From 4d77e3ba88d085836f1e8e475e3131844dd89d04 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 27 Aug 2013 15:57:47 +1000 Subject: md/raid5: flush out all pending requests before proceeding with reshape. Some requests - particularly 'discard' and 'read' are handled differently depending on whether a reshape is active or not. It is harmless to assume reshape is active if it isn't but wrong to act as though reshape is not active when it is. So when we start reshape - after making clear to all requests that reshape has started - use mddev_suspend/mddev_resume to flush out all requests. This will ensure that no requests will be assuming the absence of reshape once it really starts. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/md') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4263df11d597..663a8e58d439 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6279,6 +6279,13 @@ static int raid5_start_reshape(struct mddev *mddev) write_seqcount_end(&conf->gen_lock); spin_unlock_irq(&conf->device_lock); + /* Now make sure any requests that proceeded on the assumption + * the reshape wasn't running - like Discard or Read - have + * completed. + */ + mddev_suspend(mddev); + mddev_resume(mddev); + /* Add some new drives, as many as will fit. * We know there are enough to make the newly sized array work. * Don't add devices if we are reducing the number of -- cgit v1.2.3-58-ga151