Ext4 Test Files

These are the ext4 test images we use to test the capability of the reader.

Note: There are many flags/properties, and it would be too verbose to be exhaustive. Only notable properties will be mentioned.

1file.img

The most basic, just has one file in the root directory.

Properties

• 1 KiB Block Size
• Single block group

Flags

• 32 bit

Directory Tree

/
├── file1
└── lost+found/

extents.img

Contains large files with extent depth > 0, trailing zero pages, sparse files and multiple nested directories.

Properties

• 1 KiB Block Size
• 2 block groups
• largefile (inode 14) has extent tree with depth 2
• sparsefile (inode 12) has extent tree with depth 2, logical blocks are not contiguous
• trailingzeropages has a small amount of data at the head, but is truncated to 100000 bytes.

Flags

• 32 bit
• Large files
• Huge files

Directory Tree

/
├── a/
│   └── multi/
│       └── dir/
│           └── path/
│               └── within/
│                   └── this/
│                       └── crowded/
│                           └── extents/
│                               └── test/
│                                   └── img/
│                                       └── empty
├── trailingzeropages
├── largefile
├── lost+found/
├── smallfile
└── sparsefile

nest.img

Test that we can walk into a sub-directory.

Properties

• 1 KiB Block Size
• Single block group

Flags

• 32 bit

Directory Tree

/
├── file1
├── inner/
│   └── file2
└── lost+found/

xattr.img

Test that we can read extended attributes, both from the inode and a separate block.

Properties

• 1 KiB Block Size
• Single block group

Flags

• 32 bit

Directory Tree

/
├── file1
├── file_many
├── subdir/
│   └── file2
└── lost+found/