[PATCH] qla2xxx: Fix possible race that could hang kthread_stop()

From: Bandan Das
Date: Thu Jan 27 2011 - 17:02:42 EST

There is a small race window in qla2x00_do_dpc() between
checking for kthread_should_stop() and going to sleep after
setting TASK_INTERRUPTIBLE. If qla2x00_free_device() is called
in this window, kthread_stop will wait forever because there
will be no one to wake up the process.

Signed-off-by: Bandan Das <bandan.das@xxxxxxxxxxx>
Signed-off-by: Nate Dailey <nate.dailey@xxxxxxxxxxx>
drivers/scsi/qla2xxx/qla_os.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index c194c23..8d14d77 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -3286,6 +3286,8 @@ qla2x00_do_dpc(void *data)
DEBUG3(printk("qla2x00: DPC handler sleeping\n"));

+ if (kthread_should_stop())
+ break;

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