The dumping of tty peers is somewhat tricky. And it became more
complex once we allowed to migrate/inherit sessions.
It's being found (in screen c/r) that we've a problem in looking
up of session leaders while dumping tty.
Let me explain with more details. Here is an example of screen
session
PID GID SID
20567 20567 20567 SCREEN
20568 20568 20568 pts/3 \_ /bin/bash
The screen opens master peer (ptmx) and then provides
bash the slave peer (pts/3) where bash sets up a session
leader on it.
Thus we get interesting scenario -- our pstree construction
is done in lazy fashion, we run parasite code to fetch sid/pgid
of a process tree item only when we're really dumping the task.
Thus when we start dumping ptmx peer (which belongs to SCREEN)
we've not yet constructed the process tree item for children
(ie /bin/bash) and the lookup function in tty code (which walks
over all process items in a tree) simply fails to find sid of
child, because we've not yet dumped it.
Thus, to resolve such situation we verify tty sids at late stage
of dumping.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On my testing machine these defs are not present
so define them where needed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Get the info from kernel diag message (it should always be there)
and restore the shutdown at the very end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be required to support socket bound to devices.
When restoring w/o net namespaces -- collect existing devices.
When restoring with them -- collect what is received from image.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This option will tells the tool to procceed dumping
even if a root task is not a session leader.
This implies that this option will allow to "migrate"
one external tty connection. Say a person may dump
"top" application in one bash shell and restore it
in another shell session.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We will need it for slave ttys migration. They serve for one purpose --
to clone self stdio descriptor and use it with tty layer, which will
be addressed in further patches.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It should fit the sa_sigaction declaration, otherwise compiler
complains about uncasted assignments.
| restorer.c: In function тАШ__export_restore_taskтАЩ:
| restorer.c:318:20: error: assignment from incompatible pointer type [-Werror]
So just use siginfo_t here from the system signal.h header.
Signed-off-by: Andrew Grigorev <andrew@ei-grad.ru>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
No magic here, just fetch info using getpriority and sched_getxxx calls.
Good news is that the mentioned syscalls take pid as argument and do work
with it, i.e. -- no need in parasite help here.
Restore is splitted into prep -- copy sched bits from image on restorer
args -- and the restore itself. It's done to avoid restoring tasks info
with IDLE priority ;) To make restorer not-fail sched bits are validated
for sanity on prep stage.
Minimal sanity test is also there.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Some file-type specific parameters can be fetched with
parasite code only, so lets carry parasite control block
pointer in struct fd_parms.
This is a bit ugly but requires less code to touch and
enough for now. In long terms we need some more generalized
routine/hooks which would depends on file type.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Will need it to fetch tty link parameters. This is
because the kernel provides SID/PGID related to the
caller context, and if we're dumping the process inside
namespace -- we need local SID/PGIDs, not global ones.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if here no task found which would restore
controlling terminal -- exit with error instead of
continue with just error message.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
No need for memcpy here, it's plain integer value
which need to be filled.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Dumping them is performed via parasite, since calling the getgroups
is the only way of getting the complete list. Currently the nr of
groups to dump is limited explicitly with the size of shared memory
between crtools and parasite. This is MUCH more that we have seen
on real apps so far.
Restoring is done early, before restorer blob not to carry the undefined
array of grpous in there. This is OK, since groups do not affect us at
that point and are not affected by subsequent creds restore.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Getting groups can be done vie proc, but there's only 32 on them,
while task may have up to 65k :( We will use parasite for that and
thus require this syscall definition.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently move there the secbits dumping, which is not dumped
via misc-dumping command. This patch is required to support
per-task groups dumping (setgroups/getgroups) -- we'll have to
drain the groups from parasite.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I believe this make sense to keep this structure
in pstree.h where pstree related data lives.
