[PATCH] kNFSd: NFSv4: new argument to nfsd_access()

NFSv4 defines a new field in the ACCESS response: a bitmap to indicate
which access bits requested by the client are "supported", i.e. meaningful
for the object in question.

This patch adds a new parameter @supported to nfsd_access(), so that
nfsd_access() can set the value of this bitmap.

fs/nfsd/nfs3proc.c

@@ -134,7 +134,7 @@ nfsd3_proc_access(struct svc_rqst *rqstp, struct nfsd3_accessargs *argp,
 
 	fh_copy(&resp->fh, &argp->fh);
 	resp->access = argp->access;
-	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access);
+	nfserr = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
 	RETURN_STATUS(nfserr);
 }
 

fs/nfsd/vfs.c

@@ -348,12 +348,12 @@ static struct accessmap	nfs3_anyaccess[] = {
 };
 
 int
-nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access)
+nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
 {
 	struct accessmap	*map;
 	struct svc_export	*export;
 	struct dentry		*dentry;
-	u32			query, result = 0;
+	u32			query, result = 0, sresult = 0;
 	unsigned int		error;
 
 	error = fh_verify(rqstp, fhp, 0, MAY_NOP);
@@ -375,6 +375,9 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access)
 	for  (; map->access; map++) {
 		if (map->access & query) {
 			unsigned int err2;
+
+			sresult |= map->access;
+
 			err2 = nfsd_permission(export, dentry, map->how);
 			switch (err2) {
 			case nfs_ok:
@@ -395,6 +398,8 @@ nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access)
 		}
 	}
 	*access = result;
+	if (supported)
+		*supported = sresult;
 
  out:
 	return error;

include/linux/nfsd/nfsd.h

@@ -86,7 +86,7 @@ int		nfsd_create(struct svc_rqst *, struct svc_fh *,
 				char *name, int len, struct iattr *attrs,
 				int type, dev_t rdev, struct svc_fh *res);
 #ifdef CONFIG_NFSD_V3
-int		nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *);
+int		nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
 int		nfsd_create_v3(struct svc_rqst *, struct svc_fh *,
 				char *name, int len, struct iattr *attrs,
 				struct svc_fh *res, int createmode,