From 2ac8740151b082f045e58010eb92560c3a23a0e9 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 1 Jun 2010 19:37:29 +1000 Subject: md/raid5: add simple plugging infrastructure. md/raid5 uses the plugging infrastructure provided by the block layer and 'struct request_queue'. However when we plug raid5 under dm there is no request queue so we cannot use that. So create a similar infrastructure that is much lighter weight and use it for raid5. Signed-off-by: NeilBrown --- drivers/md/md.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/md/md.h') diff --git a/drivers/md/md.h b/drivers/md/md.h index c88b04745e85..5be0d6921b9d 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -29,6 +29,26 @@ typedef struct mddev_s mddev_t; typedef struct mdk_rdev_s mdk_rdev_t; +/* generic plugging support - like that provided with request_queue, + * but does not require a request_queue + */ +struct plug_handle { + void (*unplug_fn)(struct plug_handle *); + struct timer_list unplug_timer; + struct work_struct unplug_work; + unsigned long unplug_flag; +}; +#define PLUGGED_FLAG 1 +void plugger_init(struct plug_handle *plug, + void (*unplug_fn)(struct plug_handle *)); +void plugger_set_plug(struct plug_handle *plug); +int plugger_remove_plug(struct plug_handle *plug); +static inline void plugger_flush(struct plug_handle *plug) +{ + del_timer_sync(&plug->unplug_timer); + cancel_work_sync(&plug->unplug_work); +} + /* * MD's 'extended' device */ -- cgit v1.2.1