From: Artem Savkov <asavkov@redhat.com>
To: David Howells <dhowells@redhat.com>
Cc: linux-cachefs@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Use proper lock in fscache_objlist_config.
Date: Tue, 4 Oct 2016 17:54:17 +0200 [thread overview]
Message-ID: <20161004155417.GC19785@shodan.usersys.redhat.com> (raw)
In-Reply-To: <7737.1475595811@warthog.procyon.org.uk>
On Tue, Oct 04, 2016 at 04:43:31PM +0100, David Howells wrote:
> Artem Savkov <asavkov@redhat.com> wrote:
>
> > fscache_objlist_config doesn't hold rkey->sem when calling user_key_payload,
> > that can result in a "suspicious RCU usage" warning. It does hold
> > rcu_read_lock, so it either needs to use unprotected rcu_dereference,
> > or take rkey->sem instead of rcu_read_lock.
>
> It shouldn't take key->sem. The RCU lock should be necessary as
> user_key_payload() wraps a call to rcu_dereference().
>
> Did you encounter a lockdep report or did you visually inspect this?
I didn't see a lockdep report for this one, I just assumed it would be
the same as with the nfs_idmap_get_key case.
--
Regards,
Artem
prev parent reply other threads:[~2016-10-04 15:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-04 13:38 [PATCH] Use proper lock in fscache_objlist_config Artem Savkov
2016-10-04 15:43 ` David Howells
2016-10-04 15:54 ` Artem Savkov [this message]
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