* [LSF/Filesystems][ATTEND] [not found] <alpine.LFD.2.00.1005171556240.16844@jlentini-linux.nane.netapp.com> @ 2010-05-17 21:23 ` Madan, Anshul 2010-05-17 22:24 ` [LSF/Filesystems][ATTEND] Joel Becker 0 siblings, 1 reply; 3+ messages in thread From: Madan, Anshul @ 2010-05-17 21:23 UTC (permalink / raw) To: lsf10-pc; +Cc: linux-fsdevel, Lentini, James, Myklebust, Trond, Joel.Becker Requesting Attendance: Trond Myklebust, James Lentini and Anshul Madan Proposal: We propose to discuss the design and implementation issues involved in introducing a new copy() system call into the Linux kernel. The goal of this session would be to determine the required functionality and obtain a general consensus on the necessary VFS interface changes. We believe that the LSF Summit offers a unique opportunity to discuss this topic and gain consensus with developers from several different file system communities. We are implementing the NFS copy offload operations and associated system call(s). We would contribute to the discussions on API capabilities, design issues, and other VFS issues. We would provide insights into different design trade-offs in the VFS layer, and also report on the progress of our implementation. Keywords: File systems Background: There is an emerging trend for file systems to support intelligent copies. OCFS2 supports intelligent copies via a reflink ioctl(2). At the same time, a proposal has been made for the NFS protocol to support intelligent copy operations, see IETF draft draft-lentini-nfsv4-server-side-copy. We expect other file systems to add support for intelligent copy capabilities in the future. To take full advantage of these capabilities, the Linux kernel's system call interface must be expanded to allow userspace applications to use this feature in a uniform way. This topic has been discussed both on Linux development mailing lists [1] and at previous LSF summits. Joel Becker originally proposed a syscall called reflink() that was specific to copying an inode to a copy-on-write snapshot. Since then, the need for a generic copy interface that encompassed the reflink semantics as well as less restrictive ones has been recognized based on discussion between Linus Torvalds and Joel. Motivation: Intelligent copies have performance advantages over a traditional read/write copy. With data deduplication, fragments of data can be shared between files. Thus using conventional syscalls like read() and write() for doing a copy may lead to the unnecessary data transfers to and from the file system. Using a copy() syscall, the file system can make use of it's intelligence and thus avoid unnecessary data transfers. The IT trend toward virtualization via hypervisors has created an emerging use case to copy a virtual disk over NFS. The use of a copy operation will save network bandwidth on the client and server, and intra-server file copy has the potential to avoid all physical data copies, if the file system is deduplicated as described above. Implementing a VFS inode operation which has a generic interface applicable to all types of file systems would allow applications to access this functionality in a uniform way. The VFS copy() inode operation and corresponding interface should encompass the semantics of various file system copy() implementations, such as support for asynchronous copies, copy status, and copy abort calls. --- [1] Relevant posts: http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04347.html http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04395.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [LSF/Filesystems][ATTEND] 2010-05-17 21:23 ` [LSF/Filesystems][ATTEND] Madan, Anshul @ 2010-05-17 22:24 ` Joel Becker 2010-05-25 19:00 ` [Lsf10-pc] [LSF/Filesystems][ATTEND] Ric Wheeler 0 siblings, 1 reply; 3+ messages in thread From: Joel Becker @ 2010-05-17 22:24 UTC (permalink / raw) To: Madan, Anshul; +Cc: lsf10-pc, linux-fsdevel, Lentini, James, Myklebust, Trond On Mon, May 17, 2010 at 05:23:22PM -0400, Madan, Anshul wrote: > Requesting Attendance: > > Trond Myklebust, James Lentini and Anshul Madan I (Joel Becker ) would like to request attendance to join in this conversation. I'm the original proposer of reflink(2). > This topic has been discussed both on Linux development mailing lists > [1] and at previous LSF summits. Joel Becker originally proposed a > syscall called reflink() that was specific to copying an inode to a > copy-on-write snapshot. Since then, the need for a generic copy > interface that encompassed the reflink semantics as well as less > restrictive ones has been recognized based on discussion between Linus > Torvalds and Joel. My last proposal for the copyfile(2) interface is reference [2]. I think it is a good starting point, but I'm very interested in what the network filesystem community has to say. NFS's server copy capability is something I definitely had in mind. > [1] Relevant posts: > > http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04347.html > http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04395.html Joel -- "Reader, suppose you were and idiot. And suppose you were a member of Congress. But I repeat myself." - Mark Twain Joel Becker Principal Software Developer Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Lsf10-pc] [LSF/Filesystems][ATTEND] 2010-05-17 22:24 ` [LSF/Filesystems][ATTEND] Joel Becker @ 2010-05-25 19:00 ` Ric Wheeler 0 siblings, 0 replies; 3+ messages in thread From: Ric Wheeler @ 2010-05-25 19:00 UTC (permalink / raw) To: Madan, Anshul, lsf10-pc, linux-fsdevel, Lentini, James, "Myklebust, Trond" <Trond.My On 05/17/2010 06:24 PM, Joel Becker wrote: > On Mon, May 17, 2010 at 05:23:22PM -0400, Madan, Anshul wrote: > >> Requesting Attendance: >> >> Trond Myklebust, James Lentini and Anshul Madan >> > I (Joel Becker ) would like to request attendance to join in > this conversation. I'm the original proposer of reflink(2). > > >> This topic has been discussed both on Linux development mailing lists >> [1] and at previous LSF summits. Joel Becker originally proposed a >> syscall called reflink() that was specific to copying an inode to a >> copy-on-write snapshot. Since then, the need for a generic copy >> interface that encompassed the reflink semantics as well as less >> restrictive ones has been recognized based on discussion between Linus >> Torvalds and Joel. >> > My last proposal for the copyfile(2) interface is reference [2]. > I think it is a good starting point, but I'm very interested in what the > network filesystem community has to say. NFS's server copy capability > is something I definitely had in mind. > > >> [1] Relevant posts: >> >> http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04347.html >> http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04395.html >> > Joel > I think that this would be an interesting subject as well, especially given the mix of storage & FS people at the event. Ric ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-05-25 19:02 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <alpine.LFD.2.00.1005171556240.16844@jlentini-linux.nane.netapp.com>
2010-05-17 21:23 ` [LSF/Filesystems][ATTEND] Madan, Anshul
2010-05-17 22:24 ` [LSF/Filesystems][ATTEND] Joel Becker
2010-05-25 19:00 ` [Lsf10-pc] [LSF/Filesystems][ATTEND] Ric Wheeler
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.