From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: Btrfs st_nlink for directories Date: Sat, 23 Jan 2010 19:33:36 -0500 Message-ID: <20100124003336.GP23006@think> References: <20100123022812.GA16124@arctrix.com> <878wbomu24.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Neil Schemenauer , linux-btrfs@vger.kernel.org To: "Aneesh Kumar K. V" Return-path: In-Reply-To: <878wbomu24.fsf@linux.vnet.ibm.com> List-ID: On Sun, Jan 24, 2010 at 02:12:59AM +0530, Aneesh Kumar K. V wrote: > On Fri, 22 Jan 2010 20:28:12 -0600, Neil Schemenauer wrote: > > Hi, > > > > It looks like Btrfs does not follow Unix traditions for st_nlink > > attribute of directories. It seems to be always one, no matter the > > number of sub-directories. > > > > Is this intentional? I couldn't find it discussed anywhere. I > > gather the Mac OS HFS+ doesn't follow traditional st_nlink behavior > > as well. The 'find' man page has this note: > > I have sent patches with message-id > 1264279089-14913-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com > to the list. Let me know if they works for your Thanks for taking a look at this Aneesh, but in btrfs we always have a link count of one on directories. It's a design decision so that we don't end up limited in the total number of subdirs we can create. reiser3 did something similar, switching to 1 when the link count got high. I think the other filesystems may have added something along these lines as well by now. Btrfs just leaves it at one all the time. -chris