[PATCH 07/13] Fix get_empty_slot()

[Nadia.Derbey@bull.net]

[-- Attachment #1: ridr_get_empty_slot.patch --]
[-- Type: text/plain, Size: 1372 bytes --]

[PATCH 07/13]

This patch only fixes the ridr_get_empty_slot() portion of ridr.c, to make
it RCU based.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>

---
 lib/ridr.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Index: linux-2.6.25-rc8-mm1/lib/ridr.c
===================================================================
--- linux-2.6.25-rc8-mm1.orig/lib/ridr.c	2008-04-11 17:51:34.000000000 +0200
+++ linux-2.6.25-rc8-mm1/lib/ridr.c	2008-04-11 17:55:37.000000000 +0200
@@ -198,7 +198,6 @@ static int ridr_get_empty_slot(struct ri
 {
 	struct ridr_layer *p, *new;
 	int layers, v, id;
-	unsigned long flags;
 
 	id = starting_id;
 build_up:
@@ -224,23 +223,21 @@ build_up:
 			 * The allocation failed.  If we built part of
 			 * the structure tear it down.
 			 */
-			spin_lock_irqsave(&idp->lock, flags);
 			for (new = p; p && p != idp->top; new = p) {
 				p = p->ary[0];
 				new->ary[0] = NULL;
 				new->bitmap = new->count = 0;
 				free_layer(new);
 			}
-			spin_unlock_irqrestore(&idp->lock, flags);
 			return -1;
 		}
-		new->ary[0] = p;
+		rcu_assign_pointer(new->ary[0], p);
 		new->count = 1;
 		if (p->bitmap == IDR_FULL)
 			__set_bit(0, &new->bitmap);
-		p = new;
+		rcu_assign_pointer(p, new);
 	}
-	idp->top = p;
+	rcu_assign_pointer(idp->top, p);
 	idp->layers = layers;
 	v = sub_alloc(idp, &id, pa);
 	if (v == -2)

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