From 77d30b14d24e557f89c41980011d72428514d729 Mon Sep 17 00:00:00 2001
From: Benjamin LaHaise <bcrl@kvack.org>
Date: Fri, 30 Aug 2013 11:12:50 -0400
Subject: [PATCH] aio: fix rcu sparse warnings introduced by ioctx table lookup
patch
Sseveral sparse warnings were caused by missing rcu_dereference() annotations
for dereferencing mm->ioctx_table. Thankfully, none of those were actual bugs
as the deref was protected by a spin lock in all instances.
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
---
fs/aio.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index d0defcb0a493..6e267553604c 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -470,7 +470,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
struct aio_ring *ring;
spin_lock(&mm->ioctx_lock);
- table = mm->ioctx_table;
+ table = rcu_dereference(mm->ioctx_table);
while (1) {
if (table)
@@ -498,7 +498,7 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
table->nr = new_nr;
spin_lock(&mm->ioctx_lock);
- old = mm->ioctx_table;
+ old = rcu_dereference(mm->ioctx_table);
if (!old) {
rcu_assign_pointer(mm->ioctx_table, table);
@@ -622,7 +622,7 @@ static void kill_ioctx(struct mm_struct *mm, struct kioctx *ctx)
struct kioctx_table *table;
spin_lock(&mm->ioctx_lock);
- table = mm->ioctx_table;
+ table = rcu_dereference(mm->ioctx_table);
WARN_ON(ctx != table->table[ctx->id]);
table->table[ctx->id] = NULL;
--
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