We have the same check a few lines above.

v2: fix the subject
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

$ cat /proc/self/mountinfo
...
1 1 0:2 / / rw - rootfs rootfs rw,size=373396k,nr_inodes=93349
...

You can see that mnt_id and parent_mnt_id are equals here.
This patch interpretes this case as a root mount in a tree.

0'th mount is rootfs, which is mounted in init_mount_tree().

We don't see it in cases when system makes chroot, because of

static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
	...
	/* mountpoints outside of chroot jail will give SEQ_SKIP on this */
	err = seq_path_root(m, &mnt_path, &root, " \t\n\\");

Cc: beproject criu <beprojectcriu@gmail.com>
Cc: Christopher Covington <cov@codeaurora.org>
Reported-by: beproject criu <beprojectcriu@gmail.com>
Reviewed-by: Christopher Covington <cov@codeaurora.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Pid is 10 chars maximum.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

When we compare sets in cg_set_compare() we presume that controller
names are properly sorted but because of use of strcmp(cc->path, path)
it's not true. In particular in case if there are two same sets which
differ in paths only

(00.126812) cg:  `- New css ID 2
(00.127051) cg:     `- [memory] -> [/vz-1]
(00.127079) cg:     `- [name=systemd] -> [/vz-1]
(00.127108) cg:     `- [net_cls] -> [/vz-1]

(00.239829) cg:  `- New css ID 3
(00.240067) cg:     `- [memory] -> [/vz-1]
(00.240096) cg:     `- [net_cls] -> [/vz-1]
(00.240154) cg:     `- [name=systemd] -> [/vz-1/system.slice/dbus.service]

we currently refuse to dump such configuretion. Thus remove
path comparision from the first place.

CC: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

mntinfo contains mounts from all namespaces, so we can validate it only
once after collecting mounts.

v2: add a fake comment about goto
v3: add a real comment about goto
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

I'm not quite sure what the difference is (I have gcc 4.8, but there are
probably also header differences), but when I compile the service on 14.04 I
get:

  CC       cr-service.o
cr-service.c: In function ‘start_page_server_req’:
cr-service.c:536:8: error: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Werror=unused-result]
   write(start_pipe[1], &ret, sizeof(ret));
        ^
cr-service.c:544:6: error: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Werror=unused-result]
  read(start_pipe[0], &ret, sizeof(ret));
      ^
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Tested-by: https://travis-ci.org/avagin/criu/builds/34990769Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

avoid err() for regular msg reporting
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

tmpfs has the "size" option, which is not standard.

Execute zdtm/live/static/mountpoints
./mountpoints --pidfile=mountpoints.pid --outfile=mountpoints.out
Dump 2737
WARNING: mountpoints returned 1 and left running for debug needs
Test: zdtm/live/static/mountpoints, Result: FAIL
==================================== ERROR ====================================
Test: zdtm/live/static/mountpoints, Namespace:
Dump log   : /root/git/criu/test/dump/static/mountpoints/2737/1/dump.log
--------------------------------- grep Error ---------------------------------
(00.146444) Error (mount.c:399): Two shared mounts 50, 67 have different sets of children
(00.146460) Error (mount.c:402): 67:./zdtm_mpts/dev/share-1 doesn't have a proper point for 54:./zdtm_mpts/dev/share-3/test.mnt.share
(00.146820) Error (cr-dump.c:1921): Dumping FAILED.
------------------------------------- END -------------------------------------
================================= ERROR OVER =================================
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Tested-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Currently we stript options only one of brothers, but
mount_equal() thinks that two brothers should have the same options.

Execute zdtm/live/static/mountpoints
./mountpoints --pidfile=mountpoints.pid --outfile=mountpoints.out
Dump 2737
WARNING: mountpoints returned 1 and left running for debug needs
Test: zdtm/live/static/mountpoints, Result: FAIL
==================================== ERROR ====================================
Test: zdtm/live/static/mountpoints, Namespace:
Dump log   : /root/git/criu/test/dump/static/mountpoints/2737/1/dump.log
--------------------------------- grep Error ---------------------------------
(00.146444) Error (mount.c:399): Two shared mounts 50, 67 have different sets of children
(00.146460) Error (mount.c:402): 67:./zdtm_mpts/dev/share-1 doesn't have a proper point for 54:./zdtm_mpts/dev/share-3/test.mnt.share
(00.146820) Error (cr-dump.c:1921): Dumping FAILED.
------------------------------------- END -------------------------------------
================================= ERROR OVER =================================
Reported-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Tested-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

"continue" is called by mistake, so we skip a few checks for shared
mounts without siblings.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We have a slight mess with how criu restores root task.
Right now we have the following options.

