xref: /linux-6.15/include/linux/bio.h (revision e73173db)
1 /*
2  * 2.5 block I/O model
3  *
4  * Copyright (C) 2001 Jens Axboe <[email protected]>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public Licens
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
19  */
20 #ifndef __LINUX_BIO_H
21 #define __LINUX_BIO_H
22 
23 #include <linux/highmem.h>
24 #include <linux/mempool.h>
25 #include <linux/ioprio.h>
26 
27 #ifdef CONFIG_BLOCK
28 
29 #include <asm/io.h>
30 
31 #define BIO_DEBUG
32 
33 #ifdef BIO_DEBUG
34 #define BIO_BUG_ON	BUG_ON
35 #else
36 #define BIO_BUG_ON
37 #endif
38 
39 #define BIO_MAX_PAGES		256
40 #define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
41 #define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)
42 
43 /*
44  * was unsigned short, but we might as well be ready for > 64kB I/O pages
45  */
46 struct bio_vec {
47 	struct page	*bv_page;
48 	unsigned int	bv_len;
49 	unsigned int	bv_offset;
50 };
51 
52 struct bio_set;
53 struct bio;
54 struct bio_integrity_payload;
55 typedef void (bio_end_io_t) (struct bio *, int);
56 typedef void (bio_destructor_t) (struct bio *);
57 
58 /*
59  * main unit of I/O for the block layer and lower layers (ie drivers and
60  * stacking drivers)
61  */
62 struct bio {
63 	sector_t		bi_sector;	/* device address in 512 byte
64 						   sectors */
65 	struct bio		*bi_next;	/* request queue link */
66 	struct block_device	*bi_bdev;
67 	unsigned long		bi_flags;	/* status, command, etc */
68 	unsigned long		bi_rw;		/* bottom bits READ/WRITE,
69 						 * top bits priority
70 						 */
71 
72 	unsigned short		bi_vcnt;	/* how many bio_vec's */
73 	unsigned short		bi_idx;		/* current index into bvl_vec */
74 
75 	/* Number of segments in this BIO after
76 	 * physical address coalescing is performed.
77 	 */
78 	unsigned int		bi_phys_segments;
79 
80 	unsigned int		bi_size;	/* residual I/O count */
81 
82 	/*
83 	 * To keep track of the max segment size, we account for the
84 	 * sizes of the first and last mergeable segments in this bio.
85 	 */
86 	unsigned int		bi_seg_front_size;
87 	unsigned int		bi_seg_back_size;
88 
89 	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */
90 
91 	unsigned int		bi_comp_cpu;	/* completion CPU */
92 
93 	atomic_t		bi_cnt;		/* pin count */
94 
95 	struct bio_vec		*bi_io_vec;	/* the actual vec list */
96 
97 	bio_end_io_t		*bi_end_io;
98 
99 	void			*bi_private;
100 #if defined(CONFIG_BLK_DEV_INTEGRITY)
101 	struct bio_integrity_payload *bi_integrity;  /* data integrity */
102 #endif
103 
104 	bio_destructor_t	*bi_destructor;	/* destructor */
105 
106 	/*
107 	 * We can inline a number of vecs at the end of the bio, to avoid
108 	 * double allocations for a small number of bio_vecs. This member
109 	 * MUST obviously be kept at the very end of the bio.
110 	 */
111 	struct bio_vec		bi_inline_vecs[0];
112 };
113 
114 /*
115  * bio flags
116  */
117 #define BIO_UPTODATE	0	/* ok after I/O completion */
118 #define BIO_RW_BLOCK	1	/* RW_AHEAD set, and read/write would block */
119 #define BIO_EOF		2	/* out-out-bounds error */
120 #define BIO_SEG_VALID	3	/* bi_phys_segments valid */
121 #define BIO_CLONED	4	/* doesn't own data */
122 #define BIO_BOUNCED	5	/* bio is a bounce bio */
123 #define BIO_USER_MAPPED 6	/* contains user pages */
124 #define BIO_EOPNOTSUPP	7	/* not supported */
125 #define BIO_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
126 #define BIO_NULL_MAPPED 9	/* contains invalid user pages */
127 #define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
128 #define BIO_QUIET	11	/* Make BIO Quiet */
129 #define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
130 
131 /*
132  * top 4 bits of bio flags indicate the pool this bio came from
133  */
134 #define BIO_POOL_BITS		(4)
135 #define BIO_POOL_NONE		((1UL << BIO_POOL_BITS) - 1)
136 #define BIO_POOL_OFFSET		(BITS_PER_LONG - BIO_POOL_BITS)
137 #define BIO_POOL_MASK		(1UL << BIO_POOL_OFFSET)
138 #define BIO_POOL_IDX(bio)	((bio)->bi_flags >> BIO_POOL_OFFSET)
139 
140 /*
141  * bio bi_rw flags
142  *
143  * bit 0 -- data direction
144  *	If not set, bio is a read from device. If set, it's a write to device.
