From: Matthew Wilcox <willy@infradead.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>,
Christian Brauner <christian@brauner.io>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-api@vger.kernel.org, jannh@google.com, fweimer@redhat.com,
oleg@redhat.com, tglx@linutronix.de,
torvalds@linux-foundation.org, arnd@arndb.de, shuah@kernel.org,
tkjos@android.com, ldv@altlinux.org, miklos@szeredi.hu,
linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org,
linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH 1/2] open: add close_range()
Date: Tue, 21 May 2019 12:59:28 -0700 [thread overview]
Message-ID: <20190521195928.GB6738@bombadil.infradead.org> (raw)
In-Reply-To: <20190521192009.GK17978@ZenIV.linux.org.uk>
On Tue, May 21, 2019 at 08:20:09PM +0100, Al Viro wrote:
> On Tue, May 21, 2019 at 05:30:27PM +0100, David Howells wrote:
>
> > If we can live with close_from(int first) rather than close_range(), then this
> > can perhaps be done a lot more efficiently by:
> >
> > new = alloc_fdtable(first);
> > spin_lock(&files->file_lock);
> > old = files_fdtable(files);
> > copy_fds(new, old, 0, first - 1);
> > rcu_assign_pointer(files->fdt, new);
> > spin_unlock(&files->file_lock);
> > clear_fds(old, 0, first - 1);
> > close_fdt_from(old, first);
> > kfree_rcu(old);
>
> I really hate to think how that would interact with POSIX locks...
POSIX locks store current->files in fl_owner; David's resizing the
underlying files->fdt, just like growing from 64 to 256 fds.
prev parent reply other threads:[~2019-05-21 20:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-21 11:34 [PATCH 1/2] open: add close_range() Christian Brauner
2019-05-21 11:34 ` [PATCH 2/2] tests: add close_range() tests Christian Brauner
2019-05-21 12:09 ` [PATCH 1/2] open: add close_range() Florian Weimer
2019-05-21 13:04 ` Christian Brauner
2019-05-21 13:10 ` Florian Weimer
2019-05-21 13:18 ` Christian Brauner
2019-05-21 13:23 ` Christian Brauner
2019-05-21 15:00 ` Al Viro
2019-05-21 16:53 ` Christian Brauner
2019-05-21 16:30 ` David Howells
2019-05-21 16:41 ` Christian Brauner
2019-05-21 20:23 ` Linus Torvalds
2019-05-22 8:12 ` Christian Brauner
2019-05-21 19:20 ` Al Viro
2019-05-21 19:59 ` Matthew Wilcox [this message]
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