From 4d92a9beb39d80a7d8ff7c04ae12a10290105ae5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 29 May 2014 08:09:00 -0600 Subject: [PATCH] block: remove 'magic' from struct blk_plug I don't think we've ever caught any bugs with this, and there's the list poisoning for the plug lists to catch uninitialized cases. So remove the magic member and save 8 bytes in the struct. Signed-off-by: Jens Axboe --- block/blk-core.c | 5 ----- include/linux/blkdev.h | 1 - 2 files changed, 6 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index d87be5b4e554..40d654861c33 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2957,8 +2957,6 @@ int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, } EXPORT_SYMBOL(kblockd_schedule_delayed_work_on); -#define PLUG_MAGIC 0x91827364 - /** * blk_start_plug - initialize blk_plug and track it inside the task_struct * @plug: The &struct blk_plug that needs to be initialized @@ -2977,7 +2975,6 @@ void blk_start_plug(struct blk_plug *plug) { struct task_struct *tsk = current; - plug->magic = PLUG_MAGIC; INIT_LIST_HEAD(&plug->list); INIT_LIST_HEAD(&plug->mq_list); INIT_LIST_HEAD(&plug->cb_list); @@ -3074,8 +3071,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) LIST_HEAD(list); unsigned int depth; - BUG_ON(plug->magic != PLUG_MAGIC); - flush_plug_callbacks(plug, from_schedule); if (!list_empty(&plug->mq_list)) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 913f1c2d3be0..098304576d51 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1060,7 +1060,6 @@ static inline void blk_post_runtime_resume(struct request_queue *q, int err) {} * schedule() where blk_schedule_flush_plug() is called. */ struct blk_plug { - unsigned long magic; /* detect uninitialized use-cases */ struct list_head list; /* requests */ struct list_head mq_list; /* blk-mq requests */ struct list_head cb_list; /* md requires an unplug callback */ -- 2.30.2