On Thu, 2013-02-21 at 12:37 +0100, Ric Wheeler wrote: > We have debated the need to have a system call to allow for offloading copy > operations, for example to an NFS server (part to the new NFS 4.2 > specification), SCSI target device (two different SCSI commands do this), > local > file systems (reflink, etc) and I suspect many other possible parts of the > stack > could implement this.
sendfile64() pretty much already has the right arguments for a "copyfile", however it would be nice to add a 'flags' parameter: the NFSv4.2 version would use that to specify whether or not to copy file metadata. > The earliest discussion of such a system call I saw happened back in 2001, I > know we had another more recent flurry (2-3 years back?) as well that got > tangled up and died away. > > Given the new popularity of this in storage devices and the use case for virt > guests, any chance to get a proposal floated this year that might be able to > land upstream in our life times :) ? I'm planning on soon dusting off the NFS prototype that NetApp wrote 3 years ago and converting at least the client implementation into something that can go upstream. We do also have a server prototype for Linux, but the copy offload between 2 different servers is a hack and would need significant work. -- Trond Myklebust Linux NFS client maintainer NetApp trond.mykleb...@netapp.com www.netapp.com -- 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/
