kernel - Add per-mount token to replace mplock.
* Fix issues with dupfdopen() not being MPSAFE.
* Implement a dummy mount structure for devfs-synthesized vnodes prior
to the root mount.
* Wrap all VFS_*() calls, including vfs_init() and vfs_uninit(), to
acquire the per-mount token if not flagged as being MPSAFE.
* Wrap all VOP_*() calls to acquire the per-mount token if not flagged
as being MPSAFE.
* Move VOP_READ/VOP_WRITE MPSAFE flags to the mount structure.
* Make fifoops MPSAFE (so HAMMER can flag read & write as being
MPSAFE generally).
* The VFS code currently also acquires the MP lock when not MPSAFE
(there are things called by VFSes which are not yet MPSAFE), except
for read() and write().
15 files changed: