ipr: wait for aborted command responses
authorBrian King <brking@linux.vnet.ibm.com>
Thu, 30 Oct 2014 22:27:10 +0000 (17:27 -0500)
committerChristoph Hellwig <hch@lst.de>
Mon, 19 Jan 2015 09:46:20 +0000 (10:46 +0100)
commit6cdb08172bc89f0a39e1643c5e7eab362692fd1b
tree455a246fb286c335b737d14d03b3f50ef629d3c7
parent70a0f2c1898c6abf53670e55642b6e840b003892
ipr: wait for aborted command responses

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.

Cc: <stable@vger.kernel.org>
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>
drivers/scsi/ipr.c
drivers/scsi/ipr.h