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[S390] dasd: fix refcounting.

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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 <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Stefan Haberland 2010-02-26 22:37:47 +01:00 committed by Martin Schwidefsky
parent 9eb251225a
commit 589c74d507
2 changed files with 25 additions and 12 deletions
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24
drivers/s390/block/dasd.c
View File

@ -1003,12 +1003,20 @@ static void dasd_handle_killed_request(struct ccw_device *cdev,
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 @@ static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
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 @@ int dasd_generic_set_online(struct ccw_device *cdev,
} 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;
}

13
drivers/s390/block/dasd_devmap.c
View File

@ -874,12 +874,19 @@ dasd_discipline_show(struct device *dev, struct device_attribute *attr,
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;
}