[PATCH 1/2] driver core: tell caller if the device/kboject is really released
From: Ming Lei <hidden>
Date: 2021-09-30 05:21:45
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, library code, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Andrew Morton, Linus Torvalds
Return if the device/kobject is really released to caller. One use case is scsi_device_put() and the scsi device's release handler runs async work to clean up things. We have to piggyback the module_put() into the async work for avoiding to touch unmapped module page. Signed-off-by: Ming Lei <redacted> --- drivers/base/core.c | 5 +++-- include/linux/device.h | 2 +- include/linux/kobject.h | 2 +- lib/kobject.c | 5 +++-- 4 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index e65dd803a453..cd1365a934b9 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c@@ -3459,11 +3459,12 @@ EXPORT_SYMBOL_GPL(get_device); * put_device - decrement reference count. * @dev: device in question. */ -void put_device(struct device *dev) +int put_device(struct device *dev) { /* might_sleep(); */ if (dev) - kobject_put(&dev->kobj); + return kobject_put(&dev->kobj); + return 0; } EXPORT_SYMBOL_GPL(put_device);
diff --git a/include/linux/device.h b/include/linux/device.h
index e270cb740b9e..ab089d743667 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h@@ -949,7 +949,7 @@ extern int (*platform_notify_remove)(struct device *dev); * */ struct device *get_device(struct device *dev); -void put_device(struct device *dev); +int put_device(struct device *dev); bool kill_device(struct device *dev); #ifdef CONFIG_DEVTMPFS
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index ea30529fba08..c83cc8a7a170 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h@@ -111,7 +111,7 @@ extern int __must_check kobject_move(struct kobject *, struct kobject *); extern struct kobject *kobject_get(struct kobject *kobj); extern struct kobject * __must_check kobject_get_unless_zero( struct kobject *kobj); -extern void kobject_put(struct kobject *kobj); +extern int kobject_put(struct kobject *kobj); extern const void *kobject_namespace(struct kobject *kobj); extern void kobject_get_ownership(struct kobject *kobj,
diff --git a/lib/kobject.c b/lib/kobject.c
index ea53b30cf483..7ebdd6b99064 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c@@ -743,15 +743,16 @@ static void kobject_release(struct kref *kref) * * Decrement the refcount, and if 0, call kobject_cleanup(). */ -void kobject_put(struct kobject *kobj) +int kobject_put(struct kobject *kobj) { if (kobj) { if (!kobj->state_initialized) WARN(1, KERN_WARNING "kobject: '%s' (%p): is not initialized, yet kobject_put() is being called.\n", kobject_name(kobj), kobj); - kref_put(&kobj->kref, kobject_release); + return kref_put(&kobj->kref, kobject_release); } + return 0; } EXPORT_SYMBOL(kobject_put);
--
2.31.1