1 files changed, 90 insertions, 50 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 29cb7b812d71..9abdc4b75813 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -71,7 +71,6 @@ nfserrno (int errno)
 		{ nfserr_acces, -EACCES },
 		{ nfserr_exist, -EEXIST },
 		{ nfserr_xdev, -EXDEV },
-		{ nfserr_mlink, -EMLINK },
 		{ nfserr_nodev, -ENODEV },
 		{ nfserr_notdir, -ENOTDIR },
 		{ nfserr_isdir, -EISDIR },
@@ -1461,7 +1460,7 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	struct inode	*dirp;
 	struct iattr	*iap = attrs->na_iattr;
 	__be32		err;
-	int		host_err;
+	int		host_err = 0;
 
 	dentry = fhp->fh_dentry;
 	dirp = d_inode(dentry);
@@ -1488,28 +1487,15 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 			nfsd_check_ignore_resizing(iap);
 		break;
 	case S_IFDIR:
-		host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
-		if (!host_err && unlikely(d_unhashed(dchild))) {
-			struct dentry *d;
-			d = lookup_one_len(dchild->d_name.name,
-					   dchild->d_parent,
-					   dchild->d_name.len);
-			if (IS_ERR(d)) {
-				host_err = PTR_ERR(d);
-				break;
-			}
-			if (unlikely(d_is_negative(d))) {
-				dput(d);
-				err = nfserr_serverfault;
-				goto out;
-			}
+		dchild = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
+		if (IS_ERR(dchild)) {
+			host_err = PTR_ERR(dchild);
+		} else if (d_is_negative(dchild)) {
+			err = nfserr_serverfault;
+			goto out;
+		} else if (unlikely(dchild != resfhp->fh_dentry)) {
 			dput(resfhp->fh_dentry);
-			resfhp->fh_dentry = dget(d);
-			err = fh_update(resfhp);
-			dput(dchild);
-			dchild = d;
-			if (err)
-				goto out;
+			resfhp->fh_dentry = dget(dchild);
 		}
 		break;
 	case S_IFCHR:
@@ -1530,7 +1516,8 @@ nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
 
 out:
-	dput(dchild);
+	if (!IS_ERR(dchild))
+		dput(dchild);
 	return err;
 
 out_nfserr:
@@ -1699,9 +1686,17 @@ out:
 	return err;
 }
 
-/*
- * Create a hardlink
- * N.B. After this call _both_ ffhp and tfhp need an fh_put
+/**
+ * nfsd_link - create a link
+ * @rqstp: RPC transaction context
+ * @ffhp: the file handle of the directory where the new link is to be created
+ * @name: the filename of the new link
+ * @len: the length of @name in octets
+ * @tfhp: the file handle of an existing file object
+ *
+ * After this call _both_ ffhp and tfhp need an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
  */
 __be32
 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
@@ -1709,6 +1704,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 {
 	struct dentry	*ddir, *dnew, *dold;
 	struct inode	*dirp;
+	int		type;
 	__be32		err;
 	int		host_err;
 
@@ -1728,11 +1724,11 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 	if (isdotent(name, len))
 		goto out;
 
+	err = nfs_ok;
+	type = d_inode(tfhp->fh_dentry)->i_mode & S_IFMT;
 	host_err = fh_want_write(tfhp);
-	if (host_err) {
-		err = nfserrno(host_err);
+	if (host_err)
 		goto out;
-	}
 
 	ddir = ffhp->fh_dentry;
 	dirp = d_inode(ddir);
@@ -1740,7 +1736,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 
 	dnew = lookup_one_len(name, ddir, len);
 	if (IS_ERR(dnew)) {
-		err = nfserrno(PTR_ERR(dnew));
+		host_err = PTR_ERR(dnew);
 		goto out_unlock;
 	}
 
