node. That is needed for a layered filesystem to be able to construct a full
fs_vnode out of a volume/inode pair.
* Adapt places where get_vnode is used. Sadly this is a C API and we can't just
use a default NULL for that argument.
* Introduce a flag B_VNODE_WANTS_OVERLAY_SUB_NODE that can be returned in the
flags field of a fs get_vnode call. A filesystem can use this flag to indicate
that it doesn't support the full set of fs features (attributes, write support)
and it'd like to have unsupported calls emulated by an overlay sub node.
* Add a perliminary overlay filesystem that emulates file attributes using files
on a filesystem where attributes aren't supported. It does currently only
support reading attributes/attribute directories though. All other calls are
just passed through to the super filesystem.
* Adjust places where a HAS_FS_CALL() is taken as a guarantee that the operation
is supported. For the overlay filesystem we may later return a B_UNSUPPORTED,
so make sure that in that case proper fallback options are taken.
* Make the iso9660 filesystem request overlay sub nodes. This can be fine tuned
later to only trigger where there are features on a CD that need emulation
at all.
If you happened to know the attribute file format and location you could build
an iso with read-only attribute support now. Note that this won't be enough to
get a bootable iso-only image as the query and index support is yet missing.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29177 a95241bf-73f2-0310-859d-f6bbb57e9c96