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@xxxxxxxxxxxxx> --- 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 506c025..385d6e8 100644 --- a/lib/ext2fs/openfs.c +++ b/lib/ext2fs/openfs.c @@ -416,7 +416,8 @@ 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 (ext2fs_has_feature_meta_bg(fs->super)) { + if (ext2fs_has_feature_meta_bg(fs->super) && + !(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;