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 01:40:48 +0000 (17:40 -0800)
commite614e0c6e088c4066b3118a8c1d228b54fff33fb
tree3b941451bb76041ee53f49c55345ac485e711577
parent4de16a49e7fbdec6f54387a34b21b531ee41dd0f
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