From: Tejun Heo <tj@kernel.org>
Date: Thu, 4 Feb 2010 08:57:37 +0000 (+0900)
Subject: idr: revert misallocation bug fix
X-Git-Tag: v2.6.33-rc7~15
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6f14a668f1a8b715a6e855f4e32705e54a6e86a1;p=platform%2Fkernel%2Flinux-3.10.git

idr: revert misallocation bug fix

Commit 859ddf09743a8cc680af33f7259ccd0fd36bfe9d tried to fix
misallocation bug but broke full bit marking by not clearing
pa[idp->layers] and also is causing X failures due to lookup failure
in drm code.  The cause of the latter hasn't been found yet.  Revert
the fix for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/lib/idr.c b/lib/idr.c
index ba7d37c..1cac726 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -140,7 +140,8 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
 	id = *starting_id;
  restart:
 	p = idp->top;
-	l = p->layer;
+	l = idp->layers;
+	pa[l--] = NULL;
 	while (1) {
 		/*
 		 * We run around this while until we reach the leaf node...
@@ -154,8 +155,8 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa)
 			oid = id;
 			id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
 
-			/* did id go over the limit? */
-			if (id >= (1 << (idp->layers * IDR_BITS))) {
+			/* if already at the top layer, we need to grow */
+			if (!(p = pa[l])) {
 				*starting_id = id;
 				return IDR_NEED_TO_GROW;
 			}