[PATCH 21/27] ubifs: introduce lprops lib

[Dongsheng Yang]

Copy lprops.c from kernel to ubifs-utils/.

Signed-off-by: Dongsheng Yang <yangds.fnst at cn.fujitsu.com>
---
 ubifs-utils/include/lprops.h |  6 ++++
 ubifs-utils/lib/lprops.c     | 79 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 ubifs-utils/include/lprops.h
 create mode 100644 ubifs-utils/lib/lprops.c

diff --git a/ubifs-utils/include/lprops.h b/ubifs-utils/include/lprops.h
new file mode 100644
index 0000000..5bf3108
--- /dev/null
+++ b/ubifs-utils/include/lprops.h
@@ -0,0 +1,6 @@
+#ifndef __UBIFS_LPROPS_H__
+#define __UBIFS_LPROPS_H__
+
+int ubifs_categorize_lprops(const struct ubifs_info *c,
+			    const struct ubifs_lprops *lprops);
+#endif
diff --git a/ubifs-utils/lib/lprops.c b/ubifs-utils/lib/lprops.c
new file mode 100644
index 0000000..818d220
--- /dev/null
+++ b/ubifs-utils/lib/lprops.c
@@ -0,0 +1,79 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * 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
+ *
+ * Authors: Adrian Hunter
+ *          Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * This file implements the functions that access LEB properties and their
+ * categories. LEBs are categorized based on the needs of UBIFS, and the
+ * categories are stored as either heaps or lists to provide a fast way of
+ * finding a LEB in a particular category. For example, UBIFS may need to find
+ * an empty LEB for the journal, or a very dirty LEB for garbage collection.
+ */
+
+#include "ubifs_common.h"
+
+/* common.h requires the PROGRAM_NAME macro */
+#define PROGRAM_NAME "ubifs-lprops"
+#include "common.h"
+
+#include "ubifs.h"
+
+/**
+ * ubifs_categorize_lprops - categorize LEB properties.
+ * @c: UBIFS file-system description object
+ * @lprops: LEB properties to categorize
+ *
+ * LEB properties are categorized to enable fast find operations. This function
+ * returns the LEB category to which the LEB properties belong. Note however
+ * that if the LEB category is stored as a heap and the heap is full, the
+ * LEB properties may have their category changed to %LPROPS_UNCAT.
+ */
+int ubifs_categorize_lprops(const struct ubifs_info *c,
+			    const struct ubifs_lprops *lprops)
+{
+	if (lprops->flags & LPROPS_TAKEN)
+		return LPROPS_UNCAT;
+
+	if (lprops->free == c->leb_size) {
+		ubifs_assert(!(lprops->flags & LPROPS_INDEX));
+		return LPROPS_EMPTY;
+	}
+
+	if (lprops->free + lprops->dirty == c->leb_size) {
+		if (lprops->flags & LPROPS_INDEX)
+			return LPROPS_FRDI_IDX;
+		else
+			return LPROPS_FREEABLE;
+	}
+
+	if (lprops->flags & LPROPS_INDEX) {
+		if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
+			return LPROPS_DIRTY_IDX;
+	} else {
+		if (lprops->dirty >= c->dead_wm &&
+		    lprops->dirty > lprops->free)
+			return LPROPS_DIRTY;
+		if (lprops->free > 0)
+			return LPROPS_FREE;
+	}
+
+	return LPROPS_UNCAT;
+}
-- 
1.8.4.2