If you try to limit your search to just files and directories which begin with "ext2" (excluding, in theory, any "ext2" in the root directory, but there is no such directory in any regular package anyway), apt-file should not ignore this and display all matches which contain "ext2" anywhere in them.
Binary package hint: apt-file
If you try to limit your search to just files and directories which begin with "ext2" (excluding, in theory, any "ext2" in the root directory, but there is no such directory in any regular package anyway), apt-file should not ignore this and display all matches which contain "ext2" anywhere in them.
This is on a pretty vanilla Gutsy system:
vnix$ apt-file search /ext2 | head autofs/ mount_ext2. so autofs/ mount_ext2. so autofs/ mount_ext2. so common- lisp/source/ cmucl-hemlock/ htext2. lisp common- lisp/source/ cmucl-hemlock/ htext2. lisp common- lisp/source/ cmucl-hemlock/ htext2. lisp common- lisp/source/ cmucl/hemlock/ htext2. lisp
autofs: usr/lib/
autofs: usr/lib/
autofs: usr/lib/
awesfx: usr/bin/text2sf
awesfx: usr/bin/text2sf
awesfx: usr/bin/text2sf
cmucl-source: usr/share/
cmucl-source: usr/share/
cmucl-source: usr/share/
cmucl-source: usr/share/
(Obviously, bug #174134 is also at play here.)