- LOCKPARENT is no longer relevant for lookup(), relookup() or VOP_LOOKUP().
these now always return the parent vnode locked. namei() works as before.
lookup() and various other paths no longer acquire vnode locks in the
wrong order via vrele(). fixes PR 32535.
as a nice side effect, path lookup is also up to 25% faster.
- the above allows us to get rid of PDIRUNLOCK.
- also get rid of WANTPARENT (just use LOCKPARENT and unlock it).
- remove an assumption in layer_node_find() that all file systems implement
a recursive VOP_LOCK() (unionfs doesn't).
- require that all file systems supply vfs_vptofh and vfs_fhtovp routines.
fill in eopnotsupp() for file systems that don't support being exported
and remove the checks for NULL. (layerfs calls these without checking.)
- in union_lookup1(), don't change refcounts in the ISDOTDOT case, just
adjust which vnode is locked. fixes PR 33374.
- apply fixes for ufs_rename() from ufs_vnops.c rev. 1.61 to ext2fs_rename().
The code supports read access to all media types that CD/DVD type drives
can recognize including DVD-RAM and BD- drives as well as harddisc partions
and vnd devices. UDF versions upto the latest 2.60 are to be supported
though due to lack of test media version 2.50 and 2.60 are not implemented
yet though easy to add. Both open and closed media are supported.
Write access is planned and in preparation. To facilitate this some hooks
are present in the code that are not strictly needed in a read-only
implementation but which allow writing to be added more easily.
Implemented and tested media types are CD-ROM, CD-R, CD-RW, CD-MRW,
DVD-ROM, DVD*R, DVD*RW, DVD+MRW but the same code can also read DVD-RAM,
HD-DVD and BluRay discs. Also vnd devices have been tested with several
sector sizes.
Discs created and written by UDFclient, Nero's InCD and Roxio's
DirectCD/Drag2Disc read fine.
