If we've met a hanging up terminal we can escape
lot of work but dump a minimum information needed
for restore.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This patch squashes tty_get_sid, tty_get_pgrp into
one tty_get_sid_pgrp helper (which allows to detect
if dumping terminal is hanging up, the real use of
this ability will be addressed in next patch).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The dangling slave peers might have no data associate
with them if master peer is closed and link is hanging
up. Thus make this parameters optional to not blow the
image with data which never will be used.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Add ability to use the same macros in restorer code.
In the future we will add ability to show arguments like printf.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Instead -- mmap it once in root task and then mremap it later.
No mremap of original restorer can be done, since in that case
the restorer vma would be tied to crtools binary which in turn
will make set-exe-file prctl to fail with EBUSY.

Note -- after mremap the original vmas list becomes non relevant,
but it's OK. Only new holes appear inside which is OK for munmap.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

This will avoid exec bit on restorer args and will make
it possible for shared restorer eventually.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

There was a strange thing -- task args size is aligned, but when
threads args ptr is get this alignment was lost. Fix this and make
all the bufs page-aligned.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

Put the states into in one place.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

pid == pid && fd == fd equals fle == fle :)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

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

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

Testcase: fork child, chdir into /proc/$pid and kill child.

test for http://bugzilla.openvz.org/show_bug.cgi?id=2315Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Redirect standard descriptors of a test init process in to the log file.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It was lost for tests which executed in a new namespaces.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The test creates two processes.
A first process creates a tcp server, a second one connects to it.
The first process is dumped and restored.
Then the test checks that the TCP connection is alive.

v2: fix compilation :)
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: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We're using get_service_fd in file engine,
better to make it fast. This patch caches
the limits system provides us, instead of
calling getrlimit() every time.

This patch introduces is_service_fd helper
which will be used instead of get_service_fd
where it make sense.
Signed-off-by: Cyrill Gorcunov <gorcunov@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>

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

Add test for screen c/r.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
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>

Non-opened control terminal

* Set a control terminal
* Close a file descriptor on it
* Dump/restore
* Open the control terminal (/dev/tty)
* Check, that it connected to the master end
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The test is tricky -- it opens master in task 1
and dup it in task 2, then close in task 1 and
do C/R.

Thus we need to setup SID of master terminal
somehow in children, which usually fails in
currnt tty restore implementation.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Two slaves on same pty.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The idea behind is pretty simple -- once we find
that there is a controlling terminal present we
do call ioctl on appropriate /dev/pts/N.

This is done in a bit unusuall manner. When we
find that there is a controling terminal present
we do create an additional FdinfoEntry for it
with object id taken from existing master peer.

The file engine stack this new FdinfoEntry on
fd_info_head head list. Thus we will have at
least two entries on this list. One for real
Fdinfo associated with master peer and one for
our new generated Fdfinfo entry, it depends on
pid which one become a file master.

Finally we do use post_open_fd hook in our
tty code which allows us to open controlling
terminal and yield proper ioctl on it.

v2:
 - restore control terminals via service fd,
   still need to speedup service fd retrieval.

v3:
 - use prepare_ctl_tty() helper to generate
   control terminal fdinfo entry

v4:
 - use post_open_fd
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>

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

Usually the PTYs represent a pair of links -- master peer and slave
peer. Master peer must be opened before slave. Internally, when kernel
creates master peer it also generates a slave interface in a form of
/dev/pts/N, where N is that named pty "index". Master/slave connection
unambiguously identified by this index.

Still, one master can carry multiple slaves -- for example a user opens
one master via /dev/ptmx and appropriate /dev/pts/N in sequence.
The result will be the following

master
`- slave 1
`- slave 2

both slave will have same master index but different file descriptors.
Still inside the kernel pty parameters are same for both slaves. Thus
only one slave parameters should be restored, there is no need to carry
all parameters for every slave peer we've found.

Not yet addressed problems:

- At moment of restore the master peer might be already closed for
  any reason so to resolve such problem we need to open a fake master
  peer with proper index and hook a slave on it, then we close
  master peer.

- Need to figure out how to deal with ttys which have some
  data in buffers not yet flushed, at moment this data will
  be simply lost during c/r

- Need to restore control terminals

- Need to fetch tty flags such as exclusive/packet-mode,
  this can't be done without kernel patching

[ avagin@:
   - ideas on contol terminals restore
   - overall code redesign and simplification
]

v4:
 - drop redundant pid from dump_chrdev
 - make sure optional fown is passed on regular ptys
 - add a comments about zeroifying termios
 - get rid of redundant empty line in files.c

v5 (by avagin@):
 - complete rework of tty image format, now we have
   two files -- tty.img and tty-info.img. The idea
   behind to reduce data being stored.

v6 (by xemul@):
 - packet mode should be set to true in image,
   until properly fetched from the kernel
 - verify image data on retrieval
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

When we will be restoring ttys we need that restore
procedure for master peers will be yielded earlier
than for slave peers due to ttys specifics. With this
commit we introduce @tty_slaves list which will allow
us to order tty file restore procesure.

Because we need to fetch which list to be used depending
on tty type this patch extend select_ps_list with fdinfo_list_entry
parameter.

v2 (by xemul@):
 - make sure the epoll list is still last
Signed-off-by: Cyrill Gorcunov <gorcunov@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>

This is normal situation -- eventpoll fd may have no fds attached
thus resulting in empty fdinfo file. Report OK in that case.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Otherwise a transport fd may be added to eventfd...
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It will be used for restoring epollfd.
Currently a transport fd may be added to epollfd.
epollfd should be populated, when all descriptors were already received.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

I tried to fix that by:
commit bc2ac71c
Author: Andrey Vagin <avagin@openvz.org>
Date:   Wed Sep 12 15:16:39 2012 +0400

    sk-unix: don't add a socket in a second time

but made a mistake and now a peer would be added only if it's in a list.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Before we checked only one connection.
With this patch the test reproduces a bug:

Error (sk-unix.c:395): BUG at sk-unix.c:395
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

A socket can be added in a list two times, if two other sockets
are connected to it.

This patch fixes a problem:
    Error (sk-unix.c:395): BUG at sk-unix.c:395
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

* A message about external sockets is printed before any action.
* Add a message, when a peer is added in a list of sockets.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>