145  * bit 1 -- rw-ahead when set
146  * bit 2 -- barrier
147  *	Insert a serialization point in the IO queue, forcing previously
148  *	submitted IO to be completed before this one is issued.
149  * bit 3 -- synchronous I/O hint.
150  * bit 4 -- Unplug the device immediately after submitting this bio.
151  * bit 5 -- metadata request
152  *	Used for tracing to differentiate metadata and data IO. May also
153  *	get some preferential treatment in the IO scheduler
154  * bit 6 -- discard sectors
155  *	Informs the lower level device that this range of sectors is no longer
156  *	used by the file system and may thus be freed by the device. Used
157  *	for flash based storage.
158  * bit 7 -- fail fast device errors
159  * bit 8 -- fail fast transport errors
160  * bit 9 -- fail fast driver errors
161  *	Don't want driver retries for any fast fail whatever the reason.
162  * bit 10 -- Tell the IO scheduler not to wait for more requests after this
163 	one has been submitted, even if it is a SYNC request.
164  */
165 #define BIO_RW		0	/* Must match RW in req flags (blkdev.h) */
166 #define BIO_RW_AHEAD	1	/* Must match FAILFAST in req flags */
167 #define BIO_RW_BARRIER	2
168 #define BIO_RW_SYNCIO	3
169 #define BIO_RW_UNPLUG	4
170 #define BIO_RW_META	5
171 #define BIO_RW_DISCARD	6
172 #define BIO_RW_FAILFAST_DEV		7
173 #define BIO_RW_FAILFAST_TRANSPORT	8
174 #define BIO_RW_FAILFAST_DRIVER		9
175 #define BIO_RW_NOIDLE	10
176 
177 #define bio_rw_flagged(bio, flag)	((bio)->bi_rw & (1 << (flag)))
178 
179 /*
180  * Old defines, these should eventually be replaced by direct usage of
181  * bio_rw_flagged()
182  */
183 #define bio_barrier(bio)	bio_rw_flagged(bio, BIO_RW_BARRIER)
184 #define bio_sync(bio)		bio_rw_flagged(bio, BIO_RW_SYNCIO)
185 #define bio_unplug(bio)		bio_rw_flagged(bio, BIO_RW_UNPLUG)
186 #define bio_failfast_dev(bio)	bio_rw_flagged(bio, BIO_RW_FAILFAST_DEV)
187 #define bio_failfast_transport(bio)	\
188 		bio_rw_flagged(bio, BIO_RW_FAILFAST_TRANSPORT)
189 #define bio_failfast_driver(bio) 	\
190 		bio_rw_flagged(bio, BIO_RW_FAILFAST_DRIVER)
191 #define bio_rw_ahead(bio)	bio_rw_flagged(bio, BIO_RW_AHEAD)
192 #define bio_rw_meta(bio)	bio_rw_flagged(bio, BIO_RW_META)
193 #define bio_discard(bio)	bio_rw_flagged(bio, BIO_RW_DISCARD)
194 #define bio_noidle(bio)		bio_rw_flagged(bio, BIO_RW_NOIDLE)
195 
196 /*
197  * upper 16 bits of bi_rw define the io priority of this bio
198  */
199 #define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
200 #define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
201 #define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))
202 
203 #define bio_set_prio(bio, prio)		do {			\
204 	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
205 	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
206 	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
207 } while (0)
208 
209 /*
210  * various member access, note that bio_data should of course not be used
211  * on highmem page vectors
212  */
213 #define bio_iovec_idx(bio, idx)	(&((bio)->bi_io_vec[(idx)]))
214 #define bio_iovec(bio)		bio_iovec_idx((bio), (bio)->bi_idx)
215 #define bio_page(bio)		bio_iovec((bio))->bv_page
216 #define bio_offset(bio)		bio_iovec((bio))->bv_offset
217 #define bio_segments(bio)	((bio)->bi_vcnt - (bio)->bi_idx)
218 #define bio_sectors(bio)	((bio)->bi_size >> 9)
219 #define bio_empty_barrier(bio)	(bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
220 
221 static inline unsigned int bio_cur_sectors(struct bio *bio)
222 {
223 	if (bio->bi_vcnt)
224 		return bio_iovec(bio)->bv_len >> 9;
225 	else /* dataless requests such as discard */
226 		return bio->bi_size >> 9;
227 }
228 
229 static inline void *bio_data(struct bio *bio)
230 {