@@ -1756,17 +1752,26 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
 	fh_fill_post_attrs(ffhp);
 	inode_unlock(dirp);
 	if (!host_err) {
-		err = nfserrno(commit_metadata(ffhp));
-		if (!err)
-			err = nfserrno(commit_metadata(tfhp));
-	} else {
-		err = nfserrno(host_err);
+		host_err = commit_metadata(ffhp);
+		if (!host_err)
+			host_err = commit_metadata(tfhp);
 	}
+
 	dput(dnew);
 out_drop_write:
 	fh_drop_write(tfhp);
+	if (host_err == -EBUSY) {
+		/*
+		 * See RFC 8881 Section 18.9.4 para 1-2: NFSv4 LINK
+		 * wants a status unique to the object type.
+		 */
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	}
 out:
-	return err;
+	return err != nfs_ok ? err : nfserrno(host_err);
 
 out_dput:
 	dput(dnew);
@@ -1795,9 +1800,19 @@ nfsd_has_cached_files(struct dentry *dentry)
 	return ret;
 }
 
-/*
- * Rename a file
- * N.B. After this call _both_ ffhp and tfhp need an fh_put
+/**
+ * nfsd_rename - rename a directory entry
+ * @rqstp: RPC transaction context
+ * @ffhp: the file handle of parent directory containing the entry to be renamed
+ * @fname: the filename of directory entry to be renamed
+ * @flen: the length of @fname in octets
+ * @tfhp: the file handle of parent directory to contain the renamed entry
+ * @tname: the filename of the new entry
+ * @tlen: the length of @tlen in octets
+ *
+ * After this call _both_ ffhp and tfhp need an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
  */
 __be32
 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
@@ -1805,6 +1820,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
 {
 	struct dentry	*fdentry, *tdentry, *odentry, *ndentry, *trap;
 	struct inode	*fdir, *tdir;
+	int		type = S_IFDIR;
 	__be32		err;
 	int		host_err;
 	bool		close_cached = false;
@@ -1862,11 +1878,14 @@ retry:
 	host_err = -EINVAL;
 	if (odentry == trap)
 		goto out_dput_old;
+	type = d_inode(odentry)->i_mode & S_IFMT;
 
 	ndentry = lookup_one_len(tname, tdentry, tlen);
 	host_err = PTR_ERR(ndentry);
 	if (IS_ERR(ndentry))
 		goto out_dput_old;
+	if (d_inode(ndentry))
+		type = d_inode(ndentry)->i_mode & S_IFMT;
 	host_err = -ENOTEMPTY;
 	if (ndentry == trap)
 		goto out_dput_new;
@@ -1904,7 +1923,18 @@ retry:
  out_dput_old:
 	dput(odentry);
  out_nfserr:
-	err = nfserrno(host_err);
+	if (host_err == -EBUSY) {
+		/*
+		 * See RFC 8881 Section 18.26.4 para 1-3: NFSv4 RENAME
+		 * wants a status unique to the object type.
+		 */
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	} else {
+		err = nfserrno(host_err);
+	}
 
 	if (!close_cached) {
 		fh_fill_post_attrs(ffhp);
@@ -1931,9 +1961,17 @@ out:
 	return err;
 }
 
-/*
- * Unlink a file or directory
- * N.B. After this call fhp needs an fh_put
+/**
+ * nfsd_unlink - remove a directory entry
+ * @rqstp: RPC transaction context
+ * @fhp: the file handle of the parent directory to be modified
+ * @type: enforced file type of the object to be removed
+ * @fname: the name of directory entry to be removed
+ * @flen: length of @fname in octets
+ *
+ * After this call fhp needs an fh_put.
+ *
+ * Returns a generic NFS status code in network byte-order.
  */
 __be32
 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
@@ -2007,15 +2045,17 @@ out_drop_write:
 	fh_drop_write(fhp);
 out_nfserr:
 	if (host_err == -EBUSY) {
-		/* name is mounted-on. There is no perfect
-		 * error status.
+		/*
+		 * See RFC 8881 Section 18.25.4 para 4: NFSv4 REMOVE
+		 * wants a status unique to the object type.
 		 */
-		err = nfserr_file_open;
-	} else {
-		err = nfserrno(host_err);
+		if (type != S_IFDIR)
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
 	}
 out:
-	return err;
+	return err != nfs_ok ? err : nfserrno(host_err);
 out_unlock:
 	inode_unlock(dirp);
 	goto out_drop_write;