On Fri, Feb 12, 2016 at 11:10:46AM -0800, Christoph Hellwig wrote: > On Thu, Feb 11, 2016 at 08:40:58AM +1100, Dave Chinner wrote: > > I run into that from time to time (maybe once a month) on a vanilla > > kernel. > > > > IIRC, the problem is the delayed allocation extent split runs out of > > it's reserved block count if you split it enough times. The case > > I've seen is that the indlen calculated in xfs_bmap_worst_indlen() > > ends up too small for a subsequent allocation after we've called > > xfs_bmap_del_extent() to delete the middle of a delalloc extent too > > many times. > > > > Brian had some patches that attempted to solve it - we may have > > simply dropped the ball on this (again). > > > > http://oss.sgi.com/archives/xfs/2014-09/msg00337.html > > I'm pretty sure that is a separate issue. With the refcount btree we may > allocate an extent (or rather just a single block) in xfs_alloc_ag_vextent > as called from xfs_refcountbt_alloc_block. The reservation helps us to > ensure this block is always available, but we still need to account for > that in xfs_trans_reserve(), which we currently don't do for itruncate > transactions. Ok, so we may have two different issues with a similar failure symptom. As it is, I don't think this is a show stopper - we're expecting to find these sorts of issues as we go along (hence the experimental tag on the feature) and I think, at this point, getting review and an initial merge done is more important... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
