dm thin: add timeout to stop out-of-data-space mode holding IO forever
authorJoe Thornber <ejt@redhat.com>
Fri, 9 May 2014 14:59:38 +0000 (15:59 +0100)
committerMike Snitzer <snitzer@redhat.com>
Wed, 14 May 2014 20:11:37 +0000 (16:11 -0400)
commit85ad643b7e7e52d37620fb272a9fd577a8095647
treee7599aa49a532c6ae05ac99a31bf901341ce2b45
parent8d07e8a5f5bc7b90f755d9b427ea930024f4c986
dm thin: add timeout to stop out-of-data-space mode holding IO forever

If the pool runs out of data space, dm-thin can be configured to
either error IOs that would trigger provisioning, or hold those IOs
until the pool is resized.  Unfortunately, holding IOs until the pool is
resized can result in a cascade of tasks hitting the hung_task_timeout,
which may render the system unavailable.

Add a fixed timeout so IOs can only be held for a maximum of 60 seconds.
If LVM is going to resize a thin-pool that is out of data space it needs
to be prompt about it.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.14+
drivers/md/dm-thin.c