All of lore.kernel.org
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@osdl.org>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Joel Becker <Joel.Becker@oracle.com>,
	Chris Friesen <cfriesen@nortelnetworks.com>,
	Jamie Lokier <jamie@shareable.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: statfs() / statvfs() syscall ballsup...
Date: Fri, 10 Oct 2003 11:05:08 -0700 (PDT)	[thread overview]
Message-ID: <Pine.LNX.4.44.0310101059330.20420-100000@home.osdl.org> (raw)
In-Reply-To: <16262.62026.603149.157026@charged.uio.no>


On Fri, 10 Oct 2003, Trond Myklebust wrote:
>
> Apart from O_DIRECT, we have nothing in the kernel as it stands that
> will allow userland to deal with this case.

Oh, but that's just another case of the general notion of allowing people 
to control the page cache a bit more. 

There's nothing wrong with having kernel interfaces that say "this region
is potentially stale" or "this region is dirty" or "this region is not
needed any more".

For example, using DIRECT_IO to make sure that something is uptodate is
just _stupid_, because clearly it only matters to shared-disk (either over
networks/FC or though things like SCSI device sharing) setups. So now the 
app has to have a way to query for whether the storage is shared, and 
have two totally different code-paths depending on the answer. 

This is another example of a bad design, that ends up causing more
problems (remember why this thread started in the first place: bad design
of O_DIRECT causing the app to have to care about something _else_ it
shouldn't care about. At all).

If you had a "this region is stale" thing, you'd just use it. And if it 
was local disk, it wouldn't do anything. 

		Linus


  reply	other threads:[~2003-10-10 18:05 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-10-09 22:16 Trond Myklebust
2003-10-09 22:26 ` Linus Torvalds
2003-10-09 23:19   ` Ulrich Drepper
2003-10-10  0:22     ` viro
2003-10-10  4:49       ` Jamie Lokier
2003-10-10  5:26         ` Trond Myklebust
2003-10-10 12:37           ` Jamie Lokier
2003-10-10 13:46             ` Trond Myklebust
2003-10-10 14:35               ` Jamie Lokier
2003-10-10 15:32                 ` Misc NFSv4 (was Re: statfs() / statvfs() syscall ballsup...) Trond Myklebust
2003-10-10 15:53                   ` Jamie Lokier
2003-10-10 16:07                     ` Trond Myklebust
2003-10-10 15:55                   ` Michael Shuey
2003-10-10 16:20                     ` Trond Myklebust
2003-10-10 16:45                     ` J. Bruce Fields
2003-10-10 14:39               ` statfs() / statvfs() syscall ballsup Jamie Lokier
2003-10-09 23:31   ` Trond Myklebust
2003-10-10 12:27   ` Joel Becker
2003-10-10 14:59     ` Linus Torvalds
2003-10-10 15:27       ` Joel Becker
2003-10-10 16:00         ` Linus Torvalds
2003-10-10 16:26           ` Joel Becker
2003-10-10 16:50             ` Linus Torvalds
2003-10-10 17:33               ` Joel Becker
2003-10-10 17:51                 ` Linus Torvalds
2003-10-10 18:13                   ` Joel Becker
2003-10-10 16:27           ` Valdis.Kletnieks
2003-10-10 16:33           ` Chris Friesen
2003-10-10 17:04             ` Linus Torvalds
2003-10-10 17:07               ` Linus Torvalds
2003-10-10 17:21                 ` Joel Becker
2003-10-10 16:01         ` Jamie Lokier
2003-10-10 16:33           ` Joel Becker
2003-10-10 16:58             ` Chris Friesen
2003-10-10 17:05               ` Trond Myklebust
2003-10-10 17:20               ` Joel Becker
2003-10-10 17:33                 ` Chris Friesen
2003-10-10 17:40                 ` Linus Torvalds
2003-10-10 17:54                   ` Trond Myklebust
2003-10-10 18:05                     ` Linus Torvalds [this message]
2003-10-10 20:40                       ` Trond Myklebust
2003-10-10 21:09                         ` Linus Torvalds
2003-10-10 22:17                           ` Trond Myklebust
2003-10-11  2:53                     ` Andrew Morton
2003-10-11  3:47                       ` Trond Myklebust
2003-10-10 18:05                   ` Joel Becker
2003-10-10 18:31                     ` Andrea Arcangeli
2003-10-10 20:33                     ` Helge Hafting
2003-10-10 20:07             ` Jamie Lokier
2003-10-12 15:31             ` Greg Stark
2003-10-12 16:13               ` Linus Torvalds
2003-10-12 22:09                 ` Greg Stark
2003-10-13  8:45                   ` Helge Hafting
2003-10-15 13:25                     ` Ingo Oeser
2003-10-15 15:03                       ` Greg Stark
2003-10-15 18:37                         ` Helge Hafting
2003-10-16 10:29                         ` Ingo Oeser
2003-10-16 14:02                           ` Greg Stark
2003-10-21 11:47                             ` Ingo Oeser
2003-10-10 18:20           ` Andrea Arcangeli
2003-10-10 18:36             ` Linus Torvalds
2003-10-10 19:03               ` Andrea Arcangeli
2003-10-09 23:16 ` Andreas Dilger
2003-10-09 23:24   ` Linus Torvalds

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=Pine.LNX.4.44.0310101059330.20420-100000@home.osdl.org \
    --to=torvalds@osdl.org \
    --cc=Joel.Becker@oracle.com \
    --cc=cfriesen@nortelnetworks.com \
    --cc=jamie@shareable.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=trond.myklebust@fys.uio.no \
    --subject='Re: statfs() / statvfs() syscall ballsup...' \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.