From aade6c0dfb46ff7ce7df0ed7a2ef15d2d3c47f05 Mon Sep 17 00:00:00 2001
From: Stefan Haberland <stefan.haberland@de.ibm.com>
Date: Tue, 10 May 2011 17:13:38 +0200
Subject: [PATCH] [S390] dasd: prevent IO error during reserve/release loop
The termination of running CQR caused by reserve/release operations
may lead to an IO error if reserve/release is done in a tight loop.
Prevent this by increasing the retry counter after termination.
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
drivers/s390/block/dasd.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 475e603fc584..86b6f1cc1b10 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1742,11 +1742,20 @@ int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
static inline int _dasd_term_running_cqr(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
+ int rc;
if (list_empty(&device->ccw_queue))
return 0;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
- return device->discipline->term_IO(cqr);
+ rc = device->discipline->term_IO(cqr);
+ if (!rc)
+ /*
+ * CQR terminated because a more important request is pending.
+ * Undo decreasing of retry counter because this is
+ * not an error case.
+ */
+ cqr->retries++;
+ return rc;
}
int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)