag(bio, BIO_THROTTLED);\
478 	(bio)->bi_disk = (bdev)->bd_disk;	\
479 	(bio)->bi_partno = (bdev)->bd_partno;	\
480 	bio_associate_blkg(bio);		\
481 } while (0)
482 
483 #define bio_copy_dev(dst, src)			\
484 do {						\
485 	(dst)->bi_disk = (src)->bi_disk;	\
486 	(dst)->bi_partno = (src)->bi_partno;	\
487 	bio_clone_blkg_association(dst, src);	\
488 } while (0)
489 
490 #define bio_dev(bio) \
491 	disk_devt((bio)->bi_disk)
492 
493 #ifdef CONFIG_BLK_CGROUP
494 void bio_associate_blkg(struct bio *bio);
495 void bio_associate_blkg_from_css(struct bio *bio,
496 				 struct cgroup_subsys_state *css);
497 void bio_clone_blkg_association(struct bio *dst, struct bio *src);
498 #else	/* CONFIG_BLK_CGROUP */
bio_associate_blkg(struct bio * bio)499 static inline void bio_associate_blkg(struct bio *bio) { }
bio_associate_blkg_from_css(struct bio * bio,struct cgroup_subsys_state * css)500 static inline void bio_associate_blkg_from_css(struct bio *bio,
501 					       struct cgroup_subsys_state *css)
502 { }
bio_clone_blkg_association(struct bio * dst,struct bio * src)503 static inline void bio_clone_blkg_association(struct bio *dst,
504 					      struct bio *src) { }
505 #endif	/* CONFIG_BLK_CGROUP */
506 
507 #ifdef CONFIG_HIGHMEM
508 /*
509  * remember never ever reenable interrupts between a bvec_kmap_irq and
510  * bvec_kunmap_irq!
511  */
bvec_kmap_irq(struct bio_vec * bvec,unsigned long * flags)512 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
513 {
514 	unsigned long addr;
515 
516 	/*
517 	 * might not be a highmem page, but the preempt/irq count
518 	 * balancing is a lot nicer this way
519 	 */
520 	local_irq_save(*flags);
521 	addr = (unsigned long) kmap_atomic(bvec->bv_page);
522 
523 	BUG_ON(addr & ~PAGE_MASK);
524 
525 	return (char *) addr + bvec->bv_offset;
526 }
527 
bvec_kunmap_irq(char * buffer,unsigned long * flags)528 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
529 {
530 	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
531 
532 	kunmap_atomic((void *) ptr);
533 	local_irq_restore(*flags);
534 }
535 
536 #else
bvec_kmap_irq(struct bio_vec * bvec,unsigned long * flags)537 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
538 {
539 	return page_address(bvec->bv_page) + bvec->bv_offset;
540 }
541 
bvec_kunmap_irq(char * buffer,unsigned long * flags)542 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
543 {
544 	*flags = 0;
545 }
546 #endif
547 
548 /*
549  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
550  *
551  * A bio_list anchors a singly-linked list of bios chained through the bi_next
552  * member of the bio.  The bio_list also caches the last list member to allow
553  * fast access to the tail.
