From: Al Viro <viro@ZenIV.linux.org.uk>
To: Trond Myklebust <trondmy@primarydata.com>
Cc: Oleg Drokin <green@linuxhacker.ru>,
"J. Bruce Fields" <bfields@redhat.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"<linux-kernel@vger.kernel.org> Mailing List"
<linux-kernel@vger.kernel.org>,
"<linux-fsdevel@vger.kernel.org>" <linux-fsdevel@vger.kernel.org>
Subject: Re: NFS/d_splice_alias breakage
Date: Fri, 3 Jun 2016 04:28:53 +0100 [thread overview]
Message-ID: <20160603032853.GK14480@ZenIV.linux.org.uk> (raw)
In-Reply-To: <F0790F28-A8F9-406E-8B1A-F3F3773DA28E@primarydata.com>
On Fri, Jun 03, 2016 at 12:44:51AM +0000, Trond Myklebust wrote:
> That would have to be a really tight race, since the code in _nfs4_open_and_get_state() currently reads:
>
> d_drop(dentry);
> alias = d_exact_alias(dentry, state->inode);
> if (!alias)
> alias = d_splice_alias(igrab(state->inode), dentry);
>
> IOW: something would have to be acting between the d_drop() and d_splice_alias() above...
How? dentry is
* negative (it would better be, or we are _really_ fucked)
* unhashed
How does whoever's rehashing it stumble across that thing?
next prev parent reply other threads:[~2016-06-03 3:28 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-02 22:46 NFS/d_splice_alias breakage Oleg Drokin
2016-06-02 23:59 ` [PATCH] Allow d_splice_alias to accept hashed dentries green
2016-06-03 0:25 ` Oleg Drokin
2016-06-03 0:44 ` NFS/d_splice_alias breakage Trond Myklebust
2016-06-03 0:44 ` Trond Myklebust
2016-06-03 0:54 ` Oleg Drokin
2016-06-03 0:54 ` Oleg Drokin
2016-06-03 3:26 ` Al Viro
2016-06-03 3:38 ` Al Viro
2016-06-03 3:28 ` Al Viro [this message]
2016-06-03 3:37 ` Al Viro
2016-06-03 3:43 ` Oleg Drokin
2016-06-03 4:26 ` Al Viro
2016-06-03 4:42 ` Al Viro
2016-06-03 4:53 ` Al Viro
2016-06-03 4:58 ` Oleg Drokin
2016-06-03 5:56 ` Al Viro
2016-06-06 23:36 ` Oleg Drokin
2016-06-10 1:33 ` Oleg Drokin
2016-06-10 16:49 ` Oleg Drokin
2016-06-20 13:25 ` Oleg Drokin
2016-06-20 14:08 ` Al Viro
2016-06-20 14:54 ` Trond Myklebust
2016-06-20 14:54 ` Trond Myklebust
2016-06-20 15:28 ` Al Viro
2016-06-20 15:43 ` Anna Schumaker
2016-06-20 15:45 ` Oleg Drokin
2016-06-20 15:47 ` Trond Myklebust
2016-06-20 15:47 ` Trond Myklebust
2016-06-03 16:38 ` Dcache oops Oleg Drokin
2016-06-03 18:22 ` Al Viro
2016-06-03 18:35 ` Oleg Drokin
2016-06-03 20:07 ` Al Viro
2016-06-03 21:17 ` Oleg Drokin
2016-06-03 21:46 ` Al Viro
2016-06-03 22:17 ` Al Viro
2016-06-03 21:18 ` Linus Torvalds
2016-06-03 21:26 ` Al Viro
2016-06-03 22:00 ` Linus Torvalds
2016-06-03 22:23 ` Al Viro
2016-06-03 22:29 ` Al Viro
2016-06-03 22:36 ` Linus Torvalds
2016-06-03 22:42 ` Oleg Drokin
2016-06-03 22:43 ` Al Viro
2016-06-03 22:37 ` Al Viro
2016-06-03 22:49 ` Oleg Drokin
2016-06-03 23:58 ` Oleg Drokin
2016-06-04 0:56 ` Al Viro
2016-06-04 12:25 ` Jeff Layton
2016-06-04 16:12 ` Oleg Drokin
2016-06-04 16:21 ` [PATCH] nfs4: Fix potential use after free of state in nfs4_do_reclaim green
2016-06-04 19:57 ` Jeff Layton
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