forked from mirrors/linux
		
	 03100aada9
			
		
	
	
		03100aada9
		
	
	
	
	
		
			
			The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
		
			
				
	
	
		
			801 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			801 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * 2.5 block I/O model
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|  *
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|  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  *
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public Licens
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
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|  */
 | |
| #ifndef __LINUX_BIO_H
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| #define __LINUX_BIO_H
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| 
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| #include <linux/highmem.h>
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| #include <linux/mempool.h>
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| #include <linux/ioprio.h>
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| #include <linux/bug.h>
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| 
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| #ifdef CONFIG_BLOCK
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| 
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| #include <asm/io.h>
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| 
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| /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
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| #include <linux/blk_types.h>
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| 
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| #define BIO_DEBUG
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| 
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| #ifdef BIO_DEBUG
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| #define BIO_BUG_ON	BUG_ON
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| #else
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| #define BIO_BUG_ON
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| #endif
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| 
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| #define BIO_MAX_PAGES		256
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| #define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
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| #define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)
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| 
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| /*
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|  * upper 16 bits of bi_rw define the io priority of this bio
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|  */
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| #define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
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| #define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
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| #define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))
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| 
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| #define bio_set_prio(bio, prio)		do {			\
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| 	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
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| 	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
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| 	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
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| } while (0)
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| 
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| /*
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|  * various member access, note that bio_data should of course not be used
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|  * on highmem page vectors
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|  */
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| #define __bvec_iter_bvec(bvec, iter)	(&(bvec)[(iter).bi_idx])
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| 
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| #define bvec_iter_page(bvec, iter)				\
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| 	(__bvec_iter_bvec((bvec), (iter))->bv_page)
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| 
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| #define bvec_iter_len(bvec, iter)				\
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| 	min((iter).bi_size,					\
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| 	    __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
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| 
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| #define bvec_iter_offset(bvec, iter)				\
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| 	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
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| 
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| #define bvec_iter_bvec(bvec, iter)				\
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| ((struct bio_vec) {						\
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| 	.bv_page	= bvec_iter_page((bvec), (iter)),	\
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| 	.bv_len		= bvec_iter_len((bvec), (iter)),	\
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| 	.bv_offset	= bvec_iter_offset((bvec), (iter)),	\
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| })
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| 
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| #define bio_iter_iovec(bio, iter)				\
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| 	bvec_iter_bvec((bio)->bi_io_vec, (iter))
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| 
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| #define bio_iter_page(bio, iter)				\
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| 	bvec_iter_page((bio)->bi_io_vec, (iter))
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| #define bio_iter_len(bio, iter)					\
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| 	bvec_iter_len((bio)->bi_io_vec, (iter))
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| #define bio_iter_offset(bio, iter)				\
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| 	bvec_iter_offset((bio)->bi_io_vec, (iter))
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| 
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| #define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
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| #define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
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| #define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
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| 
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| #define bio_multiple_segments(bio)				\
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| 	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
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| #define bio_sectors(bio)	((bio)->bi_iter.bi_size >> 9)
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| #define bio_end_sector(bio)	((bio)->bi_iter.bi_sector + bio_sectors((bio)))
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| 
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| /*
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|  * Check whether this bio carries any data or not. A NULL bio is allowed.
