[PATCH 0/5] pnfs DLM cluster only use read iomode layouts

andros
2010-02-05T17:09:35Z

Applies against 2.6.33-rc6 pnfs-all branch.

In a DLM cluster, writing to a node other than the node where the open call
occurred and where meta data is cached will have performance implications when
the write causes meta data changes that need to be propagated to the open call
node.

Return NFS4ERR_BADIOMODE for LAYOUTGET requests with LAYOUTIOMODE4_RW iomode.

Plus a couple of error code fixes.

0001-pnfsd-fix-NFS4ERR_BADIOMODE-in-layoutget.patch
0002-pnfsd-fix-pnfs_export_operations-layoutget-valid-err.patch
0003-pnfsd-DLM-file-layout-only-support-read-iomode-layou.patch
0004-pnfsd-fix-DLM-file-layout-no-device-return.patch

Allow the client to fail a RW iomode layout and still grab a RO iomode layout.
0005-pnfs-set-failed-layout-bit-per-iomode.patch

Testing: Connectathon tests pass. Basic test shows RW iomode layout for
'bigfile' fails with NFS4ERR_BADIOMODE with writes going through the MDS,
and RO layout for 'bigfile' is obtained with reads going to the DS.

-->Andy