On Tue, Jul 21, 2009 at 05:47:17PM -0400, David V. Cloud wrote: > Hi all, > I was playing with nfs4 delegation, finding out that write delegations have > never been granted. I am using Benny Halevy's git tree with latest > pnfs-block-all branch. With rpcdebug, I found out that the write-delegation > grant was rejected due to setlease failure with error code (-11, which is > -EAGAIN). I finally figured out that this failure was caused by the > following lines in generic_setlease function, > > if ((arg == F_WRLCK) > && ((atomic_read(&dentry->d_count) > 1) > || (atomic_read(&inode->i_count) > 1))) > goto out; > > In my nfsd, the i_count, and d_count turn out to be 2 (no conflicts actaully > exist in my test case), so write-delegations always failed. I did find some > similar posts on nfs4 related mail lists about this problem. One possible > hack by Ajay could be found at > http://osdir.com/ml/linux.nfsv4/2006-08/msg00063.html > > I am curious whether there is any progress in awarding write delegation in > current linux nfs4 implementation (for example, any git branch with write > delegation enabled I can pull?) Or, is write-delegation feature available in > other systems like OpenSolaris? > > Any suggestion if I would like to enable and test write delegation? I think > some changes are needed to the setlease interface, right? I really don't want to enable write delegations until we figure out how to enforce them correctly against local (non-nfs) users of the exported filesystem as well. In addition to breaking delegations on read opens, that means breaking delegations or doing a cb_getattr on operations like stat. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