231 	if (bio->bi_vcnt)
232 		return page_address(bio_page(bio)) + bio_offset(bio);
233 
234 	return NULL;
235 }
236 
237 static inline int bio_has_allocated_vec(struct bio *bio)
238 {
239 	return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
240 }
241 
242 /*
243  * will die
244  */
245 #define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
246 #define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
247 
248 /*
249  * queues that have highmem support enabled may still need to revert to
250  * PIO transfers occasionally and thus map high pages temporarily. For
251  * permanent PIO fall back, user is probably better off disabling highmem
252  * I/O completely on that queue (see ide-dma for example)
253  */
254 #define __bio_kmap_atomic(bio, idx, kmtype)				\
255 	(kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) +	\
256 		bio_iovec_idx((bio), (idx))->bv_offset)
257 
258 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
259 
260 /*
261  * merge helpers etc
262  */
263 
264 #define __BVEC_END(bio)		bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
265 #define __BVEC_START(bio)	bio_iovec_idx((bio), (bio)->bi_idx)
266 
267 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
268 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
269 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
270 
271 /*
272  * allow arch override, for eg virtualized architectures (put in asm/io.h)
273  */
274 #ifndef BIOVEC_PHYS_MERGEABLE
275 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
276 	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
277 #endif
278 
279 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
280 	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
281 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
282 	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
283 #define BIO_SEG_BOUNDARY(q, b1, b2) \
284 	BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
285 
286 #define bio_io_error(bio) bio_endio((bio), -EIO)
287 
288 /*
289  * drivers should not use the __ version unless they _really_ want to
290  * run through the entire bio and not just pending pieces
291  */
292 #define __bio_for_each_segment(bvl, bio, i, start_idx)			\
293 	for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx);	\
294 	     i < (bio)->bi_vcnt;					\
295 	     bvl++, i++)
296 
297 #define bio_for_each_segment(bvl, bio, i)				\
298 	__bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
299 
300 /*
301  * get a reference to a bio, so it won't disappear. the intended use is
302  * something like:
303  *
304  * bio_get(bio);
305  * submit_bio(rw, bio);
306  * if (bio->bi_flags ...)
307  *	do_something
308  * bio_put(bio);
309  *
310  * without the bio_get(), it could potentially complete I/O before submit_bio
311  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
312  * runs
313  */
314 #define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)
315 
316 #if defined(CONFIG_BLK_DEV_INTEGRITY)
317 /*
318  * bio integrity payload
319  */
320 struct bio_integrity_payload {
321 	struct bio		*bip_bio;	/* parent bio */
322 	struct bio_vec		*bip_vec;	/* integrity data vector */
323 
324 	sector_t		bip_sector;	/* virtual start sector */
325 
326 	void			*bip_buf;	/* generated integrity data */
327 	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
328 
329 	unsigned int		bip_size;
330 
331 	unsigned short		bip_pool;	/* pool the ivec came from */
332 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
333 	unsigned short		bip_idx;	/* current bip_vec index */
334 
335 	struct work_struct	bip_work;	/* I/O completion */
336 };
337 #endif /* CONFIG_BLK_DEV_INTEGRITY */
338 
339 /*
340  * A bio_pair is used when we need to split a bio.