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|  */
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| static inline bool bio_has_data(struct bio *bio)
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| {
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| 	if (bio &&
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| 	    bio->bi_iter.bi_size &&
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| 	    !(bio->bi_rw & REQ_DISCARD))
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| 		return true;
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| 
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| 	return false;
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| }
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| 
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| static inline bool bio_is_rw(struct bio *bio)
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| {
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| 	if (!bio_has_data(bio))
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| 		return false;
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| 
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| 	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
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| 		return false;
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| 
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| 	return true;
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| }
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| 
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| static inline bool bio_mergeable(struct bio *bio)
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| {
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| 	if (bio->bi_rw & REQ_NOMERGE_FLAGS)
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| 		return false;
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| 
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| 	return true;
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| }
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| 
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| static inline unsigned int bio_cur_bytes(struct bio *bio)
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| {
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| 	if (bio_has_data(bio))
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| 		return bio_iovec(bio).bv_len;
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| 	else /* dataless requests such as discard */
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| 		return bio->bi_iter.bi_size;
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| }
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| 
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| static inline void *bio_data(struct bio *bio)
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| {
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| 	if (bio_has_data(bio))
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| 		return page_address(bio_page(bio)) + bio_offset(bio);
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| 
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| 	return NULL;
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| }
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| 
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| /*
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|  * will die
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|  */
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| #define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
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| #define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
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| 
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| /*
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|  * queues that have highmem support enabled may still need to revert to
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|  * PIO transfers occasionally and thus map high pages temporarily. For
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|  * permanent PIO fall back, user is probably better off disabling highmem
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|  * I/O completely on that queue (see ide-dma for example)
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|  */
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| #define __bio_kmap_atomic(bio, iter)				\
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| 	(kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) +	\
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| 		bio_iter_iovec((bio), (iter)).bv_offset)
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| 
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| #define __bio_kunmap_atomic(addr)	kunmap_atomic(addr)
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| 
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| /*
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|  * merge helpers etc
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|  */
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| 
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| /* Default implementation of BIOVEC_PHYS_MERGEABLE */
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| #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
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| 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
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| 
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| /*
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|  * allow arch override, for eg virtualized architectures (put in asm/io.h)
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|  */
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| #ifndef BIOVEC_PHYS_MERGEABLE
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| #define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
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| 	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
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| #endif
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| 
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| #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
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| 	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
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| #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
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| 	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
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| 
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| /*
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|  * drivers should _never_ use the all version - the bio may have been split
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|  * before it got to the driver and the driver won't own all of it
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|  */
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| #define bio_for_each_segment_all(bvl, bio, i)				\
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| 	for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
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| 
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| static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
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| 				     unsigned bytes)
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| {
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| 	WARN_ONCE(bytes > iter->bi_size,
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| 		  "Attempted to advance past end of bvec iter\n");
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| 
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| 	while (bytes) {
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| 		unsigned len = min(bytes, bvec_iter_len(bv, *iter));
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| 
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| 		bytes -= len;
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| 		iter->bi_size -= len;
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| 		iter->bi_bvec_done += len;
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| 
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| 		if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
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| 			iter->bi_bvec_done = 0;
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| 			iter->bi_idx++;
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| 		}
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| 	}
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| }
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| 
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| #define for_each_bvec(bvl, bio_vec, iter, start)			\
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| 	for (iter = (start);						\
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| 	     (iter).bi_size &&						\
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| 		((bvl = bvec_iter_bvec((bio_vec), (iter))), 1);	\
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| 	     bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
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| 
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| 
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| static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
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| 				    unsigned bytes)
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| {
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| 	iter->bi_sector += bytes >> 9;
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| 
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| 	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
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| 		iter->bi_size -= bytes;
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| 	else
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| 		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
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| }
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| 
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| #define __bio_for_each_segment(bvl, bio, iter, start)			\
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| 	for (iter = (start);						\
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| 	     (iter).bi_size &&						\
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| 		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
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| 	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
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| 
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| #define bio_for_each_segment(bvl, bio, iter)				\
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| 	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
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| 
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| #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
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| 
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| static inline unsigned bio_segments(struct bio *bio)
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| {
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| 	unsigned segs = 0;
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| 	struct bio_vec bv;
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| 	struct bvec_iter iter;
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| 
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| 	/*
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| 	 * We special case discard/write same, because they interpret bi_size
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| 	 * differently:
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| 	 */
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| 
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| 	if (bio->bi_rw & REQ_DISCARD)
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| 		return 1;
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| 
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| 	if (bio->bi_rw & REQ_WRITE_SAME)
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| 		return 1;
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| 
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| 	bio_for_each_segment(bv, bio, iter)
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| 		segs++;
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| 
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| 	return segs;
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| }
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| 
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| /*
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|  * get a reference to a bio, so it won't disappear. the intended use is
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|  * something like:
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|  *
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|  * bio_get(bio);
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|  * submit_bio(rw, bio);
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|  * if (bio->bi_flags ...)
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|  *	do_something
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|  * bio_put(bio);
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|  *
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|  * without the bio_get(), it could potentially complete I/O before submit_bio
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|  * returns. and then bio would be freed memory when if (bio->bi_flags ...)
