Two walkers -- in forward and reverse directions -- are required
for correct (u)mounting of subtrees. Implement them using a helper
macro which walks the tree in both directions.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Namespace restore goes in two steps -- first, clean old mountpoints
(except root) that are left after clone(CLONE_NEWNS) call. Next,
repopulate the namespace with new mountpoints (except root) read
from the image file.

This patch adds the skeleton for the above -- reading the mountpoints
from current proc and image and calling for mount/umount. The real
action will come in further patches.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Build a tree of mountpoins that can be (u)mounted in a straight
(forward or backward) order without EBUSY errors.

The tree is built in two steps -- first create hierarchy based
on mount iDs. Next -- resort siblings in the path depth order.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Encode it in u32 since we have to check filesystem name anyway
(not everyone ie easily migratable).

Dump _any_ root fs as we need the root entry on restore though
do not mount it then -- it should be provided before crtools
restore start.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Dumping is straightforward -- just copy all the mount_info
fields into the new image file. Dump everything but fstype,
this one will come in a separate patch.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This structure will be used on restore and will be created
from the image, thus the name proc_ is not suitable.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

On the restore path this structure will be used and it
will be better to have them char * rather than char[64].

When scanning proc use the %ms specifier for this.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It's not required more, because parasite_status_t was removed.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In olden times, when people didn't know how to write,
they sent a courier with a letter.

Now we can write messages from parasite, so SET_PARASITE_RET may be dropped.
Signed-off-by: Andrey Vagin <avagin@openvz.org>

Looks good to me as well. Maybe we will refine messages to be able
to identify where exactly parasite failed (say line). But it better
to do in another patch.
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

 - add argument names
 - align members
 - add extern kw
 - group struct decl. on top
 - make file_desc_ops::type being unsigned
   integer similar to fdtype_ops::type
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

These are declared in files-reg.h, so get rid of
them and add files-reg.h inclusion where needed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

* check, that pseudoterminals are restored
* check, that a control terminal is restred
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

    2     2 session00
    4     4  \_ session00		# {NEWSID, },
    2     5  \_ session00		# {0, },
    8     8  \_ session00
    2     9  |   \_ session00           # {CHANGESID, }
   10    10  \_ session00
   11    11      \_ session00
    2    12          \_ session00	# {DOUBLE_CHANGESID | CHANGESID, }
    2     3 session00			# {DETACH, },
    6     7 session00			# {DETACH|NEWSID, },
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Don't fail if a root non-init task has another sid, because
it's inherited from parent and can't be restored and
it's expected behaviour, when a subtree is dumped.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Now crtools can restore sid in all cases.
A restore of pgid will be added soon and now it will fail on restore.

It's prevent testing of restoring SIDs.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It's sign, that a parent has been changed sid after forking a child.
We should know a sid with which a process was born, because in a processes
chain, more then one process might change SID.

v2: fix names of variables
v3: prevent rewriting of born_sid
v4: Abort the restorer with error message if a born_sid can't be determing.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

* Create helpers for processes which have been reparented to init.
* Insert helpers in a process tree.
* Helpers will exit after constructing a process tree.

v2: fix variables names and check errors
v3: add comments in code
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

They will be used for restoring sid. For example, if a session
group leader is absent, a helper process is created with this id
and it will die after restoring all other tasks.

Before this patch restore failed if anyone exited.
Now we should skip helpers, which exited successfully. It's a bit tricky.
All children are collected in sigchld_handler, but we have a point,
where we want to wait all helpers. For that waitpit is used and ECHLD
is ignored, because it signs that a helper exited and has been waited in
sigchld_handler.

v2: check that me isn't NULL in the sig handler
v3: move code about waiting helpers in a separate function
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It will be used for allocating PIDs for helper tasks
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

s/pid/virt/
s/real_pid/real/
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

to require dumping pid namespace. Dump and restore will be failed if
a tress doesn't contain a process init.

pid namespace will be created implicitly if a process init in the tree.

v2: fix comments from Pavel
v3: Restore of pidns should be approved by user
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Current if/if/else scheme is ... not so easy to understand. Here's an
attempt to make it more readable. Bonus: free comments.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

When creating transport we have to find the corresponding fle. Currently
this is done by desc list scan %) but this is an overkill -- the required
fle is already at our hands.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In the open_fdinfo we need to get a file_desc associated with the given
fdinfo_list_entry. This is done by searching the hash of descs, but this
can be speeded up by saving the desc pointer on the fdinfo at the time
of collecting them.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

because now it cares about tid_addr and thread id.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Victor konyashkin <vkonyashkin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

xmalloc'ed gf and gf->path are not freed if something failed.
Not a big deal since we're ususally interrupt program execution
on error and do exit, but anyway.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This eliminates holes in structures. No func changes.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

No need to carry static per-file variable, we need
it in one non-recursive function only so make it
stack based instead.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Instead of spreading regular files handling code over
files.c and cr-dump.c move it to files-reg.c.

This allows to extend regular file handling code in
future without disturbing other source files and
make code logically coupled, where files.c is mostly
a place for general file handling code unrelated to
file type specifics.

While mostly it was code tossing there is some change
I have to notice -- the structure ghost_file was previously
declared in two paces cr-dump.c and files.c, in cr-dump.c
it was used for dumping while in files.c it was used
for restore. The structure had different members.

So to resolve this conflict the ghost_file structure
was renamed to ghost_file_dumpee.

Nothing else is changed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

bash returned the error : No such file or directory
and doesn't add three test cases to the list.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The socket_desc is being looked up in dump_unix/dump_inet. In
the dump_socket this desc is only required to obtain a family,
which in turn can be done with a getsockopt.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>