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block: move bvec iterator into include/linux/bvec.h
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bvec iterator helpers should be used to implement by
iterate_bvec():lib/iov_iter.c too, and move them into
one header, so that we can keep bvec iterator header
out of CONFIG_BLOCK. Then we can remove the reinventing
of wheel in iterate_bvec().

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Tested-by: Hannes Reinecke <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
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Ming Lei authored and axboe committed Jun 9, 2016
1 parent 52b9c33 commit 8fc5545
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51 changes: 1 addition & 50 deletions include/linux/bio.h
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@

/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
#include <linux/blk_types.h>
#include <linux/bvec.h>

#define BIO_DEBUG

Expand All @@ -47,29 +48,6 @@
#define bio_prio(bio) (bio)->bi_ioprio
#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)

/*
* various member access, note that bio_data should of course not be used
* on highmem page vectors
*/
#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])

#define bvec_iter_page(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_page)

#define bvec_iter_len(bvec, iter) \
min((iter).bi_size, \
__bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)

#define bvec_iter_offset(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)

#define bvec_iter_bvec(bvec, iter) \
((struct bio_vec) { \
.bv_page = bvec_iter_page((bvec), (iter)), \
.bv_len = bvec_iter_len((bvec), (iter)), \
.bv_offset = bvec_iter_offset((bvec), (iter)), \
})

#define bio_iter_iovec(bio, iter) \
bvec_iter_bvec((bio)->bi_io_vec, (iter))

Expand Down Expand Up @@ -188,33 +166,6 @@ static inline void *bio_data(struct bio *bio)
#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 bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
unsigned bytes)
{
WARN_ONCE(bytes > iter->bi_size,
"Attempted to advance past end of bvec iter\n");

while (bytes) {
unsigned len = min(bytes, bvec_iter_len(bv, *iter));

bytes -= len;
iter->bi_size -= len;
iter->bi_bvec_done += len;

if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
iter->bi_bvec_done = 0;
iter->bi_idx++;
}
}
}

#define for_each_bvec(bvl, bio_vec, iter, start) \
for (iter = (start); \
(iter).bi_size && \
((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))


static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
unsigned bytes)
{
Expand Down
74 changes: 74 additions & 0 deletions include/linux/bvec.h
Original file line number Diff line number Diff line change
@@ -0,0 +1,74 @@
/*
* bvec iterator
*
* Copyright (C) 2001 Ming Lei <[email protected]>
*
* 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_BVEC_ITER_H
#define __LINUX_BVEC_ITER_H

#include <linux/blk_types.h>

/*
* various member access, note that bio_data should of course not be used
* on highmem page vectors
*/
#define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])

#define bvec_iter_page(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_page)

#define bvec_iter_len(bvec, iter) \
min((iter).bi_size, \
__bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)

#define bvec_iter_offset(bvec, iter) \
(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)

#define bvec_iter_bvec(bvec, iter) \
((struct bio_vec) { \
.bv_page = bvec_iter_page((bvec), (iter)), \
.bv_len = bvec_iter_len((bvec), (iter)), \
.bv_offset = bvec_iter_offset((bvec), (iter)), \
})

static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
unsigned bytes)
{
WARN_ONCE(bytes > iter->bi_size,
"Attempted to advance past end of bvec iter\n");

while (bytes) {
unsigned len = min(bytes, bvec_iter_len(bv, *iter));

bytes -= len;
iter->bi_size -= len;
iter->bi_bvec_done += len;

if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
iter->bi_bvec_done = 0;
iter->bi_idx++;
}
}
}

#define for_each_bvec(bvl, bio_vec, iter, start) \
for (iter = (start); \
(iter).bi_size && \
((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))

#endif /* __LINUX_BVEC_ITER_H */

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