nfsd: clean up mnt_want_write calls

Multiple mnt_want_write() calls in the switch statement looks really
ugly.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/vfs.c

@@ -1250,36 +1250,34 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		iap->ia_mode = 0;
 	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
 
+	err = nfserr_inval;
+	if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
+		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
+		       type);
+		goto out;
+	}
+
+	host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
+	if (host_err)
+		goto out_nfserr;
+
 	/*
 	 * Get the dir op function pointer.
 	 */
 	err = 0;
 	switch (type) {
 	case S_IFREG:
-		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
-		if (host_err)
-			goto out_nfserr;
 		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
 		break;
 	case S_IFDIR:
-		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
-		if (host_err)
-			goto out_nfserr;
 		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
 		break;
 	case S_IFCHR:
 	case S_IFBLK:
 	case S_IFIFO:
 	case S_IFSOCK:
-		host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
-		if (host_err)
-			goto out_nfserr;
 		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
 		break;
-	default:
-	        printk("nfsd: bad file type %o in nfsd_create\n", type);
-		host_err = -EINVAL;
-		goto out_nfserr;
 	}
 	if (host_err < 0) {
 		mnt_drop_write(fhp->fh_export->ex_path.mnt);
@@ -1291,7 +1289,6 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		write_inode_now(dchild->d_inode, 1);
 	}
 
-
 	err2 = nfsd_create_setattr(rqstp, resfhp, iap);
 	if (err2)
 		err = err2;