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s390: use device_remove_file_self() instead of device_schedule_callback()

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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 <tj@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo 2014-02-03 14:03:04 -05:00 committed by Greg Kroah-Hartman
parent ac0ece9174
commit 0b60f9ead5
4 changed files with 32 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/s390/include/asm/ccwgroup.h
View file

@ -23,6 +23,7 @@ struct ccwgroup_device {
unsigned int count;
struct device dev;
struct ccw_device *cdev[0];
struct work_struct ungroup_work;
};
/**

18
arch/s390/pci/pci_sysfs.c
View file

@ -48,29 +48,27 @@ static ssize_t show_pfgid(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR(pfgid, S_IRUGO, show_pfgid, NULL);
static void recover_callback(struct device *dev)
static ssize_t store_recover(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct zpci_dev *zdev = get_zdev(pdev);
int ret;
if (!device_remove_file_self(dev, attr))
return count;
pci_stop_and_remove_bus_device(pdev);
ret = zpci_disable_device(zdev);
if (ret)
return;
return ret;
ret = zpci_enable_device(zdev);
if (ret)
return;
return ret;
pci_rescan_bus(zdev->bus);
}
static ssize_t store_recover(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int rc = device_schedule_callback(dev, recover_callback);
return rc ? rc : count;
return count;
}
static DEVICE_ATTR(recover, S_IWUSR, NULL, store_recover);

14
drivers/s390/block/dcssblk.c
View file

@ -304,12 +304,6 @@ dcssblk_load_segment(char *name, struct segment_info **seg_info)
return rc;
}
static void dcssblk_unregister_callback(struct device *dev)
{
device_unregister(dev);
put_device(dev);
}
/*
* device attribute for switching shared/nonshared (exclusive)
* operation (show + store)
@ -397,7 +391,13 @@ dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const ch
blk_cleanup_queue(dev_info->dcssblk_queue);
dev_info->gd->queue = NULL;
put_disk(dev_info->gd);
rc = device_schedule_callback(dev, dcssblk_unregister_callback);
up_write(&dcssblk_devices_sem);
if (device_remove_file_self(dev, attr)) {
device_unregister(dev);
put_device(dev);
}
return rc;
out:
up_write(&dcssblk_devices_sem);
return rc;

26
drivers/s390/cio/ccwgroup.c
View file

@ -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;
}