1) CLI
	a) Usually
	task calling criu
	 `- criu
	     `- root restored task

	b) when --restore-detached AND root has pdeath_sig

	task calling criu
	 `- criu
	 `- root restored task

2) Library/SWRK
	task using lib/swrk
	 `- criu
	 `- root restored task

3) Standalone service
	a) Usually
	service
	 `- service sub task
	     `- root restored task

	b) when root has pdeath_sig
	criu service
	 `- criu sub task
	 `- root restored task

It would be better is CRIU always restored the root task as sibling,
but we have 3 constraints:

First, the case 1.a is kept for zdtm to run tests in pid namespaces
on 3.11, which in turn doesn't allow CLONE_PARENT | CLONE_NEWPID.

Second, CLI w/o --restore-detach waits for the restored task to die and
this behavior can be "expected" already.

Third, in case of standalone service tasks shouldn't become service's
children.

And I have one "plan". The p.haul project while live migrating tasks
on destination node starts a service, which uses library/swrk mode. In
this case the restored processes become p.haul service's kids which is
also not great.

That said, here's the option called --restore-child that pairs the
--restore-detach like this:

* detached AND child:

task
 `- criu restore (exits at the end)
 `- root task

The root task will become task's child.
This will be default to library/swrk.
This is what LXC needs.

* detach AND !child

task
 `- criu restore (exits at the end)
     `- root task

The root task will get re-parented to init.
This will be compatible with 1.3.
This will be default to standalone service and
to my wish with the p.haul case.

* !detach AND child

task
 `- criu restore (waits for root task to die)
 `- root task

This should be deprecated, so that criu restore doesn't mess
 with task <-> root task signalling.

* !detach AND !child

task
 `- criu restore (waits for root task to die)
     `- root task

This is how plain criu restore works now.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Andrew Vagin <avagin@openvz.org>

root_as_sibling was used in criu_signals_setup(), but was only defined later
(when forking the root task for the first time). This meant that the
SA_NOCLDSTOP was never masked off, which meant SIGCHLD was never delivered
after ptracing the root task. Thus, when the a child of the root task died
(e.g. from cr_system), the root task sat in PTRACE_STOP, and the restore task
never PTRACE_CONT'd, resulting in a deadlock.

Instead, we only unmask SA_NOCLDSTOP right before we PTRACE_SEIZE, after the
value is defined.

v2: re-work the condition for CLONE_PARENT
v3: move unmasking of SA_NOCLDSTOP to restore_root_task
v4: keep all the comments in the original code
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

Since the command line for checkpointing and restoring Docker containers
is very long and there are some manual steps involved before restoring
a container, it's much easier to use a shell script to automate the work.

One would simply do:

$ sudo docker_cr.sh -c
$ sudo docker_cr.sh -r
Signed-off-by: Saied Kazemi <saied@google.com>
Acked-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

zdtm.sh with zero iterations of dumping/restoring checks correctness of
tests.

$ bash test/zdtm.sh -i 0 zdtm/inotify00
Output file: /root/git/orig/criu/test/zdtm/live/static/inotify00.out
------------------------------------------------------------------------------
19:16:29.601:  6905: 	unlink 02       : event      0x200 -> IN_DELETE
19:16:29.602:  6905: 	unlink 02       : event      0x200 -> IN_DELETE
19:16:29.602:  6905: 	unlink 02       : event        0x8 -> IN_CLOSE_WRITE
19:16:29.602:  6905: 	unlink 02       : event        0x8 -> IN_CLOSE_WRITE
19:16:29.602:  6905: 	unlink 02       : event      0x400 -> IN_DELETE_SELF
19:16:29.602:  6905: 	unlink 02       : event     0x8000 -> IN_IGNORED
19:16:29.602:  6905: 	unlink 02       : read  6 events
19:16:29.614:  6905: 	after           : event        0x8 -> IN_CLOSE_WRITE
19:16:29.614:  6905: 	after           : read  1 events
19:16:29.614:  6905: FAIL: inotify00.c:217: Unhandled events in emask 0x200 -> IN_DELETE (errno = 11 (Resource temporarily unavailable))
------------------------------------- END -------------------------------------
================================= ERROR OVER =================================

This patch removes logic about linked files, because it's useless.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

BTRFS returns subvolume dev-id instead of superblock dev-id,
in such case return device obtained from mountinfo (ie subvolume0).

v2: fix up devices only for btrfs files.
v3: use phys_stat_dev_match instead of phys_stat_resolve_dev
v4: fix cosmetic whims

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

11: POSIX  ADVISORY  WRITE 1 b6:a4111:136512 0 EOF
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It turns out that we can't be too strict about
queued events -- criu itself generates a number
of them and there is no clear way yet how to resolve
this situation. So defer "strict" mode for now
but print a warning.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

When service starts page server all the preparations (log, wdir, img dir, etc.)
happen in parent task, then we fork page server.

This is OK for now, but when we will serve several requests per connection, all
these resources would be leaked in parent.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The problem with several requests is that criu leaks resources after
doing dump/restore. It's OK since process exits anyway, but for
multy requests per connection it's better to audit this thing.

For now -- allow to do requests after the page-server-start one only.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

That's preparation to "several requests per connection" patch.
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>

It is called from prepare_cgroup_sfd() and cr_restore_tasks().

