s390/dasd: fix hanging device after clear subchannel

When a device is in a status where CIO has killed all I/O by itself the
interrupt for a clear request may not contain an irb to determine the
clear function. Instead it contains an error pointer -EIO.
This was ignored by the DASD int_handler leading to a hanging device
waiting for a clear interrupt.

Handle -EIO error pointer correctly for requests that are clear pending and
treat the clear as successful.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 8973d34ce5ba0f786afbe228e201fa36befe9f37..fb1b56a714753f208c29511c9cc6cea0550daffd 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1643,9 +1643,18 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
        u8 *sense = NULL;
        int expires;
 
+       cqr = (struct dasd_ccw_req *) intparm;
        if (IS_ERR(irb)) {
                switch (PTR_ERR(irb)) {
                case -EIO:
+                       if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
+                               device = (struct dasd_device *) cqr->startdev;
+                               cqr->status = DASD_CQR_CLEARED;
+                               dasd_device_clear_timer(device);
+                               wake_up(&dasd_flush_wq);
+                               dasd_schedule_device_bh(device);
+                               return;
+                       }
                        break;
                case -ETIMEDOUT:
                        DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
@@ -1661,7 +1670,6 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
        }
 
        now = get_tod_clock();
-       cqr = (struct dasd_ccw_req *) intparm;
        /* check for conditions that should be handled immediately */
        if (!cqr ||
            !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&