when AOP_WRITEPAGE_ACTIVATE is returned (as NFS does when it detects
congestion) it is important that the folio is redirtied.
nfs_writepage_locked() doesn't do this, so files can become corrupted as
writes can be lost.
Note that this is not needed in v6.8 as AOP_WRITEPAGE_ACTIVATE cannot be
returned. It is needed for kernels v5.18..v6.7. Prior to 6.3 the patch
is different as it needs to mention "page", not "folio".
Reported-and-tested-by: Jacek Tomaka <Jacek.Tomaka@poczta.fm> Fixes: 6df25e58532b ("nfs: remove reliance on bdi congestion") Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>