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authorDavid Woodhouse <dwmw2@infradead.org>2006-10-21 16:46:04 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2006-10-21 16:46:04 +0100
commit513b046c96cc2fbce730a3474f6f7ff0c4fdd05c (patch)
treee8006368b6f643067486f92405a404757807d6da /fs/ext4/bitmap.c
parent82810b7b6cc7a74c68881a13b0eb66c7a6370fcc (diff)
parentc7a3bd177f248d01ee18a01d22048c80e071c331 (diff)
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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'fs/ext4/bitmap.c')
-rw-r--r--fs/ext4/bitmap.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/fs/ext4/bitmap.c b/fs/ext4/bitmap.c
new file mode 100644
index 000000000000..11e93c169bcf
--- /dev/null
+++ b/fs/ext4/bitmap.c
@@ -0,0 +1,32 @@
+/*
+ * linux/fs/ext4/bitmap.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/jbd2.h>
+#include <linux/ext4_fs.h>
+
+#ifdef EXT4FS_DEBUG
+
+static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
+
+unsigned long ext4_count_free (struct buffer_head * map, unsigned int numchars)
+{
+ unsigned int i;
+ unsigned long sum = 0;
+
+ if (!map)
+ return (0);
+ for (i = 0; i < numchars; i++)
+ sum += nibblemap[map->b_data[i] & 0xf] +
+ nibblemap[(map->b_data[i] >> 4) & 0xf];
+ return (sum);
+}
+
+#endif /* EXT4FS_DEBUG */
+