nfs: fix kernel warning when removing proc entry
I saw the following kernel warning:
[ 1852.321222] ------------[ cut here ]------------
[ 1852.326527] WARNING: CPU: 0 PID: 118 at fs/proc/generic.c:521 remove_proc_entry+0x154/0x16b()
[ 1852.335630] remove_proc_entry: removing non-empty directory 'fs/nfsfs', leaking at least 'volumes'
[ 1852.344084] CPU: 0 PID: 118 Comm: kworker/u8:2 Not tainted 3.16.0+ #540
[ 1852.350036] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1852.354992] Workqueue: netns cleanup_net
[ 1852.358701]
0000000000000000 ffff880116f2fbd0 ffffffff819c03e9 ffff880116f2fc18
[ 1852.366474]
ffff880116f2fc08 ffffffff810744ee ffffffff811e0e6e ffff8800d4e96238
[ 1852.373507]
ffffffff81dbe665 ffff8800d46a5948 0000000000000005 ffff880116f2fc68
[ 1852.380224] Call Trace:
[ 1852.381976] [<
ffffffff819c03e9>] dump_stack+0x4d/0x66
[ 1852.385495] [<
ffffffff810744ee>] warn_slowpath_common+0x7a/0x93
[ 1852.389869] [<
ffffffff811e0e6e>] ? remove_proc_entry+0x154/0x16b
[ 1852.393987] [<
ffffffff8107457b>] warn_slowpath_fmt+0x4c/0x4e
[ 1852.397999] [<
ffffffff811e0e6e>] remove_proc_entry+0x154/0x16b
[ 1852.402034] [<
ffffffff8129c73d>] nfs_fs_proc_net_exit+0x53/0x56
[ 1852.406136] [<
ffffffff812a103b>] nfs_net_exit+0x12/0x1d
[ 1852.409774] [<
ffffffff81785bc9>] ops_exit_list+0x44/0x55
[ 1852.413529] [<
ffffffff81786389>] cleanup_net+0xee/0x182
[ 1852.417198] [<
ffffffff81088c9e>] process_one_work+0x209/0x40d
[ 1852.502320] [<
ffffffff81088bf7>] ? process_one_work+0x162/0x40d
[ 1852.587629] [<
ffffffff810890c1>] worker_thread+0x1f0/0x2c7
[ 1852.673291] [<
ffffffff81088ed1>] ? process_scheduled_works+0x2f/0x2f
[ 1852.759470] [<
ffffffff8108e079>] kthread+0xc9/0xd1
[ 1852.843099] [<
ffffffff8109427f>] ? finish_task_switch+0x3a/0xce
[ 1852.926518] [<
ffffffff8108dfb0>] ? __kthread_parkme+0x61/0x61
[ 1853.008565] [<
ffffffff819cbeac>] ret_from_fork+0x7c/0xb0
[ 1853.076477] [<
ffffffff8108dfb0>] ? __kthread_parkme+0x61/0x61
[ 1853.140653] ---[ end trace
69c4c6617f78e32d ]---
It looks wrong that we add "/proc/net/nfsfs" in nfs_fs_proc_net_init()
while remove "/proc/fs/nfsfs" in nfs_fs_proc_net_exit().
Fixes: commit
65b38851a17 (NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes)
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Dan Aloni <dan@kernelim.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
[Trond: replace uses of remove_proc_entry() with remove_proc_subtree()
as suggested by Al Viro]
Cc: stable@vger.kernel.org # 3.4.x : 65b38851a17: NFS: Fix /proc/fs/nfsfs/servers
Cc: stable@vger.kernel.org # 3.4.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>