Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <willy@infradead.org>,
	Miklos Szeredi <miklos@szeredi.hu>,
	Al Viro <viro@zeniv.linux.org.uk>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	Greg Kurz <groug@kaod.org>,
	linux-fsdevel@vger.kernel.org,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Miklos Szeredi <mszeredi@redhat.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Giuseppe Scrivano <gscrivan@redhat.com>,
	Daniel J Walsh <dwalsh@redhat.com>,
	Chirantan Ekbote <chirantan@chromium.org>
Subject: Re: xattr names for unprivileged stacking?
Date: Tue, 1 Sep 2020 11:14:53 -0400	[thread overview]
Message-ID: <20200901151453.GC558530@mit.edu> (raw)
In-Reply-To: <20200901145205.GA558530@mit.edu>

On Tue, Sep 01, 2020 at 10:52:05AM -0400, Theodore Y. Ts'o wrote:
> On Tue, Sep 01, 2020 at 01:34:05PM +1000, Dave Chinner wrote:
> > 
> > But, unlike your implication that this is -really complex and hard
> > to do-, it's actually relatively trivial to do with the XFS
> > implementation I mentioned as each ADS stream is a fully fledged
> > inode that can point to shared data extents. If you can do data
> > manipulation on a regular inode, you'll be able to do it on an ADS,
> > and that includes copying ADS streams via reflink.
> 
> Is the reflink system call on a file with ADS's atomic, or not?  What
> if there are a million files is ADS hierarchy which is 100
> subdirectories deep in some places, comprising several TB's worth of
> data?  Is that all going to fit in a single XFS transaction?  What if
> you crash in the middle of it?  Is a partially reflinked copy of an
> ADS file OK?  Or a reflinked ADS file missing some portion of the
> alternate data streams?

Oh, and if the answer is that the ADS inodes should be reflinked
individually in userspace, wonderful!  An ADS inode could then just be
a directory, like it was in the NeXT operating system, and copying an
ADS file could *also* be done in userspace, as a cp -r.   :-)

That's fine too, and keeps the file system completely out of it.  :-)

              	    	     	       	    - Ted

  reply	other threads:[~2020-09-01 15:15 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28 10:55 Dr. David Alan Gilbert
2020-07-28 13:08 ` Greg Kurz
2020-07-28 13:55   ` Christian Schoenebeck
2020-08-04 11:28     ` Dr. David Alan Gilbert
2020-08-04 13:51       ` Christian Schoenebeck
2020-08-12 11:18         ` Dr. David Alan Gilbert
2020-08-12 13:34           ` Christian Schoenebeck
2020-08-12 14:33             ` Dr. David Alan Gilbert
2020-08-13  9:01               ` Christian Schoenebeck
2020-08-16 22:56                 ` Dave Chinner
2020-08-16 23:09                   ` Matthew Wilcox
2020-08-17  0:29                     ` Dave Chinner
2020-08-17 10:37                       ` file forks vs. xattr (was: xattr names for unprivileged stacking?) Christian Schoenebeck
2020-08-23 23:40                         ` Dave Chinner
2020-08-24 15:30                           ` Christian Schoenebeck
2020-08-24 20:01                             ` Miklos Szeredi
2020-08-24 21:26                             ` Frank van der Linden
2020-08-24 22:29                             ` Theodore Y. Ts'o
2020-08-25 15:12                               ` Christian Schoenebeck
2020-08-25 15:32                                 ` Miklos Szeredi
2020-08-27 12:02                                   ` Christian Schoenebeck
2020-08-27 12:25                                     ` Matthew Wilcox
2020-08-27 13:48                                       ` Christian Schoenebeck
2020-08-27 14:01                                         ` Matthew Wilcox
2020-08-27 14:23                                           ` Christian Schoenebeck
2020-08-27 14:25                                             ` Matthew Wilcox
2020-08-27 14:44                                             ` Al Viro
2020-08-27 16:29                                               ` Dr. David Alan Gilbert
2020-08-27 16:35                                                 ` Matthew Wilcox
2020-08-28  9:11                                                 ` Christian Schoenebeck
2020-08-28 14:46                                                   ` Theodore Y. Ts'o
2020-08-27 15:22                       ` xattr names for unprivileged stacking? Matthew Wilcox
2020-08-27 22:24                         ` Dave Chinner
2020-08-29 16:07                           ` Matthew Wilcox
2020-08-29 16:13                             ` Al Viro
2020-08-29 17:51                               ` Miklos Szeredi
2020-08-29 18:04                                 ` Al Viro
2020-08-29 18:22                                   ` Christian Schoenebeck
2020-08-29 19:13                                   ` Miklos Szeredi
2020-08-29 19:25                                     ` Al Viro
2020-08-30 19:05                                       ` Miklos Szeredi
2020-08-30 19:10                                         ` Matthew Wilcox
2020-08-31  7:34                                           ` Miklos Szeredi
2020-08-31 11:37                                             ` Matthew Wilcox
2020-08-31 11:51                                               ` Miklos Szeredi
2020-08-31 13:23                                                 ` Matthew Wilcox
2020-08-31 14:21                                                   ` Miklos Szeredi
2020-08-31 14:25                                                   ` Theodore Y. Ts'o
2020-08-31 14:45                                                     ` Matthew Wilcox
2020-08-31 14:49                                                       ` Miklos Szeredi
2020-09-01  3:34                                                     ` Dave Chinner
2020-09-01 14:52                                                       ` Theodore Y. Ts'o
2020-09-01 15:14                                                         ` Theodore Y. Ts'o [this message]
2020-09-02  5:19                                                           ` Dave Chinner
2020-08-31 18:02                                                   ` Andreas Dilger
2020-09-01  3:48                                                     ` Dave Chinner
2020-08-29 19:17                               ` Matthew Wilcox
2020-08-29 19:40                                 ` Al Viro
2020-08-29 20:12                                   ` Matthew Wilcox
2020-08-31 14:23                                     ` Theodore Y. Ts'o
2020-08-31 14:40                                       ` Matthew Wilcox
2020-08-31 16:11                                       ` Christian Schoenebeck

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200901151453.GC558530@mit.edu \
    --to=tytso@mit.edu \
    --cc=chirantan@chromium.org \
    --cc=david@fromorbit.com \
    --cc=dgilbert@redhat.com \
    --cc=dwalsh@redhat.com \
    --cc=groug@kaod.org \
    --cc=gscrivan@redhat.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=mszeredi@redhat.com \
    --cc=stefanha@redhat.com \
    --cc=vgoyal@redhat.com \
    --cc=viro@zeniv.linux.org.uk \
    --cc=willy@infradead.org \
    --subject='Re: xattr names for unprivileged stacking?' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).