forked from mirrors/linux
		
	Pull iov_iter updates from Al Viro:
 - bio_{map,copy}_user_iov() series; those are cleanups - fixes from the
   same pile went into mainline (and stable) in late September.
 - fs/iomap.c iov_iter-related fixes
 - new primitive - iov_iter_for_each_range(), which applies a function
   to kernel-mapped segments of an iov_iter.
   Usable for kvec and bvec ones, the latter does kmap()/kunmap() around
   the callback. _Not_ usable for iovec- or pipe-backed iov_iter; the
   latter is not hard to fix if the need ever appears, the former is by
   design.
   Another related primitive will have to wait for the next cycle - it
   passes page + offset + size instead of pointer + size, and that one
   will be usable for everything _except_ kvec. Unfortunately, that one
   didn't get exposure in -next yet, so...
 - a bit more lustre iov_iter work, including a use case for
   iov_iter_for_each_range() (checksum calculation)
 - vhost/scsi leak fix in failure exit
 - misc cleanups and detritectomy...
* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits)
  iomap_dio_actor(): fix iov_iter bugs
  switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range()
  lustre: switch struct ksock_conn to iov_iter
  vhost/scsi: switch to iov_iter_get_pages()
  fix a page leak in vhost_scsi_iov_to_sgl() error recovery
  new primitive: iov_iter_for_each_range()
  lnet_return_rx_credits_locked: don't abuse list_entry
  xen: don't open-code iov_iter_kvec()
  orangefs: remove detritus from struct orangefs_kiocb_s
  kill iov_shorten()
  bio_alloc_map_data(): do bmd->iter setup right there
  bio_copy_user_iov(): saner bio size calculation
  bio_map_user_iov(): get rid of copying iov_iter
  bio_copy_from_iter(): get rid of copying iov_iter
  move more stuff down into bio_copy_user_iov()
  blk_rq_map_user_iov(): move iov_iter_advance() down
  bio_map_user_iov(): get rid of the iov_for_each()
  bio_map_user_iov(): move alignment check into the main loop
  don't rely upon subsequent bio_add_pc_page() calls failing
  ... and with iov_iter_get_pages_alloc() it becomes even simpler
  ...
		
	
			
		
			
				
	
	
		
			815 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			815 lines
		
	
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
 | 
						|
 *
 | 
						|
 * This program is free software; you can redistribute it and/or modify
 | 
						|
 * it under the terms of the GNU General Public License version 2 as
 | 
						|
 * published by the Free Software Foundation.
 | 
						|
 *
 | 
						|
 * This program is distributed in the hope that it will be useful,
 | 
						|
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
						|
 *
 | 
						|
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 | 
						|
 * GNU General Public License for more details.
 | 
						|
 *
 | 
						|
 * You should have received a copy of the GNU General Public Licens
 | 
						|
 * along with this program; if not, write to the Free Software
 | 
						|
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
 | 
						|
 */
 | 
						|
#ifndef __LINUX_BIO_H
 | 
						|
#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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						|
 | 
						|
#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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						|
 | 
						|
#ifdef CONFIG_THP_SWAP
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						|
#if HPAGE_PMD_NR > 256
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						|
#define BIO_MAX_PAGES		HPAGE_PMD_NR
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						|
#else
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						|
#define BIO_MAX_PAGES		256
 | 
						|
#endif
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						|
#else
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						|
#define BIO_MAX_PAGES		256
 | 
						|
#endif
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						|
 | 
						|
#define bio_prio(bio)			(bio)->bi_ioprio
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						|
#define bio_set_prio(bio, prio)		((bio)->bi_ioprio = prio)
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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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						|
 | 
						|
#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))
 | 
						|
#define bio_iter_offset(bio, iter)				\
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						|
	bvec_iter_offset((bio)->bi_io_vec, (iter))
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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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						|
 | 
						|
#define bio_multiple_segments(bio)				\
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						|
	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
 | 
						|
#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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						|
 * Return the data direction, READ or WRITE.
