ufs: don't touch mtime/ctime of directory being moved

See "ext2: Do not update mtime of a moved directory" (and followup in
"ext2: fix unbalanced kmap()/kunmap()") for background; this is UFS
equivalent - the same problem exists here.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/ufs/dir.c

@@ -87,7 +87,8 @@ ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
 
 /* Releases the page */
 void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
-		  struct page *page, struct inode *inode)
+		  struct page *page, struct inode *inode,
+		  bool update_times)
 {
 	loff_t pos = page_offset(page) +
 			(char *) de - (char *) page_address(page);
@@ -103,6 +104,7 @@ void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
 
 	err = ufs_commit_chunk(page, pos, len);
 	ufs_put_page(page);
+	if (update_times)
 		dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	mark_inode_dirty(dir);
 }

fs/ufs/namei.c

@@ -276,7 +276,7 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		new_de = ufs_find_entry(new_dir, &new_dentry->d_name, &new_page);
 		if (!new_de)
 			goto out_dir;
-		ufs_set_link(new_dir, new_de, new_page, old_inode);
+		ufs_set_link(new_dir, new_de, new_page, old_inode, 1);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
 			drop_nlink(new_inode);
@@ -299,7 +299,12 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
-		ufs_set_link(old_inode, dir_de, dir_page, new_dir);
+		if (old_dir != new_dir)
+			ufs_set_link(old_inode, dir_de, dir_page, new_dir, 0);
+		else {
+			kunmap(dir_page);
+			page_cache_release(dir_page);
+		}
 		inode_dec_link_count(old_dir);
 	}
 	return 0;

fs/ufs/ufs.h

@@ -106,7 +106,7 @@ extern int ufs_delete_entry(struct inode *, struct ufs_dir_entry *, struct page
 extern int ufs_empty_dir (struct inode *);
 extern struct ufs_dir_entry *ufs_dotdot(struct inode *, struct page **);
 extern void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
-			 struct page *page, struct inode *inode);
+			 struct page *page, struct inode *inode, bool update_times);
 
 /* file.c */
 extern const struct inode_operations ufs_file_inode_operations;