Ironclad supports EXT-series filesystems read-only and read-write.
While a user may be used to the ext2/3/4 distinction, EXT internally works as an independent set of features, with the version numbers specifying a widely understood, assumed, and inconsistent set of features.
Ironclad supports the feature list: sparse_super, large_file,
filetype, resize_inode, dir_index, ext_attr.
Those features should translate to ext2 read-write support, and ext3 read-only support.
Some ioctl calls exist for files inside EXT-series FSs, which can help
manage specialized FS-specific inode flags and permissions, they are:
EXT_GETFLAGS = 0x5600 EXT_SETFLAGS = 0x5601 ioctl(fd, EXT_GETFLAGS, pointer_to_u32); // Get EXT's flags inode field. ioctl(fd, EXT_SETFLAGS, pointer_to_u32); // Set EXT's flags inode field.
EXT features a error policy on EXT internal errors that dictates for the kernel to panic when triggered. While other operating systems honor the policy as-is, Ironclad deliverately acts on it was a "Remount read only" policy. This is done to avoid denial of service attacks by mounting deliverately faulty flesystems.