[Ocfs2-devel] [GIT PULL] ocfs2 changes for 2.6.32

[Linus Torvalds]

On Tue, 15 Sep 2009, Joel Becker wrote:
>
> 	Perhaps ->copyfile takes the following flags:
> 
> #define ALLOW_COW_SHARED	0x0001
> #define REQUIRE_COW_SHARED	0x0002
> #define REQUIRE_BASIC_ATTRS	0x0004
> #define REQUIRE_FULL_ATTRS	0x0008
> #define REQUIRE_ATOMIC		0x0010
> #define SNAPSHOT		(REQUIRE_COW_SHARED |
> 				 REQUIRE_BASIC_ATTRS |
> 				 REQUIRE_ATOMIC)
> #define SNAPSHOT_PRESERVE	(SNAPSHOT | REQUIRE_FULL_ATTRS)
> 
> Thus, sys_reflink/sys_snapfile(oldpath, newpath, 0) becomes:
> ...

Yes. The above all sounds sane to me.

I still worry that especially the non-atomic case will want some kind of 
partial-copy updates (think graphical file managers that want to show the 
progress of the copy), and that (think EINTR and continuing) makes me 
think "that could get really complex really quickly", but that's something 
that the NFS/SMB people would have to pipe up on. I'm pretty sure the NFS 
spec has some kind "partial completion notification" model, I dunno about 
SMB.

			Linus