From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 3/4] fs: Lock the inode LRU list separately Date: Thu, 28 Oct 2010 06:25:21 -0400 Message-ID: <20101028102521.GA6141@infradead.org> References: <1288153384-8878-1-git-send-email-david@fromorbit.com> <1288153384-8878-4-git-send-email-david@fromorbit.com> <20101027090530.GB16443@infradead.org> <20101027222444.GC2715@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , viro@ZenIV.linux.org.uk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Dave Chinner Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:48573 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757061Ab0J1KZ3 (ORCPT ); Thu, 28 Oct 2010 06:25:29 -0400 Content-Disposition: inline In-Reply-To: <20101027222444.GC2715@dastard> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: > That doesn't happen because the counter is only modified when > the inode is moved on/off the list and there are checks to avoid > removing an inode that is not on the list. Also, the inode is not > removed from the LRU in dispose_one_inode - it is always done when > the inode is marked I_FREEING while the i_lock is held before > calling dispose_one_inode(). > > Basically I wanted to remove the strange "inode is not on the LRU if > it is dirty or under writeback" accounting checks and make the > accounting symmetric with adding/removing the inodes from the LRU. > These are protected by list_empty() checks, so should always end up > with the correct accounting. > > hence the only special case now is prune_icache() which already > holds the inode_lru_lock() so can't call the helper. Besides, we > don't need any checks there because we know the inode is on the LRU > already.... Indeed. What about adding a BUG_ON(!list_empty(&inode->i_lru)); to evict to ensure this invariant?