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|  * runs
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|  */
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| static inline void bio_get(struct bio *bio)
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| {
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| 	bio->bi_flags |= (1 << BIO_REFFED);
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| 	smp_mb__before_atomic();
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| 	atomic_inc(&bio->__bi_cnt);
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| }
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| 
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| static inline void bio_cnt_set(struct bio *bio, unsigned int count)
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| {
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| 	if (count != 1) {
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| 		bio->bi_flags |= (1 << BIO_REFFED);
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| 		smp_mb__before_atomic();
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| 	}
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| 	atomic_set(&bio->__bi_cnt, count);
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| }
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| 
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| static inline bool bio_flagged(struct bio *bio, unsigned int bit)
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| {
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| 	return (bio->bi_flags & (1U << bit)) != 0;
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| }
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| 
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| static inline void bio_set_flag(struct bio *bio, unsigned int bit)
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| {
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| 	bio->bi_flags |= (1U << bit);
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| }
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| 
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| static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
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| {
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| 	bio->bi_flags &= ~(1U << bit);
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| }
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| 
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| enum bip_flags {
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| 	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
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| 	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
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| 	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
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| 	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
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| 	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
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| };
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| 
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| #if defined(CONFIG_BLK_DEV_INTEGRITY)
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| 
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| static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
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| {
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| 	if (bio->bi_rw & REQ_INTEGRITY)
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| 		return bio->bi_integrity;
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| 
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| 	return NULL;
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| }
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| 
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| /*
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|  * bio integrity payload
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|  */
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| struct bio_integrity_payload {
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| 	struct bio		*bip_bio;	/* parent bio */
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| 
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| 	struct bvec_iter	bip_iter;
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| 
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| 	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
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| 
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| 	unsigned short		bip_slab;	/* slab the bip came from */
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| 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
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| 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
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| 	unsigned short		bip_flags;	/* control flags */
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| 
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| 	struct work_struct	bip_work;	/* I/O completion */
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| 
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| 	struct bio_vec		*bip_vec;
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| 	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
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| };
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| 
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| static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
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| {
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| 	struct bio_integrity_payload *bip = bio_integrity(bio);
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| 
 | |
| 	if (bip)
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| 		return bip->bip_flags & flag;
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| 
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| 	return false;
 | |
| }
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| 
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| static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
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| {
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| 	return bip->bip_iter.bi_sector;
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| }
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| 
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| static inline void bip_set_seed(struct bio_integrity_payload *bip,
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| 				sector_t seed)
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| {
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| 	bip->bip_iter.bi_sector = seed;
 | |
| }
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| 
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| #endif /* CONFIG_BLK_DEV_INTEGRITY */
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| 
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| extern void bio_trim(struct bio *bio, int offset, int size);
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| extern struct bio *bio_split(struct bio *bio, int sectors,
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| 			     gfp_t gfp, struct bio_set *bs);
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| 
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| /**
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|  * bio_next_split - get next @sectors from a bio, splitting if necessary
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|  * @bio:	bio to split
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|  * @sectors:	number of sectors to split from the front of @bio
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|  * @gfp:	gfp mask
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|  * @bs:		bio set to allocate from
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|  *
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|  * Returns a bio representing the next @sectors of @bio - if the bio is smaller
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|  * than @sectors, returns the original bio unchanged.
