Linux Ext2 filesystem

The Linux Ext2 filesystem provided in QNX Neutrino provides transparent access to Linux disk partitions.

Not all Ext2 features are supported, including the following:

file fragments (subblock allocation)
large files greater than 2 GB
filetype extension
compression
B-tree directories

The fs-ext2.so shared object provides filesystem support for Ext2. This shared object is automatically loaded by the devb-* drivers when mounting an Ext2 filesystem.

CAUTION:

Although Ext2 is the main filesystem for Linux systems, we don't recommend that you use fs-ext2.so as a replacement for the Power-Safe (fs-qnx6.so) filesystem. Currently, we don't support booting from Ext2 partitions. Also, the Ext2 filesystem relies heavily on its filesystem checker to maintain integrity; this and other support utilities (e.g., mke2fs) aren't currently available for QNX Neutrino.

If an Ext2 filesystem isn't unmounted properly, a filesystem checker is usually responsible for cleaning up the next time the filesystem is mounted. Although the fs-ext2.so module is equipped to perform a quick test, it automatically mounts the filesystem as read-only if it detects any significant problems (which should be fixed using a filesystem checker).

This filesystem allows the same characters in a filename as the Power-Safe filesystem; see “Power-Safe filesystem,” earlier in this chapter.