During the dump phase, /proc/cgroups is parsed to find co-mounted cgroups.
Then, for each task /proc/self/cgroup is parsed for the cgroups that it is a
member of, and that cgroup is traversed to find any child cgroups which may
also need restoring. Any cgroups not currently mounted will be temporarily
mounted and traversed. All of this information is persisted along with the
original cg_sets, which indicate which cgroups a task is a member of.

On restore, an initial phase creates all the cgroups which were saved. Tasks
are then restored into these cgroups via cg_sets as usual.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

If pfn = 0 it means we hit something very strange
condition but better to not yield BUG_ON here,
better exit with error for future investigation.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Cyrill:  we exclude these tests because of braindamaged scheme
         btrfs uses for subvolume device numbering which we don't
	 yet support in inrmaps.

Test: zdtm/live/static/inotify_irmap, Result: FAIL
==================================== ERROR ====================================
Test: zdtm/live/static/inotify_irmap, Namespace: 1
Dump log   : /mnt/btrfs/workspace/test/dump/inotify_irmap/16077/1/dump.log
--------------------------------- grep Error ---------------------------------
(00.024342) Error (irmap.c:80): irmap: Can't stat /var/spool: No such file or directory
(00.024365) Error (irmap.c:80): irmap: Can't stat /lib/udev: No such file or directory
(00.024378) Error (irmap.c:80): irmap: Can't stat /no-such-path: No such file or directory
(00.024383) Error (fsnotify.c:184): fsnotify: Can't dump that handle
(00.024397) Error (cr-dump.c:1563): Dump files (pid: 16090) failed with -1
(00.024779) Error (cr-dump.c:1911): Dumping FAILED.
------------------------------------- END -------------------------------------
================================= ERROR OVER =================================
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Make pre-dump twice and then dump and restore.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Reported-by: Robert Reinecke <reinecke@rbg.informatik.tu-darmstadt.de>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

As per current top commit (9c0c23c0) the amount of code in CRIU
_without_ the contents of the test/ directory is

$ git grep -l . | egrep -v ^test | xargs wc -l
...
49999

This is the only chance for such a great one-liner :)

The place in the code is not completely random -- it's one of the
few occurrences of two consecutive empty lines in a .c file.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Tested-by: Andrew Vagin <avagin@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Ruslan Kuprieiev <kupruser@gmail.com>

It will be rmdir-ed a bit later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

CRIU doesn't support relative unix sockets paths, so
tune the test to use absolute.

(v2: Off-by-one spotted by Filipe)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Otherwise the connection can be disconnected due to a timeout, because
the kernel may drop packets from a receive queue (RcvPruned in
/proc/net/netstat).

Half of buffers always stay in the socket, another half is circulated.
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>

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

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

When cwd is removed (it can be) we need to collect the respective
file_desc before starting opening any files to properly handle
ghost refcounts. Otherwise we will miss one refcount from the
cwd's on ghost, which in turn will either BUG inside ghost removal,
or will fail the cwd due to the respective dir being removed too
early.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

The prepare one will become more complicated soon.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

If we have opened and rmdir-ed directory, the dump works OK
creating the ghost file and remap, but restore creates _file_
instead of directory.

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

Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

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

When we have opened and unlinked chr or blk device, we
shouls also take care of their rdev value. Thus -- new
field in image and some new steps on dump and restore.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

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

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

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

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

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

Some tests require custom options for dump and restore. Instead
of hard-coding test names into zdth.sh, introduce the $test.opts
file from which zdtm would pick the needed options.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

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

On ARM some PTRACE_... constants are not declared in sys/ptrace.h file.
They are in linux/ptrace.h, but on x86 this file somewhat conflicts with
the sys/ one. For now fix ARM compilation by using criu/ one and think
of it later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

Andrey validly pointed out, that restoring pdeath_sig is not
compatible with criu_restore_child() call -- after criu restore
children, it will exit and fire the pdeath_sig into restored
tree root, potentially killing it.

The fix for that could be -- when started in swrk more, criu can
restore tree not as children tasks, but as siblings, using the
CLONE_PARENT flag when fork()-ing the root task.

With this we should also take care about errors handing -- right
now criu catches the SIGCHILD from dying children tasks, and
since we plan to create them be children of the criu parent (the
library caller) we will not be able to catch them. To do so we
SEIZE the root task in advance thus causing all SIGCHLD-s go to
criu, not to its parent.

Having this done we no longer need the SUBREAPER trick in the
library call -- tasks get restored right as callers kids :)

Some thoughts for future -- using this trick we can finally make
"natural" restoration of shell jobs. I.e. -- make criu restore
some subtree right under bash, w/o leaving itself as intermediate
task and w/o re-parenting the subtree to init after restore.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Andrey Vagin <avagin@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>