Also I've added some comments on struct pid members.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
- @list member closer to @children
- add some comments on memebers
- add space lines for members grouping
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Remove the restorer-log and link log-simple into restorer
blob. Now we can use the normal pr_foo API.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's supposed to be used by parasite and restorer blob. It
has API equal to the core one -- with setfd, set_loglevel and
(the main thing) print_on_level fn. It currently supports only
strings, decimal and hex numbers (int and long).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It reads /proc/PID/fd and close all descriptors except service fds.
v2: s/is_one_of_service_fds/is_any_service_fd
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For executing an external tools we need to block a SIGCHLD
and to juggle file descriptors.
SIGCHLD is blocked for getting an exit code.
A problem with file descriptors can be if we want to set 2 to STDIN,
1 to STDERR, 0 to STDOUT for example.
v2: use helpers reopen_fd_as and move_img_fd
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
By default crtools shouldn't modify the environment, except for
killing the dumped tasks. The link remap does so and should sit
under explicit cmdline option.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
These are not ghost, as they are still on fs, so we cannot take
them with us in the image. Neither we can easily find the other name
of that file. Sad :(
To make it work we linkat() the new name to that file using the
AT_EMPTY_PATH flag to link directly to the opened fd. If we could
openat() the fd's parent we would better do it, but we can't and
thus have to create the link name by explicit absolute path :(
This modifies the fs we're dumping, so I'll introduce one more cmd
line option for that soon.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For linked remaps we'll use similar technique as for ghost
files, but lighter. For that sake make reg_file_info remap
to file_remap, not to the whole host_file.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The biggest acheivement since v0.1 -- initial support for LXC containers!
Other less notable (but still great) things done are:
* Implemented support for TTY-s
* Added support for packet sockets
* Bug-fix here and there
Note, that images generated by v0.1 tool are accepted by v0.2 one.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We don't support yet detached terminals migration,
so fail early if we can't proceed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In commit 97cfb707 we extended scm_fdset structure
up to 7K thus we need to increase the parasite stack
size enough to hold it. It was not noticed simply because
we were poking arguments area of memory.
The memory map of args and stack for parasite look like
+-----------+ min address
| | |
| arguments | v (8K)
| |
+-----------+
| |
| stack | ^ (16K)
| | |
+-----------+ max address
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Otherwise there is a race between files with same names:
link(name -> ghost) link(name->ghost)
open(name)
unlink(name)
open(name) -> ENOENT
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
One function is used on restoring and one is used on dumping,
so each function has own prefix rst or cpt.
The both functions have the same effect, so the main part of the names
is same and it describes "unlock_tcp_connections".
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Scripts are executed when external actions required.
CRTOOLS_SCRIPT_ACTION contains a required action.
If a script doesn't know a current action, it should exit with 0.
The first usecase will be lock/unlock network.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
TCP_REPAIR should be droppet when a network is unlocked.
A network should be unlocked at the last moment, because
after this moment restore must not failed, otherwise a state of
a tcp connection can be changed and a state of one side in our image
will be invalid.
v2: use xremalloc instead of mmap and remmap
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Use sys_setsockopt and declare a function in a header as "static inline"
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
There are places when we have to select which fd to ->open
and which to ->receive. To avoid deadlocks we sort them in
an ascending order on { pid, fd } pair.
Make this idea more formal by introducing an explicit function
doing this check and call it where appropriate (pipe.c master
selection is also simplified to fit new ... API).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Don't do explicit switch by file type in files.c and don't export
intimate knowledge of pty being master/slave. Use a file desc op
for that.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We need to do two non-trivial things with ttys -- interconnect
slaves to masters (or to each other) and setup ctl-tty restoring
task.
Now this is done in subsequently depending on each other steps:
1. collect ttys
2. interconnect slaves and mark ctl-tty tasks
3. collect fake fds for tty-ctl tasks
4. setup orphaned slaves
We can relax this logic in two ways:
1. don't split marking ctl-tty tasks and then creating fds for them
do it in one step at the end
2. don't interconnect slaves with masters and orphaned slaves in
two steps -- do it in one place after fds are collected
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if there is no master peer associated
with a slave peer we have two cases
- the master peer was closed before slave
- we just have no master peer at all, but
only slave one
This patch addresses only first case -- we open
fake master and hook slaves on it, then close it
immediately.
The second case will be addressed later.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
