crtools should not failed, if new images are absent.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
* The following files goes into the directory arch/x86/include/asm unmodified:
- include/atomic.h,
- include/linkage.h,
- include/memcpy_64.h,
- include/types.h,
- include/bitops.h,
- pie/parasite-head-x86-64.S,
- include/processor-flags.h,
- include/syscall-x86-64.def.
* Changed include directives in the source files that include the headers
listed above.
* Modified build scripts to reflect the source moves.
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We need to test every even index (which represents a slave
peer) thus use modulo operation here.
Reported-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since we have find_next_bit in our sources now, lets
use for_each_bit helper to speedup a search procedure.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we're dumping the peer which another
end belongs not to us but some other application
the attempts to flush data may lead to endless
SIGTTOU storm:
| 1158 ioctl(53, TCFLSH, 0x2) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
| 1158 --- SIGTTOU {si_signo=SIGTTOU, si_code=SI_KERNEL, si_value={int=5, ptr=0x5}} ---
| 1158 --- stopped by SIGTTOU ---
| 1158 ioctl(53, TCFLSH, 0x2) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
| 1158 --- SIGTTOU {si_signo=SIGTTOU, si_code=SI_KERNEL, si_value={int=5, ptr=0x5}} ---
| 1158 --- stopped by SIGTTOU ---
so simply don't flush data, the initial attempt to use
TCIOFLUSH was rather "hey, we don't have a way to
say the kernel to freeze tty link for a while, lets
try to workaround this limitation" but without proper
kernel help this won't work anyway as Andrey has discovered.
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The controling terminal should be sestored by a session leader,
thus we need to test if the SID we've found in process tree
is a leader.
Otherwise we might have pretty interesting situation: the user
passed -j on dump, ie telling us to inherit shell jobs and on
restore procedure the SID get inherited from the crtools but
session leader for this sid doesn't belong to our peocess tree
and thus we should not try to restore controlling terminal
but inherit it as well.
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's almost the same as find_first_sid, lets use
it instead.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have own mechanism to restore controlling
terminal thus we don't need the kernel to create
it in implicit way.
#2409
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's being found that we fail to restore tasks which
are not session leaders but have controlling terminals.
This patch reworks tty_find_restoring_task logic to fix
the problem. The problem itself basically was the following --
in case if there no sid present even on master peer or on both
master/slave peers, we were trying to find a restoring task,
and that's wrong since we have peers which do not belong our
session.
#2409
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The slave peer should be restoring the controlling terminal.
It works for most of programs but need some more investigation
in future.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
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>
The sid may be present not only on slave peer
so fix up the message. Also extend it showing
peer type.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
No need for tricks, we fetch everything we need
from the parasite.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if at checkpoint time we've fetched zero sid
associated with tty peer it doesn't obligatory means
that we've met a hangig up terminal, in particular
zero sid may be obtained if the slave peer do not
belong to the session the task run in but inherited
from the parent. Thus if --shell-job passed we should
handle such situation gracefully.
[ https://bugzilla.openvz.org/show_bug.cgi?id=2405 ]
Reported-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is rather a code tossing for the next patch.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case of errors it provides us more information about what is going on.
For example, in my test case I now can see where the error came from
| (00.027248) tty: Unpaired slave 0
| (00.027261) tty: Unpaired slave 2
| (00.027273) Error (tty.c:174): tty: Only one slave external peer is allowed (index 2)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if we've dumped a slave peer only (say a user dumped `top'
application) we should migrate it on current active terminal, which
barely an own standart stream prepared for us by the file engine.
Note only one external slave peer is allowed simply because
otherwise we can't distinguish which indices should be used
for each of them.
The patch basically does the following things
- Check if the SID present on peer exist in current
process tree, we need to be sure that we can restore
peer parameters and controlling terminal if present
- Rename pty_open_fake_ptmx to pty_open_unpaired_slave
because we might be inheriting SELF_STDIN_OFF instead
of opening fake master peer
- Do inherit SELF_STDIN_OFF and restore tty group if
we are restoring external tty
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We need to make sure that the only one external tty
is present, since otherwise we have no idea on which
pts index to connect them on restore.
This patch extends tty_verify_active_pairs procedure to
count how many external tty is present in the dump image.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Upon reception of tty we need to mark it in @tty_active_pairs
bitmam thus we will be able to verify if
- all active ttys obtained are paired
- if not paired then only one external tty is allowed
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>
We need to use namespace local sid/pgid parameters
assigned on tty link, thus use parasite helper.
Otherwise we might fail on restoring controlling
terminal inside namespace (though everything else
will work even without this patch).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since we've started fetching sid/pgid from the
dumpee context we're allowed to obtain sid/pgid
on a slave peer. This is perfectly valid. So
drop this test.
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>
The system termios structure and our PB
equivalent defined quite different, while
first defined as plain array we use dynamically
allocated memory. Thus the use of min() macro
is incorrect here and always produce the size of
pointer.
Fix it using the size of array from the system
provided structure. The BUILD_BUG_ON will prevent
from accidental changes.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
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>
Will need it to verify that live tty pairs exist.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
To trace paired ttys we will need one more bitmap
so rename tty_test_and_set_index to tty_test_and_set
because we will need this helper in another context.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
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>
tty entries might have no parameters assigned if they
are hanging on closed master, we should take into
account when we do verify them.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
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>
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>
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>
