NFSD: Do the grace period check in ->proc_layoutget

RFC 8881 Section 18.43.3 states:
> If the metadata server is in a grace period, and does not persist
> layouts and device ID to device address mappings, then it MUST
> return NFS4ERR_GRACE (see Section 8.4.2.1).

Jeff observed that this suggests the grace period check is better
done by the individual layout type implementations, because checking
for the server grace period is unnecessary for some layout types.

Suggested-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/linux-nfs/7h5p5ktyptyt37u6jhpbjfd5u6tg44lriqkdc7iz7czeeabrvo@ijgxz27dw4sg/T/#t
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: chucklever

fs/nfsd/blocklayout.c

@@ -18,8 +18,8 @@
 
 
 static __be32
-nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
-		struct nfsd4_layoutget *args)
+nfsd4_block_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode,
+		const struct svc_fh *fhp, struct nfsd4_layoutget *args)
 {
 	struct nfsd4_layout_seg *seg = &args->lg_seg;
 	struct super_block *sb = inode->i_sb;
@@ -29,6 +29,9 @@ nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
 	u32 device_generation = 0;
 	int error;
 
+	if (locks_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
 	if (seg->offset & (block_size - 1)) {
 		dprintk("pnfsd: I/O misaligned\n");
 		goto out_layoutunavailable;

fs/nfsd/flexfilelayout.c

@@ -20,8 +20,8 @@
 #define NFSDDBG_FACILITY	NFSDDBG_PNFS
 
 static __be32
-nfsd4_ff_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
-		struct nfsd4_layoutget *args)
+nfsd4_ff_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode,
+		const struct svc_fh *fhp, struct nfsd4_layoutget *args)
 {
 	struct nfsd4_layout_seg *seg = &args->lg_seg;
 	u32 device_generation = 0;

fs/nfsd/nfs4proc.c

@@ -2435,7 +2435,6 @@ static __be32
 nfsd4_layoutget(struct svc_rqst *rqstp,
 		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
 {
-	struct net *net = SVC_NET(rqstp);
 	struct nfsd4_layoutget *lgp = &u->layoutget;
 	struct svc_fh *current_fh = &cstate->current_fh;
 	const struct nfsd4_layout_ops *ops;
@@ -2487,10 +2486,6 @@ nfsd4_layoutget(struct svc_rqst *rqstp,
 	if (lgp->lg_seg.length == 0)
 		goto out;
 
-	nfserr = nfserr_grace;
-	if (locks_in_grace(net))
-		goto out;
-
 	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lgp->lg_sid,
 						true, lgp->lg_layout_type, &ls);
 	if (nfserr) {
@@ -2502,7 +2497,7 @@ nfsd4_layoutget(struct svc_rqst *rqstp,
 	if (atomic_read(&ls->ls_stid.sc_file->fi_lo_recalls))
 		goto out_put_stid;
 
-	nfserr = ops->proc_layoutget(d_inode(current_fh->fh_dentry),
+	nfserr = ops->proc_layoutget(rqstp, d_inode(current_fh->fh_dentry),
 				     current_fh, lgp);
 	if (nfserr)
 		goto out_put_stid;

fs/nfsd/pnfs.h

@@ -29,8 +29,8 @@ struct nfsd4_layout_ops {
 	__be32 (*encode_getdeviceinfo)(struct xdr_stream *xdr,
 			const struct nfsd4_getdeviceinfo *gdevp);
 
-	__be32 (*proc_layoutget)(struct inode *, const struct svc_fh *fhp,
-			struct nfsd4_layoutget *lgp);
+	__be32 (*proc_layoutget)(struct svc_rqst *rqstp, struct inode *inode,
+			const struct svc_fh *fhp, struct nfsd4_layoutget *lgp);
 	__be32 (*encode_layoutget)(struct xdr_stream *xdr,
 			const struct nfsd4_layoutget *lgp);