driver core: force NOIO allocations during unplug (b8530017) · Commits · 戴 / test

There is one overlooked situation under which a driver must not do IO to allocate memory. You cannot do that while disconnecting a device. A device being disconnected is no longer functional in most cases, yet IO may fail only when the handler runs. Signed-off-by:

Oliver Neukum <oneukum@suse.com> Link: https://lore.kernel.org/r/20200916191544.5104-1-oneukum@suse.com Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/core.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <linux/pm_runtime.h>
		#include <linux/netdevice.h>
		#include <linux/sched/signal.h>
		#include <linux/sched/mm.h>
		#include <linux/sysfs.h>

		#include "base.h"
		@@ -3062,6 +3063,7 @@ void device_del(struct device *dev)
		struct device *parent = dev->parent;
		struct kobject *glue_dir = NULL;
		struct class_interface *class_intf;
		unsigned int noio_flag;

		device_lock(dev);
		kill_device(dev);
		@@ -3073,6 +3075,7 @@ void device_del(struct device *dev)
		/* Notify clients of device removal. This call must come
		* before dpm_sysfs_remove().
		*/
		noio_flag = memalloc_noio_save();
		if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
		BUS_NOTIFY_DEL_DEVICE, dev);
		@@ -3114,6 +3117,7 @@ void device_del(struct device *dev)
		glue_dir = get_glue_dir(dev);
		kobject_del(&dev->kobj);
		cleanup_glue_dir(dev, glue_dir);
		memalloc_noio_restore(noio_flag);
		put_device(parent);
		}
		EXPORT_SYMBOL_GPL(device_del);

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