UBIFS: fix available blocks count
Take into account that 2 eraseblocks are never available because
they are reserved for the index. This gives more realistic count
of FS blocks.
To avoid future confusions like this, introduce a constant.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index f8ef7c1..543e850 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -63,6 +63,14 @@
#define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL
#define SQNUM_WATERMARK 0xFFFFFFFFFF000000ULL
+/*
+ * Minimum amount of LEBs reserved for the index. At present the index needs at
+ * least 2 LEBs: one for the index head and one for in-the-gaps method (which
+ * currently does not cater for the index head and so excludes it from
+ * consideration).
+ */
+#define MIN_INDEX_LEBS 2
+
/* Minimum amount of data UBIFS writes to the flash */
#define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8)