Reduction global superblock lock contention near ENOSPC. The existing per-cpu superblock counter code uses the global superblock spin lock when we approach ENOSPC for global synchronisation. On large
Fix UP build breakage due to undefined m_icsb_mutex. The following file(s) were checked into: longdrop.melbourne.sgi.com:/isms/linux/2.6.x-xfs-melb Modid: xfs-linux-melb:xfs-kern:27692a fs/xfs/xfs_mo