 | 
						|
 */
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						|
#define bio_data_dir(bio) \
 | 
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	(op_is_write(bio_op(bio)) ? WRITE : READ)
 | 
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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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static inline bool bio_has_data(struct bio *bio)
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{
 | 
						|
	if (bio &&
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						|
	    bio->bi_iter.bi_size &&
 | 
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	    bio_op(bio) != REQ_OP_DISCARD &&
 | 
						|
	    bio_op(bio) != REQ_OP_SECURE_ERASE &&
 | 
						|
	    bio_op(bio) != REQ_OP_WRITE_ZEROES)
 | 
						|
		return true;
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						|
 | 
						|
	return false;
 | 
						|
}
 | 
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 | 
						|
static inline bool bio_no_advance_iter(struct bio *bio)
 | 
						|
{
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						|
	return bio_op(bio) == REQ_OP_DISCARD ||
 | 
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	       bio_op(bio) == REQ_OP_SECURE_ERASE ||
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	       bio_op(bio) == REQ_OP_WRITE_SAME ||
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						|
	       bio_op(bio) == REQ_OP_WRITE_ZEROES;
 | 
						|
}
 | 
						|
 | 
						|
static inline bool bio_mergeable(struct bio *bio)
 | 
						|
{
 | 
						|
	if (bio->bi_opf & REQ_NOMERGE_FLAGS)
 | 
						|
		return false;
 | 
						|
 | 
						|
	return true;
 | 
						|
}
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						|
 | 
						|
static inline unsigned int bio_cur_bytes(struct bio *bio)
 | 
						|
{
 | 
						|
	if (bio_has_data(bio))
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						|
		return bio_iovec(bio).bv_len;
 | 
						|
	else /* dataless requests such as discard */
 | 
						|
		return bio->bi_iter.bi_size;
 | 
						|
}
 | 
						|
 | 
						|
static inline void *bio_data(struct bio *bio)
 | 
						|
{
 | 
						|
	if (bio_has_data(bio))
 | 
						|
		return page_address(bio_page(bio)) + bio_offset(bio);
 | 
						|
 | 
						|
	return NULL;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * will die
 | 
						|
 */
 | 
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#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
 | 
						|
 | 
						|
/*
 | 
						|
 * merge helpers etc
 | 
						|
 */
 | 
						|
 | 
						|
/* Default implementation of BIOVEC_PHYS_MERGEABLE */
 | 
						|
#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
 | 
						|
	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 | 
						|
 | 
						|
/*
 | 
						|
 * allow arch override, for eg virtualized architectures (put in asm/io.h)
 | 
						|
 */
 | 
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#ifndef BIOVEC_PHYS_MERGEABLE
 | 
						|
#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
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						|
	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
 | 
						|
#endif
 | 
						|
 | 
						|
#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 | 
						|
	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 | 
						|
#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 | 
						|
	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 | 
						|
 | 
						|
/*
 | 
						|
 * drivers should _never_ use the all version - the bio may have been split
 | 
						|
 * before it got to the driver and the driver won't own all of it
 | 
						|
 */
 | 
						|
#define bio_for_each_segment_all(bvl, bio, i)				\
 | 
						|
	for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
 | 
						|
 | 
						|
static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
 | 
						|
				    unsigned bytes)
 | 
						|
{
 | 
						|
	iter->bi_sector += bytes >> 9;
 | 
						|
 | 
						|
	if (bio_no_advance_iter(bio)) {
 | 
						|
		iter->bi_size -= bytes;
 | 
						|
		iter->bi_done += bytes;
 | 
						|
	} else {
 | 
						|
		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
 | 
						|
		/* TODO: It is reasonable to complete bio with error here. */
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter,
 | 
						|
		unsigned int bytes)
 | 
						|
{
 | 
						|
	iter->bi_sector -= bytes >> 9;
 | 
						|
 | 
						|
	if (bio_no_advance_iter(bio)) {
 | 
						|
		iter->bi_size += bytes;
 | 
						|
		iter->bi_done -= bytes;
 | 
						|
		return true;
 | 
						|
	}
 | 
						|
 | 
						|
	return bvec_iter_rewind(bio->bi_io_vec, iter, bytes);
 | 
						|
}
 | 
						|
 | 
						|
#define __bio_for_each_segment(bvl, bio, iter, start)			\
 | 
						|
	for (iter = (start);						\
 | 
						|
	     (iter).bi_size &&						\
 | 
						|
		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
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						|
	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
 | 
						|
 | 
						|
#define bio_for_each_segment(bvl, bio, iter)				\
 | 
						|
	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
 | 
						|
 | 
						|
#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
 | 
						|
 | 
						|
static inline unsigned bio_segments(struct bio *bio)
 | 
						|
{
 | 
						|
	unsigned segs = 0;
 | 
						|
	struct bio_vec bv;
 | 
						|
	struct bvec_iter iter;
 | 
						|
 | 
						|
	/*
 | 
						|
	 * We special case discard/write same/write zeroes, because they
 | 
						|
	 * interpret bi_size differently:
 | 
						|
	 */
 | 
						|
 | 
						|
	switch (bio_op(bio)) {
 | 
						|
	case REQ_OP_DISCARD:
 | 
						|
	case REQ_OP_SECURE_ERASE:
 | 
						|
	case REQ_OP_WRITE_ZEROES:
 | 
						|
		return 0;
 | 
						|
	case REQ_OP_WRITE_SAME:
 | 
						|
		return 1;
 | 
						|
	default:
 | 
						|
		break;
 | 
						|
	}
 | 
						|
 | 
						|
	bio_for_each_segment(bv, bio, iter)
 | 
						|
		segs++;
 | 
						|
 | 
						|
	return segs;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * get a reference to a bio, so it won't disappear. the intended use is
 | 
						|
 * something like:
 | 
						|
 *
 | 
						|
 * bio_get(bio);
 | 
						|
 * submit_bio(rw, bio);
 | 
						|
 * if (bio->bi_flags ...)
