linux-kernel - [proposal] creating anonymous files

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Message-ID: <9641a91e0905011711j75e33219yf520d0e40171908e@mail.gmail.com>
Date:	Sat, 2 May 2009 10:11:21 +1000
From:	john slee <indigoid@...corollas.org>
To:	linux-kernel@...r.kernel.org
Subject: [proposal] creating anonymous files

Hi,

At present developers seem to go through all kinds of ridiculous
antics to try to open a temporary file with some degree of safety.
Most of these seem to revolve around choosing a name, and in
many cases it gets unlinked immediately after open() anyway.

Temporary file creation/handling would be far less unpleasant if
it went something like this:

/* need to establish which fs the new inode goes on */
dirfd = open("/etc", O_RDONLY);

fd = openfdat(dirfd, O_CREAT, S_IWUSR|S_IRUSR);
/* file has no links, no need to unlink.  now use fd */

/* if we want to keep the file, add a link */
if (all_ok) {
    linkfdat(dirfd, fd, "nsswitch.conf");
} else {
   /* no cleanup required, inode has no links and */
   /* disappears at process exit */
}

I had a quick look through the Free/OpenBSD and Solaris 10
manpages in case they had implemented something similar, but
it seems that they haven't.

Sorry about lack of attached patch.  I did have a good look through
fs/namei.c and fs/open.c but I am more a sysadmin than a kernel
hacker

Comments/constructive abuse appreciated...

John

-- 
P-plate adventurer -- http://indigoid.org/
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