Hi, based on a recent discussion with Dave and Neil [1] I have tried to implement NOFS, NOIO, NOFAIL support for the vmalloc to make life of kvmalloc users easier. A requirement for NOFAIL support for kvmalloc was new to me but this seems to be really needed by the xfs code. NOFS/NOIO was a known and a long term problem which was hoped to be handled by the scope API. Those scope should have been used at the reclaim recursion boundaries both to document them and also to remove the necessity of NOFS/NOIO constrains for all allocations within that scope. Instead workarounds were developed to wrap a single allocation instead (like ceph_kvmalloc). First patch implements NOFS/NOIO support for vmalloc. The second one adds NOFAIL support and the third one bundles all together into kvmalloc and drops ceph_kvmalloc which can use kvmalloc directly now. Please note that this is RFC and I haven't done any testing on this yet. I hope I haven't missed anything in the vmalloc allocator. It would be really great if Christoph and Uladzislau could have a look. Thanks! [1] http://lkml.kernel.org/r/163184741778.29351.16920832234899124642.stgit@noble.brown