554  */
555 struct bio_list {
556 	struct bio *head;
557 	struct bio *tail;
558 };
559 
bio_list_empty(const struct bio_list * bl)560 static inline int bio_list_empty(const struct bio_list *bl)
561 {
562 	return bl->head == NULL;
563 }
564 
bio_list_init(struct bio_list * bl)565 static inline void bio_list_init(struct bio_list *bl)
566 {
567 	bl->head = bl->tail = NULL;
568 }
569 
570 #define BIO_EMPTY_LIST	{ NULL, NULL }
571 
572 #define bio_list_for_each(bio, bl) \
573 	for (bio = (bl)->head; bio; bio = bio->bi_next)
574 
bio_list_size(const struct bio_list * bl)575 static inline unsigned bio_list_size(const struct bio_list *bl)
576 {
577 	unsigned sz = 0;
578 	struct bio *bio;
579 
580 	bio_list_for_each(bio, bl)
581 		sz++;
582 
583 	return sz;
584 }
585 
bio_list_add(struct bio_list * bl,struct bio * bio)586 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
587 {
588 	bio->bi_next = NULL;
589 
590 	if (bl->tail)
591 		bl->tail->bi_next = bio;
592 	else
593 		bl->head = bio;
594 
595 	bl->tail = bio;
596 }
597 
bio_list_add_head(struct bio_list * bl,struct bio * bio)598 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
599 {
600 	bio->bi_next = bl->head;
601 
602 	bl->head = bio;
603 
604 	if (!bl->tail)
605 		bl->tail = bio;
606 }
607 
bio_list_merge(struct bio_list * bl,struct bio_list * bl2)608 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
609 {
610 	if (!bl2->head)
611 		return;
612 
613 	if (bl->tail)
614 		bl->tail->bi_next = bl2->head;
615 	else
616 		bl->head = bl2->head;
617 
618 	bl->tail = bl2->tail;
619 }
620 
bio_list_merge_head(struct bio_list * bl,struct bio_list * bl2)621 static inline void bio_list_merge_head(struct bio_list *bl,
622 				       struct bio_list *bl2)
623 {
624 	if (!bl2->head)
625 		return;
626 
627 	if (bl->head)
628 		bl2->tail->bi_next = bl->head;
629 	else
630 		bl->tail = bl2->tail;
631 
632 	bl->head = bl2->head;
633 }
634 
bio_list_peek(struct bio_list * bl)635 static inline struct bio *bio_list_peek(struct bio_list *bl)
636 {
637 	return bl->head;
638 }
639 
bio_list_pop(struct bio_list * bl)640 static inline struct bio *bio_list_pop(struct bio_list *bl)
641 {
642 	struct bio *bio = bl->head;
643 
644 	if (bio) {
645 		bl->head = bl->head->bi_next;
646 		if (!bl->head)
647 			bl->tail = NULL;
648 
649 		bio->bi_next = NULL;
650 	}
651 
652 	return bio;
653 }
654 
bio_list_get(struct bio_list * bl)655 static inline struct bio *bio_list_get(struct bio_list *bl)
656 {
657 	struct bio *bio = bl->head;
658 
659 	bl->head = bl->tail = NULL;
660 
661 	return bio;
662 }
663 
664 /*
665  * Increment chain count for the bio. Make sure the CHAIN flag update
666  * is visible before the raised count.
667  */
bio_inc_remaining(struct bio * bio)668 static inline void bio_inc_remaining(struct bio *bio)
669 {
670 	bio_set_flag(bio, BIO_CHAIN);
671 	smp_mb__before_atomic();
672 	atomic_inc(&bio->__bi_remaining);
673 }
674 
675 /*
676  * bio_set is used to allow other portions of the IO system to
677  * allocate their own private memory pools for bio and iovec structures.
678  * These memory pools in turn all allocate from the bio_slab
679  * and the bvec_slabs[].
680  */
681 #define BIO_POOL_SIZE 2
682 
683 struct bio_set {
684 	struct kmem_cache *bio_slab;
685 	unsigned int front_pad;
686 
687 	mempool_t bio_pool;
688 	mempool_t bvec_pool;
689 #if defined(CONFIG_BLK_DEV_INTEGRITY)
690 	mempool_t bio_integrity_pool;
691 	mempool_t bvec_integrity_pool;
692 #endif
693 
694 	/*
695 	 * Deadlock avoidance for stacking block drivers: see comments in
696 	 * bio_alloc_bioset() for details
697 	 */
698 	spinlock_t		rescue_lock;
699 	struct bio_list		rescue_list;
700 	struct work_struct	rescue_work;
701 	struct workqueue_struct	*rescue_workqueue;
702 
703 	ANDROID_KABI_RESERVE(1);
704 	ANDROID_KABI_RESERVE(2);
705 	ANDROID_KABI_RESERVE(3);
706 	ANDROID_KABI_RESERVE(4);
707 };
708 
709 struct biovec_slab {
710 	int nr_vecs;
711 	char *name;
712 	struct kmem_cache *slab;
713 };
714 
bioset_initialized(struct bio_set * bs)715 static inline bool bioset_initialized(struct bio_set *bs)
716 {
717 	return bs->bio_slab != NULL;
718 }
719 
720 /*
721  * a small number of entries is fine, not going to be performance critical.
