linux-kernel - Re: [RFC PATCH 0/7] cross rename

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <524CCF38.9000304@zytor.com>
Date:	Wed, 02 Oct 2013 18:58:16 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Miklos Szeredi <miklos@...redi.hu>
CC:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	viro@...IV.linux.org.uk, torvalds@...ux-foundation.org,
	hch@...radead.org, akpm@...ux-foundation.org, dhowells@...hat.com,
	zab@...hat.com, jack@...e.cz, tytso@....edu, mszeredi@...e.cz
Subject: Re: [RFC PATCH 0/7] cross rename

On 10/01/2013 09:00 AM, Miklos Szeredi wrote:
> This series adds a new syscall, renameat2(), which is the same as renameat() but
> with a flags argument.  Internally i_op->reaname2() is also added, which can
> later be merged with ->rename() but is kept separately for now, since this would
> just blow up this patch without helping review.
> 
> The purpose of extending rename is to add cross-rename, a symmetric variant of
> rename, which exchanges the two files.  This allows interesting things, which
> were not possible before, for example atomically replacing a directory tree with
> a symlink, etc...
> 

I would suggest it shouldn't be renameat2() but rather renameat3(), i.e.
rename file A -> B, if B exists rename B to C.  It may not be desirable
to expose the stale B in the same namespace as A, but still want it to
be possible to scavenge it.  Obviously, A=C is a valid subcase.

	-hpa


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/