On Mon, Aug 04, 2025 at 08:16:39AM -0600, Keith Busch wrote: > On Fri, Aug 01, 2025 at 10:02:49PM -0400, Mike Snitzer wrote: > > On Fri, Aug 01, 2025 at 04:47:36PM -0700, Keith Busch wrote: > > > From: Keith Busch <kbusch@xxxxxxxxxx> > > > > > > No more callers. > > > > > > Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx> > > > > You had me up until this last patch. > > > > I'm actually making use of iov_iter_is_aligned() in a series of > > changes for both NFS and NFSD. Chuck has included some of the > > NFSD changes in his nfsd-testing branch, see: > > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?h=nfsd-testing&id=5d78ac1e674b45f9c9e3769b48efb27c44f4e4d3 > > > > And the balance of my work that is pending review/inclusion is: > > https://lore.kernel.org/linux-nfs/20250731230633.89983-1-snitzer@xxxxxxxxxx/ > > https://lore.kernel.org/linux-nfs/20250801171049.94235-1-snitzer@xxxxxxxxxx/ > > > > I only need iov_iter_aligned_bvec, but recall I want to relax its > > checking with this patch: > > https://lore.kernel.org/linux-nfs/20250708160619.64800-5-snitzer@xxxxxxxxxx/ > > > > Should I just add iov_iter_aligned_bvec() to fs/nfs_common/ so that > > both NFS and NFSD can use it? > > If at all possible, I recommend finding a place that already walks the > vectors and do an opprotunistic check for the alignments there. This > will save CPU cycles. For example, nfsd_iter_read already iterates the > bvec while setting each page. Could you check the alignment while doing > that instead of iterating a second time immediately after? Nice goal, I'll see if I can pull it off. I'm currently using iov_iter_is_aligned() in 3 new call sites (for READ and WRITE) in both NFS and NFSD: nfs_local_iter_init, nfsd_iter_read, nfsd_vfs_write nfsd_vfs_write is the only one that doesn't iterate the bvec as-is, but it does work that _should_ obviate the need to doable check the alignment.