722  * basically we just need to survive
723  */
724 #define BIO_SPLIT_ENTRIES 2
725 
726 #if defined(CONFIG_BLK_DEV_INTEGRITY)
727 
728 #define bip_for_each_vec(bvl, bip, iter)				\
729 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
730 
731 #define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
732 	for_each_bio(_bio)						\
733 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
734 
735 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
736 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
737 extern bool bio_integrity_prep(struct bio *);
738 extern void bio_integrity_advance(struct bio *, unsigned int);
739 extern void bio_integrity_trim(struct bio *);
740 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
741 extern int bioset_integrity_create(struct bio_set *, int);
742 extern void bioset_integrity_free(struct bio_set *);
743 extern void bio_integrity_init(void);
744 
745 #else /* CONFIG_BLK_DEV_INTEGRITY */
746 
bio_integrity(struct bio * bio)747 static inline void *bio_integrity(struct bio *bio)
748 {
749 	return NULL;
750 }
751 
bioset_integrity_create(struct bio_set * bs,int pool_size)752 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
753 {
754 	return 0;
755 }
756 
bioset_integrity_free(struct bio_set * bs)757 static inline void bioset_integrity_free (struct bio_set *bs)
758 {
759 	return;
760 }
761 
bio_integrity_prep(struct bio * bio)762 static inline bool bio_integrity_prep(struct bio *bio)
763 {
764 	return true;
765 }
766 
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)767 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
768 				      gfp_t gfp_mask)
769 {
770 	return 0;
771 }
772 
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)773 static inline void bio_integrity_advance(struct bio *bio,
774 					 unsigned int bytes_done)
775 {
776 	return;
777 }
778 
bio_integrity_trim(struct bio * bio)779 static inline void bio_integrity_trim(struct bio *bio)
780 {
781 	return;
782 }
783 
bio_integrity_init(void)784 static inline void bio_integrity_init(void)
785 {
786 	return;
787 }
788 
bio_integrity_flagged(struct bio * bio,enum bip_flags flag)789 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
790 {
791 	return false;
792 }
793 
bio_integrity_alloc(struct bio * bio,gfp_t gfp,unsigned int nr)794 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
795 								unsigned int nr)
796 {
797 	return ERR_PTR(-EINVAL);
798 }
799 
bio_integrity_add_page(struct bio * bio,struct page * page,unsigned int len,unsigned int offset)800 static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
801 					unsigned int len, unsigned int offset)
802 {
803 	return 0;
804 }
805 
806 #endif /* CONFIG_BLK_DEV_INTEGRITY */
807 
808 /*
809  * Mark a bio as polled. Note that for async polled IO, the caller must
810  * expect -EWOULDBLOCK if we cannot allocate a request (or other resources).
811  * We cannot block waiting for requests on polled IO, as those completions
812  * must be found by the caller. This is different than IRQ driven IO, where
813  * it's safe to wait for IO to complete.
814  */
bio_set_polled(struct bio * bio,struct kiocb * kiocb)815 static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb)
816 {
817 	bio->bi_opf |= REQ_HIPRI;
818 	if (!is_sync_kiocb(kiocb))
819 		bio->bi_opf |= REQ_NOWAIT;
820 }
821 
822 #endif /* __LINUX_BIO_H */
823