[PATCH] kNFSd: NFSdV4 fixes for replaying open requests.

From: NeilBrown <neilb@cse.unsw.edu.au>

Since the open op changes the current filehandle, we can't correctly replay
compounds containing opens unless we save the filehandle resulting from the
open as well as the encoded reply.

fs/nfsd/nfs4proc.c

@@ -89,6 +89,12 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 	if (!status) {
 		set_change_info(&open->op_cinfo, current_fh);
 		fh_dup2(current_fh, &resfh);
+		/* XXXJBF: keep a saved svc_fh struct instead?? */
+		open->op_stateowner->so_replay.rp_openfh_len =
+			resfh.fh_handle.fh_size;
+		memcpy(open->op_stateowner->so_replay.rp_openfh,
+				&resfh.fh_handle.fh_base,
+				resfh.fh_handle.fh_size);
 
 		accmode = MAY_NOP;
 		if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
@@ -116,6 +122,19 @@ nfsd4_open(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open
 
 	/* check seqid for replay. set nfs4_owner */
 	status = nfsd4_process_open1(open);
+	if (status == NFSERR_REPLAY_ME) {
+		struct nfs4_replay *rp = &open->op_stateowner->so_replay;
+		fh_put(current_fh);
+		current_fh->fh_handle.fh_size = rp->rp_openfh_len;
+		memcpy(&current_fh->fh_handle.fh_base, rp->rp_openfh,
+				rp->rp_openfh_len);
+		status = fh_verify(rqstp, current_fh, 0, MAY_NOP);
+		if (status)
+			dprintk("nfsd4_open: replay failed"
+				" restoring previous filehandle\n");
+		else
+			status = NFSERR_REPLAY_ME;
+	}
 	if (status)
 		return status;
 	/*

fs/nfsd/nfs4xdr.c

@@ -1913,6 +1913,7 @@ nfsd4_encode_open(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_open
 	default:
 		BUG();
 	}
+	/* XXX save filehandle here */
 
 	ENCODE_SEQID_OP_TAIL(open->op_stateowner);
 }

include/linux/nfsd/state.h

@@ -113,6 +113,8 @@ struct nfs4_replay {
 	unsigned int		rp_buflen;
 	char			*rp_buf;
 	unsigned		intrp_allocated;
+	int			rp_openfh_len;
+	char			rp_openfh[NFS4_FHSIZE];
 	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
 };