From ff483d55ba6fb50a8d6f99e808da35218533b1ef Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 13 Jan 2014 13:55:05 -0800
Subject: Revert "s390: use device_remove_file_self() instead of
device_schedule_callback()"
This reverts commit bdbb0a1376635d80e096f6433595a38984cf5408.
Tejun writes:
I'm sorry but can you please revert the whole series?
get_active() waiting while a node is deactivated has potential
to lead to deadlock and that deactivate/reactivate interface is
something fundamentally flawed and that cgroup will have to work
with the remove_self() like everybody else. IOW, I think the
first posting was correct.
Cc: 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>
---
arch/s390/include/asm/ccwgroup.h | 1 -
arch/s390/pci/pci_sysfs.c | 18 ++++++++++--------
drivers/s390/block/dcssblk.c | 14 +++++++-------
drivers/s390/cio/ccwgroup.c | 26 ++++++++++----------------
4 files changed, 27 insertions(+), 32 deletions(-)
diff --git a/arch/s390/include/asm/ccwgroup.h b/arch/s390/include/asm/ccwgroup.h
index 6e670f88d125..23723ce5ca7a 100644
--- a/arch/s390/include/asm/ccwgroup.h
+++ b/arch/s390/include/asm/ccwgroup.h
@@ -23,7 +23,6 @@ struct ccwgroup_device {
unsigned int count;
struct device dev;
struct ccw_device *cdev[0];
- struct work_struct ungroup_work;
};
/**
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index ab4a91393005..cf8a12ff733b 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -48,27 +48,29 @@ static ssize_t show_pfgid(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR(pfgid, S_IRUGO, show_pfgid, NULL);
-static ssize_t store_recover(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static void recover_callback(struct device *dev)
{
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 ret;
+ return;
ret = zpci_enable_device(zdev);
if (ret)
- return ret;
+ return;
pci_rescan_bus(zdev->bus);
- return count;
+}
+
+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;
}
static DEVICE_ATTR(recover, S_IWUSR, NULL, store_recover);
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 2e2f454a05a1..6eca019bcf30 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -304,6 +304,12 @@ 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)
@@ -391,13 +397,7 @@ removeseg:
blk_cleanup_queue(dev_info->dcssblk_queue);
dev_info->gd->queue = NULL;
put_disk(dev_info->gd);
- up_write(&dcssblk_devices_sem);
-
- if (device_remove_file_self(dev, attr)) {
- device_unregister(dev);
- put_device(dev);
- }
- return rc;
+ rc = device_schedule_callback(dev, dcssblk_unregister_callback);
out:
up_write(&dcssblk_devices_sem);
return rc;
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 67b9dc9044c2..959135a01847 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -168,12 +168,14 @@ 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(struct ccwgroup_device *gdev)
+static void ccwgroup_ungroup_callback(struct device *dev)
{
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+
mutex_lock(&gdev->reg_mutex);
if (device_is_registered(&gdev->dev)) {
__ccwgroup_remove_symlinks(gdev);
- device_unregister(&gdev->dev);
+ device_unregister(dev);
__ccwgroup_remove_cdev_refs(gdev);
}
mutex_unlock(&gdev->reg_mutex);
@@ -193,9 +195,10 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev,
rc = -EINVAL;
goto out;
}
-
- if (device_remove_file_self(dev, attr))
- ccwgroup_ungroup(gdev);
+ /* 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);
out:
if (rc) {
if (rc != -EAGAIN)
@@ -221,14 +224,6 @@ 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));
@@ -328,7 +323,6 @@ 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;
@@ -410,10 +404,10 @@ EXPORT_SYMBOL(ccwgroup_create_dev);
static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
void *data)
{
- struct ccwgroup_device *gdev = to_ccwgroupdev(data);
+ struct device *dev = data;
if (action == BUS_NOTIFY_UNBIND_DRIVER)
- schedule_work(&gdev->ungroup_work);
+ device_schedule_callback(dev, ccwgroup_ungroup_callback);
return NOTIFY_OK;
}
--
cgit