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|  */
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| static inline struct bio *bio_next_split(struct bio *bio, int sectors,
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| 					 gfp_t gfp, struct bio_set *bs)
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| {
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| 	if (sectors >= bio_sectors(bio))
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| 		return bio;
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| 
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| 	return bio_split(bio, sectors, gfp, bs);
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| }
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| 
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| extern struct bio_set *bioset_create(unsigned int, unsigned int);
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| extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
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| extern void bioset_free(struct bio_set *);
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| extern mempool_t *biovec_create_pool(int pool_entries);
 | |
| 
 | |
| extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
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| extern void bio_put(struct bio *);
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| 
 | |
| extern void __bio_clone_fast(struct bio *, struct bio *);
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| extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
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| extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
 | |
| 
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| extern struct bio_set *fs_bio_set;
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| 
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| static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
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| {
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| 	return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
 | |
| }
 | |
| 
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| static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
 | |
| {
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| 	return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
 | |
| }
 | |
| 
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| static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 | |
| {
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| 	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
 | |
| }
 | |
| 
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| static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
 | |
| {
 | |
| 	return bio_clone_bioset(bio, gfp_mask, NULL);
 | |
| 
 | |
| }
 | |
| 
 | |
| extern void bio_endio(struct bio *);
 | |
| 
 | |
| static inline void bio_io_error(struct bio *bio)
 | |
| {
 | |
| 	bio->bi_error = -EIO;
 | |
| 	bio_endio(bio);
 | |
| }
 | |
| 
 | |
| struct request_queue;
 | |
| extern int bio_phys_segments(struct request_queue *, struct bio *);
 | |
| 
 | |
| extern int submit_bio_wait(int rw, struct bio *bio);
 | |
| extern void bio_advance(struct bio *, unsigned);
 | |
| 
 | |
| extern void bio_init(struct bio *);
 | |
| extern void bio_reset(struct bio *);
 | |
| void bio_chain(struct bio *, struct bio *);
 | |
| 
 | |
| extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 | |
| extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 | |
| 			   unsigned int, unsigned int);
 | |
| struct rq_map_data;
 | |
| extern struct bio *bio_map_user_iov(struct request_queue *,
 | |
| 				    const struct iov_iter *, gfp_t);
 | |
| extern void bio_unmap_user(struct bio *);
 | |
| extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 | |
| 				gfp_t);
 | |
| extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 | |
| 				 gfp_t, int);
 | |
| extern void bio_set_pages_dirty(struct bio *bio);
 | |
| extern void bio_check_pages_dirty(struct bio *bio);
 | |
| 
 | |
| void generic_start_io_acct(int rw, unsigned long sectors,
 | |
| 			   struct hd_struct *part);
 | |
| void generic_end_io_acct(int rw, struct hd_struct *part,
 | |
| 			 unsigned long start_time);
 | |
| 
 | |
| #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 | |
| # error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 | |
| #endif
 | |
| #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 | |
| extern void bio_flush_dcache_pages(struct bio *bi);
 | |
| #else
 | |
| static inline void bio_flush_dcache_pages(struct bio *bi)
 | |
| {
 | |
| }
 | |
| #endif
 | |
| 
 | |
| extern void bio_copy_data(struct bio *dst, struct bio *src);
 | |
| extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
 | |
| 
 | |
| extern struct bio *bio_copy_user_iov(struct request_queue *,
 | |
| 				     struct rq_map_data *,
 | |
| 				     const struct iov_iter *,
 | |
| 				     gfp_t);
 | |
| extern int bio_uncopy_user(struct bio *);
 | |
| void zero_fill_bio(struct bio *bio);
 | |
| extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
 | |
| extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
 | |
| extern unsigned int bvec_nr_vecs(unsigned short idx);
 | |
| 
 | |
| #ifdef CONFIG_BLK_CGROUP
 | |
| int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
 | |
| int bio_associate_current(struct bio *bio);
 | |
| void bio_disassociate_task(struct bio *bio);
 | |
| #else	/* CONFIG_BLK_CGROUP */
 | |
| static inline int bio_associate_blkcg(struct bio *bio,
 | |
| 			struct cgroup_subsys_state *blkcg_css) { return 0; }
 | |
| static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
 | |
| static inline void bio_disassociate_task(struct bio *bio) { }
 | |
| #endif	/* CONFIG_BLK_CGROUP */
 | |
| 
 | |
| #ifdef CONFIG_HIGHMEM
 | |
| /*
 | |
|  * remember never ever reenable interrupts between a bvec_kmap_irq and
 | |
|  * bvec_kunmap_irq!
