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Date: Wed, 27 Mar 2013 10:39:52 -0700
From: Kent Overstreet <koverstreet@...gle.com>
To: axboe@...nel.dk, linux-kernel@...r.kernel.org,
linux-fsdevel@...r.kernel.org, dm-devel@...r.kernel.org
Cc: tj@...nel.org, neilb@...e.de,
Kent Overstreet <koverstreet@...gle.com>,
"Martin K. Petersen" <martin.petersen@...cle.com>
Subject: [PATCH 22/22] block: Don't copy bvecs when cloning bios, just share them
Now that immutable biovecs are plumbed through, most users of
bio_clone() don't need it to clone the biovec - we can share the
original bio's biovec.
Add bio_clone_biovec() for the users that do need to modify the biovec
(the bounce buffer code).
Signed-off-by: Kent Overstreet <koverstreet@...gle.com>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: "Martin K. Petersen" <martin.petersen@...cle.com>
---
fs/bio-integrity.c | 35 +++++++++--------------------------
fs/bio.c | 47 ++++++++++++++++++++++++++++++++++++++++-------
include/linux/bio.h | 2 +-
mm/bounce.c | 1 +
4 files changed, 51 insertions(+), 34 deletions(-)
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index 61f41ff..8a17399 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -592,7 +592,6 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
{
struct blk_integrity *bi;
struct bio_integrity_payload *bip = bio->bi_integrity;
- unsigned int nr_sectors;
if (bio_integrity(bio) == 0)
return;
@@ -601,27 +600,17 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
BUG_ON(bi == NULL);
BUG_ON(bip->bip_vcnt != 1);
- nr_sectors = bio_integrity_hw_sectors(bi, sectors);
-
bp->bio1.bi_integrity = &bp->bip1;
bp->bio2.bi_integrity = &bp->bip2;
- bp->iv1 = bip->bip_vec[bip->bip_iter.bi_idx];
- bp->iv2 = bip->bip_vec[bip->bip_iter.bi_idx];
-
- bp->bip1.bip_vec = &bp->iv1;
- bp->bip2.bip_vec = &bp->iv2;
+ bp->bip1.bip_vec = bip->bip_vec;
+ bp->bip2.bip_vec = bip->bip_vec;
- bp->iv1.bv_len = sectors * bi->tuple_size;
- bp->iv2.bv_offset += sectors * bi->tuple_size;
- bp->iv2.bv_len -= sectors * bi->tuple_size;
+ bp->bip1.bip_iter = bip->bip_iter;
+ bp->bip2.bip_iter = bip->bip_iter;
- bp->bip1.bip_iter.bi_sector = bio->bi_integrity->bip_iter.bi_sector;
- bp->bip2.bip_iter.bi_sector =
- bio->bi_integrity->bip_iter.bi_sector + nr_sectors;
-
- bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
- bp->bip1.bip_iter.bi_idx = bp->bip2.bip_iter.bi_idx = 0;
+ bio_integrity_trim(&bp->bio1, 0, sectors);
+ bio_integrity_advance(&bp->bio2, sectors << 9);
}
EXPORT_SYMBOL(bio_integrity_split);
@@ -639,17 +628,11 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
struct bio_integrity_payload *bip;
- BUG_ON(bip_src == NULL);
-
- bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
-
+ bip = bio_integrity_alloc(bio, gfp_mask, 0);
if (bip == NULL)
- return -EIO;
-
- memcpy(bip->bip_vec, bip_src->bip_vec,
- bip_src->bip_vcnt * sizeof(struct bio_vec));
+ return -ENOMEM;
- bip->bip_vcnt = bip_src->bip_vcnt;
+ bip->bip_vec = bip_src->bip_vec;
bip->bip_iter = bip_src->bip_iter;
return 0;
diff --git a/fs/bio.c b/fs/bio.c
index 6acb7b7..f365405 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -524,20 +524,17 @@ EXPORT_SYMBOL(bio_phys_segments);
*/
void __bio_clone(struct bio *bio, struct bio *bio_src)
{
- memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
- bio_src->bi_max_vecs * sizeof(struct bio_vec));
+ BUG_ON(BIO_POOL_IDX(bio) != BIO_POOL_NONE);
/*
* most users will be overriding ->bi_bdev with a new target,
* so we don't set nor calculate new physical/hw segment counts here
*/
- bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
bio->bi_bdev = bio_src->bi_bdev;
bio->bi_flags |= 1 << BIO_CLONED;
bio->bi_rw = bio_src->bi_rw;
- bio->bi_vcnt = bio_src->bi_vcnt;
- bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
- bio->bi_iter.bi_idx = bio_src->bi_iter.bi_idx;
+ bio->bi_iter = bio_src->bi_iter;
+ bio->bi_io_vec = bio_src->bi_io_vec;
}
EXPORT_SYMBOL(__bio_clone);
@@ -554,7 +551,7 @@ struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask,
{
struct bio *b;
- b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bs);
+ b = bio_alloc_bioset(gfp_mask, 0, bs);
if (!b)
return NULL;
@@ -575,6 +572,42 @@ struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask,
}
EXPORT_SYMBOL(bio_clone_bioset);
+int bio_clone_biovec(struct bio *bio, gfp_t gfp_mask)
+{
+ unsigned long idx = BIO_POOL_NONE;
+ unsigned nr_iovecs = 0;
+ struct bio_vec bv, *bvl = NULL;
+ struct bvec_iter iter;
+
+ BUG_ON(bio->bi_vcnt);
+ BUG_ON(bio->bi_io_vec == bio->bi_inline_vecs ||
+ BIO_POOL_IDX(bio) != BIO_POOL_NONE);
+
+ bio_for_each_segment(bv, bio, iter)
+ nr_iovecs++;
+
+ if (nr_iovecs > BIO_INLINE_VECS) {
+ bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bio->bi_pool->bvec_pool);
+ if (!bvl)
+ return -ENOMEM;
+ } else if (nr_iovecs) {
+ bvl = bio->bi_inline_vecs;
+ }
+
+ bio_for_each_segment(bv, bio, iter)
+ bvl[bio->bi_vcnt++] = bv;
+
+ bio->bi_io_vec = bvl;
+ bio->bi_iter.bi_idx = 0;
+ bio->bi_iter.bi_bvec_done = 0;
+
+ bio->bi_flags &= BIO_POOL_MASK - 1;
+ bio->bi_flags |= idx << BIO_POOL_OFFSET;
+
+ return 0;
+}
+EXPORT_SYMBOL(bio_clone_biovec);
+
/**
* bio_get_nr_vecs - return approx number of vecs
* @bdev: I/O target
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 80ffe15..acfab48 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -276,7 +276,6 @@ struct bio_pair {
struct bio_vec bv1, bv2;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
struct bio_integrity_payload bip1, bip2;
- struct bio_vec iv1, iv2;
#endif
atomic_t cnt;
int error;
@@ -293,6 +292,7 @@ extern void bio_put(struct bio *);
extern void __bio_clone(struct bio *, struct bio *);
extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
+extern int bio_clone_biovec(struct bio *bio, gfp_t gfp_mask);
extern struct bio_set *fs_bio_set;
diff --git a/mm/bounce.c b/mm/bounce.c
index deaf1b0..e60953e 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -228,6 +228,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
return;
bounce:
bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set);
+ bio_clone_biovec(bio, GFP_NOIO);
bio_for_each_segment_all(to, bio, i) {
struct page *page = to->bv_page;
--
1.8.1.3
--
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