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From 074479bdf9cc93bbf161e7ba9dce20c81e1c7a31 Mon Sep 17 00:00:00 2001
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From: Cong Wang <xiyou.wangcong@gmail.com>
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Date: Sat, 16 Aug 2014 12:36:46 -0700
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Subject: [PATCH] nfs: fix kernel warning when removing proc entry
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I saw the following kernel warning:
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[ 1852.321222] ------------[ cut here ]------------
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[ 1852.326527] WARNING: CPU: 0 PID: 118 at fs/proc/generic.c:521 remove_proc_entry+0x154/0x16b()
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[ 1852.335630] remove_proc_entry: removing non-empty directory 'fs/nfsfs', leaking at least 'volumes'
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[ 1852.344084] CPU: 0 PID: 118 Comm: kworker/u8:2 Not tainted 3.16.0+ #540
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[ 1852.350036] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
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[ 1852.354992] Workqueue: netns cleanup_net
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[ 1852.358701]  0000000000000000 ffff880116f2fbd0 ffffffff819c03e9 ffff880116f2fc18
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[ 1852.366474]  ffff880116f2fc08 ffffffff810744ee ffffffff811e0e6e ffff8800d4e96238
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[ 1852.373507]  ffffffff81dbe665 ffff8800d46a5948 0000000000000005 ffff880116f2fc68
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[ 1852.380224] Call Trace:
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[ 1852.381976]  [<ffffffff819c03e9>] dump_stack+0x4d/0x66
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[ 1852.385495]  [<ffffffff810744ee>] warn_slowpath_common+0x7a/0x93
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[ 1852.389869]  [<ffffffff811e0e6e>] ? remove_proc_entry+0x154/0x16b
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[ 1852.393987]  [<ffffffff8107457b>] warn_slowpath_fmt+0x4c/0x4e
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[ 1852.397999]  [<ffffffff811e0e6e>] remove_proc_entry+0x154/0x16b
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[ 1852.402034]  [<ffffffff8129c73d>] nfs_fs_proc_net_exit+0x53/0x56
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[ 1852.406136]  [<ffffffff812a103b>] nfs_net_exit+0x12/0x1d
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[ 1852.409774]  [<ffffffff81785bc9>] ops_exit_list+0x44/0x55
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[ 1852.413529]  [<ffffffff81786389>] cleanup_net+0xee/0x182
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[ 1852.417198]  [<ffffffff81088c9e>] process_one_work+0x209/0x40d
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[ 1852.502320]  [<ffffffff81088bf7>] ? process_one_work+0x162/0x40d
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[ 1852.587629]  [<ffffffff810890c1>] worker_thread+0x1f0/0x2c7
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[ 1852.673291]  [<ffffffff81088ed1>] ? process_scheduled_works+0x2f/0x2f
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[ 1852.759470]  [<ffffffff8108e079>] kthread+0xc9/0xd1
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[ 1852.843099]  [<ffffffff8109427f>] ? finish_task_switch+0x3a/0xce
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[ 1852.926518]  [<ffffffff8108dfb0>] ? __kthread_parkme+0x61/0x61
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[ 1853.008565]  [<ffffffff819cbeac>] ret_from_fork+0x7c/0xb0
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[ 1853.076477]  [<ffffffff8108dfb0>] ? __kthread_parkme+0x61/0x61
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[ 1853.140653] ---[ end trace 69c4c6617f78e32d ]---
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It looks wrong that we add "/proc/net/nfsfs" in nfs_fs_proc_net_init()
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while remove "/proc/fs/nfsfs" in nfs_fs_proc_net_exit().
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Bugzilla: 1132368
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Upstream-status: Sent for 3.17-rcX
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Fixes: commit 65b38851a17 (NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes)
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Cc: Eric W. Biederman <ebiederm@xmission.com>
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Cc: Trond Myklebust <trond.myklebust@primarydata.com>
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Cc: Dan Aloni <dan@kernelim.com>
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Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
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---
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 fs/nfs/client.c | 4 ++--
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 1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/fs/nfs/client.c b/fs/nfs/client.c
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index 1c5ff6d58385..c117b96c7da9 100644
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--- a/fs/nfs/client.c
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+++ b/fs/nfs/client.c
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@@ -1418,7 +1418,7 @@ int nfs_fs_proc_net_init(struct net *net)
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 error_2:
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 	remove_proc_entry("servers", nn->proc_nfsfs);
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 error_1:
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-	remove_proc_entry("fs/nfsfs", NULL);
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+	remove_proc_entry("nfsfs", net->proc_net);
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 error_0:
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 	return -ENOMEM;
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 }
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@@ -1429,7 +1429,7 @@ void nfs_fs_proc_net_exit(struct net *net)
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 	remove_proc_entry("volumes", nn->proc_nfsfs);
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 	remove_proc_entry("servers", nn->proc_nfsfs);
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-	remove_proc_entry("fs/nfsfs", NULL);
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+	remove_proc_entry("nfsfs", net->proc_net);
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 }
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 /*
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-- 
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1.9.3
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