Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753042AbYJTSCg (ORCPT ); Mon, 20 Oct 2008 14:02:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753931AbYJTSCN (ORCPT ); Mon, 20 Oct 2008 14:02:13 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:32906 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753878AbYJTSCL (ORCPT ); Mon, 20 Oct 2008 14:02:11 -0400 To: cl@linux-foundation.org CC: miklos@szeredi.hu, penberg@cs.helsinki.fi, nickpiggin@yahoo.com.au, hugh@veritas.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org In-reply-to: <48FC9CCC.3040006@linux-foundation.org> (message from Christoph Lameter on Mon, 20 Oct 2008 09:59:24 -0500) Subject: Re: SLUB defrag pull request? References: <1223883004.31587.15.camel@penberg-laptop> <1223883164.31587.16.camel@penberg-laptop> <200810132354.30789.nickpiggin@yahoo.com.au> <48F378C6.7030206@linux-foundation.org> <48FC9CCC.3040006@linux-foundation.org> Message-Id: From: Miklos Szeredi Date: Mon, 20 Oct 2008 20:01:58 +0200 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1707 Lines: 40 On Mon, 20 Oct 2008, Christoph Lameter wrote: > >> kick_inodes() only works on inodes that first have undergone > >> get_inodes() where we establish a refcount under inode_lock(). The final > >> cleanup in kick_inodes() is done under iprune_mutex. You are looking at > >> the loop that does writeback and invalidates attached dentries. This can > >> fail for various reasons. > > > > Yes, but I'm not at all sure that calling remove_inode_buffers() or > > invalidate_mapping_pages() is OK on a live inode. They should be done > > after checking the refcount, just like prune_icache() does. > > Dont we do the same on a truncate? Yes, with i_mutex and i_alloc_sem held. > > > Also, while d_invalidate() is not actually wrong here, because you > > check S_ISDIR(), but it's still the wrong function to use. You really > > just want to shrink the children. Invalidation means: the filesystem > > found out that the cached inode is invalid, so we want to throw it > > away. In the future it might actually be able to do it for > > directories as well, but currently it cannot because of possible > > mounts on the dentry. > > Thats the same issue as with the dentries. The new function could deal with > both situations? Sure. The big issue is dealing with umount. You could do something like grab_super() on sb before getting a ref on the inode/dentry. But I'm not sure this is a good idea. There must be a simpler way to achieve this... Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/