+ criu restore --file-locks --tcp-established --evasive-devices --link-remap --root /var/lib/vz/root/101 --restore-detached --action-script /usr/local/libexec/vzctl/scripts/vps-rst-env -D /vz/dump/Dump.101 -o restore.log -vvvv --pidfile /var/lib/vzctl/vepid/101
*** Error in `criu': double free or corruption (fasttop): 0x00000000006bcd40 ***

Program terminated with signal 6, Aborted.
Missing separate debuginfos, use: debuginfo-install glibc-2.17-20.fc19.x86_64 libgcc-4.8.3-1.fc19.x86_64 protobuf-c-0.15-7.fc19.x86_64
(gdb) bt
 #0  0x00007ffff72179e9 in raise () from /lib64/libc.so.6
 #1  0x00007ffff72190f8 in abort () from /lib64/libc.so.6
 #2  0x00007ffff7257d17 in __libc_message () from /lib64/libc.so.6
 #3  0x00007ffff725f0b8 in _int_free () from /lib64/libc.so.6
 #4  0x0000000000426971 in cr_restore_tasks () at cr-restore.c:1833
 #5  0x0000000000418426 in main (argc=<optimized out>, argv=0x7fffffffeb38, envp=<optimized out>) at crtools.c:479
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To show which events are coming and flush events before dump as required by new fsnotify mode.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

If a controller is mounted during dumping processes, criu may fail with error:
Error (cgroup.c:768): cg: Set 3 is not subset of 2

so lets create all test controllers before executing tests.

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

Events are not dumped/restored. An idea of ignoring them isn't good.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

There is a potential attack here where if someone is restoring something and
criu write the pid to a file the attacker controls, the attacker can then
re-write that to whatever pid they want. ciru should instead open the file with
O_EXCL so that the restore fails if the file exists.

We don't need O_TRUNC here since we're O_EXCL-ing the file.
Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

If we need to check if current loglevel will suppress
our messagess (say you need to run pr_debug in a cycle)
we can use this helper to eliminate unneded calls.

Like
  if (!pr_quelled(LOG_DEBUG)) {
    ... do something specific to LOG_DEBUG ...
  }
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

All marks are collected in a list and then they are written in
the eventpoll image as a repeated field.

This images merge reduces the amount of image files criu
generates and may simplify the fix of mentioned above issue

v2: save the original order of entries
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

All marks are collected in a list and then they are written in
the fanotify image as a repeated field.

This images merge reduces the amount of image files criu
generates and may simplify the fix of mentioned above issue

v2: don't leak fe.mark_entry
v3: save the original order of marks
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

All watch descriptors are collected in a list and then
they are written in inotify image as a repeated field.

This images merge reduces the amount of image files criu
generates and may simplify the fix of mentioned above issue.

v2: use free_inotify_wd_entry() instead of xfree in dump_one_inotify()
v3: don't leak ie.wd_entry
v4: save the original order of watchers
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The swrk action is turning out to be a cool thing. We can
spawn criu with swrk action with some FD being open, then
ask for dump/pre-dump/page-server telling it that some
descriptor it needs is "out there".

This patch lets us specify that the page server communication
channel is already in criu's fdtable.

TODO: teach regular service to accept fd via service socket.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Here we define new api to be used in plugins.

 - Plugin should provide a descriptor with help of
   CR_PLUGIN_REGISTER macro, or in case if plugin require
   no init/exit functions -- with CR_PLUGIN_REGISTER_DUMMY.

 - Plugin should define a plugin hook with help of
   CR_PLUGIN_REGISTER_HOOK macro.

 - Now init/exit functions of plugins takes @stage
   argument which tells plugin which stage of criu
   it's been called on dump/restore. For exit it
   also takes @ret which allows plugin to know if
   something went wrong and it needs to cleanup
   own resources.

The idea behind is to not limit plugins authors with names
of functions they might need to use for particular hook.

Such new API deprecates olds plugins structure but to keep
backward compatibility we will provide a tiny layer of
additional code to support old plugins for at least a couple
of release cycles.

For example a trivial plugin might look like

 | #include <sys/types.h>
 | #include <sys/stat.h>
 | #include <fcntl.h>
 | #include <libgen.h>
 | #include <errno.h>
 |
 | #include <sys/socket.h>
 | #include <linux/un.h>
 |
 | #include <stdio.h>
 | #include <stdlib.h>
 | #include <string.h>
 | #include <unistd.h>
 |
 | #include "criu-plugin.h"
 | #include "criu-log.h"
 |
 | static int dump_ext_file(int fd, int id)
 | {
 |	pr_info("dump_ext_file: fd %d id %d\n", fd, id);
 |	return 0;
 | }
 |
 | CR_PLUGIN_REGISTER_DUMMY("trivial")
 | CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__DUMP_EXT_FILE, dump_ext_file)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

 - use custom multiline comments style
 - ending #endif comment
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

These guys may have pids that are not met in pstree.
This is not the reason for skipping those, try to
resolve flocks anyway.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Criu may re-lock the lock, thus spoiling the pid, so compare
the file inode number instead.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>