On Mon, Feb 01, 2016 at 01:38:05PM -0500, bfields wrote: > On Sun, Jan 31, 2016 at 08:50:10PM +0800, Kinglong Mee wrote: > > ltp fsync02 will cause nfs sending LAYOUTCOMMIT with length > > larger than two pages. nfsd returns NFSERR_BAD_XDR right now. > > This is with the xfs block layout? > > Christoph, do we know anything about average or worst-case sizes for > that layout update field? > > > This patch lets nfsd supports read buffer from multiples pages. > > Hm. We'll end up kmalloc()ing the passed-in field length: > > p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL); > > We still do still have that (avail + argp->pagelen) limit, so we're not > going to pass arbitrarily large nbytes straight from the network to > kmalloc. But we do try to avoid depending on higher-order allocations. (Which it looks like we were allowing before, possibly by accident. But I doubt they were actually happening in practice, so that's not evidence that we don't need to worry about allocations greater than a page.) --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
