From: Al Viro <viro@ZenIV.linux.org.uk>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: npiggin@kernel.dk, linux-fsdevel@vger.kernel.org
Subject: Re: [2.6.38] Deadlock between rename_lock and vfsmount_lock.
Date: Fri, 18 Mar 2011 12:13:05 +0000 [thread overview]
Message-ID: <20110318121305.GI22723@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20110318120748.GH22723@ZenIV.linux.org.uk>
On Fri, Mar 18, 2011 at 12:07:48PM +0000, Al Viro wrote:
> Actually, why do we hold vfsmount_lock over that loop at all? We already
> hold namespace_sem, so ->mnt_parent is protected...
Argh... No, it isn't. We flip it to final (mnt->mnt_parent = mnt)
outside of namespace_sem in release_mounts(). HOWEVER, by that point
we have already cleared ->mnt_ns - under namespace_sem.
So what we need is check_mnt(new.mnt) in addition to test for root.mnt
we already have there. That'll be enough.
next prev parent reply other threads:[~2011-03-18 12:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-16 8:54 [2.6.38] Possible deadlock at pivot_root? Tetsuo Handa
2011-03-17 5:01 ` [2.6.38] Deadlock between rename_lock and vfsmount_lock Tetsuo Handa
2011-03-18 10:59 ` Tetsuo Handa
2011-03-18 11:06 ` Al Viro
2011-03-18 11:54 ` Tetsuo Handa
2011-03-18 12:07 ` Al Viro
2011-03-18 12:13 ` Al Viro [this message]
2011-03-18 12:52 ` Al Viro
2011-03-18 13:18 ` Al Viro
2011-03-19 2:39 ` Tetsuo Handa
2011-03-23 23:00 ` Greg KH
2011-03-24 0:04 ` Tetsuo Handa
2011-03-24 0:10 ` Greg KH
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