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[3.13.y.z,extended,stable] Patch "nfs: fix kernel warning when removing proc entry" has been added to staging queue

Message ID 1412806448-30957-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Oct. 8, 2014, 10:14 p.m. UTC
This is a note to let you know that I have just added a patch titled

    nfs: fix kernel warning when removing proc entry

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

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From 9784e963b715a2e7a93cf4f7f8ecb9f8cc9e2290 Mon Sep 17 00:00:00 2001
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon, 8 Sep 2014 16:17:55 -0700
Subject: nfs: fix kernel warning when removing proc entry

commit 21e81002f9788a3af591416b6dec60d7b67f2fb2 upstream.

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]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 fs/nfs/client.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

--
1.9.1
diff mbox

Patch

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 180d1ec..6e37cd0 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1404,24 +1404,18 @@  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);
 }

 /*