Re: Copy on write hard links?

2013-12-13 Thread Jörn Engel
On Wed, 25 September 2013 16:28:53 +0200, Thomas Meyer wrote: > > I wonder how hard it would be to implement this on vfs layer? As an ugly hack: a few weeks maybe. Did it back in 2005 or so. If you have higher standards, you will need support from the underlying filesystem. Especially in

Re: Copy on write hard links?

2013-12-13 Thread Jörn Engel
On Wed, 25 September 2013 16:28:53 +0200, Thomas Meyer wrote: I wonder how hard it would be to implement this on vfs layer? As an ugly hack: a few weeks maybe. Did it back in 2005 or so. If you have higher standards, you will need support from the underlying filesystem. Especially in order

Re: Copy on write hard links?

2013-09-29 Thread Pádraig Brady
On 09/29/2013 08:14 AM, Richard Weinberger wrote: > On Sun, Sep 29, 2013 at 7:22 AM, Pádraig Brady wrote: >> On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: >>> On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer wrote: Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: > On

Re: Copy on write hard links?

2013-09-29 Thread Richard Weinberger
On Sun, Sep 29, 2013 at 7:22 AM, Pádraig Brady wrote: > On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: >> On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer wrote: >>> Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: > Hi,

Re: Copy on write hard links?

2013-09-29 Thread Richard Weinberger
On Sun, Sep 29, 2013 at 7:22 AM, Pádraig Brady p...@draigbrady.com wrote: On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer tho...@m3y3r.de wrote: Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: On 09/24/2013 01:36:56 PM, Thomas

Re: Copy on write hard links?

2013-09-29 Thread Pádraig Brady
On 09/29/2013 08:14 AM, Richard Weinberger wrote: On Sun, Sep 29, 2013 at 7:22 AM, Pádraig Brady p...@draigbrady.com wrote: On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer tho...@m3y3r.de wrote: Am Mittwoch, den 25.09.2013, 08:59 -0500

Re: Copy on write hard links?

2013-09-28 Thread Pádraig Brady
On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: > On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer wrote: >> Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: >>> On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? >>> >>> In the kernel's vfs

Re: Copy on write hard links?

2013-09-28 Thread Pádraig Brady
On 09/25/2013 03:37 PM, richard -rw- weinberger wrote: On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer tho...@m3y3r.de wrote: Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? In the kernel's vfs layer?

Re: Copy on write hard links?

2013-09-25 Thread richard -rw- weinberger
On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer wrote: > Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: >> On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: >> > Hi, >> > >> > Is there such a thing? >> >> In the kernel's vfs layer? > > Yes, that would be a nice feature! You mean

Re: Copy on write hard links?

2013-09-25 Thread Thomas Meyer
Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: > On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: > > Hi, > > > > Is there such a thing? > > In the kernel's vfs layer? Yes, that would be a nice feature! > No, although some filesystems (ala btrfs) do > things like that with

Re: Copy on write hard links?

2013-09-25 Thread Rob Landley
On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? In the kernel's vfs layer? No, although some filesystems (ala btrfs) do things like that with snapshots. In userspace? Breaking hardlinks when updating a file is fairly normal, that's why they distinguish between

Re: Copy on write hard links?

2013-09-25 Thread Rob Landley
On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? In the kernel's vfs layer? No, although some filesystems (ala btrfs) do things like that with snapshots. In userspace? Breaking hardlinks when updating a file is fairly normal, that's why they distinguish between

Re: Copy on write hard links?

2013-09-25 Thread Thomas Meyer
Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? In the kernel's vfs layer? Yes, that would be a nice feature! No, although some filesystems (ala btrfs) do things like that with snapshots.

Re: Copy on write hard links?

2013-09-25 Thread richard -rw- weinberger
On Wed, Sep 25, 2013 at 4:28 PM, Thomas Meyer tho...@m3y3r.de wrote: Am Mittwoch, den 25.09.2013, 08:59 -0500 schrieb Rob Landley: On 09/24/2013 01:36:56 PM, Thomas Meyer wrote: Hi, Is there such a thing? In the kernel's vfs layer? Yes, that would be a nice feature! You mean reflinks?

Re: Copy on write hard links?

2013-09-24 Thread Adam Borowski
On Tue, Sep 24, 2013 at 08:36:56PM +0200, Thomas Meyer wrote: > Is there such a thing? In mainline, AFAIK no. The vserver patchset, on the other hand, adds a new xattr, iunlink, that copies the whole file when needed. That works on most filesystems. That's quite a hack, though, and I think

Copy on write hard links?

2013-09-24 Thread Thomas Meyer
Hi, Is there such a thing? With kind regards Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Copy on write hard links?

2013-09-24 Thread Thomas Meyer
Hi, Is there such a thing? With kind regards Thomas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/

Re: Copy on write hard links?

2013-09-24 Thread Adam Borowski
On Tue, Sep 24, 2013 at 08:36:56PM +0200, Thomas Meyer wrote: Is there such a thing? In mainline, AFAIK no. The vserver patchset, on the other hand, adds a new xattr, iunlink, that copies the whole file when needed. That works on most filesystems. That's quite a hack, though, and I think