[PATCH 01/10] nfsd: replace fh_fill_both_attrs() with fh_fill_post_noop()

From: NeilBrown <neil-+NVA1uvv1dVBDLzU/[email protected]>

fh_fill_both_attrs() is only needed for open/create and is used in the
case when the target already existed so no creating happens.

As part of refactoring this code it is changed to call
fh_fill_pre_attrs() once early on (so errors only need to be caught in
one place) and then to use a new fh_fill_post_noop() when it is
determined that no creation happened.

fh_fill_pre_attrs() now stores the attrs (which it had to get all of
anyway)_ in ->fh_post_attr.  fh_fill_post_noop() simply marks them as
valid.  fh_fill_post_attrs() replaces them.

Signed-off-by: NeilBrown <neil-+NVA1uvv1dVBDLzU/[email protected]>
---
 fs/nfsd/nfs4proc.c | 20 +++++++++-----------
 fs/nfsd/nfsfh.c    | 40 +++++++++++-----------------------------
 fs/nfsd/nfsfh.h    | 13 ++++++++++++-
 3 files changed, 32 insertions(+), 41 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 669896be08b6..06de0cfd8e90 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -327,9 +327,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		/* NFSv4 protocol requires change attributes even though
 		 * no change happened.
 		 */
-		status = fh_fill_both_attrs(fhp);
-		if (status != nfs_ok)
-			goto out;
+		fh_fill_post_noop(fhp);
 
 		status = fh_compose(resfhp, fhp->fh_export, child, fhp);
 		if (status != nfs_ok)
@@ -376,9 +374,6 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	if (!IS_POSIXACL(inode))
 		iap->ia_mode &= ~current_umask();
 
-	status = fh_fill_pre_attrs(fhp);
-	if (status != nfs_ok)
-		goto out;
 	status = nfsd4_vfs_create(fhp, &child, open);
 	if (status != nfs_ok)
 		goto out;
@@ -464,6 +459,9 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 	fh_init(*resfh, NFS4_FHSIZE);
 	open->op_truncate = false;
 
+	status = fh_fill_pre_attrs(current_fh);
+	if (status)
+		goto out;
 	if (open->op_create) {
 		/* FIXME: check session persistence and pnfs flags.
 		 * The nfsv4.1 spec requires the following semantics:
@@ -495,11 +493,11 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru
 	} else {
 		status = nfsd_lookup(rqstp, current_fh,
 				     open->op_fname, open->op_fnamelen, *resfh);
-		if (status == nfs_ok)
-			/* NFSv4 protocol requires change attributes even though
-			 * no change happened.
-			 */
-			status = fh_fill_both_attrs(current_fh);
+		/*
+		 * NFSv4 protocol requires change attributes even though
+		 * no change happened.
+		 */
+		fh_fill_post_noop(current_fh);
 	}
 	if (status)
 		goto out;
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 8b1a95e1d058..58de7b7c4238 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -784,26 +784,31 @@ __be32 fh_getattr(const struct svc_fh *fhp, struct kstat *stat)
  * fh_fill_pre_attrs - Fill in pre-op attributes
  * @fhp: file handle to be updated
  *
+ * Post-op attrs are filled and pre-op attrs are copied
+ * from there.  The post-op attrs can later be replaced by
+ * fh_fill_post_attrs() or activated by fh_fill_post_noop().
+ *
+ * Returns: error from vfs_getattr() which must be checked.
  */
 __be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp)
 {
 	bool v4 = (fhp->fh_maxsize == NFS4_FHSIZE);
-	struct kstat stat;
 	__be32 err;
 
 	if (fhp->fh_no_wcc || fhp->fh_pre_saved)
 		return nfs_ok;
 
-	err = fh_getattr(fhp, &stat);
+	err = fh_getattr(fhp, &fhp->fh_post_attr);
 	if (err)
 		return err;
 
 	if (v4)
-		fhp->fh_pre_change = nfsd4_change_attribute(&stat);
+		fhp->fh_pre_change = fhp->fh_post_change =
+			nfsd4_change_attribute(&fhp->fh_post_attr);
 
-	fhp->fh_pre_mtime = stat.mtime;
-	fhp->fh_pre_ctime = stat.ctime;
-	fhp->fh_pre_size  = stat.size;
+	fhp->fh_pre_mtime = fhp->fh_post_attr.mtime;
+	fhp->fh_pre_ctime = fhp->fh_post_attr.ctime;
+	fhp->fh_pre_size  = fhp->fh_post_attr.size;
 	fhp->fh_pre_saved = true;
 	return nfs_ok;
 }
@@ -835,29 +840,6 @@ __be32 fh_fill_post_attrs(struct svc_fh *fhp)
 	return nfs_ok;
 }
 
-/**
- * fh_fill_both_attrs - Fill pre-op and post-op attributes
- * @fhp: file handle to be updated
- *
- * This is used when the directory wasn't changed, but wcc attributes
- * are needed anyway.
- */
-__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp)
-{
-	__be32 err;
-
-	err = fh_fill_post_attrs(fhp);
-	if (err)
-		return err;
-
-	fhp->fh_pre_change = fhp->fh_post_change;
-	fhp->fh_pre_mtime = fhp->fh_post_attr.mtime;
-	fhp->fh_pre_ctime = fhp->fh_post_attr.ctime;
-	fhp->fh_pre_size = fhp->fh_post_attr.size;
-	fhp->fh_pre_saved = true;
-	return nfs_ok;
-}
-
 /*
  * Release a file handle.
  */
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
index cdeb5eea65a8..e8b271a92024 100644
--- a/fs/nfsd/nfsfh.h
+++ b/fs/nfsd/nfsfh.h
@@ -338,5 +338,16 @@ static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp)
 u64 nfsd4_change_attribute(const struct kstat *stat);
 __be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp);
 __be32 fh_fill_post_attrs(struct svc_fh *fhp);
-__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp);
+
+/**
+ * fh_fill_post_noop - Copy pre attrs to post attrs
+ * @fhp: file handle to be updated
+ *
+ * This is used when the directory wasn't changed, but wcc attributes
+ * are needed anyway.
+ */
+static inline void fh_fill_post_noop(struct svc_fh *fhp)
+{
+	fhp->fh_post_saved = true;
+}
 #endif /* _LINUX_NFSD_NFSFH_H */
-- 
2.50.0.107.gf914562f5916.dirty