dm thin: irqsave must always be used with the pool->lock spinlock
authorJoe Thornber <ejt@redhat.com>
Tue, 8 Apr 2014 10:08:41 +0000 (11:08 +0100)
committerMike Snitzer <snitzer@redhat.com>
Tue, 8 Apr 2014 14:10:51 +0000 (10:10 -0400)
commit5e3283e2920a0bd8a806964d80274b8756e0dd7f
tree3472cec2ea93f35e013a1c1997b231e16c32f264
parent0596661f0a16d9d69bf1033320e70b6ff52b5e81
dm thin: irqsave must always be used with the pool->lock spinlock

Commit c140e1c4e23 ("dm thin: use per thin device deferred bio lists")
incorrectly stopped disabling irqs when taking the pool's spinlock.

Irqs must be disabled when taking the pool's spinlock otherwise a thread
could spin_lock(), then get interrupted to service thin_endio() in
interrupt context, which would then deadlock in spin_lock_irqsave().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm-thin.c