From fc9ed72f64b0e6689eaed1faa33e3a333b995bf7 Mon Sep 17 00:00:00 2001
From: Kazuya Mio <k-mio@sx.jp.nec.com>
Date: Sat, 17 Mar 2018 14:56:15 -0400
Subject: [PATCH 05/16] libext2fs: fix ext2fs_open2() error for meta_bg image
 file

commit 8b061a641dff1a0becf645f8e6002de79b997b95

dumpe2fs/debugfs can examine the image file by using the -i option.
However, if meta_bg feature is enabled, dumpe2fs/debugfs cannot open
the image file.

$ dumpe2fs -i test.img
dumpe2fs: Attempt to read block from filesystem resulted in short read while trying to open test.img
Couldn't find valid filesystem superblock.

In case of specifying an image file, the location of block group descriptors
is the same as the case of default filesystem regardless of meta_bg feature.
So if EXT2_FLAG_IMAGE_FILE flag is set in ext2fs_open2(),
don't use the meta_bg handling.

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
 lib/ext2fs/openfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/ext2fs/openfs.c b/lib/ext2fs/openfs.c
index ba501e6a..200f7815 100644
--- a/lib/ext2fs/openfs.c
+++ b/lib/ext2fs/openfs.c
@@ -378,7 +378,8 @@ errcode_t ext2fs_open2(const char *name, const char *io_options,
 #ifdef WORDS_BIGENDIAN
 	groups_per_block = EXT2_DESC_PER_BLOCK(fs->super);
 #endif
-	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) {
+	if ((fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) &&
+	    !(flags & EXT2_FLAG_IMAGE_FILE)) {
 		first_meta_bg = fs->super->s_first_meta_bg;
 		if (first_meta_bg > fs->desc_blocks)
 			first_meta_bg = fs->desc_blocks;
-- 
2.20.1