On Fri, Aug 13, 2021 at 04:09:39AM +0100, Matthew Wilcox wrote: > On Thu, Aug 12, 2021 at 09:22:06PM +0100, David Howells wrote: > > Trying to use a swapfile on NFS results in every DIO write failing with > > ETXTBSY because generic_write_checks(), as called by nfs_direct_write() > > from nfs_direct_IO(), forbids writes to swapfiles. > > Why does nfs_direct_write() call generic_write_checks()? > > ie call generic_write_checks() earlier, and only swap would bypass them. Yes, something like that is a good idea probably. Additionally I'd like to move to a separate of for swap I/O ASAP given that NFS only implemens ->direct_IO for swap.