[LU-925] land Async Glimpse Lock (AGL) to master to pre-fetch size/block attributes from OSTs for statahead

• Type: Task
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.2.0
• Affects Version/s: Lustre 2.2.0
• Story Points: 2
• Assignee: nasf (Inactive)
• Reporter: Andreas Dilger

Description

Lustre-2.x supports statahead, which pre-fetches object's attributes (like owner/mode/xtime/ACL, etc) from MDS, then most MDS-side RPCs are overlapped with other traversing process. But there is not file size/block attributes pre-fetching, the traversing thread has to send synchronous glimpse size RPC to OST(s) for that by itself. Before SOM is available, we should consider asynchronous glimpse size for per-fetching size/block attributes from OST(s). This

http://review.whamcloud.com/#change,1243

Issue Links

• Trackbacks: Changelog 2.2 version 2.2.0 Support for networks: o2iblnd OFED 1.5.4 Server support for kernels: 2.6.32220.4.2.el6 (RHEL6) Client support for unpatched kernels: 2.6.18274.18.1.el5 (RHEL5) 2.6.32220.4.2.el6 (RHEL6) 2.6.32.360....
• Trackbacks: Lustre 2.2 Lustre 2.2 is scheduled for release at the end of Q1 2012. This is its anticipated support matrix. Server Support \ Client Support \ RHEL 6, \ CentOS 6 \ RHEL 6, \ CentOS 6, \ RHEL 5, \ CentOS 5, \ SLES 11 ,...