From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Monakhov Subject: [PATCH 08/10] ext4: endless truncate due to nonlocked dio readers V2 Date: Mon, 24 Sep 2012 15:44:18 +0400 Message-ID: <1348487060-19598-9-git-send-email-dmonakhov@openvz.org> References: <1348487060-19598-1-git-send-email-dmonakhov@openvz.org> Cc: tytso@mit.edu, jack@suse.cz, lczerner@redhat.com, Dmitry Monakhov To: linux-ext4@vger.kernel.org Return-path: Received: from mail-lb0-f174.google.com ([209.85.217.174]:62207 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754735Ab2IXLom (ORCPT ); Mon, 24 Sep 2012 07:44:42 -0400 Received: by mail-lb0-f174.google.com with SMTP id gj3so6549540lbb.19 for ; Mon, 24 Sep 2012 04:44:42 -0700 (PDT) In-Reply-To: <1348487060-19598-1-git-send-email-dmonakhov@openvz.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: If we have enough aggressive DIO readers, truncate and other dio waiters will wait forever inside inode_dio_wait(). It is reasonable to disable nonlock DIO read optimization during truncate. Signed-off-by: Dmitry Monakhov --- fs/ext4/inode.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 32e9701..d3f86e7 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4330,9 +4330,13 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_size != inode->i_size) { truncate_setsize(inode, attr->ia_size); - /* Inode size will be reduced, wait for dio in flight */ - if (orphan) + /* Inode size will be reduced, wait for dio in flight. + * Temproraly disable unlocked DIO to prevent livelock */ + if (orphan) { + ext4_inode_block_unlocked_dio(inode); inode_dio_wait(inode); + ext4_inode_resume_unlocked_dio(inode); + } } ext4_truncate(inode); } -- 1.7.7.6