Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: wiFJuqrdmzV+svAi58Tshev5UQb3eCtzreDDcALkcPEXaMHn2+5Rw/TWukgwUi9CXW1XE0Ztou
 tYxNj/pStu2Q==
From:   SeongJae Park <sjpark@amazon.com>
To:     <davem@davemloft.net>
CC:     <viro@zeniv.linux.org.uk>, <kuba@kernel.org>,
        <gregkh@linuxfoundation.org>, <edumazet@google.com>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        SeongJae Park <sjpark@amazon.de>
Subject: [PATCH net 2/2] Revert "sockfs: switch to ->free_inode()"
Date:   Tue, 5 May 2020 09:28:41 +0200
Message-ID: <20200505072841.25365-3-sjpark@amazon.com>
In-Reply-To: <20200505072841.25365-1-sjpark@amazon.com>
References: <20200505072841.25365-1-sjpark@amazon.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: SeongJae Park <sjpark@amazon.de>

This reverts commit 6d7855c54e1e269275d7c504f8f62a0b7a5b3f18.

The commit 6d7855c54e1e ("sockfs: switch to ->free_inode()") made the
deallocation of 'socket_alloc' to be done asynchronously using RCU, as
same to 'sock.wq'.

The change made 'socket_alloc' live longer than before.  As a result,
user programs intensively repeating allocations and deallocations of
sockets could cause memory pressure on recent kernels.

To avoid the problem, this commit reverts the change.
---
 net/socket.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index e274ae4b45e4..27174021f47f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -273,12 +273,12 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void sock_free_inode(struct inode *inode)
+static void sock_destroy_inode(struct inode *inode)
 {
 	struct socket_alloc *ei;
 
 	ei = container_of(inode, struct socket_alloc, vfs_inode);
-	kfree(ei->socket.wq);
+	kfree_rcu(ei->socket.wq, rcu);
 	kmem_cache_free(sock_inode_cachep, ei);
 }
 
@@ -303,7 +303,7 @@ static void init_inodecache(void)
 
 static const struct super_operations sockfs_ops = {
 	.alloc_inode	= sock_alloc_inode,
-	.free_inode	= sock_free_inode,
+	.destroy_inode	= sock_destroy_inode,
 	.statfs		= simple_statfs,
 };
 
-- 
2.17.1