From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id nBANm00t127599 for ; Thu, 10 Dec 2009 17:48:01 -0600 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D86321956578 for ; Thu, 10 Dec 2009 15:48:36 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id UDB1TKDmO3BgEuJp for ; Thu, 10 Dec 2009 15:48:36 -0800 (PST) Date: Thu, 10 Dec 2009 18:48:36 -0500 From: Christoph Hellwig Subject: Re: [PATCH 6/6] [XFS] Reference count per-ag structures Message-ID: <20091210234836.GA4774@infradead.org> References: <1259734299-20306-1-git-send-email-david@fromorbit.com> <1259734299-20306-7-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1259734299-20306-7-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On Wed, Dec 02, 2009 at 05:11:39PM +1100, Dave Chinner wrote: > Reference count the per-ag structures to ensure that we keep get/put > pairs balanced. Assert that the reference counts are zero at unmount > time to catch leaks. In future, reference counts will enable us to > safely remove perag structures by allowing us to detect when they > are no longer in use. > > Signed-off-by: Dave Chinner > --- > fs/xfs/xfs_ag.h | 4 ++-- > fs/xfs/xfs_alloc.c | 2 +- > fs/xfs/xfs_inode.c | 5 ++++- > fs/xfs/xfs_mount.c | 1 + > fs/xfs/xfs_mount.h | 11 +++++++++-- > 5 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h > index a5d54bf..b384a3c 100644 > --- a/fs/xfs/xfs_ag.h > +++ b/fs/xfs/xfs_ag.h > index 2d076e2..d1349b1 100644 > --- a/fs/xfs/xfs_alloc.c > +++ b/fs/xfs/xfs_alloc.c > @@ -2545,7 +2545,6 @@ xfs_alloc_vextent( > } > xfs_perag_put(args->pag); > } > - xfs_perag_put(args->pag); > if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) { > if (args->agno == sagno) > mp->m_agfrotor = (mp->m_agfrotor + 1) % > @@ -2571,6 +2570,7 @@ xfs_alloc_vextent( > args->len); > #endif > } > + xfs_perag_put(args->pag); > return 0; > error0: > xfs_perag_put(args->pag); Should be folded into the earlier patches. > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index 44a1168..e6c178e 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -2729,7 +2729,7 @@ xfs_iflush_cluster( > ilist_size = inodes_per_cluster * sizeof(xfs_inode_t *); > ilist = kmem_alloc(ilist_size, KM_MAYFAIL|KM_NOFS); > if (!ilist) > - return 0; > + goto out_put; > > mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1); > first_index = XFS_INO_TO_AGINO(mp, ip->i_ino) & mask; > @@ -2798,6 +2798,8 @@ xfs_iflush_cluster( > out_free: > read_unlock(&pag->pag_ici_lock); > kmem_free(ilist); > +out_put: > + xfs_perag_put(pag); > return 0; > > > @@ -2841,6 +2843,7 @@ cluster_corrupt_out: > */ > xfs_iflush_abort(iq); > kmem_free(ilist); > + xfs_perag_put(pag); > return XFS_ERROR(EFSCORRUPTED); Same here. > static inline xfs_perag_t * > xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno) > @@ -393,6 +393,12 @@ xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno) > > spin_lock(&mp->m_perag_lock); > pag = radix_tree_lookup(&mp->m_perag_tree, agno); > + if (pag) { > + ASSERT(atomic_read(&pag->pag_ref) >= 0); > + /* catch leaks in the positive direction during testing */ > + ASSERT(atomic_read(&pag->pag_ref) < 1000); Is there any good reason why we should not be able to hit this number? Patch looks good, although I'm a bit worried about the performance overhead. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs