From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 23 Nov 2009 12:24:38 +0000 (-0500)
Subject: ext4: fix uninit block bitmap initialization when s_meta_first_bg is non-zero
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8dadb198cb70ef811916668fe67eeec82e8858dd;p=linux-beck.git

ext4: fix uninit block bitmap initialization when s_meta_first_bg is non-zero

The number of old-style block group descriptor blocks is
s_meta_first_bg when the meta_bg feature flag is set.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
---

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 1d0418980f8d..f3032c919a22 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -761,7 +761,13 @@ static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
 static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
 					ext4_group_t group)
 {
-	return ext4_bg_has_super(sb, group) ? EXT4_SB(sb)->s_gdb_count : 0;
+	if (!ext4_bg_has_super(sb, group))
+		return 0;
+
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG))
+		return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
+	else
+		return EXT4_SB(sb)->s_gdb_count;
 }
 
 /**