From c78afc6261b09f74abff8c0719b80692a4959768 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Thu, 11 Jul 2013 22:39:53 -0700 Subject: bcache/md: Use raid stripe size Now that we've got code for raid5/6 stripe awareness, bcache just needs to know about the stripes and when writing partial stripes is expensive - we probably don't want to enable this optimization for raid1 or 10, even though they have stripes. So add a flag to queue_limits. Signed-off-by: Kent Overstreet --- block/blk-settings.c | 4 ++++ drivers/md/bcache/super.c | 6 ++++++ drivers/md/raid5.c | 1 + include/linux/blkdev.h | 1 + 4 files changed, 12 insertions(+) diff --git a/block/blk-settings.c b/block/blk-settings.c index 05e826793e4e..5d21239bc859 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -592,6 +592,10 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, ret = -1; } + t->raid_partial_stripes_expensive = + max(t->raid_partial_stripes_expensive, + b->raid_partial_stripes_expensive); + /* Find lowest common alignment_offset */ t->alignment_offset = lcm(t->alignment_offset, alignment) & (max(t->physical_block_size, t->io_min) - 1); diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 63ebef78df4a..e363efcf2b76 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1134,6 +1134,12 @@ static int cached_dev_init(struct cached_dev *dc, unsigned block_size) hlist_add_head(&io->hash, dc->io_hash + RECENT_IO); } + dc->disk.stripe_size = q->limits.io_opt >> 9; + + if (dc->disk.stripe_size) + dc->partial_stripes_expensive = + q->limits.raid_partial_stripes_expensive; + ret = bcache_device_init(&dc->disk, block_size, dc->bdev->bd_part->nr_sects - dc->sb.data_offset); if (ret) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index eea63372e4d3..1cfb22c025b6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6101,6 +6101,7 @@ static int run(struct mddev *mddev) blk_queue_io_min(mddev->queue, chunk_size); blk_queue_io_opt(mddev->queue, chunk_size * (conf->raid_disks - conf->max_degraded)); + mddev->queue->limits.raid_partial_stripes_expensive = 1; /* * We can only discard a whole stripe. It doesn't make sense to * discard data disk but write parity disk diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 02cb6f0ea71d..0375654adb28 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -291,6 +291,7 @@ struct queue_limits { unsigned char discard_misaligned; unsigned char cluster; unsigned char discard_zeroes_data; + unsigned char raid_partial_stripes_expensive; }; struct request_queue { -- cgit v1.2.3