From 55c6c814ae0aa896781d3c51e4608de542624f64 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Sat, 28 Jun 2014 08:10:12 -0400
Subject: percpu-refcount, aio: use percpu_ref_cancel_init() in ioctx_alloc()

ioctx_alloc() reaches inside percpu_ref and directly frees
->pcpu_count in its failure path, which is quite gross.  percpu_ref
has been providing a proper interface to do this,
percpu_ref_cancel_init(), for quite some time now.  Let's use that
instead.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Kent Overstreet <kmo@daterainc.com>

diff --git a/fs/aio.c b/fs/aio.c
index 4f078c0..5e0d7f9 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -715,8 +715,8 @@ err_ctx:
 err:
 	mutex_unlock(&ctx->ring_lock);
 	free_percpu(ctx->cpu);
-	free_percpu(ctx->reqs.pcpu_count);
-	free_percpu(ctx->users.pcpu_count);
+	percpu_ref_cancel_init(&ctx->reqs);
+	percpu_ref_cancel_init(&ctx->users);
 	kmem_cache_free(kioctx_cachep, ctx);
 	pr_debug("error allocating ioctx %d\n", err);
 	return ERR_PTR(err);
-- 
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