From: Stefan Haberland <[email protected]>
The function dasd_device_from_cdev returns a reference to the dasd
device and increases the refcount by one. If an exception occurs,
the refcount was not decreased in all cases
e.g. in dasd_discipline_show.
Prevent the offline processing from hang by correcting two functions
to decrease the refcount even if an error occured.
Signed-off-by: Stefan Haberland <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---
drivers/s390/block/dasd.c | 24 +++++++++++++++---------
drivers/s390/block/dasd_devmap.c | 13 ++++++++++---
2 files changed, 25 insertions(+), 12 deletions(-)
Index: quilt-2.6/drivers/s390/block/dasd.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dasd.c 2010-02-24 09:44:27.000000000 +0100
+++ quilt-2.6/drivers/s390/block/dasd.c 2010-02-24 09:44:29.000000000 +0100
@@ -1003,12 +1003,20 @@
return;
}
- device = (struct dasd_device *) cqr->startdev;
- if (device == NULL ||
- device != dasd_device_from_cdev_locked(cdev) ||
- strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+ device = dasd_device_from_cdev_locked(cdev);
+ if (IS_ERR(device)) {
+ DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+ "unable to get device from cdev");
+ return;
+ }
+
+ if (!cqr->startdev ||
+ device != cqr->startdev ||
+ strncmp(cqr->startdev->discipline->ebcname,
+ (char *) &cqr->magic, 4)) {
DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
"invalid device in request");
+ dasd_put_device(device);
return;
}
@@ -2291,11 +2299,6 @@
if (ret)
pr_warning("%s: Setting the DASD online failed with rc=%d\n",
dev_name(&cdev->dev), ret);
- else {
- struct dasd_device *device = dasd_device_from_cdev(cdev);
- wait_event(dasd_init_waitq, _wait_for_device(device));
- dasd_put_device(device);
- }
}
/*
@@ -2430,6 +2433,9 @@
} else
pr_debug("dasd_generic device %s found\n",
dev_name(&cdev->dev));
+
+ wait_event(dasd_init_waitq, _wait_for_device(device));
+
dasd_put_device(device);
return rc;
}
Index: quilt-2.6/drivers/s390/block/dasd_devmap.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dasd_devmap.c 2010-02-24 09:28:13.000000000 +0100
+++ quilt-2.6/drivers/s390/block/dasd_devmap.c 2010-02-24 09:44:29.000000000 +0100
@@ -874,12 +874,19 @@
ssize_t len;
device = dasd_device_from_cdev(to_ccwdev(dev));
- if (!IS_ERR(device) && device->discipline) {
+ if (IS_ERR(device))
+ goto out;
+ else if (!device->discipline) {
+ dasd_put_device(device);
+ goto out;
+ } else {
len = snprintf(buf, PAGE_SIZE, "%s\n",
device->discipline->name);
dasd_put_device(device);
- } else
- len = snprintf(buf, PAGE_SIZE, "none\n");
+ return len;
+ }
+out:
+ len = snprintf(buf, PAGE_SIZE, "none\n");
return len;
}