From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 20 Nov 2013 21:05:25 +0000 (-0800)
Subject: Merge tag 'md/3.13' of git://neil.brown.name/md
X-Git-Tag: upstream/snapshot3+hdmi~3920
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6d6e352c80f22c446d933ca8103e02bac1f09129;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

Merge tag 'md/3.13' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Mostly optimisations and obscure bug fixes.
   - raid5 gets less lock contention
   - raid1 gets less contention between normal-io and resync-io during
     resync"

* tag 'md/3.13' of git://neil.brown.name/md:
  md/raid5: Use conf->device_lock protect changing of multi-thread resources.
  md/raid5: Before freeing old multi-thread worker, it should flush them.
  md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE.
  UAPI: include <asm/byteorder.h> in linux/raid/md_p.h
  raid1: Rewrite the implementation of iobarrier.
  raid1: Add some macros to make code clearly.
  raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array.
  raid1: Add a field array_frozen to indicate whether raid in freeze state.
  md: Convert use of typedef ctl_table to struct ctl_table
  md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.
  md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
  md: fix some places where mddev_lock return value is not checked.
  raid5: Retry R5_ReadNoMerge flag when hit a read error.
  raid5: relieve lock contention in get_active_stripe()
  raid5: relieve lock contention in get_active_stripe()
  wait: add wait_event_cmd()
  md/raid5.c: add proper locking to error path of raid5_start_reshape.
  md: fix calculation of stacking limits on level change.
  raid5: Use slow_path to release stripe when mddev->thread is null
---

6d6e352c80f22c446d933ca8103e02bac1f09129
diff --cc drivers/md/raid5.c
index 7f0e17a,c7db410..47da0af
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@@ -287,14 -320,77 +320,63 @@@ static void do_release_stripe(struct r5
  	}
  }
  
- static void __release_stripe(struct r5conf *conf, struct stripe_head *sh)
+ static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
+ 			     struct list_head *temp_inactive_list)
  {
  	if (atomic_dec_and_test(&sh->count))
- 		do_release_stripe(conf, sh);
+ 		do_release_stripe(conf, sh, temp_inactive_list);
+ }
+ 
+ /*
+  * @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
+  *
+  * Be careful: Only one task can add/delete stripes from temp_inactive_list at
+  * given time. Adding stripes only takes device lock, while deleting stripes
+  * only takes hash lock.
+  */
+ static void release_inactive_stripe_list(struct r5conf *conf,
+ 					 struct list_head *temp_inactive_list,
+ 					 int hash)
+ {
+ 	int size;
+ 	bool do_wakeup = false;
+ 	unsigned long flags;
+ 
+ 	if (hash == NR_STRIPE_HASH_LOCKS) {
+ 		size = NR_STRIPE_HASH_LOCKS;
+ 		hash = NR_STRIPE_HASH_LOCKS - 1;
+ 	} else
+ 		size = 1;
+ 	while (size) {
+ 		struct list_head *list = &temp_inactive_list[size - 1];
+ 
+ 		/*
+ 		 * We don't hold any lock here yet, get_active_stripe() might
+ 		 * remove stripes from the list
+ 		 */
+ 		if (!list_empty_careful(list)) {
+ 			spin_lock_irqsave(conf->hash_locks + hash, flags);
+ 			if (list_empty(conf->inactive_list + hash) &&
+ 			    !list_empty(list))
+ 				atomic_dec(&conf->empty_inactive_list_nr);
+ 			list_splice_tail_init(list, conf->inactive_list + hash);
+ 			do_wakeup = true;
+ 			spin_unlock_irqrestore(conf->hash_locks + hash, flags);
+ 		}
+ 		size--;
+ 		hash--;
+ 	}
+ 
+ 	if (do_wakeup) {
+ 		wake_up(&conf->wait_for_stripe);
+ 		if (conf->retry_read_aligned)
+ 			md_wakeup_thread(conf->mddev->thread);
+ 	}
  }
  
 -static struct llist_node *llist_reverse_order(struct llist_node *head)
 -{
 -	struct llist_node *new_head = NULL;
 -
 -	while (head) {
 -		struct llist_node *tmp = head;
 -		head = head->next;
 -		tmp->next = new_head;
 -		new_head = tmp;
 -	}
 -
 -	return new_head;
 -}
 -
  /* should hold conf->device_lock already */
- static int release_stripe_list(struct r5conf *conf)
+ static int release_stripe_list(struct r5conf *conf,
+ 			       struct list_head *temp_inactive_list)
  {
  	struct stripe_head *sh;
  	int count = 0;