341  * This can only happen for a bio that refers to just one
342  * page of data, and in the unusual situation when the
343  * page crosses a chunk/device boundary
344  *
345  * The address of the master bio is stored in bio1.bi_private
346  * The address of the pool the pair was allocated from is stored
347  *   in bio2.bi_private
348  */
349 struct bio_pair {
350 	struct bio			bio1, bio2;
351 	struct bio_vec			bv1, bv2;
352 #if defined(CONFIG_BLK_DEV_INTEGRITY)
353 	struct bio_integrity_payload	bip1, bip2;
354 	struct bio_vec			iv1, iv2;
355 #endif
356 	atomic_t			cnt;
357 	int				error;
358 };
359 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
360 extern void bio_pair_release(struct bio_pair *dbio);
361 
362 extern struct bio_set *bioset_create(unsigned int, unsigned int);
363 extern void bioset_free(struct bio_set *);
364 
365 extern struct bio *bio_alloc(gfp_t, int);
366 extern struct bio *bio_kmalloc(gfp_t, int);
367 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
368 extern void bio_put(struct bio *);
369 extern void bio_free(struct bio *, struct bio_set *);
370 
371 extern void bio_endio(struct bio *, int);
372 struct request_queue;
373 extern int bio_phys_segments(struct request_queue *, struct bio *);
374 
375 extern void __bio_clone(struct bio *, struct bio *);
376 extern struct bio *bio_clone(struct bio *, gfp_t);
377 
378 extern void bio_init(struct bio *);
379 
380 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
381 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
382 			   unsigned int, unsigned int);
383 extern int bio_get_nr_vecs(struct block_device *);
384 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
385 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
386 				unsigned long, unsigned int, int, gfp_t);
387 struct sg_iovec;
388 struct rq_map_data;
389 extern struct bio *bio_map_user_iov(struct request_queue *,
390 				    struct block_device *,
391 				    struct sg_iovec *, int, int, gfp_t);
392 extern void bio_unmap_user(struct bio *);
393 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
394 				gfp_t);
395 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
396 				 gfp_t, int);
397 extern void bio_set_pages_dirty(struct bio *bio);
398 extern void bio_check_pages_dirty(struct bio *bio);
399 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
400 				 unsigned long, unsigned int, int, gfp_t);
401 extern struct bio *bio_copy_user_iov(struct request_queue *,
402 				     struct rq_map_data *, struct sg_iovec *,
403 				     int, int, gfp_t);
404 extern int bio_uncopy_user(struct bio *);
405 void zero_fill_bio(struct bio *bio);
406 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
407 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
408 extern unsigned int bvec_nr_vecs(unsigned short idx);
409 
410 /*
411  * Allow queuer to specify a completion CPU for this bio
412  */
413 static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
414 {
415 	bio->bi_comp_cpu = cpu;
416 }
417 
418 /*
419  * bio_set is used to allow other portions of the IO system to
420  * allocate their own private memory pools for bio and iovec structures.
421  * These memory pools in turn all allocate from the bio_slab
422  * and the bvec_slabs[].
423  */
424 #define BIO_POOL_SIZE 2
425 #define BIOVEC_NR_POOLS 6
426 #define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)
427 
428 struct bio_set {
429 	struct kmem_cache *bio_slab;
430 	unsigned int front_pad;
431 
432 	mempool_t *bio_pool;
433 	mempool_t *bvec_pool;
434 };
435 
436 struct biovec_slab {
437 	int nr_vecs;
438 	char *name;
439 	struct kmem_cache *slab;
440 };
441 
442 extern struct bio_set *fs_bio_set;
443 extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
444 
445 /*
446  * a small number of entries is fine, not going to be performance critical.
447  * basically we just need to survive
448  */
449 #define BIO_SPLIT_ENTRIES 2
450 
451 #ifdef CONFIG_HIGHMEM
452 /*
453  * remember never ever reenable interrupts between a bvec_kmap_irq and
454  * bvec_kunmap_irq!
455  *
456  * This function MUST be inlined - it plays with the CPU interrupt flags.
457  */
458 static __always_inline char *bvec_kmap_irq(struct bio_vec *bvec,
459 		unsigned long *flags)
460 {
461 	unsigned long addr;
462 
463 	/*
464 	 * might not be a highmem page, but the preempt/irq count
465 	 * balancing is a lot nicer this way
466 	 */
467 	local_irq_save(*flags);
468 	addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
469 
470 	BUG_ON(addr & ~PAGE_MASK);
471 
472 	return (char *) addr + bvec->bv_offset;
473 }
474 
475 static __always_inline void bvec_kunmap_irq(char *buffer,
476 		unsigned long *flags)
477 {
478 	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
479 
480 	kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
481 	local_irq_restore(*flags);
482 }
483 
484 #else
485 #define bvec_kmap_irq(bvec, flags)	(page_address((bvec)->bv_page) + (bvec)->bv_offset)
486 #define bvec_kunmap_irq(buf, flags)	do { *(flags) = 0; } while (0)
487 #endif
488 
489 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
490 				   unsigned long *flags)
491 {
492 	return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
493 }
494 #define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)
495 
496 #define bio_kmap_irq(bio, flags) \
497 	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
498 #define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
499 
500 /*
501  * Check whether this bio carries any data or not. A NULL bio is allowed.
502  */
503 static inline int bio_has_data(struct bio *bio)
504 {
505 	return bio && bio->bi_io_vec != NULL;
506 }
507 
508 /*
509  * BIO list managment for use by remapping drivers (e.g. DM or MD).
