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Date: Thu, 22 Jan 2026 10:57:01 -0800
From: "Darrick J. Wong" <djwong@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: cem@kernel.org, r772577952@gmail.com, stable@vger.kernel.org,
	linux-xfs@vger.kernel.org
Subject: Re: [PATCH 1/4] xfs: check the return value of xchk_xfile_*_descr
 calls
Message-ID: <20260122185701.GO5966@frogsfrogsfrogs>
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In-Reply-To: <20260122055748.GA23964@lst.de>

On Thu, Jan 22, 2026 at 06:57:48AM +0100, Christoph Hellwig wrote:
> On Wed, Jan 21, 2026 at 10:22:08AM -0800, Darrick J. Wong wrote:
> > > xchk_xfile_*_descr is used to pass the name to xfarray_create or
> > > xfblob_create.  I still think it would make this a lot more robust if
> > > those took a format string and varags, and then we'd have wrappers for
> > > the common types.  Even if that still ends up doing kasprintf underneath,
> > > that would be isolated to the low-level functions that only need to
> > > implement error handling and freeing once.
> > 
> > Alternately we just drop all the helpers and kasprintf crap in favor of
> > feeding the raw string ("iunlinked next pointers") all the way through
> > to shmem_kernel_file_setup.
> 
> But wouldn't we get duplicate names for different inodes?

Yes, but that's only used for readlink of /proc/$pid/fd/* so (AFAICT) it
makes tracing more confusing but doesn't affect functionality.
xfs_healthmon just passes in "xfs_healthmon" and I can run healers on
multiple filesystems just fine.

anon inodes are ... uh ... magic.

> Anyway, I did a quick take at format string / varags version of the
> helpers, and that works out nicely, but that _descr macros still confuse
> me a bit.  Maybe I'll have something until the start of your Thursday.

--D