On 07/16/2013 02:57 PM, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@xxxxxxxxx>
>
> Since kernel version 3.3, workqueue names could be
> sprintf'ed instead of just pointing to a name. This
> wasn't used a lot so never needed to be backported,
> but now it's used everywhere. Backport this API.
>
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> ---
> backport/backport-include/linux/workqueue.h | 47 ++++++++++++++++----
> backport/compat/compat-3.3.c | 69 +++++++++++++++++++++++++++++
> 2 files changed, 108 insertions(+), 8 deletions(-)
>
> diff --git a/backport/backport-include/linux/workqueue.h b/backport/backport-include/linux/workqueue.h
> index 9958715..54c9090 100644
> --- a/backport/backport-include/linux/workqueue.h
> +++ b/backport/backport-include/linux/workqueue.h
> @@ -14,16 +14,47 @@ bool mod_delayed_work(struct workqueue_struct *wq, struct delayed_work *dwork,
> #define create_freezable_workqueue create_freezeable_workqueue
> #endif
>
> -#ifndef alloc_ordered_workqueue
> -#define alloc_ordered_workqueue(name, flags) create_singlethread_workqueue(name)
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
Why not do a check for #ifndef WQ_UNBOUND that way we do not get that
many problems when someone tries a kernel that already backported this.
> +#define WQ_UNBOUND 0
> #endif
> -
> -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
> -#define alloc_workqueue(name, flags, max_active) __create_workqueue(name, flags, max_active)
> +#define __WQ_ORDERED 0
> +/*
> + * commit b196be89cdc14a88cc637cdad845a75c5886c82d
> + * Author: Tejun Heo <tj@xxxxxxxxxx>
> + * Date: Tue Jan 10 15:11:35 2012 -0800
> + *
> + * workqueue: make alloc_workqueue() take printf fmt and args for name
> + */
> +struct workqueue_struct *
> +backport_alloc_workqueue(const char *fmt, unsigned int flags,
> + int max_active, struct lock_class_key *key,
> + const char *lock_name, ...);
> +#undef alloc_workqueue
> +#ifdef CONFIG_LOCKDEP
> +#define alloc_workqueue(fmt, flags, max_active, args...) \
> +({ \
> + static struct lock_class_key __key; \
> + const char *__lock_name; \
> + \
> + if (__builtin_constant_p(fmt)) \
> + __lock_name = (fmt); \
> + else \
> + __lock_name = #fmt; \
> + \
> + backport_alloc_workqueue((fmt), (flags), (max_active), \
> + &__key, __lock_name, ##args); \
> +})
> +#else
> +#define alloc_workqueue(fmt, flags, max_active, args...) \
> + backport_alloc_workqueue((fmt), (flags), (max_active), \
> + NULL, NULL, ##args)
> #endif
> -
> -#ifndef alloc_workqueue
> -#define alloc_workqueue(name, flags, max_active) __create_workqueue(name, flags, max_active, 0)
> +#undef alloc_ordered_workqueue
> +#define alloc_ordered_workqueue(fmt, flags, args...) \
> + alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
> +#define destroy_workqueue backport_destroy_workqueue
The #undef destroy_workqueue in compat-3.3.c does not look nice to me.
What about this and then call orig_destroy_workqueue(wq)?
static inline void orig_destroy_workqueue(struct workqueue_struct *wq)
{
destroy_workqueue(wq);
}
#define destroy_workqueue(wq) backport_destroy_workqueue(wq)
> +void backport_destroy_workqueue(struct workqueue_struct *wq);
> #endif
>
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
> diff --git a/backport/compat/compat-3.3.c b/backport/compat/compat-3.3.c
> index a44f59d..d86b40e 100644
> --- a/backport/compat/compat-3.3.c
> +++ b/backport/compat/compat-3.3.c
> @@ -12,6 +12,7 @@
> #include <linux/version.h>
> #include <linux/skbuff.h>
> #include <linux/module.h>
> +#include <linux/workqueue.h>
> #include <net/dst.h>
> #include <net/xfrm.h>
>
> @@ -171,3 +172,71 @@ out:
> return n;
> }
> EXPORT_SYMBOL_GPL(__pskb_copy);
> +
> +static DEFINE_SPINLOCK(wq_name_lock);
> +static struct list_head wq_name_list;
> +
> +struct wq_name {
> + struct list_head list;
> + struct workqueue_struct *wq;
> + char name[24];
> +};
> +
> +struct workqueue_struct *
> +backport_alloc_workqueue(const char *fmt, unsigned int flags,
> + int max_active, struct lock_class_key *key,
> + const char *lock_name, ...)
> +{
> + struct workqueue_struct *wq;
> + struct wq_name *n = kzalloc(sizeof(*n), GFP_KERNEL);
> + va_list args;
> +
> + if (!n)
> + return NULL;
> +
> + va_start(args, lock_name);
> + vsnprintf(n->name, sizeof(n->name), fmt, args);
> + va_end(args);
> +
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,36)
> + wq = __create_workqueue_key(n->name, max_active == 1, 0,
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,28)
> + 0,
> +#endif
> + key, lock_name);
> +#else
> + wq = __alloc_workqueue_key(n->name, flags, max_active, key, lock_name);
> +#endif
> + if (!wq) {
> + kfree(n);
> + return NULL;
> + }
> +
> + n->wq = wq;
> + spin_lock(&wq_name_lock);
> + list_add(&n->list, &wq_name_list);
> + spin_unlock(&wq_name_lock);
> +
> + return wq;
> +}
> +EXPORT_SYMBOL_GPL(backport_alloc_workqueue);
> +
> +void backport_destroy_workqueue(struct workqueue_struct *wq)
> +{
> + struct wq_name *n, *tmp;
> +
> + /* call original */
> +#undef destroy_workqueue
> + destroy_workqueue(wq);
> +
> + spin_lock(&wq_name_lock);
> + list_for_each_entry_safe(n, tmp, &wq_name_list, list) {
> + if (n->wq == wq) {
> + list_del(&n->list);
> + kfree(n);
> + break;
> + }
> + }
> + spin_unlock(&wq_name_lock);
> +}
> +EXPORT_SYMBOL_GPL(backport_destroy_workqueue);
>
--
To unsubscribe from this list: send the line "unsubscribe backports" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
