James, >> > > Isn't a better way to handle it simply to give >> > > transport_container_unregister() the semantics everyone is expecting >> > > (i.e. to wait for everything to be tidied up and gone)? That way none >> > > of the transport classes needs updating, and we don't have to handle the >> > > rather nasty release and unload races. > > I was thinking of a wait_event driven system checking for > list_empty(cont->containers.k_list) I hope this is more in line with what you were thinking..... -- james s Signed-off-by: James Smart <James.Smart@xxxxxxxxxx> diff -upNr a/drivers/base/attribute_container.c b/drivers/base/attribute_container.c --- a/drivers/base/attribute_container.c 2007-08-16 02:59:50.000000000 -0400 +++ b/drivers/base/attribute_container.c 2007-08-17 05:02:03.000000000 -0400 @@ -19,6 +19,7 @@ #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> +#include <linux/sched.h> #include "base.h" @@ -75,6 +76,8 @@ int attribute_container_register(struct attribute_container *cont) { INIT_LIST_HEAD(&cont->node); + init_waitqueue_head(&cont->cont_wait); + cont->flags &= ~ATTRIBUTE_CONTAINER_EVENT_PENDING; klist_init(&cont->containers,internal_container_klist_get, internal_container_klist_put); @@ -89,23 +92,26 @@ EXPORT_SYMBOL_GPL(attribute_container_re /** * attribute_container_unregister - remove a container registration * + * Semantics have now changed - we never return until the list goes empty + * * @cont: previously registered container to remove */ int attribute_container_unregister(struct attribute_container *cont) { - int retval = -EBUSY; mutex_lock(&attribute_container_mutex); spin_lock(&cont->containers.k_lock); - if (!list_empty(&cont->containers.k_list)) - goto out; - retval = 0; - list_del(&cont->node); - out: + if (!list_empty(&cont->containers.k_list)) + cont->flags |= ATTRIBUTE_CONTAINER_EVENT_PENDING; spin_unlock(&cont->containers.k_lock); mutex_unlock(&attribute_container_mutex); - return retval; - + wait_event(cont->cont_wait, + !(cont->flags & ATTRIBUTE_CONTAINER_EVENT_PENDING)); + mutex_lock(&attribute_container_mutex); + list_del(&cont->node); + mutex_unlock(&attribute_container_mutex); + + return 0; } EXPORT_SYMBOL_GPL(attribute_container_unregister); @@ -234,6 +240,15 @@ attribute_container_remove_device(struct class_device_unregister(&ic->classdev); } } + + if (cont->flags & ATTRIBUTE_CONTAINER_EVENT_PENDING) { + spin_lock(&cont->containers.k_lock); + if (list_empty(&cont->containers.k_list)) + cont->flags &= + ~ATTRIBUTE_CONTAINER_EVENT_PENDING; + spin_unlock(&cont->containers.k_lock); + wake_up(&cont->cont_wait); + } } mutex_unlock(&attribute_container_mutex); } diff -upNr a/include/linux/attribute_container.h b/include/linux/attribute_container.h --- a/include/linux/attribute_container.h 2007-08-16 03:00:10.000000000 -0400 +++ b/include/linux/attribute_container.h 2007-08-17 03:46:01.000000000 -0400 @@ -20,7 +20,9 @@ struct attribute_container { struct class_device_attribute **attrs; int (*match)(struct attribute_container *, struct device *); #define ATTRIBUTE_CONTAINER_NO_CLASSDEVS 0x01 +#define ATTRIBUTE_CONTAINER_EVENT_PENDING 0x02 unsigned long flags; + wait_queue_head_t cont_wait; }; static inline int - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html