On Sat, 14 Jun 2025, Chuck Lever wrote:

From: Chuck Lever <redacted>

Mike has expressed interest in making NFSD perform direct, uncached,
or asynchronous I/O, independent of how the target file might have
been opened by the file cache. To do that, the idea is to pass in
RWF_ flags during each VFS read and write.

However, Christoph suggested APIs that already exist which
streamline the I/O operation a bit and expose the per-I/O flag
setting directly. The suggestion looks to me like a straightforward
and sensible general clean up of these code paths.

This series refactors nfsd_iter_read() and nfsd_vfs_write() to use
those APIs instead of vfs_iter_read() and vfs_iter_write(),
respectively, as a first baby step down this path. No behavior
change is expected.

Chuck Lever (2):
  NFSD: Use vfs_iocb_iter_read()
  NFSD: Use vfs_iocb_iter_write()

It important part of this change (as I see it) is that we no longer have
to go through kiocb_set_rw_flags() (which vfs_iter_read/vfs_iter_write
do) but can set the IOCB_ flags directly. Eminently sensible.

Reviewed-by: NeilBrown <neil@brown.name>

Thanks,
NeilBrown

 fs/nfsd/vfs.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

-- 
2.49.0