 | |
|  */
 | |
| static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 | |
| {
 | |
| 	unsigned long addr;
 | |
| 
 | |
| 	/*
 | |
| 	 * might not be a highmem page, but the preempt/irq count
 | |
| 	 * balancing is a lot nicer this way
 | |
| 	 */
 | |
| 	local_irq_save(*flags);
 | |
| 	addr = (unsigned long) kmap_atomic(bvec->bv_page);
 | |
| 
 | |
| 	BUG_ON(addr & ~PAGE_MASK);
 | |
| 
 | |
| 	return (char *) addr + bvec->bv_offset;
 | |
| }
 | |
| 
 | |
| static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 | |
| {
 | |
| 	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
 | |
| 
 | |
| 	kunmap_atomic((void *) ptr);
 | |
| 	local_irq_restore(*flags);
 | |
| }
 | |
| 
 | |
| #else
 | |
| static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
 | |
| {
 | |
| 	return page_address(bvec->bv_page) + bvec->bv_offset;
 | |
| }
 | |
| 
 | |
| static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
 | |
| {
 | |
| 	*flags = 0;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
 | |
| 				   unsigned long *flags)
 | |
| {
 | |
| 	return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
 | |
| }
 | |
| #define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)
 | |
| 
 | |
| #define bio_kmap_irq(bio, flags) \
 | |
| 	__bio_kmap_irq((bio), (bio)->bi_iter, (flags))
 | |
| #define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
 | |
| 
 | |
| /*
 | |
|  * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
 | |
|  *
 | |
|  * A bio_list anchors a singly-linked list of bios chained through the bi_next
 | |
|  * member of the bio.  The bio_list also caches the last list member to allow
 | |
|  * fast access to the tail.
 | |
|  */
 | |
| struct bio_list {
 | |
| 	struct bio *head;
 | |
| 	struct bio *tail;
 | |
| };
 | |
| 
 | |
| static inline int bio_list_empty(const struct bio_list *bl)
 | |
| {
 | |
| 	return bl->head == NULL;
 | |
| }
 | |
| 
 | |
| static inline void bio_list_init(struct bio_list *bl)
 | |
| {
 | |
| 	bl->head = bl->tail = NULL;
 | |
| }
 | |
| 
 | |
| #define BIO_EMPTY_LIST	{ NULL, NULL }
 | |
| 
 | |
| #define bio_list_for_each(bio, bl) \
 | |
| 	for (bio = (bl)->head; bio; bio = bio->bi_next)
 | |
| 
 | |
| static inline unsigned bio_list_size(const struct bio_list *bl)
 | |
| {
 | |
| 	unsigned sz = 0;
 | |
| 	struct bio *bio;
 | |
| 
 | |
| 	bio_list_for_each(bio, bl)
 | |
| 		sz++;
 | |
| 
 | |
| 	return sz;
 | |
| }
 | |
| 
 | |
| static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
 | |
| {
 | |
| 	bio->bi_next = NULL;
 | |
| 
 | |
| 	if (bl->tail)
 | |
| 		bl->tail->bi_next = bio;
 | |
| 	else
 | |
| 		bl->head = bio;
 | |
| 
 | |
| 	bl->tail = bio;
 | |
| }
 | |
| 
 | |
| static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
 | |
| {
 | |
| 	bio->bi_next = bl->head;
 | |
| 
 | |
| 	bl->head = bio;
 | |
| 
 | |
| 	if (!bl->tail)
 | |
| 		bl->tail = bio;
 | |
| }
 | |
| 
 | |
| static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
 | |
| {
 | |
| 	if (!bl2->head)
 | |
| 		return;
 | |
| 
 | |
| 	if (bl->tail)
 | |
| 		bl->tail->bi_next = bl2->head;
 | |
| 	else
 | |
| 		bl->head = bl2->head;
 | |
| 
 | |
| 	bl->tail = bl2->tail;
 | |
| }
 | |
| 
 | |
| static inline void bio_list_merge_head(struct bio_list *bl,
 | |
| 				       struct bio_list *bl2)
 | |
| {
 | |
| 	if (!bl2->head)
 | |
| 		return;
 | |
| 
 | |
| 	if (bl->head)
 | |
| 		bl2->tail->bi_next = bl->head;
 | |
| 	else
 | |
| 		bl->tail = bl2->tail;
 | |
| 
 | |
| 	bl->head = bl2->head;
 | |
| }
 | |
| 
 | |
| static inline struct bio *bio_list_peek(struct bio_list *bl)
 | |
| {
 | |
| 	return bl->head;
 | |
| }
 | |
| 
 | |
| static inline struct bio *bio_list_pop(struct bio_list *bl)
 | |
| {
 | |
| 	struct bio *bio = bl->head;
 | |
| 
 | |
| 	if (bio) {
 | |
| 		bl->head = bl->head->bi_next;
 | |
| 		if (!bl->head)
 | |
| 			bl->tail = NULL;
 | |
| 
 | |
| 		bio->bi_next = NULL;
 | |
| 	}
 | |
| 
 | |
| 	return bio;
 | |
| }
 | |
| 
 | |
| static inline struct bio *bio_list_get(struct bio_list *bl)
 | |
| {
 | |
| 	struct bio *bio = bl->head;
 | |
| 
 | |
| 	bl->head = bl->tail = NULL;
 | |
| 
 | |
| 	return bio;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * bio_set is used to allow other portions of the IO system to
 | |
|  * allocate their own private memory pools for bio and iovec structures.
