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Date:   Sun, 9 May 2021 04:58:26 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Jia He <justin.he@arm.com>, Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Jonathan Corbet <corbet@lwn.net>,
        Al Viro <viro@ftp.linux.org.uk>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        "Eric W . Biederman" <ebiederm@xmission.com>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
        Ira Weiny <ira.weiny@intel.com>,
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        "Ahmed S. Darwish" <a.darwish@linutronix.de>,
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Subject: Re: [PATCH RFC 1/3] fs: introduce helper d_path_fast()
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On Sun, May 09, 2021 at 02:20:32AM +0000, Al Viro wrote:
> Umm...  Interesting, especially considering the way dyname_dname() looks like.
                                                      dynamic_dname(), obviously.

> Looks like there's a piece of prepend() open-coded in it.  And
> since all ->d_dname() instances are either simple_dname() or end up
> with call of dynamic_dname()...
> 
> Might make sense to turn that method into
> 	int (*d_dname)(struct dentry *, struct prepend_buffer *);
> 
> Followup patch, obviously, but it might be worth looking into.
> 
> Another thing that keeps bugging me about prepend_path() is the
> set of return values.  I mean, 0/1/2/3/-ENAMETOOLONG, and all
> except 0 are unlikely?  Might as well make that 0/1/2/3/-1, if
> not an outright 0/1/2/3/4.  And prepend() could return bool, while
> we are at it (true - success, false - overflow)...

OK...  I think I see how to carve it up sanely, will post after I
get some sleep.