From 0b60f9ead5d4816e7e3d6e28f4a0d22d4a1b2513 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 3 Feb 2014 14:03:04 -0500 Subject: s390: use device_remove_file_self() instead of device_schedule_callback() driver-core now supports synchrnous self-deletion of attributes and the asynchrnous removal mechanism is scheduled for removal. Use it instead of device_schedule_callback(). * Conversions in arch/s390/pci/pci_sysfs.c and drivers/s390/block/dcssblk.c are straightforward. * drivers/s390/cio/ccwgroup.c is a bit more tricky because ccwgroup_notifier() was (ab)using device_schedule_callback() to purely obtain a process context to kick off ungroup operation which may block from a notifier callback. Rename ccwgroup_ungroup_callback() to ccwgroup_ungroup() and make it take ccwgroup_device * instead. The new function is now called directly from ccwgroup_ungroup_store(). ccwgroup_notifier() chain is updated to explicitly bounce through ccwgroup_device->ungroup_work. This also removes possible failure from memory pressure. Only compile-tested. Signed-off-by: Tejun Heo Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/s390/cio/ccwgroup.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) (limited to 'drivers/s390/cio') diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index fd3367a1dc7a..dfd7bc681c25 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -168,14 +168,12 @@ static ssize_t ccwgroup_online_show(struct device *dev, * Provide an 'ungroup' attribute so the user can remove group devices no * longer needed or accidentially created. Saves memory :) */ -static void ccwgroup_ungroup_callback(struct device *dev) +static void ccwgroup_ungroup(struct ccwgroup_device *gdev) { - struct ccwgroup_device *gdev = to_ccwgroupdev(dev); - mutex_lock(&gdev->reg_mutex); if (device_is_registered(&gdev->dev)) { __ccwgroup_remove_symlinks(gdev); - device_unregister(dev); + device_unregister(&gdev->dev); __ccwgroup_remove_cdev_refs(gdev); } mutex_unlock(&gdev->reg_mutex); @@ -195,10 +193,9 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev, rc = -EINVAL; goto out; } - /* Note that we cannot unregister the device from one of its - * attribute methods, so we have to use this roundabout approach. - */ - rc = device_schedule_callback(dev, ccwgroup_ungroup_callback); + + if (device_remove_file_self(dev, attr)) + ccwgroup_ungroup(gdev); out: if (rc) { if (rc != -EAGAIN) @@ -224,6 +221,14 @@ static const struct attribute_group *ccwgroup_attr_groups[] = { NULL, }; +static void ccwgroup_ungroup_workfn(struct work_struct *work) +{ + struct ccwgroup_device *gdev = + container_of(work, struct ccwgroup_device, ungroup_work); + + ccwgroup_ungroup(gdev); +} + static void ccwgroup_release(struct device *dev) { kfree(to_ccwgroupdev(dev)); @@ -323,6 +328,7 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv, atomic_set(&gdev->onoff, 0); mutex_init(&gdev->reg_mutex); mutex_lock(&gdev->reg_mutex); + INIT_WORK(&gdev->ungroup_work, ccwgroup_ungroup_workfn); gdev->count = num_devices; gdev->dev.bus = &ccwgroup_bus_type; gdev->dev.parent = parent; @@ -404,10 +410,10 @@ EXPORT_SYMBOL(ccwgroup_create_dev); static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action, void *data) { - struct device *dev = data; + struct ccwgroup_device *gdev = to_ccwgroupdev(data); if (action == BUS_NOTIFY_UNBIND_DRIVER) - device_schedule_callback(dev, ccwgroup_ungroup_callback); + schedule_work(&gdev->ungroup_work); return NOTIFY_OK; } -- cgit v1.2.3-59-g8ed1b