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authorStefan Haberland <stefan.haberland@de.ibm.com>2010-02-26 22:37:47 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-02-26 22:37:32 +0100
commit589c74d5076dd1bde13a5a36d97ca79be8bd72b2 (patch)
tree252349a17326853d7e026b357921da6192958d26 /drivers/s390
parent[S390] dasd: fix online/offline race (diff)
downloadlinux-589c74d5076dd1bde13a5a36d97ca79be8bd72b2.tar.xz
linux-589c74d5076dd1bde13a5a36d97ca79be8bd72b2.zip
[S390] dasd: fix refcounting.
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>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/block/dasd.c24
-rw-r--r--drivers/s390/block/dasd_devmap.c13
2 files changed, 25 insertions, 12 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 56df3c5ed385..302ca14a69e5 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -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;
}
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 4cac5b54f26a..d49766f3b940 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -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;
}