From 197cec2853cb112e7a5c2adeccf4d2b09e7a36e2 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Sat, 24 Apr 2021 12:12:38 +0200 Subject: [PATCH] s390/ccwgroup: release the cdevs from within dev->release() Wiring up the cdevs is an essential part of the gdev creation. So release them during the gdev destruction, ie. on the last put_device(). This could cause us to hold on to the cdevs a tiny bit longer, but that's not a real concern. As we have much less certainty of what context this put_device() is executed from, switch to irqsave locking. Signed-off-by: Julian Wiedmann Signed-off-by: Vasily Gorbik --- drivers/s390/cio/ccwgroup.c | 49 +++++++++++++------------------------ 1 file changed, 17 insertions(+), 32 deletions(-) diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 444385da5792..49f816c78873 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -45,27 +45,6 @@ static void __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev) } } -/* - * Remove references from ccw devices to ccw group device and from - * ccw group device to ccw devices. - */ -static void __ccwgroup_remove_cdev_refs(struct ccwgroup_device *gdev) -{ - struct ccw_device *cdev; - int i; - - for (i = 0; i < gdev->count; i++) { - cdev = gdev->cdev[i]; - if (!cdev) - continue; - spin_lock_irq(cdev->ccwlock); - dev_set_drvdata(&cdev->dev, NULL); - spin_unlock_irq(cdev->ccwlock); - gdev->cdev[i] = NULL; - put_device(&cdev->dev); - } -} - /** * ccwgroup_set_online() - enable a ccwgroup device * @gdev: target ccwgroup device @@ -175,7 +154,6 @@ static void ccwgroup_ungroup(struct ccwgroup_device *gdev) if (device_is_registered(&gdev->dev)) { __ccwgroup_remove_symlinks(gdev); device_unregister(&gdev->dev); - __ccwgroup_remove_cdev_refs(gdev); } mutex_unlock(&gdev->reg_mutex); } @@ -228,7 +206,23 @@ static void ccwgroup_ungroup_workfn(struct work_struct *work) static void ccwgroup_release(struct device *dev) { - kfree(to_ccwgroupdev(dev)); + struct ccwgroup_device *gdev = to_ccwgroupdev(dev); + unsigned int i; + + for (i = 0; i < gdev->count; i++) { + struct ccw_device *cdev = gdev->cdev[i]; + unsigned long flags; + + if (cdev) { + spin_lock_irqsave(cdev->ccwlock, flags); + if (dev_get_drvdata(&cdev->dev) == gdev) + dev_set_drvdata(&cdev->dev, NULL); + spin_unlock_irqrestore(cdev->ccwlock, flags); + put_device(&cdev->dev); + } + } + + kfree(gdev); } static int __ccwgroup_create_symlinks(struct ccwgroup_device *gdev) @@ -396,15 +390,6 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv, mutex_unlock(&gdev->reg_mutex); return 0; 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; - } mutex_unlock(&gdev->reg_mutex); put_device(&gdev->dev); return rc; -- 2.39.5