This is a note to let you know that I've just added the patch titled md/raid10: submit bio directly to replacement disk to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: md-raid10-submit-bio-directly-to-replacement-disk.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 5 10:28:31 CEST 2017 From: Shaohua Li <shli@xxxxxx> Date: Thu, 23 Feb 2017 12:26:41 -0800 Subject: md/raid10: submit bio directly to replacement disk From: Shaohua Li <shli@xxxxxx> [ Upstream commit 6d399783e9d4e9bd44931501948059d24ad96ff8 ] Commit 57c67df(md/raid10: submit IO from originating thread instead of md thread) submits bio directly for normal disks but not for replacement disks. There is no point we shouldn't do this for replacement disks. Cc: NeilBrown <neilb@xxxxxxxx> Signed-off-by: Shaohua Li <shli@xxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/raid10.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1407,11 +1407,24 @@ retry_write: mbio->bi_private = r10_bio; atomic_inc(&r10_bio->remaining); + + cb = blk_check_plugged(raid10_unplug, mddev, + sizeof(*plug)); + if (cb) + plug = container_of(cb, struct raid10_plug_cb, + cb); + else + plug = NULL; spin_lock_irqsave(&conf->device_lock, flags); - bio_list_add(&conf->pending_bio_list, mbio); - conf->pending_count++; + if (plug) { + bio_list_add(&plug->pending, mbio); + plug->pending_cnt++; + } else { + bio_list_add(&conf->pending_bio_list, mbio); + conf->pending_count++; + } spin_unlock_irqrestore(&conf->device_lock, flags); - if (!mddev_check_plugged(mddev)) + if (!plug) md_wakeup_thread(mddev->thread); } } Patches currently in stable-queue which might be from shli@xxxxxx are queue-4.9/md-raid10-submit-bio-directly-to-replacement-disk.patch