 | |
|  * These memory pools in turn all allocate from the bio_slab
 | |
|  * and the bvec_slabs[].
 | |
|  */
 | |
| #define BIO_POOL_SIZE 2
 | |
| #define BIOVEC_NR_POOLS 6
 | |
| #define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)
 | |
| 
 | |
| struct bio_set {
 | |
| 	struct kmem_cache *bio_slab;
 | |
| 	unsigned int front_pad;
 | |
| 
 | |
| 	mempool_t *bio_pool;
 | |
| 	mempool_t *bvec_pool;
 | |
| #if defined(CONFIG_BLK_DEV_INTEGRITY)
 | |
| 	mempool_t *bio_integrity_pool;
 | |
| 	mempool_t *bvec_integrity_pool;
 | |
| #endif
 | |
| 
 | |
| 	/*
 | |
| 	 * Deadlock avoidance for stacking block drivers: see comments in
 | |
| 	 * bio_alloc_bioset() for details
 | |
| 	 */
 | |
| 	spinlock_t		rescue_lock;
 | |
| 	struct bio_list		rescue_list;
 | |
| 	struct work_struct	rescue_work;
 | |
| 	struct workqueue_struct	*rescue_workqueue;
 | |
| };
 | |
| 
 | |
| struct biovec_slab {
 | |
| 	int nr_vecs;
 | |
| 	char *name;
 | |
| 	struct kmem_cache *slab;
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * a small number of entries is fine, not going to be performance critical.
 | |
|  * basically we just need to survive
 | |
|  */
 | |
| #define BIO_SPLIT_ENTRIES 2
 | |
| 
 | |
| #if defined(CONFIG_BLK_DEV_INTEGRITY)
 | |
| 
 | |
| #define bip_for_each_vec(bvl, bip, iter)				\
 | |
| 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
 | |
| 
 | |
| #define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
 | |
| 	for_each_bio(_bio)						\
 | |
| 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
 | |
| 
 | |
| extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
 | |
| extern void bio_integrity_free(struct bio *);
 | |
| extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 | |
| extern bool bio_integrity_enabled(struct bio *bio);
 | |
| extern int bio_integrity_prep(struct bio *);
 | |
| extern void bio_integrity_endio(struct bio *);
 | |
| extern void bio_integrity_advance(struct bio *, unsigned int);
 | |
| extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
 | |
| extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
 | |
| extern int bioset_integrity_create(struct bio_set *, int);
 | |
| extern void bioset_integrity_free(struct bio_set *);
 | |
| extern void bio_integrity_init(void);
 | |
| 
 | |
| #else /* CONFIG_BLK_DEV_INTEGRITY */
 | |
| 
 | |
| static inline void *bio_integrity(struct bio *bio)
 | |
| {
 | |
| 	return NULL;
 | |
| }
 | |
| 
 | |
| static inline bool bio_integrity_enabled(struct bio *bio)
 | |
| {
 | |
| 	return false;
 | |
| }
 | |
| 
 | |
| static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static inline void bioset_integrity_free (struct bio_set *bs)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline int bio_integrity_prep(struct bio *bio)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static inline void bio_integrity_free(struct bio *bio)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 | |
| 				      gfp_t gfp_mask)
 | |
| {
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static inline void bio_integrity_advance(struct bio *bio,
 | |
| 					 unsigned int bytes_done)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
 | |
| 				      unsigned int sectors)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline void bio_integrity_init(void)
 | |
| {
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
 | |
| {
 | |
| 	return false;
 | |
| }
 | |
| 
 | |
| #endif /* CONFIG_BLK_DEV_INTEGRITY */
 | |
| 
 | |
| #endif /* CONFIG_BLOCK */
 | |
| #endif /* __LINUX_BIO_H */
 |