From 05a72772fcaae4ac88052b6c93aa0d116ff0a748 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Mon, 26 Jan 2015 11:35:38 +0100 Subject: [PATCH] drbd: drbdsetup detach of an unresponsive local disk should not block IO "forever" When detaching, we make sure no application IO is in-flight by internally suspending IO, then trigger the state change, wait for the result, and finally internally resume IO again. Once we triggered the stat change to "Failed", we expect it to change from Failed to Diskless. (To avoid races, we actually wait for it to leave "Failed"). On an unresponsive local IO backend, this may not happen, ever. Don't have a "hung" detach block IO "forever", but resume IO before waiting for the state change to Diskless. We may well be able to continue IO to and from a healthy peer. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_nl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index af78f0906cb2..331b378b7d0b 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1929,9 +1929,9 @@ static int adm_detach(struct drbd_device *device, int force) retcode = drbd_request_state(device, NS(disk, D_FAILED)); drbd_md_put_buffer(device); /* D_FAILED will transition to DISKLESS. */ + drbd_resume_io(device); ret = wait_event_interruptible(device->misc_wait, device->state.disk != D_FAILED); - drbd_resume_io(device); if ((int)retcode == (int)SS_IS_DISKLESS) retcode = SS_NOTHING_TO_DO; if (ret) -- 2.20.1