From 21e81002f9788a3af591416b6dec60d7b67f2fb2 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 8 Sep 2014 16:17:55 -0700 Subject: [PATCH] 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] [] dump_stack+0x4d/0x66 [ 1852.385495] [] warn_slowpath_common+0x7a/0x93 [ 1852.389869] [] ? remove_proc_entry+0x154/0x16b [ 1852.393987] [] warn_slowpath_fmt+0x4c/0x4e [ 1852.397999] [] remove_proc_entry+0x154/0x16b [ 1852.402034] [] nfs_fs_proc_net_exit+0x53/0x56 [ 1852.406136] [] nfs_net_exit+0x12/0x1d [ 1852.409774] [] ops_exit_list+0x44/0x55 [ 1852.413529] [] cleanup_net+0xee/0x182 [ 1852.417198] [] process_one_work+0x209/0x40d [ 1852.502320] [] ? process_one_work+0x162/0x40d [ 1852.587629] [] worker_thread+0x1f0/0x2c7 [ 1852.673291] [] ? process_scheduled_works+0x2f/0x2f [ 1852.759470] [] kthread+0xc9/0xd1 [ 1852.843099] [] ? finish_task_switch+0x3a/0xce [ 1852.926518] [] ? __kthread_parkme+0x61/0x61 [ 1853.008565] [] ret_from_fork+0x7c/0xb0 [ 1853.076477] [] ? __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 Cc: Trond Myklebust Cc: Dan Aloni Signed-off-by: Cong Wang [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 --- fs/nfs/client.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 1c5ff6d58385..6a4f3666e273 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -1412,24 +1412,18 @@ int nfs_fs_proc_net_init(struct net *net) p = proc_create("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs, &nfs_volume_list_fops); if (!p) - goto error_2; + goto error_1; return 0; -error_2: - remove_proc_entry("servers", nn->proc_nfsfs); error_1: - remove_proc_entry("fs/nfsfs", NULL); + remove_proc_subtree("nfsfs", net->proc_net); error_0: return -ENOMEM; } void nfs_fs_proc_net_exit(struct net *net) { - struct nfs_net *nn = net_generic(net, nfs_net_id); - - remove_proc_entry("volumes", nn->proc_nfsfs); - remove_proc_entry("servers", nn->proc_nfsfs); - remove_proc_entry("fs/nfsfs", NULL); + remove_proc_subtree("nfsfs", net->proc_net); } /*