Date: Thu, 31 Mar 2005 10:42:58 +1000
From: Nathan Scott <nathans@sgi.com>
To: David Malone <dwmalone@maths.tcd.ie>, linux-xfs@oss.sgi.com,
       linux-kernel@vger.kernel.org
Subject: Re: Directory link count wrapping on Linux/XFS/i386?
Message-ID: <20050331004258.GF867@frodo>
References: <200503302043.aa27223@salmon.maths.tcd.ie> <20050330200601.GG1753@schnapps.adilger.int>
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On Wed, Mar 30, 2005 at 01:06:01PM -0700, Andreas Dilger wrote:
> On Mar 30, 2005  20:43 +0100, David Malone wrote:
> > It seems that internally xfs uses a 32 bit field for the link count,
> > and the stat64 syscalls use a 32 bit field. These fields are copied
> > via the vattr structure in xfs_vnode.h, which uses a nlink_t for
> > the link count. However, in the kernel, I think this field is
> > actually of type __kernel_nlink_t which seems to be 16 bits on many
> > platforms.

Yes, use of nlink_t looks wrong there, thanks.  Theres one/two other
uses of it in XFS as well, I'll audit those.

> The correct fix, used for reiserfs (and a patch for ext3 also) is to
> set i_nlink = 1 in case the filesystem count has wrapped.  When nlink==1
> the fts/find code no longer optimizes subdirectory traversal and checks
> each entries filetype to see if it should recurse.

Ah, I see - the INC_DIR_INODE_NLINK/DEC_DIR_INODE_NLINK macros, right.
I'll look into that too, thanks.

cheers.

-- 
Nathan
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