From a1d91404cb69daee07282b331ce58c4ab2e7a620 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Sun, 18 Jun 2017 14:38:58 +1000 Subject: [PATCH] pktcdvd: use bio_clone_fast() instead of bio_clone() 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. Reviewed-by: Christoph Hellwig Signed-off-by: NeilBrown Signed-off-by: Jens Axboe --- 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 1f363638b453..26c04baae967 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; @@ -2924,6 +2925,11 @@ 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, 0); + if (!pkt_bio_set) { + mempool_destroy(psd_pool); + return -ENOMEM; + } ret = register_blkdev(pktdev_major, DRIVER_NAME); if (ret < 0) { @@ -2956,6 +2962,7 @@ out: unregister_blkdev(pktdev_major, DRIVER_NAME); out2: mempool_destroy(psd_pool); + bioset_free(pkt_bio_set); return ret; } @@ -2969,6 +2976,7 @@ 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"); -- 2.20.1