nfsd4: warn on open failure after create

If we create the object and then return failure to the client, we're
left with an unexpected file in the filesystem.

I'm trying to eliminate such cases but not 100% sure I have so an
assertion might be helpful for now.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4proc.c

@@ -194,7 +194,6 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 {
 	struct svc_fh resfh;
 	__be32 status;
-	int created = 0;
 
 	fh_init(&resfh, NFS4_FHSIZE);
 	open->op_truncate = 0;
@@ -223,7 +222,7 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 					open->op_fname.len, &open->op_iattr,
 					&resfh, open->op_createmode,
 					(u32 *)open->op_verf.data,
-					&open->op_truncate, &created);
+					&open->op_truncate, &open->op_created);
 
 		/*
 		 * Following rfc 3530 14.2.16, use the returned bitmask
@@ -253,7 +252,7 @@ do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_o
 	/* set reply cache */
 	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
 			&resfh.fh_handle);
-	if (!created)
+	if (!open->op_created)
 		status = do_open_permission(rqstp, current_fh, open,
 					    NFSD_MAY_NOP);
 
@@ -318,6 +317,7 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	/* We don't yet support WANT bits: */
 	open->op_share_access &= NFS4_SHARE_ACCESS_MASK;
 
+	open->op_created = 0;
 	/*
 	 * RFC5661 18.51.3
 	 * Before RECLAIM_COMPLETE done, server should deny new lock
@@ -408,6 +408,7 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	 * set, (2) sets open->op_stateid, (3) sets open->op_delegation.
 	 */
 	status = nfsd4_process_open2(rqstp, &cstate->current_fh, open);
+	WARN_ON(status && open->op_created);
 out:
 	nfsd4_cleanup_open_state(open, status);
 	if (open->op_openowner)

fs/nfsd/vfs.c

@@ -1370,7 +1370,7 @@ __be32
 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		char *fname, int flen, struct iattr *iap,
 		struct svc_fh *resfhp, int createmode, u32 *verifier,
-	        int *truncp, int *created)
+	        bool *truncp, bool *created)
 {
 	struct dentry	*dentry, *dchild = NULL;
 	struct inode	*dirp;

fs/nfsd/vfs.h

@@ -62,7 +62,7 @@ __be32		nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
 __be32		do_nfsd_create(struct svc_rqst *, struct svc_fh *,
 				char *name, int len, struct iattr *attrs,
 				struct svc_fh *res, int createmode,
-				u32 *verifier, int *truncp, int *created);
+				u32 *verifier, bool *truncp, bool *created);
 __be32		nfsd_commit(struct svc_rqst *, struct svc_fh *,
 				loff_t, unsigned long);
 #endif /* CONFIG_NFSD_V3 */

fs/nfsd/xdr4.h

@@ -226,7 +226,8 @@ struct nfsd4_open {
 	u32		op_recall;          /* recall */
 	struct nfsd4_change_info  op_cinfo; /* response */
 	u32		op_rflags;          /* response */
-	int		op_truncate;        /* used during processing */
+	bool		op_truncate;        /* used during processing */
+	bool		op_created;         /* used during processing */
 	struct nfs4_openowner *op_openowner; /* used during processing */
 	struct nfs4_file *op_file;          /* used during processing */
 	struct nfs4_ol_stateid *op_stp;	    /* used during processing */