Re: [PATCH v5 29/32] d_path: prt_path()

[Kent Overstreet]

On 8/8/22 00:17, Al Viro wrote:
> On Mon, Aug 08, 2022 at 03:41:25AM +0100, Matthew Wilcox (Oracle) wrote:
> > From: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> >
> > 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.

Oof, good catch. It was to replace seq_buf_path() in this patch series, 
and is only used in trace_seq.c. I'll have to investigate what's going 
on in the tracing code, because now that you mention it that did look 
suspect.