[3.13.y.z extended stable] Patch "fs: umount on symlink leaks mnt count" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu Aug 7 21:55:36 UTC 2014
This is a note to let you know that I have just added a patch titled
fs: umount on symlink leaks mnt count
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 3.13.11.6.
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
------
>From 043734110b6307137fc6324ff3e91ad5c85a3679 Mon Sep 17 00:00:00 2001
From: Vasily Averin <vvs at parallels.com>
Date: Mon, 21 Jul 2014 12:30:23 +0400
Subject: fs: umount on symlink leaks mnt count
commit 295dc39d941dc2ae53d5c170365af4c9d5c16212 upstream.
Currently umount on symlink blocks following umount:
/vz is separate mount
# ls /vz/ -al | grep test
drwxr-xr-x. 2 root root 4096 Jul 19 01:14 testdir
lrwxrwxrwx. 1 root root 11 Jul 19 01:16 testlink -> /vz/testdir
# umount -l /vz/testlink
umount: /vz/testlink: not mounted (expected)
# lsof /vz
# umount /vz
umount: /vz: device is busy. (unexpected)
In this case mountpoint_last() gets an extra refcount on path->mnt
Signed-off-by: Vasily Averin <vvs at openvz.org>
Acked-by: Ian Kent <raven at themaw.net>
Acked-by: Jeff Layton <jlayton at primarydata.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
fs/namei.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/namei.c b/fs/namei.c
index 01aca74..31673f4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2236,9 +2236,10 @@ done:
goto out;
}
path->dentry = dentry;
- path->mnt = mntget(nd->path.mnt);
+ path->mnt = nd->path.mnt;
if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW))
return 1;
+ mntget(path->mnt);
follow_mount(path);
error = 0;
out:
--
1.9.1
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