From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965941AbdDTFpt (ORCPT ); Thu, 20 Apr 2017 01:45:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:40422 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965398AbdDTFpn (ORCPT ); Thu, 20 Apr 2017 01:45:43 -0400 From: NeilBrown To: Jens Axboe Date: Thu, 20 Apr 2017 15:38:49 +1000 Subject: [PATCH 07/11] pktcdvd: use bio_clone_fast() instead of bio_clone() Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <149266672965.27388.264586329955894592.stgit@noble> In-Reply-To: <149266645258.27388.14083229348123176454.stgit@noble> References: <149266645258.27388.14083229348123176454.stgit@noble> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org pktcdvd doesn't change the bi_io_vec of the clone bio, so it is more efficient to use bio_clone_fast(), and not clone the bi_io_vec. This requires providing a bio_set, and it is safest to provide a dedicated bio_set rather than sharing fs_bio_set, which filesytems use. This new bio_set, pkt_bio_set, can also be use for the bio_split() call as the two allocations (bio_clone_fast, and bio_split) are independent, neither can block a bio allocated by the other. Signed-off-by: NeilBrown --- drivers/block/pktcdvd.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 98394d034c29..7a437b5b8804 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -98,6 +98,7 @@ static int write_congestion_on = PKT_WRITE_CONGESTION_ON; static int write_congestion_off = PKT_WRITE_CONGESTION_OFF; static struct mutex ctl_mutex; /* Serialize open/close/setup/teardown */ static mempool_t *psd_pool; +static struct bio_set *pkt_bio_set; static struct class *class_pktcdvd = NULL; /* /sys/class/pktcdvd */ static struct dentry *pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */ @@ -2310,7 +2311,7 @@ static void pkt_end_io_read_cloned(struct bio *bio) static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio) { - struct bio *cloned_bio = bio_clone(bio, GFP_NOIO); + struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, pkt_bio_set); struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO); psd->pd = pd; @@ -2455,7 +2456,7 @@ static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio) split = bio_split(bio, last_zone - bio->bi_iter.bi_sector, - GFP_NOIO, fs_bio_set); + GFP_NOIO, pkt_bio_set); bio_chain(split, bio); } else { split = bio; @@ -2919,6 +2920,11 @@ static int __init pkt_init(void) sizeof(struct packet_stacked_data)); if (!psd_pool) return -ENOMEM; + pkt_bio_set = bioset_create(BIO_POOL_SIZE, 0); + if (!pkt_bio_set) { + mempool_destroy(psd_pool); + return -ENOMEM; + } ret = register_blkdev(pktdev_major, DRIVER_NAME); if (ret < 0) { @@ -2951,6 +2957,7 @@ static int __init pkt_init(void) unregister_blkdev(pktdev_major, DRIVER_NAME); out2: mempool_destroy(psd_pool); + bioset_free(pkt_bio_set); return ret; } @@ -2964,6 +2971,7 @@ static void __exit pkt_exit(void) unregister_blkdev(pktdev_major, DRIVER_NAME); mempool_destroy(psd_pool); + bioset_free(pkt_bio_set); } MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");