The init process can exit if it doesn't have any child processes and its
pidns is destroyed in this case. CRIU dump is running in the target pid
namespace and it kills dumped processes at the end. We need to create a
holder process to be sure that the pid namespace will not be destroy
before criu exits.
Fixes: #1775
Signed-off-by: Andrei Vagin <avagin@gmail.com>
os.WEXITSTATUS() returns the process exit status and it should be used
only if WIFEXITED() is true, i.e., the process terminated normally.
os.waitstatus_to_exitcode() does the same as os.WEXITSTATUS() but it
also handles the case when the process has been terminated by a signal.
Suggested-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
We see that on criu-ns dump/restore/dump of the process which initially
was not a session leader (with --shell-job option) we see sid == 0 for
it and fail with something like:
Error (criu/cr-dump.c:1333): A session leader of 41585(41585) is outside of its pid namespace
Note: We should not dump processes with sid 0 (even with --shell-job) as
on restore we can can put such processes from multiple sessions into
one, which is wrong.
Fixes: #232
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
PEP 394 recommends changing python shebangs to python3 when Python 3.x
is supported. This is similar to `crit-python3`.
https://www.python.org/dev/peps/pep-0394/
Signed-off-by: Radostin Stoyanov <radostin@redhat.com>
The criu-ns script creates a new PID namespace where criu is the "init"
process. When using the --restore-detached option with criu-ns, users
expect criu-ns to exit without killing the restored process tree.
Thus, criu-ns should not pass the --restore-detached to criu to prevent
it from terminating, and it should exit instead of waiting for criu's
exit status.
Resolves#1278
Suggested-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
This change extracts some of the duplicated code from
set_pidns() and set_mntns() functions.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
Raising an exception breaks out of the normal
flow of control of a code block. When an exception
is not handled, the interpreter terminates execution
of the program, or returns to its interactive main loop.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
criu-ns performs double fork, which results in criu restore
using PID=2. Thus, if a user is trying to restore a process
with that PID, the restore will fail.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
class ctypes.c_char_p
Represents the C char * datatype when it points to a zero-
terminated string. For a general character pointer that may
also point to binary data, POINTER(c_char) must be used.
The constructor accepts an integer address, or a bytes object.
https://docs.python.org/3/library/ctypes.html#ctypes.c_char_p
Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
In Py2 `range` returns a list and `xrange` creates a sequence object
that evaluates lazily. In Py3 `range` is equivalent to `xrange` in Py2.
Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
So, here's the enhanced version of the first try.
Changes are:
1. The wrapper name is criu-ns instead of crns.py
2. The CLI is absolutely the same as for criu, since the script
re-execl-s criu binary. E.g.
scripts/criu-ns dump -t 1234 ...
just works
3. Caller doesn't need to care about substituting CLI options,
instead, the scripts analyzes the command line and
a) replaces -t|--tree argument with virtual pid __if__ the
target task lives in another pidns
b) keeps the current cwd (and root) __if__ switches to another
mntns. A limitation applies here -- cwd path should be the
same in target ns, no "smart path mapping" is performed. So
this script is for now only useful for mntns clones (which
is our main goal at the moment).
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Looks-good-to: Andrey Vagin <avagin@openvz.org>