 | 
						|
 *	do_something
 | 
						|
 * bio_put(bio);
 | 
						|
 *
 | 
						|
 * without the bio_get(), it could potentially complete I/O before submit_bio
 | 
						|
 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
 | 
						|
 * runs
 | 
						|
 */
 | 
						|
static inline void bio_get(struct bio *bio)
 | 
						|
{
 | 
						|
	bio->bi_flags |= (1 << BIO_REFFED);
 | 
						|
	smp_mb__before_atomic();
 | 
						|
	atomic_inc(&bio->__bi_cnt);
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_cnt_set(struct bio *bio, unsigned int count)
 | 
						|
{
 | 
						|
	if (count != 1) {
 | 
						|
		bio->bi_flags |= (1 << BIO_REFFED);
 | 
						|
		smp_mb__before_atomic();
 | 
						|
	}
 | 
						|
	atomic_set(&bio->__bi_cnt, count);
 | 
						|
}
 | 
						|
 | 
						|
static inline bool bio_flagged(struct bio *bio, unsigned int bit)
 | 
						|
{
 | 
						|
	return (bio->bi_flags & (1U << bit)) != 0;
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_set_flag(struct bio *bio, unsigned int bit)
 | 
						|
{
 | 
						|
	bio->bi_flags |= (1U << bit);
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
 | 
						|
{
 | 
						|
	bio->bi_flags &= ~(1U << bit);
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
 | 
						|
{
 | 
						|
	*bv = bio_iovec(bio);
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
 | 
						|
{
 | 
						|
	struct bvec_iter iter = bio->bi_iter;
 | 
						|
	int idx;
 | 
						|
 | 
						|
	if (unlikely(!bio_multiple_segments(bio))) {
 | 
						|
		*bv = bio_iovec(bio);
 | 
						|
		return;
 | 
						|
	}
 | 
						|
 | 
						|
	bio_advance_iter(bio, &iter, iter.bi_size);
 | 
						|
 | 
						|
	if (!iter.bi_bvec_done)
 | 
						|
		idx = iter.bi_idx - 1;
 | 
						|
	else	/* in the middle of bvec */
 | 
						|
		idx = iter.bi_idx;
 | 
						|
 | 
						|
	*bv = bio->bi_io_vec[idx];
 | 
						|
 | 
						|
	/*
 | 
						|
	 * iter.bi_bvec_done records actual length of the last bvec
 | 
						|
	 * if this bio ends in the middle of one io vector
 | 
						|
	 */
 | 
						|
	if (iter.bi_bvec_done)
 | 
						|
		bv->bv_len = iter.bi_bvec_done;
 | 
						|
}
 | 
						|
 | 
						|
enum bip_flags {
 | 
						|
	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
 | 
						|
	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
 | 
						|
	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
 | 
						|
	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
 | 
						|
	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
 | 
						|
};
 | 
						|
 | 
						|
/*
 | 
						|
 * bio integrity payload
 | 
						|
 */
 | 
						|
struct bio_integrity_payload {
 | 
						|
	struct bio		*bip_bio;	/* parent bio */
 | 
						|
 | 
						|
	struct bvec_iter	bip_iter;
 | 
						|
 | 
						|
	unsigned short		bip_slab;	/* slab the bip came from */
 | 
						|
	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
 | 
						|
	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
 | 
						|
	unsigned short		bip_flags;	/* control flags */
 | 
						|
 | 
						|
	struct work_struct	bip_work;	/* I/O completion */
 | 
						|
 | 
						|
	struct bio_vec		*bip_vec;
 | 
						|
	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
 | 
						|
};
 | 
						|
 | 
						|
#if defined(CONFIG_BLK_DEV_INTEGRITY)
 | 
						|
 | 
						|
static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
 | 
						|
{
 | 
						|
	if (bio->bi_opf & REQ_INTEGRITY)
 | 
						|
		return bio->bi_integrity;
 | 
						|
 | 
						|
	return NULL;
 | 
						|
}
 | 
						|
 | 
						|
static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
 | 
						|
{
 | 
						|
	struct bio_integrity_payload *bip = bio_integrity(bio);
 | 
						|
 | 
						|
	if (bip)
 | 
						|
		return bip->bip_flags & flag;
 | 
						|
 | 
						|
	return false;
 | 
						|
