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Date:   Mon, 8 Aug 2022 05:17:24 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     linux-kernel@vger.kernel.org, pmladek@suse.com,
        Kent Overstreet <kent.overstreet@gmail.com>
Subject: Re: [PATCH v5 29/32] d_path: prt_path()
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On Mon, Aug 08, 2022 at 03:41:25AM +0100, Matthew Wilcox (Oracle) wrote:
> From: Kent Overstreet <kent.overstreet@gmail.com>
> 
> This implements a new printbuf version of d_path()/mangle_path(), which
> will replace the seq_buf version.
> 
> Part of what we're trying to do with printbufs is standardizing a
> calling convention so they don't have to live in lib/vsprintf.c, and can
> instead with the code for the types they're printing - so this patch
> adds prt_path() to d_path.c, another patch will switch vsprintf.c to use
> it.

To use it for *what*?  If you mean replacing %pd with it - forget about that.
Not going to happen.

There's a hard requirement for printk - it should be safe to call in any
locking environment.  d_path() isn't, and that's impossible to avoid.