From mboxrd@z Thu Jan  1 00:00:00 1970
From: Veaceslav Falico <vfalico@redhat.com>
Subject: Re: [PATCH net 0/2] bonding: fix the sysfs warning when change the
 master's name
Date: Mon, 13 Jan 2014 18:24:46 +0100
Message-ID: <20140113172446.GA2081@redhat.com>
References: <52D3E536.8080404@huawei.com>
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Cc: Jay Vosburgh <fubar@us.ibm.com>,
	"David S. Miller" <davem@davemloft.net>,
	Netdev <netdev@vger.kernel.org>,
	Eric Dumazet <edumazet@google.com>
To: Ding Tianhong <dingtianhong@huawei.com>
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On Mon, Jan 13, 2014 at 09:08:06PM +0800, Ding Tianhong wrote:
>When I change the master's name, and then rebuild the master and ensalve a nic again,
>than I got the calltrace:
>
>[329215.749344] WARNING: CPU: 0 PID: 4778 at fs/sysfs/dir.c:486 sysfs_warn_dup+0x87/0xa0()
>[329215.749347] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:03.0/0000:02:00.0/net/eth100/upper_bond0'
...snip...
>[329215.749494]  [<ffffffff81205b27>] sysfs_warn_dup+0x87/0xa0
>[329215.749500]  [<ffffffff81205eed>] sysfs_add_one+0x4d/0x50
>[329215.749505]  [<ffffffff81206f9e>] sysfs_do_create_link_sd+0xbe/0x210
>[329215.749511]  [<ffffffff812951a0>] ? sprintf+0x40/0x50
>[329215.749516]  [<ffffffff8120714b>] sysfs_create_link+0x2b/0x30
>[329215.749523]  [<ffffffff8140a708>] __netdev_adjacent_dev_insert+0x1b8/0x270
>[329215.749528]  [<ffffffff8140a7f8>] __netdev_adjacent_dev_link_lists+0x38/0x90
>[329215.749533]  [<ffffffff8140a98b>] __netdev_upper_dev_link+0x13b/0x470
>[329215.749538]  [<ffffffff8141319c>] ? __ethtool_get_settings+0x5c/0x90
>[329215.749547]  [<ffffffffa0722179>] ? bond_update_speed_duplex+0x29/0x70 [bonding]
>[329215.749552]  [<ffffffff8140acd1>] netdev_master_upper_dev_link_private+0x11/0x20
>[329215.749561]  [<ffffffffa0729246>] bond_enslave+0x806/0xe40 [bonding]
>[329215.749570]  [<ffffffffa073241f>] bonding_store_slaves+0x18f/0x1c0 [bonding]
>[329215.749576]  [<ffffffff813757ab>] dev_attr_store+0x1b/0x20
>[329215.749581]  [<ffffffff812049cc>] sysfs_write_file+0x15c/0x1f0
>[329215.749587]  [<ffffffff81188897>] vfs_write+0xc7/0x1e0

It's unrelated to bonding, as it touches any device that uses netdev_adjacent
logic.

This case (renaming stale sysfs links) should be properly handled in
dev_change_name().