From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([173.255.197.46]:52356 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311AbdKIQH3 (ORCPT ); Thu, 9 Nov 2017 11:07:29 -0500 Date: Thu, 9 Nov 2017 11:07:28 -0500 From: "J. Bruce Fields" To: Naofumi Honda Cc: linux-nfs@vger.kernel.org, jlayton@redhat.com Subject: Re: [Bug 197817] "Panic: unable to handle kernel page request" in posix_unblock_lock() called from nfs4_laundromat() Message-ID: <20171109160728.GI8773@fieldses.org> References: <1911104.BiqBl0Bicc@nausicaa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1911104.BiqBl0Bicc@nausicaa> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Nov 09, 2017 at 10:08:28AM +0900, Naofumi Honda wrote: > Dear Developers: > > > https://bugzilla.kernel.org/show_bug.cgi?id=197817 > > > > --- Comment #1 from bfields@fieldses.org --- > > Yes, I think you're right. > > > > Would it be possible for you to submit a patch to fix that typo in those two > > places? (Just mail it to me at bfields@fieldses.org, cc: to > > linux-nfs@vger.kernel.org). > > > > OK, I have attached the patch. Thanks for the investigation and the fix! For future reference, we prefer patches to be inline with the email message (not attached), and prefer them in "unified" format. But for a one-off patch I can fix it up myself; applied as follows. --b. commit c26806a20fa3 Author: Naofumi Honda Date: Thu Nov 9 10:57:16 2017 -0500 nfsd: fix panic in posix_unblock_lock called from nfs4_laundromat From kernel 4.9, my two nfsv4 servers sometimes suffer from "panic: unable to handle kernel page request" in posix_unblock_lock() called from nfs4_laundromat(). These panics diseappear if we revert the commit "nfsd: add a LRU list for blocked locks". The cause appears to be a typo in nfs4_laundromat(), which is also present in nfs4_state_shutdown_net(). Cc: stable@vger.kernel.org Fixes: 7919d0a27f1e "nfsd: add a LRU list for blocked locks" Cc: jlayton@redhat.com Signed-off-by: J. Bruce Fields diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 923243369bbc..b99830ab63aa 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4791,7 +4791,7 @@ nfs4_laundromat(struct nfsd_net *nn) spin_unlock(&nn->blocked_locks_lock); while (!list_empty(&reaplist)) { - nbl = list_first_entry(&nn->blocked_locks_lru, + nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); posix_unblock_lock(&nbl->nbl_lock); @@ -7260,7 +7260,7 @@ nfs4_state_shutdown_net(struct net *net) spin_unlock(&nn->blocked_locks_lock); while (!list_empty(&reaplist)) { - nbl = list_first_entry(&nn->blocked_locks_lru, + nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock, nbl_lru); list_del_init(&nbl->nbl_lru); posix_unblock_lock(&nbl->nbl_lock);