RE: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast()

[Justin He]

> -----Original Message-----
> From: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Sent: Friday, May 28, 2021 8:52 PM
> To: Justin He <Justin.He@xxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>; Petr Mladek
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> Senozhatsky <senozhatsky@xxxxxxxxxxxx>; Andy Shevchenko
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> Subject: Re: [PATCH RFCv2 1/3] fs: introduce helper d_path_fast()
>
> On Fri, May 28, 2021 at 07:39:49PM +0800, Jia He wrote:
> > +/**
> > + * d_path_fast - fast return the full path of a dentry without taking
> > + * any seqlock/spinlock. This helper is typical for debugging purpose
> > + */
> > +char *d_path_fast(const struct path *path, char *buf, int buflen)
>
> I'd suggest calling it d_path_unsafe().  Otherwise people will call it
> instead of d_path because who doesn't like fast?
>
Okay, thanks

> > +{
> > +   struct path root;
> > +   struct mount *mnt = real_mount(path->mnt);
> > +   DECLARE_BUFFER(b, buf, buflen);
> > +
> > +   rcu_read_lock();
> > +   get_fs_root_rcu(current->fs, &root);
> > +
> > +   prepend(&b, "", 1);
> > +   __prepend_path(path->dentry, mnt, &root, &b);
> > +   rcu_read_unlock();
> > +
> > +   return extract_string(&b);
> > +}
> > +EXPORT_SYMBOL(d_path_fast);
>
> Why export it?  What module needs this?
Okay, indeed

--
Cheers,
Justin (Jia He)


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