}
 | 
						|
 | 
						|
static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
 | 
						|
{
 | 
						|
	return bip->bip_iter.bi_sector;
 | 
						|
}
 | 
						|
 | 
						|
static inline void bip_set_seed(struct bio_integrity_payload *bip,
 | 
						|
				sector_t seed)
 | 
						|
{
 | 
						|
	bip->bip_iter.bi_sector = seed;
 | 
						|
}
 | 
						|
 | 
						|
#endif /* CONFIG_BLK_DEV_INTEGRITY */
 | 
						|
 | 
						|
extern void bio_trim(struct bio *bio, int offset, int size);
 | 
						|
extern struct bio *bio_split(struct bio *bio, int sectors,
 | 
						|
			     gfp_t gfp, struct bio_set *bs);
 | 
						|
 | 
						|
/**
 | 
						|
 * bio_next_split - get next @sectors from a bio, splitting if necessary
 | 
						|
 * @bio:	bio to split
 | 
						|
 * @sectors:	number of sectors to split from the front of @bio
 | 
						|
 * @gfp:	gfp mask
 | 
						|
 * @bs:		bio set to allocate from
 | 
						|
 *
 | 
						|
 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
 | 
						|
 * than @sectors, returns the original bio unchanged.
 | 
						|
 */
 | 
						|
static inline struct bio *bio_next_split(struct bio *bio, int sectors,
 | 
						|
					 gfp_t gfp, struct bio_set *bs)
 | 
						|
{
 | 
						|
	if (sectors >= bio_sectors(bio))
 | 
						|
		return bio;
 | 
						|
 | 
						|
	return bio_split(bio, sectors, gfp, bs);
 | 
						|
}
 | 
						|
 | 
						|
extern struct bio_set *bioset_create(unsigned int, unsigned int, int flags);
 | 
						|
enum {
 | 
						|
	BIOSET_NEED_BVECS = BIT(0),
 | 
						|
	BIOSET_NEED_RESCUER = BIT(1),
 | 
						|
};
 | 
						|
extern void bioset_free(struct bio_set *);
 | 
						|
extern mempool_t *biovec_create_pool(int pool_entries);
 | 
						|
 | 
						|
extern struct bio *bio_alloc_bioset(gfp_t, unsigned int, struct bio_set *);
 | 
						|
extern void bio_put(struct bio *);
 | 
						|
 | 
						|
extern void __bio_clone_fast(struct bio *, struct bio *);
 | 
						|
extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
 | 
						|
extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
 | 
						|
 | 
						|
extern struct bio_set *fs_bio_set;
 | 
						|
 | 
						|
static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 | 
						|
{
 | 
						|
	return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
 | 
						|
}
 | 
						|
 | 
						|
static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 | 
						|
{
 | 
						|
	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
 | 
						|
}
 | 
						|
 | 
						|
static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
 | 
						|
{
 | 
						|
	return bio_clone_bioset(bio, gfp_mask, NULL);
 | 
						|
 | 
						|
}
 | 
						|
 | 
						|
extern blk_qc_t submit_bio(struct bio *);
 | 
						|
 | 
						|
extern void bio_endio(struct bio *);
 | 
						|
 | 
						|
static inline void bio_io_error(struct bio *bio)
 | 
						|
{
 | 
						|
	bio->bi_status = BLK_STS_IOERR;
 | 
						|
	bio_endio(bio);
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_wouldblock_error(struct bio *bio)
 | 
						|
{
 | 
						|
	bio->bi_status = BLK_STS_AGAIN;
 | 
						|
	bio_endio(bio);
 | 
						|
}
 | 
						|
 | 
						|
struct request_queue;
 | 
						|
extern int bio_phys_segments(struct request_queue *, struct bio *);
 | 
						|
 | 
						|
extern int submit_bio_wait(struct bio *bio);
 | 
						|
extern void bio_advance(struct bio *, unsigned);
 | 
						|
 | 
						|
extern void bio_init(struct bio *bio, struct bio_vec *table,
 | 
						|
		     unsigned short max_vecs);
 | 
						|
extern void bio_uninit(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);
 | 
						|
int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
 | 
						|
struct rq_map_data;
 | 
						|
extern struct bio *bio_map_user_iov(struct request_queue *,
 | 
						|
