ipr: wait for aborted command responses
authorBrian King <brking@linux.vnet.ibm.com>
Thu, 30 Oct 2014 22:27:10 +0000 (17:27 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 30 Jan 2015 01:40:55 +0000 (17:40 -0800)
commit7f8e9beb905e75b5c2baeb0b88d6e417610634c3
treed7bb3a53f335c27020167b952a756ea4469b9381
parentb78dc65fd7e4fb2cd2ca6ef6866eb2989fb8ee6c
ipr: wait for aborted command responses

commit 6cdb08172bc89f0a39e1643c5e7eab362692fd1b upstream.

Fixes a race condition in abort handling that was injected
when multiple interrupt support was added. When only a single
interrupt is present, the adapter guarantees it will send
responses for aborted commands prior to the response for the
abort command itself. With multiple interrupts, these responses
generally come back on different interrupts, so we need to
ensure the abort thread waits until the aborted command is
complete so we don't perform a double completion. This race
condition was being hit frequently in environments which
were triggering command timeouts, which was resulting in
a double completion causing a kernel oops.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Wendy Xiong <wenxiong@linux.vnet.ibm.com>
Tested-by: Wendy Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/scsi/ipr.c
drivers/scsi/ipr.h