Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

* Implemented support for chroot:
- Added a "root" vnode to the io_context. It is used for resolving
paths and converting nodes to paths instead of sRoot. Some more
passing around of io_context structures was necessary.
- Introduced a new lock sIOContextRootLock to protect
io_context::root. The current uses of io_context::io_mutex
(put_vnode(), remove_vnode() while holding it) looked too suspicious
to use that mutex in vnode_path_to_vnode().
- Added _kern_change_root() syscall and chroot() libroot function.
- Added chroot coreutils program to the image. Funnily it seems to be
much easier to set up a little jail than under Linux (just copy
bash and libroot.so into respective subdirs; mount another pipefs
if you want pipe support).
With Haiku allowing direct access to directories via inode IDs
jailing is obviously not very secure at the moment.
- Added /var/empty to the image. It will be the chroot target for ssh.
* Changed vfs.cpp:get_cwd() so that the io_context::io_mutex is no
longer held when calling dir_vnode_to_path().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24673 a95241bf-73f2-0310-859d-f6bbb57e9c96

Introduce __set_errno() throughout libroot.

* add errno_private.h, which defines the __set_errno() macro with
and without tracing
* instead of setting errno manually, all libroot's code now invokes
__set_errno(), which makes it much easier to trace changes to errno
* redirect glibc's use of __set_errno() to our own version

* Implemented support for chroot:
- Added a "root" vnode to the io_context. It is used for resolving
paths and converting nodes to paths instead of sRoot. Some more
passing around of io_context structures was necessary.
- Introduced a new lock sIOContextRootLock to protect
io_context::root. The current uses of io_context::io_mutex
(put_vnode(), remove_vnode() while holding it) looked too suspicious
to use that mutex in vnode_path_to_vnode().
- Added _kern_change_root() syscall and chroot() libroot function.
- Added chroot coreutils program to the image. Funnily it seems to be
much easier to set up a little jail than under Linux (just copy
bash and libroot.so into respective subdirs; mount another pipefs
if you want pipe support).
With Haiku allowing direct access to directories via inode IDs
jailing is obviously not very secure at the moment.
- Added /var/empty to the image. It will be the chroot target for ssh.
* Changed vfs.cpp:get_cwd() so that the io_context::io_mutex is no
longer held when calling dir_vnode_to_path().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24673 a95241bf-73f2-0310-859d-f6bbb57e9c96