From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC][PATCH] nfsd regression since delayed fput()
Date: Thu, 17 Oct 2013 19:39:52 +0100 [thread overview]
Message-ID: <20131017183952.GS13318@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFwrTAZ87vS835Yk3Wvuq6X6FaVygXZZN9D03zoMMapd_g@mail.gmail.com>
On Thu, Oct 17, 2013 at 11:29:46AM -0700, Linus Torvalds wrote:
> On Thu, Oct 17, 2013 at 11:14 AM, J. Bruce Fields <bfields@fieldses.org> wrote:
> >
> > NFS isn't exportable and there aren't any plans to change that.
>
> The thing is, other filesystems have other rules. Not everybody
> necessarily supports the Unix "you can remove files that are still in
> use" semantics, so I could imagine EBUSY etc happening..
Yes, but... To get anything of that kind you would need to have a kernel
thread open a file on such fs, do IO and fput() it, then have something attempt
to unlink() it and fail with EBUSY due to fput() being delayed. If that
something is *not* the same kernel thread, it's already racy - after all, if
that unlink() happens while the kernel thread does IO, we are going to get
what we are going to get. And if it is the same thread... What would it
be? knfsd? Exporting a filesystem with possible-EBUSY-on-unlink?
I don't see any exportable examples of that...
next prev parent reply other threads:[~2013-10-17 18:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-16 18:52 [RFC][PATCH] nfsd regression since delayed fput() Al Viro
2013-10-17 4:48 ` Linus Torvalds
2013-10-17 18:14 ` J. Bruce Fields
2013-10-17 18:29 ` Linus Torvalds
2013-10-17 18:39 ` Al Viro [this message]
2013-10-17 19:09 ` Linus Torvalds
2013-10-17 20:12 ` Al Viro
2013-10-17 22:33 ` Linus Torvalds
2013-10-25 14:18 ` Al Viro
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