Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-ie0-f175.google.com ([209.85.223.175]:47619 "EHLO mail-ie0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759AbaLVCHS (ORCPT ); Sun, 21 Dec 2014 21:07:18 -0500 Received: by mail-ie0-f175.google.com with SMTP id x19so3624053ier.20 for ; Sun, 21 Dec 2014 18:07:17 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <54909E1B.4000005@Netapp.com> References: <1418756513-95187-1-git-send-email-loghyr@primarydata.com> <1418756513-95187-39-git-send-email-loghyr@primarydata.com> <54909E1B.4000005@Netapp.com> From: Peng Tao Date: Mon, 22 Dec 2014 10:06:57 +0800 Message-ID: Subject: Re: [PATCH 38/50] nfs41: add a debug warning if we destroy an unempty layout To: Anna Schumaker Cc: Tom Haynes , Trond Myklebust , Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Dec 17, 2014 at 5:03 AM, Anna Schumaker wrote: > On 12/16/2014 02:01 PM, Tom Haynes wrote: >> From: Peng Tao >> >> So that we can detect the case if some layout segments are still >> pinned which is surely a bug that we need to fix. > > How often is this hit? A patch fixing the bug would be better than a patch just to detect it :). > Never yet :) I was suspecting a bug in segment reference counting and thus added the patch. That bug turns out to be somewhere else but I thought the WARN makes sense in general sense because without it we silently ignores unfreed reference counts. Cheers, Tao > Anna > >> >> Signed-off-by: Peng Tao >> --- >> fs/nfs/pnfs.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c >> index 5f7c422..e123cfc 100644 >> --- a/fs/nfs/pnfs.c >> +++ b/fs/nfs/pnfs.c >> @@ -242,6 +242,8 @@ pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo) >> struct inode *inode = lo->plh_inode; >> >> if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) { >> + if (!list_empty(&lo->plh_segs)) >> + WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n"); >> pnfs_detach_layout_hdr(lo); >> spin_unlock(&inode->i_lock); >> pnfs_free_layout_hdr(lo); >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html