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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-13 21:51:36 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-13 21:51:36 (GMT) |
commit | a30f82b7ebc87cdec3ef48303278f02970086118 (patch) | |
tree | 9ae4816d0499319aac3f8acbc262b17524c48eaa /drivers/base | |
parent | ce9b499c9f58d7f3f680413f3ab5407f4e647ba2 (diff) | |
download | linux-a30f82b7ebc87cdec3ef48303278f02970086118.tar.xz |
Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()"
This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/core.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 4195364..9db57af 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -615,6 +615,39 @@ void device_remove_bin_file(struct device *dev, } EXPORT_SYMBOL_GPL(device_remove_bin_file); +/** + * device_schedule_callback_owner - helper to schedule a callback for a device + * @dev: device. + * @func: callback function to invoke later. + * @owner: module owning the callback routine + * + * Attribute methods must not unregister themselves or their parent device + * (which would amount to the same thing). Attempts to do so will deadlock, + * since unregistration is mutually exclusive with driver callbacks. + * + * Instead methods can call this routine, which will attempt to allocate + * and schedule a workqueue request to call back @func with @dev as its + * argument in the workqueue's process context. @dev will be pinned until + * @func returns. + * + * This routine is usually called via the inline device_schedule_callback(), + * which automatically sets @owner to THIS_MODULE. + * + * Returns 0 if the request was submitted, -ENOMEM if storage could not + * be allocated, -ENODEV if a reference to @owner isn't available. + * + * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an + * underlying sysfs routine (since it is intended for use by attribute + * methods), and if sysfs isn't available you'll get nothing but -ENOSYS. + */ +int device_schedule_callback_owner(struct device *dev, + void (*func)(struct device *), struct module *owner) +{ + return sysfs_schedule_callback(&dev->kobj, + (void (*)(void *)) func, dev, owner); +} +EXPORT_SYMBOL_GPL(device_schedule_callback_owner); + static void klist_children_get(struct klist_node *n) { struct device_private *p = to_device_private_parent(n); |