510  *
511  * A bio_list anchors a singly-linked list of bios chained through the bi_next
512  * member of the bio.  The bio_list also caches the last list member to allow
513  * fast access to the tail.
514  */
515 struct bio_list {
516 	struct bio *head;
517 	struct bio *tail;
518 };
519 
520 static inline int bio_list_empty(const struct bio_list *bl)
521 {
522 	return bl->head == NULL;
523 }
524 
525 static inline void bio_list_init(struct bio_list *bl)
526 {
527 	bl->head = bl->tail = NULL;
528 }
529 
530 #define bio_list_for_each(bio, bl) \
531 	for (bio = (bl)->head; bio; bio = bio->bi_next)
532 
533 static inline unsigned bio_list_size(const struct bio_list *bl)
534 {
535 	unsigned sz = 0;
536 	struct bio *bio;
537 
538 	bio_list_for_each(bio, bl)
539 		sz++;
540 
541 	return sz;
542 }
543 
544 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
545 {
546 	bio->bi_next = NULL;
547 
548 	if (bl->tail)
549 		bl->tail->bi_next = bio;
550 	else
551 		bl->head = bio;
552 
553 	bl->tail = bio;
554 }
555 
556 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
557 {
558 	bio->bi_next = bl->head;
559 
560 	bl->head = bio;
561 
562 	if (!bl->tail)
563 		bl->tail = bio;
564 }
565 
566 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
567 {
568 	if (!bl2->head)
569 		return;
570 
571 	if (bl->tail)
572 		bl->tail->bi_next = bl2->head;
573 	else
574 		bl->head = bl2->head;
575 
576 	bl->tail = bl2->tail;
577 }
578 
579 static inline void bio_list_merge_head(struct bio_list *bl,
580 				       struct bio_list *bl2)
581 {
582 	if (!bl2->head)
583 		return;
584 
585 	if (bl->head)
586 		bl2->tail->bi_next = bl->head;
587 	else
588 		bl->tail = bl2->tail;
589 
590 	bl->head = bl2->head;
591 }
592 
593 static inline struct bio *bio_list_pop(struct bio_list *bl)
594 {
595 	struct bio *bio = bl->head;
596 
597 	if (bio) {
598 		bl->head = bl->head->bi_next;
599 		if (!bl->head)
600 			bl->tail = NULL;
601 
602 		bio->bi_next = NULL;
603 	}
604 
605 	return bio;
606 }
607 
608 static inline struct bio *bio_list_get(struct bio_list *bl)
609 {
610 	struct bio *bio = bl->head;
611 
612 	bl->head = bl->tail = NULL;
613 
614 	return bio;
615 }
616 
617 #if defined(CONFIG_BLK_DEV_INTEGRITY)
618 
619 #define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
620 #define bip_vec(bip)		bip_vec_idx(bip, 0)
621 
622 #define __bip_for_each_vec(bvl, bip, i, start_idx)			\
623 	for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx);	\
624 	     i < (bip)->bip_vcnt;					\
625 	     bvl++, i++)
626 
627 #define bip_for_each_vec(bvl, bip, i)					\
628 	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
629 
630 #define bio_integrity(bio) (bio->bi_integrity != NULL)
631 
632 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
633 extern void bio_integrity_free(struct bio *);
634 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
635 extern int bio_integrity_enabled(struct bio *bio);
636 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
637 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
638 extern int bio_integrity_prep(struct bio *);
639 extern void bio_integrity_endio(struct bio *, int);
640 extern void bio_integrity_advance(struct bio *, unsigned int);
641 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
642 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
643 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
644 
645 #else /* CONFIG_BLK_DEV_INTEGRITY */
646 
647 #define bio_integrity(a)		(0)
648 #define bio_integrity_prep(a)		(0)
649 #define bio_integrity_enabled(a)	(0)
650 #define bio_integrity_clone(a, b, c)	(0)
651 #define bio_integrity_free(a)		do { } while (0)
652 #define bio_integrity_endio(a, b)	do { } while (0)
653 #define bio_integrity_advance(a, b)	do { } while (0)
654 #define bio_integrity_trim(a, b, c)	do { } while (0)
655 #define bio_integrity_split(a, b, c)	do { } while (0)
656 #define bio_integrity_set_tag(a, b, c)	do { } while (0)
657 #define bio_integrity_get_tag(a, b, c)	do { } while (0)
658 
659 #endif /* CONFIG_BLK_DEV_INTEGRITY */
660 
661 #endif /* CONFIG_BLOCK */
662 #endif /* __LINUX_BIO_H */
663