From:   Wenhua Zhao <whzhao@gmail.com>
Cc:     Wenhua Zhao <whzhao@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] net/socket: set socket inode times to current_time
Date:   Tue, 31 Jan 2023 20:30:19 -0800
Message-Id: <20230201043019.592994-1-whzhao@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
To:     unlisted-recipients:; (no To-header on input)
Precedence: bulk

Socket creation time are sometimes useful but not available becasue the
socket inode times are not set when initializing the inode.  This patch
sets the socket inode times to current_time().

Before the fix, the socket inode times are at epoch, for example:

    $ stat -L /proc/383/fd/3
      File: /proc/383/fd/3
      Size: 0               Blocks: 0          IO Block: 4096   socket
    Device: 0,8     Inode: 15996       Links: 1
    Access: (0777/srwxrwxrwx)  Uid: ( 1000/    arch)   Gid: ( 1000/    arch)
    Access: 1970-01-01 00:00:00.000000000 +0000
    Modify: 1970-01-01 00:00:00.000000000 +0000
    Change: 1970-01-01 00:00:00.000000000 +0000

After the fix, the inode times are the socket creation time:

    $ stat -L /proc/254/fd/3
      File: /proc/254/fd/3
      Size: 0               Blocks: 0          IO Block: 4096   socket
    Device: 0,7     Inode: 13170       Links: 1
    Access: (0777/srwxrwxrwx)  Uid: ( 1000/    arch)   Gid: ( 1000/    arch)
    Access: 2023-02-01 03:27:50.094731201 +0000
    Modify: 2023-02-01 03:27:50.094731201 +0000
    Change: 2023-02-01 03:27:50.094731201 +0000

Signed-off-by: Wenhua Zhao <whzhao@gmail.com>
---
 net/socket.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/socket.c b/net/socket.c
index 888cd618a968..c656c9599a92 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -635,6 +635,7 @@ struct socket *sock_alloc(void)
 	inode->i_uid = current_fsuid();
 	inode->i_gid = current_fsgid();
 	inode->i_op = &sockfs_inode_ops;
+	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 
 	return sock;
 }
-- 
2.39.1