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authorSebastian Ott <sebott@linux.vnet.ibm.com>2010-05-27 01:27:07 +0400
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-05-27 01:27:09 +0400
commitc560d105a197464603247bf55962fc7f23c8cb62 (patch)
tree04f9738638aff5f4825fc2567540d288ffd4518a /drivers/s390/cio
parenta65a3e82b5b5f8f70cc0d51498441585d5b381f1 (diff)
downloadlinux-c560d105a197464603247bf55962fc7f23c8cb62.tar.xz
[S390] ccwgroup: add locking around drvdata access
Several processes may concurrently try to create a group device from the same ccw_device(s). Add locking arround the drvdata access to prevent race conditions. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/ccwgroup.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 5f97ea2ee6b1..97b25d68e3e7 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -123,8 +123,10 @@ ccwgroup_release (struct device *dev)
for (i = 0; i < gdev->count; i++) {
if (gdev->cdev[i]) {
+ spin_lock_irq(gdev->cdev[i]->ccwlock);
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
+ spin_unlock_irq(gdev->cdev[i]->ccwlock);
put_device(&gdev->cdev[i]->dev);
}
}
@@ -262,11 +264,14 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
goto error;
}
/* Don't allow a device to belong to more than one group. */
+ spin_lock_irq(gdev->cdev[i]->ccwlock);
if (dev_get_drvdata(&gdev->cdev[i]->dev)) {
+ spin_unlock_irq(gdev->cdev[i]->ccwlock);
rc = -EINVAL;
goto error;
}
dev_set_drvdata(&gdev->cdev[i]->dev, gdev);
+ spin_unlock_irq(gdev->cdev[i]->ccwlock);
}
/* Check for sufficient number of bus ids. */
if (i < num_devices && !curr_buf) {
@@ -303,8 +308,10 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
error:
for (i = 0; i < num_devices; i++)
if (gdev->cdev[i]) {
+ spin_lock_irq(gdev->cdev[i]->ccwlock);
if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
+ spin_unlock_irq(gdev->cdev[i]->ccwlock);
put_device(&gdev->cdev[i]->dev);
gdev->cdev[i] = NULL;
}