From 1efc09fa17d7f24bfd196f21abf00df84a21a53b Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 13 Mar 2013 14:59:49 -0700
Subject: [PATCH] --- yaml --- r: 361298 b: refs/heads/master c:
 59bfbcf01967d4d3370a2b8294673dd709e732cc h: refs/heads/master v: v3

---
 [refs]          |  2 +-
 trunk/lib/idr.c | 38 +++++++++++++++++++++++++-------------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/[refs] b/[refs]
index b3ff6f899e62..46d43a15ea94 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 415586c9e6d35ca116af714d7d0bea9c9f998ce5
+refs/heads/master: 59bfbcf01967d4d3370a2b8294673dd709e732cc
diff --git a/trunk/lib/idr.c b/trunk/lib/idr.c
index c6fb8295507b..322e2816f2fb 100644
--- a/trunk/lib/idr.c
+++ b/trunk/lib/idr.c
@@ -106,8 +106,14 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr)
 	if (layer_idr)
 		return get_from_free_list(layer_idr);
 
-	/* try to allocate directly from kmem_cache */
-	new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
+	/*
+	 * Try to allocate directly from kmem_cache.  We want to try this
+	 * before preload buffer; otherwise, non-preloading idr_alloc()
+	 * users will end up taking advantage of preloading ones.  As the
+	 * following is allowed to fail for preloaded cases, suppress
+	 * warning this time.
+	 */
+	new = kmem_cache_zalloc(idr_layer_cache, gfp_mask | __GFP_NOWARN);
 	if (new)
 		return new;
 
@@ -115,18 +121,24 @@ static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr)
 	 * Try to fetch one from the per-cpu preload buffer if in process
 	 * context.  See idr_preload() for details.
 	 */
-	if (in_interrupt())
-		return NULL;
-
-	preempt_disable();
-	new = __this_cpu_read(idr_preload_head);
-	if (new) {
-		__this_cpu_write(idr_preload_head, new->ary[0]);
-		__this_cpu_dec(idr_preload_cnt);
-		new->ary[0] = NULL;
+	if (!in_interrupt()) {
+		preempt_disable();
+		new = __this_cpu_read(idr_preload_head);
+		if (new) {
+			__this_cpu_write(idr_preload_head, new->ary[0]);
+			__this_cpu_dec(idr_preload_cnt);
+			new->ary[0] = NULL;
+		}
+		preempt_enable();
+		if (new)
+			return new;
 	}
-	preempt_enable();
-	return new;
+
+	/*
+	 * Both failed.  Try kmem_cache again w/o adding __GFP_NOWARN so
+	 * that memory allocation failure warning is printed as intended.
+	 */
+	return kmem_cache_zalloc(idr_layer_cache, gfp_mask);
 }
 
 static void idr_layer_rcu_free(struct rcu_head *head)