Re: [GIT PULL v2] NFS LOCALIO O_DIRECT changes for Linux 6.18

[Mike Snitzer <snitzer@kernel.org>]

On Tue, Sep 30, 2025 at 04:53:49PM -0400, Anna Schumaker wrote:
> Hi Mike,
> 
> On 9/30/25 3:32 PM, Mike Snitzer wrote:
> > Hi Anna,
> > 
> > Given that my NFS LOCALIO O_DIRECT changes depend on NFSD changes
> > which will be included in the NFSD pull request for 6.18, I figured it
> > worth proposing a post-NFSD-merge pull request for your consideration
> > as the best way forward logistically (to ensure linux-next coverage,
> > you could pull this in _before_ Chuck sends his pull to Linus).
> 
> I've applied your patches with the one NFSD patch acked-by Chuck and pushed
> it out to my linux-next for a few days of wider testing. I agree with Chuck
> that the remaining fixes can go in through an -rc once they're ready.

Perfect, thanks for the update.

Note that there will be merge conflicts that both linux-next and Linus
will need to resolve.  Due to these nfsd-next commits:

c926f0298d3cd NFSD: Relocate the fh_want_write() and fh_drop_write() helpers
c1f203e46c55a NFSD: Move the fh_getattr() helper
2ee3a75e42081 nfsd: discard nfsd_file_get_local()

$ git checkout -b merge-conflict-test cel/nfsd-next
branch 'merge-conflict-test' set up to track 'cel/nfsd-next'.
Switched to a new branch 'merge-conflict-test'

$ git merge anna-nfs/linux-next
Auto-merging fs/nfsd/filecache.c
Auto-merging fs/nfsd/filecache.h
Auto-merging fs/nfsd/localio.c
Auto-merging fs/nfsd/vfs.h
CONFLICT (content): Merge conflict in fs/nfsd/vfs.h
Auto-merging include/linux/nfslocalio.h
Auto-merging include/linux/sunrpc/svc_xprt.h
Auto-merging include/linux/sunrpc/xdr.h
Auto-merging net/sunrpc/svc.c
Auto-merging net/sunrpc/svc_xprt.c
Automatic merge failed; fix conflicts and then commit the result.

Resolving the fs/nfsd/vfs.h conflict is really easy (just remove the
marked region), the problem is that the test merge I just did caused
this hunk to get dropped on the floor:

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 062cfc18d8c6..0bc2608a80b0 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -698,8 +698,12 @@ __be32 fh_getattr(const struct svc_fh *fhp, struct kstat *stat)
 		.mnt		= fhp->fh_export->ex_path.mnt,
 		.dentry		= fhp->fh_dentry,
 	};
+	struct inode *inode = d_inode(p.dentry);
 	u32 request_mask = STATX_BASIC_STATS;
 
+	if (S_ISREG(inode->i_mode))
+		request_mask |= (STATX_DIOALIGN | STATX_DIO_READ_ALIGN);
+
 	if (fhp->fh_maxsize == NFS4_FHSIZE)
 		request_mask |= (STATX_BTIME | STATX_CHANGE_COOKIE);
 
Might be a good idea to resolve the conflict in a branch for
linux-next and Linus to reference?

Thanks,
Mike