On Tue, Jan 06, 2015 at 05:28:37PM +0100, Christoph Hellwig wrote: > Add a small shim between core nfsd and filesystems to translate the > somewhat cumbersome pNFS data structures and semantics to something > more palatable for Linux filesystems. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > .../filesystems/nfs/pnfs-block-server.txt | 40 +++++ > fs/nfsd/Makefile | 2 +- > fs/nfsd/blocklayout.c | 194 +++++++++++++++++++++ > fs/nfsd/blocklayoutxdr.c | 157 +++++++++++++++++ > fs/nfsd/blocklayoutxdr.h | 62 +++++++ > fs/nfsd/nfs4layouts.c | 7 + > fs/nfsd/pnfs.h | 1 + > 7 files changed, 462 insertions(+), 1 deletion(-) > create mode 100644 Documentation/filesystems/nfs/pnfs-block-server.txt > create mode 100644 fs/nfsd/blocklayout.c > create mode 100644 fs/nfsd/blocklayoutxdr.c > create mode 100644 fs/nfsd/blocklayoutxdr.h > > diff --git a/Documentation/filesystems/nfs/pnfs-block-server.txt b/Documentation/filesystems/nfs/pnfs-block-server.txt > new file mode 100644 > index 0000000..f45d399 > --- /dev/null > +++ b/Documentation/filesystems/nfs/pnfs-block-server.txt > @@ -0,0 +1,40 @@ > +pNFS block layout server user guide > + > +The Linux NFS server now supports the pNFS block layout extension. In this > +case the NFS server acts as Metadata Server (MDS) for pNFS, which in addition > +to handling all the metadata access to the NFS export also hands out layouts > +to the clients to directly access the underlying block devices that is s/is/are/. > +shared with the client. Note that there are no Data Servers (DSs) in the > +block layout flavor of pNFS. > + > +To use pNFS block layouts with with the Linux NFS server the exported file > +system needs to support the pNFS block layouts (current just XFS), and the > +file system must sit on shared storage (typically iSCSI) that is accessible > +to the clients as well as the server. The file system needs to either sit > +directly on the exported volume, or on a RAID 0 using the MD software RAID > +driver with the version 1 superblock format. If the filesystem uses sits > +on a RAID 0 device the clients will automatically stripe their I/O over > +multiple LUNs. > + > +On the server pNFS block volume support is automatically if the file system s/automatically/automatically enabled/. So there's no server-side configuration required at all? --b. > +support its. On the client make sure the kernel has the CONFIG_PNFS_BLOCK > +option enabled, the blkmapd daemon from nfs-utils is running, and the > +file system, is mounted using the NFSv4.1 protocol version (mount -o vers=4.1). > + > +If the nfsd server needs to fence a non-responding client it calls > +/sbin/nfsd-recall-failed with the first argument set to the IP address of > +the client, and the second argument set to the device node without the /dev > +prefix for the filesystem to be fenced. Below is an example file that show > +how to translate the device into a serial number from SCSI EVPD 0x80: ... -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
