From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753994Ab1C2HIf (ORCPT ); Tue, 29 Mar 2011 03:08:35 -0400 Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:43825 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752487Ab1C2HIe (ORCPT ); Tue, 29 Mar 2011 03:08:34 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AiQIAFGDkU15LK5JTmdsb2JhbACESZQFjHYLAQEbBQMjJbJjkHiBJ4NMdwSTAA From: Dave Chinner To: torvalds@linux-foundation.org Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, ryan@bluewatersys.com Subject: [PATCH] fs: don't use igrab() while holding i_lock Date: Tue, 29 Mar 2011 18:08:50 +1100 Message-Id: <1301382530-32069-1-git-send-email-david@fromorbit.com> X-Mailer: git-send-email 1.7.2.3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Chinner Fix the incorrect use of igrab() inside the i_lock in NFS and Ceph‥ If we are already holding the i_lock, we have a reference to the inode so we can safely use ihold() to gain an extra reference. This avoids hangs due to lock recursion on the i_lock now that the inode_lock is gone and igrab() uses the i_lock itself. Signed-off-by: Dave Chinner --- fs/ceph/addr.c | 2 +- fs/ceph/snap.c | 4 ++-- fs/nfs/nfs4state.c | 3 ++- 3 files changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 561438b..37368ba 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -92,7 +92,7 @@ static int ceph_set_page_dirty(struct page *page) ci->i_head_snapc = ceph_get_snap_context(snapc); ++ci->i_wrbuffer_ref_head; if (ci->i_wrbuffer_ref == 0) - igrab(inode); + ihold(inode); ++ci->i_wrbuffer_ref; dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " "snapc %p seq %lld (%d snaps)\n", diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index f40b913..0aee66b 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -463,8 +463,8 @@ void ceph_queue_cap_snap(struct ceph_inode_info *ci) dout("queue_cap_snap %p cap_snap %p queuing under %p\n", inode, capsnap, snapc); - igrab(inode); - + ihold(inode); + atomic_set(&capsnap->nref, 1); capsnap->ci = ci; INIT_LIST_HEAD(&capsnap->ci_item); diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index ab1bf5b..a6804f7 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -590,7 +590,8 @@ nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner) state->owner = owner; atomic_inc(&owner->so_count); list_add(&state->inode_states, &nfsi->open_states); - state->inode = igrab(inode); + ihold(inode); + state->inode = inode; spin_unlock(&inode->i_lock); /* Note: The reclaim code dictates that we add stateless * and read-only stateids to the end of the list */ -- 1.7.2.3