				    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(struct request_queue *q, int rw,
 | 
						|
				unsigned long sectors, struct hd_struct *part);
 | 
						|
void generic_end_io_acct(struct request_queue *q, 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 void bio_free_pages(struct bio *bio);
 | 
						|
 | 
						|
extern struct bio *bio_copy_user_iov(struct request_queue *,
 | 
						|
				     struct rq_map_data *,
 | 
						|
				     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);
 | 
						|
 | 
						|
#define bio_set_dev(bio, bdev) 			\
 | 
						|
do {						\
 | 
						|
	(bio)->bi_disk = (bdev)->bd_disk;	\
 | 
						|
	(bio)->bi_partno = (bdev)->bd_partno;	\
 | 
						|
} while (0)
 | 
						|
 | 
						|
#define bio_copy_dev(dst, src)			\
 | 
						|
do {						\
 | 
						|
	(dst)->bi_disk = (src)->bi_disk;	\
 | 
						|
	(dst)->bi_partno = (src)->bi_partno;	\
 | 
						|
} while (0)
 | 
						|
 | 
						|
#define bio_dev(bio) \
 | 
						|
	disk_devt((bio)->bi_disk)
 | 
						|
 | 
						|
#define bio_devname(bio, buf) \
 | 
						|
	__bdevname(bio_dev(bio), (buf))
 | 
						|
 | 
						|
#ifdef CONFIG_BLK_CGROUP
 | 
						|
int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
 | 
						|
void bio_disassociate_task(struct bio *bio);
 | 
						|
void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
 | 
						|
#else	/* CONFIG_BLK_CGROUP */
 | 
						|
static inline int bio_associate_blkcg(struct bio *bio,
 | 
						|
			struct cgroup_subsys_state *blkcg_css) { return 0; }
 | 
						|
static inline void bio_disassociate_task(struct bio *bio) { }
 | 
						|
static inline void bio_clone_blkcg_association(struct bio *dst,
 | 
						|
			struct bio *src) { }
 | 
						|
#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
 | 
						|
 | 
						|
/*
 | 
						|
 * 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;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Increment chain count for the bio. Make sure the CHAIN flag update
 | 
						|
 * is visible before the raised count.
 | 
						|
 */
 | 
						|
static inline void bio_inc_remaining(struct bio *bio)
 | 
						|
{
 | 
						|
	bio_set_flag(bio, BIO_CHAIN);
 | 
						|
	smp_mb__before_atomic();
 | 
						|
	atomic_inc(&bio->__bi_remaining);
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * 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
 | 
						|
 | 
						|
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 int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
 | 
						|
extern bool bio_integrity_prep(struct bio *);
 | 
						|
extern void bio_integrity_advance(struct bio *, unsigned int);
 | 
						|
extern void bio_integrity_trim(struct bio *);
 | 
						|
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 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 bool bio_integrity_prep(struct bio *bio)
 | 
						|
{
 | 
						|
	return true;
 | 
						|
}
 | 
						|
 | 
						|
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)
 | 
						|
{
 | 
						|
	return;
 | 
						|
}
 | 
						|
 | 
						|
static inline void bio_integrity_init(void)
 | 
						|
{
 | 
						|
	return;
 | 
						|
}
 | 
						|
 | 
						|
static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
 | 
						|
{
 | 
						|
	return false;
 | 
						|
}
 | 
						|
 | 
						|
static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
 | 
						|
								unsigned int nr)
 | 
						|
{
 | 
						|
	return ERR_PTR(-EINVAL);
 | 
						|
}
 | 
						|
 | 
						|
static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
 | 
						|
					unsigned int len, unsigned int offset)
 | 
						|
{
 | 
						|
	return 0;
 | 
						|
}
 | 
						|
 | 
						|
#endif /* CONFIG_BLK_DEV_INTEGRITY */
 | 
						|
 | 
						|
#endif /* CONFIG_BLOCK */
 | 
						|
#endif /* __LINUX_BIO_H */
 |