From: NeilBrown <neilb@suse.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"Roger Pau Monne" <roger.pau@citrix.com>,
xen-devel@lists.xenproject.org
Subject: [PATCH 08/11] xen-blkfront: remove bio splitting.
Date: Thu, 20 Apr 2017 15:38:50 +1000 [thread overview]
Message-ID: <149266672984.27388.11947154313852245586.stgit@noble> (raw)
In-Reply-To: <149266645258.27388.14083229348123176454.stgit@noble>
bios that are re-submitted will pass through blk_queue_split() when
blk_queue_bio() is called, and this will split the bio if necessary.
There is no longer any need to do this splitting in xen-blkfront.
Signed-off-by: NeilBrown <neilb@suse.com>
---
drivers/block/xen-blkfront.c | 54 ++----------------------------------------
1 file changed, 3 insertions(+), 51 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index abed296ce605..b8930d9b7102 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -110,11 +110,6 @@ struct blk_shadow {
unsigned long associated_id;
};
-struct split_bio {
- struct bio *bio;
- atomic_t pending;
-};
-
static DEFINE_MUTEX(blkfront_mutex);
static const struct block_device_operations xlvbd_block_fops;
@@ -1982,28 +1977,13 @@ static int blkfront_probe(struct xenbus_device *dev,
return 0;
}
-static void split_bio_end(struct bio *bio)
-{
- struct split_bio *split_bio = bio->bi_private;
-
- if (atomic_dec_and_test(&split_bio->pending)) {
- split_bio->bio->bi_phys_segments = 0;
- split_bio->bio->bi_error = bio->bi_error;
- bio_endio(split_bio->bio);
- kfree(split_bio);
- }
- bio_put(bio);
-}
-
static int blkif_recover(struct blkfront_info *info)
{
- unsigned int i, r_index;
+ unsigned int r_index;
struct request *req, *n;
int rc;
- struct bio *bio, *cloned_bio;
- unsigned int segs, offset;
- int pending, size;
- struct split_bio *split_bio;
+ struct bio *bio;
+ unsigned int segs;
blkfront_gather_backend_features(info);
/* Reset limits changed by blk_mq_update_nr_hw_queues(). */
@@ -2042,34 +2022,6 @@ static int blkif_recover(struct blkfront_info *info)
while ((bio = bio_list_pop(&info->bio_list)) != NULL) {
/* Traverse the list of pending bios and re-queue them */
- if (bio_segments(bio) > segs) {
- /*
- * This bio has more segments than what we can
- * handle, we have to split it.
- */
- pending = (bio_segments(bio) + segs - 1) / segs;
- split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO);
- BUG_ON(split_bio == NULL);
- atomic_set(&split_bio->pending, pending);
- split_bio->bio = bio;
- for (i = 0; i < pending; i++) {
- offset = (i * segs * XEN_PAGE_SIZE) >> 9;
- size = min((unsigned int)(segs * XEN_PAGE_SIZE) >> 9,
- (unsigned int)bio_sectors(bio) - offset);
- cloned_bio = bio_clone(bio, GFP_NOIO);
- BUG_ON(cloned_bio == NULL);
- bio_trim(cloned_bio, offset, size);
- cloned_bio->bi_private = split_bio;
- cloned_bio->bi_end_io = split_bio_end;
- submit_bio(cloned_bio);
- }
- /*
- * Now we have to wait for all those smaller bios to
- * end, so we can also end the "parent" bio.
- */
- continue;
- }
- /* We don't need to split this bio */
submit_bio(bio);
}
next prev parent reply other threads:[~2017-04-20 6:22 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-20 5:38 [PATCH 00/11] block: assorted cleanup for bio splitting and cloning NeilBrown
2017-04-20 5:38 ` [PATCH 01/11] blk: remove bio_set arg from blk_queue_split() NeilBrown
2017-04-21 11:21 ` Christoph Hellwig
2017-04-21 15:14 ` Ming Lei
2017-04-22 9:16 ` Javier González
2017-04-24 2:32 ` NeilBrown
2017-04-20 5:38 ` [PATCH 02/11] blk: make the bioset rescue_workqueue optional NeilBrown
2017-04-21 11:24 ` Christoph Hellwig
2017-04-24 1:51 ` NeilBrown
2017-04-24 15:10 ` Christoph Hellwig
2017-05-01 5:00 ` NeilBrown
2017-05-01 14:02 ` Jens Axboe
2017-05-02 3:33 ` NeilBrown
2017-04-20 5:38 ` [PATCH 07/11] pktcdvd: use bio_clone_fast() instead of bio_clone() NeilBrown
2017-04-21 11:29 ` Christoph Hellwig
2017-04-20 5:38 ` [PATCH 05/11] rbd: " NeilBrown
2017-04-21 11:31 ` Christoph Hellwig
2017-04-20 5:38 ` [PATCH 03/11] blk: use non-rescuing bioset for q->bio_split NeilBrown
2017-04-21 11:25 ` Christoph Hellwig
2017-04-20 5:38 ` [PATCH 04/11] block: Improvements to bounce-buffer handling NeilBrown
2017-04-21 11:28 ` Christoph Hellwig
2017-04-21 15:39 ` Ming Lei
2017-04-20 5:38 ` [PATCH 06/11] drbd: use bio_clone_fast() instead of bio_clone() NeilBrown
2017-04-21 11:30 ` Christoph Hellwig
2017-04-20 5:38 ` [PATCH 09/11] bcache: use kmalloc to allocate bio in bch_data_verify() NeilBrown
2017-04-21 11:31 ` Christoph Hellwig
2017-04-21 11:32 ` Kent Overstreet
2017-04-21 15:41 ` Ming Lei
2017-04-20 5:38 ` NeilBrown [this message]
2017-04-20 10:00 ` [PATCH 08/11] xen-blkfront: remove bio splitting Roger Pau Monné
2017-04-21 11:36 ` Christoph Hellwig
2017-04-21 11:46 ` Roger Pau Monne
2017-04-20 5:38 ` [PATCH 11/11] block: don't check for BIO_MAX_PAGES in blk_bio_segment_split() NeilBrown
2017-04-21 11:34 ` Christoph Hellwig
2017-04-21 15:48 ` Ming Lei
2017-04-24 3:16 ` NeilBrown
2017-04-24 3:14 ` NeilBrown
2017-04-20 5:38 ` [PATCH 10/11] block: remove bio_clone() and all references NeilBrown
2017-04-21 11:32 ` Christoph Hellwig
2017-04-21 15:43 ` Ming Lei
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