This is a collection of fixes for the NFS server's encoding of NFSv4 compounds, along with a few tangentially related cleanups and bugfixes I noticed along the way. The basic problem is that we've always assumed an rpc reply is either - "small" (much less than a page), or - looks like a read (a bunch of data with a little bit at the beginning and the end). That assumption has allowed us to cover the most important cases without having to deal with some annoying details like how to encode arbitrary data across a page boundary, but: - The inability to encode attributes of more than a page annoys some people who would like to get and set extraordinarily long ACLs. - The inability to encode attributes that cross page boundaries also means we can't return more than a page of readdir data at a time, limiting readdir performance on large directories. - The NFSv4 protocol doesn't really allow us to place these sorts of arbitrary limits on the types of compounds we handle. (Well, 4.0 is a bit fuzzy on this point, but 4.1 I think definitely considers it a bug if a server won't handle, e.g., multiple read ops in a compound.) This hasn't been an issue because most of these exotic compounds aren't really useful to clients. But maybe future clients will find a use for some of them--in which case we'd prefer not to make the work around a server that doesn't meet the spec. So, the main goal is to fix those limitations. We also get to share a little more code with the client. I was hoping to merge this for 3.15, but I'm cutting this a little close now, so we'll see. I'll merge whatever's ready. Further work may include: - writing more pynfs tests for exotic compounds and odd corner cases, - auditing the annoying nfsd4_*_rsize() functions, which we now depend on for more things, - improving our (currently very sloppy) estimate of how much space we need for krb5i/krb5p to checksum/encrypt the result. - sharing some of this with the v2/v3 code (especially in the read and readdir cases), - allow rpc's whose call and reply are both very large (our one remaining dubious limit on compounds, though again something clients seem unlikely to notice for now), - on the decode side, eliminating the existing macros and sharing more helpers with the client. --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
