From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [PATCH 05/12] raid5: Don't set read-ahead when there is no queue Date: Thu, 15 Apr 2010 16:43:02 +1000 Message-ID: <20100415064302.15646.99141.stgit@notabene.brown> References: <20100415062909.15646.16.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100415062909.15646.16.stgit@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: dm-devel@redhat.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids dm-raid456 does not provide a 'queue' for raid5 to use, so we must make raid5 stop depending on the queue. First: read_ahead dm handles read-ahead adjustment fully in userspace, so simply don't do any readahead adjustments if there is no queue. Also re-arrange code slightly so all the accesses to ->queue are together. Finally, move the blk_queue_merge_bvec function into the 'if' as the ->split_io setting in dm-raid456 has the same effect. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 30 ++++++++++++++++-------------- 1 files changed, 16 insertions(+), 14 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c644190..3e97950 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5083,16 +5083,6 @@ static int run(mddev_t *mddev) "reshape"); } - /* read-ahead size must cover two whole stripes, which is - * 2 * (datadisks) * chunksize where 'n' is the number of raid devices - */ - { - int data_disks = conf->previous_raid_disks - conf->max_degraded; - int stripe = data_disks * - ((mddev->chunk_sectors << 9) / PAGE_SIZE); - if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) - mddev->queue->backing_dev_info.ra_pages = 2 * stripe; - } /* Ok, everything is just fine now */ if (mddev->to_remove == &raid5_attrs_group) @@ -5102,6 +5092,21 @@ static int run(mddev_t *mddev) printk(KERN_WARNING "raid5: failed to create sysfs attributes for %s\n", mdname(mddev)); + md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); + + if (mddev->queue) { + /* read-ahead size must cover two whole stripes, which + * is 2 * (datadisks) * chunksize where 'n' is the + * number of raid devices + */ + int data_disks = conf->previous_raid_disks - conf->max_degraded; + int stripe = data_disks * + ((mddev->chunk_sectors << 9) / PAGE_SIZE); + if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe) + mddev->queue->backing_dev_info.ra_pages = 2 * stripe; + + blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); + } mddev->queue->queue_lock = &conf->device_lock; @@ -5109,9 +5114,6 @@ static int run(mddev_t *mddev) mddev->queue->backing_dev_info.congested_data = mddev; mddev->queue->backing_dev_info.congested_fn = raid5_congested; - md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); - - blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec); chunk_size = mddev->chunk_sectors << 9; blk_queue_io_min(mddev->queue, chunk_size); blk_queue_io_opt(mddev->queue, chunk_size * @@ -5534,7 +5536,7 @@ static void end_reshape(raid5_conf_t *conf) /* read-ahead size must cover two whole stripes, which is * 2 * (datadisks) * chunksize where 'n' is the number of raid devices */ - { + if (conf->mddev->queue) { int data_disks = conf->raid_disks - conf->max_degraded; int stripe = data_disks * ((conf->chunk_sectors << 9) / PAGE_SIZE);