From: Pavel Machek <pavel@ucw.cz>
To: AEDilger Gmail <aedilger@gmail.com>
Cc: "Andreas Dilger" <adilger@dilger.ca>,
"Jörn Engel" <joern@logfs.org>,
"Andy Lutomirski" <luto@amacapital.net>,
"Zach Brown" <zab@redhat.com>,
"Myklebust, Trond" <Trond.Myklebust@netapp.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Ric Wheeler" <rwheeler@redhat.com>,
"Linux FS Devel" <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Chris L. Mason" <clmason@fusionio.com>,
"Christoph Hellwig" <hch@infradead.org>,
"Alexander Viro" <aviro@redhat.com>,
"Martin K. Petersen" <mkp@mkp.net>,
"Hannes Reinecke" <hare@suse.de>,
"Joel Becker" <jlbec@evilplan.org>
Subject: Re: New copyfile system call - discuss before LSF?
Date: Sun, 31 Mar 2013 10:25:48 +0200 [thread overview]
Message-ID: <20130331082548.GA15385@amd.pavel.ucw.cz> (raw)
In-Reply-To: <BF9B5AA3-79C2-424F-8969-53269338F049@gmail.com>
Hi!
On Sat 2013-03-30 22:38:35, AEDilger Gmail wrote:
> On 2013-03-30, at 14:45, Pavel Machek <pavel@ucw.cz> wrote:
> > On Sat 2013-03-30 13:08:39, Andreas Dilger wrote:
> >> On 2013-03-30, at 12:49 PM, Pavel Machek wrote:
> >>> Hmm, really? AFAICT it would be simple to provide an
> >>> open_deleted_file("directory") syscall. You'd open_deleted_file(),
> >>> copy source file into it, then fsync(), then link it into filesystem.
> >>>
> >>> That should have atomicity properties reflected.
> >>
> >> Actually, the open_deleted_file() syscall is quite useful for many
> >> different things all by itself. Lots of applications need to create
> >> temporary files that are unlinked at application failure (without a
> >> race if app crashes after creating the file, but before unlinking).
> >> It also avoids exposing temporary files into the namespace if other
> >> applications are accessing the directory.
> >
> > Hmm. open_deleted_file() will still need to get a directory... so it
> > will still need a path. Perhaps open("/foo/bar/mnt", O_DELETED) would
> > be acceptable interface?
>
> Yes, that would be reasonable, and/or possibly openat(fd, NULL, AT_FDCWD|AT_UNLINKED)?
openat() is better interface for this, I'd say.
BTW... I don't think this has to be done at the same time as splice()
[or how it ends up being called] changes...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2013-03-31 8:25 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-21 11:37 New copyfile system call - discuss before LSF? Ric Wheeler
2013-02-21 13:37 ` Hannes Reinecke
2013-02-21 13:51 ` Myklebust, Trond
2013-02-21 14:57 ` Ric Wheeler
2013-02-21 16:36 ` Andreas Dilger
2013-02-21 20:00 ` Paolo Bonzini
2013-02-21 20:50 ` Myklebust, Trond
2013-02-21 22:24 ` Zach Brown
2013-02-22 1:29 ` Myklebust, Trond
2013-02-23 0:32 ` Eric Wong
2013-03-30 19:45 ` Pavel Machek
2013-03-31 21:23 ` Eric Wong
2013-02-22 9:47 ` Paolo Bonzini
2013-02-22 9:52 ` Ric Wheeler
2013-02-22 18:22 ` Zach Brown
2013-02-22 22:48 ` Myklebust, Trond
2013-02-25 21:14 ` Andy Lutomirski
2013-02-25 21:49 ` Ric Wheeler
2013-02-25 21:59 ` Myklebust, Trond
2013-02-25 22:16 ` Andy Lutomirski
2013-02-25 23:28 ` Myklebust, Trond
2013-02-25 23:35 ` Andy Lutomirski
2013-02-25 23:45 ` Myklebust, Trond
2013-02-26 0:03 ` Zach Brown
2013-03-11 9:31 ` Joel Becker
2013-02-26 21:02 ` Jörn Engel
2013-02-26 22:35 ` Andy Lutomirski
2013-03-30 19:49 ` Pavel Machek
2013-03-30 20:08 ` Andreas Dilger
2013-03-30 21:45 ` Pavel Machek
2013-03-30 21:57 ` Myklebust, Trond
2013-03-30 23:21 ` Ric Wheeler
2013-03-31 2:53 ` Andreas Dilger
2013-03-31 3:52 ` Myklebust, Trond
2013-03-31 4:18 ` Andy Lutomirski
2013-03-31 4:36 ` Myklebust, Trond
2013-03-31 4:45 ` Myklebust, Trond
2013-04-01 15:49 ` J. Bruce Fields
2013-03-31 7:36 ` Pavel Machek
2013-03-31 18:27 ` Myklebust, Trond
2013-03-31 18:32 ` openat(..., AT_UNLINKED) was " Pavel Machek
2013-03-31 18:44 ` Myklebust, Trond
2013-03-31 22:50 ` Pavel Machek
2013-03-31 23:14 ` Ric Wheeler
2013-03-31 23:18 ` Pavel Machek
2013-03-31 23:28 ` Ric Wheeler
2013-03-31 23:41 ` Pavel Machek
2013-03-31 5:38 ` AEDilger Gmail
2013-03-31 8:25 ` Pavel Machek [this message]
2013-03-31 11:48 ` Pádraig Brady
2013-03-30 22:40 ` Andy Lutomirski
2013-02-21 22:05 ` Ric Wheeler
2013-02-21 22:13 ` Myklebust, Trond
2013-02-22 8:47 ` Ric Wheeler
2013-02-21 18:29 ` Jeremy Allison
2013-02-22 0:29 ` Eric Wong
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