[PATCH 41/67] aufs directory operations, header

[hooanon05@yahoo.co.jp]

From: Junjiro Okajima <hooanon05@yahoo.co.jp>

	initial commit
	aufs directory operations, header

Signed-off-by: Junjiro Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/dir.h |  146 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 146 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/dir.h b/fs/aufs/dir.h
new file mode 100644
index 0000000..94ccbd1
--- /dev/null
+++ b/fs/aufs/dir.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+ * directory operations
+ *
+ * $Id: dir.h,v 1.2 2008/04/21 01:34:26 sfjro Exp $
+ */
+
+#ifndef __AUFS_DIR_H__
+#define __AUFS_DIR_H__
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h>
+#include <linux/aufs_type.h>
+
+/* ---------------------------------------------------------------------- */
+
+/* need to be faster and smaller */
+
+#define AuSize_DEBLK	512 // todo: changeable
+#define AuSize_NHASH	32 // todo: changeable
+#if AuSize_DEBLK < NAME_MAX || PAGE_SIZE < AuSize_DEBLK
+#error invalid size AuSize_DEBLK
+#endif
+
+typedef char au_vdir_deblk_t[AuSize_DEBLK];
+
+struct au_nhash {
+	struct hlist_head heads[AuSize_NHASH];
+};
+
+struct au_vdir_destr {
+	unsigned char	len;
+	char		name[0];
+} __packed;
+
+struct au_vdir_dehstr {
+	struct hlist_node	hash;
+	struct au_vdir_destr	*str;
+};
+
+struct au_vdir_de {
+	ino_t			de_ino;
+	unsigned char		de_type;
+	/* caution: packed */
+	struct au_vdir_destr	de_str;
+} __packed;
+
+struct au_vdir_wh {
+	struct hlist_node	wh_hash;
+	aufs_bindex_t		wh_bindex;
+#ifdef CONFIG_AUFS_SHWH
+	ino_t			wh_ino;
+	unsigned char		wh_type;
+	/* caution: packed */
+#endif
+	struct au_vdir_destr	wh_str;
+} __packed;
+
+union au_vdir_deblk_p {
+	unsigned char		*p;
+	au_vdir_deblk_t		*deblk;
+	struct au_vdir_de	*de;
+};
+
+struct au_vdir {
+	au_vdir_deblk_t	**vd_deblk;
+	int		vd_nblk;
+	struct {
+		int			i;
+		union au_vdir_deblk_p	p;
+	} vd_last;
+
+	unsigned long	vd_version;
+	unsigned long	vd_jiffy;
+};
+
+/* ---------------------------------------------------------------------- */
+
+/* dir.c */
+extern struct file_operations aufs_dir_fop;
+int au_test_empty_lower(struct dentry *dentry);
+int au_test_empty(struct dentry *dentry, struct au_nhash *whlist);
+
+/* vdir.c */
+struct au_nhash *au_nhash_new(gfp_t gfp);
+void au_nhash_del(struct au_nhash *nhash);
+void au_nhash_init(struct au_nhash *nhash);
+void au_nhash_move(struct au_nhash *dst, struct au_nhash *src);
+void au_nhash_fin(struct au_nhash *nhash);
+int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
+			    int limit);
+int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int namelen);
+int au_nhash_append_wh(struct au_nhash *whlist, char *name, int namelen,
+		       ino_t ino, unsigned int d_type, aufs_bindex_t bindex,
+		    unsigned char shwh);
+void au_vdir_free(struct au_vdir *vdir);
+int au_vdir_init(struct file *file);
+int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir);
+
+/* ---------------------------------------------------------------------- */
+
+static inline
+void au_shwh_init_wh(struct au_vdir_wh *wh, ino_t ino, unsigned char d_type)
+{
+#ifdef CONFIG_AUFS_SHWH
+	wh->wh_ino = ino;
+	wh->wh_type = d_type;
+#endif
+}
+
+static inline void au_add_nlink(struct inode *dir, struct inode *h_dir)
+{
+	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
+	dir->i_nlink += h_dir->i_nlink - 2;
+	if (unlikely(h_dir->i_nlink < 2))
+		dir->i_nlink += 2;
+}
+
+static inline void au_sub_nlink(struct inode *dir, struct inode *h_dir)
+{
+	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
+	dir->i_nlink -= h_dir->i_nlink - 2;
+	if (unlikely(h_dir->i_nlink < 2))
+		dir->i_nlink -= 2;
+}
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_DIR_H__ */
-- 
1.4.4.4