It will be used to restore shared mappings
v2: clean up
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now a name of an image file is hard coded ("smth-%d.img", pid),
but the images of namespaces, shared memery, etc belong to
not one task, so they may have other formats of names, which
will describe objects.
For example a image of shared memory content may have name like
this ("pages-shmem-%ld.img", shmid)
v2: fix comment
v3: rebase
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Using absolute paths for this is dangerous - while doing c/r we should
be extremely carefully and not change tasks' roots and mount namespaces
too early. Sometimes it will not work -- when restoring containers we'll
be unable to switch to new CT and still have the ability to open images.
Rework the images opening via openat and keep the image dir fd open all
the time as the service fd (introduced earlier).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
These are the fds that help us to do c/r. We want them not to intersect
with any "real-life" ones and thus store them close the the file rlimit
boundary. For now only the logfd one is such.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Reserve more mem for bootrstrap code and put all self vmas at its tail.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Remove CR_TASK_XXX states, use the TASK_XXX ones (for image). This is
required to unseize tasks properly in the next patches.
Plus, make sure that pstree_list and the seized set coincide (i.e.
handle error in collect_task).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
When we've seized all the tasks and threads found in /proc check for
the /proc contents be the same. Do it one-by-one as we descend the tree.
This is OK, since tasks cannot create kids for anyone but themselves or
their parents (reparent will be handled later).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
While we try to seize task it can die and give its pid to
somebody else. This can break pstree consistency. Check for
parent being valid after task is seized.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Based on xemul@ patches.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This patch was designed to be generic and thus usable for all kinds of
sockets. Not sure, thah this goal has been reached, but at least I tried.
Key ideas:
1) On-stack structure for collecting sockets queues and then passing them to
parasite code.
2) Singly linked list is used for collecting structures, representing sockets
of any kind (!) with queues.
Based on xemul@ patches.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
v2: New "MSG_STEAL" functionality is used
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
v2: wrappers names become less obfuscating
This patch:
1) Updates function cr_fdset_open() to be suitable for handling fdset creation
for dump and show stages.
2) Replaces cr_fdset_open() by new wrapper function cr_fdset_dump().
3) Replaces prep_cr_fdset_for_restore() by new wrapper function cr_fdset_show().
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This patch removes collect stage and dumps tunables object right after
collect.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This commit brings the former "Rewrite task/threads stopping engine"
commit back. Handling it separately is too complex so better try
to handle it in-place.
Note some tests might fault, it's expected.
---
Stopping tasks with STOP and proceeding with SEIZE is actually excessive --
the SEIZE if enough. Moreover, just killing a task with STOP is also racy,
since task should be given some time to come to sleep before its proc
can be parsed.
Rewrite all this code to SEIZE task and all its threads from the very beginning.
With this we can distinguish stopped task state and migrate it properly (not
supported now, need to implement).
This thing however has one BIG problem -- after we SEIZE-d a task we should
seize
it's threads, but we should do it in a loop -- reading /proc/pid/task and
seizing
them again and again, until the contents of this dir stops changing (not done
now).
Besides, after we seized a task and all its threads we cannot scan it's children
list once -- task can get reparented to init and any task's child can call clone
with CLONE_PARENT flag thus repopulating the children list of the already seized
task (not done also)
This patch is ugly, yes, but splitting it doesn't help to review it much, sorry
:(
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Stopping tasks with STOP and proceeding with SEIZE is actually excessive --
the SEIZE if enough. Moreover, just killing a task with STOP is also racy,
since task should be given some time to come to sleep before its proc
can be parsed.
Rewrite all this code to SEIZE task and all its threads from the very beginning.
With this we can distinguish stopped task state and migrate it properly (not
supported now, need to implement).
This thing however has one BIG problem -- after we SEIZE-d a task we should seize
it's threads, but we should do it in a loop -- reading /proc/pid/task and seizing
them again and again, until the contents of this dir stops changing (not done now).
Besides, after we seized a task and all its threads we cannot scan it's children
list once -- task can get reparented to init and any task's child can call clone
with CLONE_PARENT flag thus repopulating the children list of the already seized
task (not done also)
This patch is ugly, yes, but splitting it doesn't help to review it much, sorry :(
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
v2: strlen() check removed from parse_ns_string()
Now '-n' option must be followed by namespaces tags, separated by commas.
Currently, only "uts" namespace is supported.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Dumping is simple. All but secbits can be read from proc, secbits
are got from parasite.
Restoring is a bit tricky -- when you change anything on kernel
cred's struct it performs sophisticated checks and can change
some more stuff than requested, so the creds restoration procedure
is carefully commented step-by-step.
Another thing to mention is that creds are restored after everything
else, i.e. right before performing final threads sync and sigreturns.
This is done to avoid potential problems with insufficient caps for
restoring other stuff (e.g. CAP_DAC_OVERRIDE or zero euid is most
likely required for opening any image file and the notorious control
/proc/sys/kernel/ns_last_pid, which in turn is performed till the
very last moment).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Only two fields are modifiable -- hostname and domainname. So
read them on dump and write on restore.
File format is simple --
u32 magic
u32 length of nodename
u8[] nodename string
u32 length of domainname
u8[] domainname string
For OpenVZ we can write the release at the end, but this is later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
New option -n to dump/restore namespaces.
Fork the namespaces dumping task and write a helper for switching a namespace.
Prepare the restorer code for restoring namespaces before root task.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Split the CR_FD_ bits into per-task and global ones and replace
of CR_FD_DESC_NOPSTREE with CR_FD_DESC_TASK, which is explicit
set of per-task bits.
The CR_FD_DESC_NS will appear soon.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Timers are dumped from inside parasite code, the format is plain -- just
3 pairs of interval/value one-by-one.
The restoration occurs in two stages -- first prepare the timer values in
restorer (and check for sanity), then setup the timers in the latest stage
before actually calling the sigreturn.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Rename prep_cr_fdset_for_dump into cr_fdset_open and make it reentable, i.e.
every next enter will open more files in the same fdset. Required for zombies
and makes the code cleaner.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
It was being done intentionally to be able to call close_cr_fdset
several times in a row, bring this ability back. Otherwise I'm
getting glibc complains about attemt to free already freed memory.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
The same as previous patch -- no need in two separate calls.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
They always go in pairs so there's no need in two calls.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Path is not needed there -- we can call the get_image_path() in prep_cr_fdset_
routines and in parasite-syscall.c when required.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This one is required on allocation -- it's already there as an argument.
It's also required on free, but we can check for fd being >= 0.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
All the places we need one in can use the direct reference on template.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Introduce a helper for walking the list and sending signals.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Currently it can only work with stream sockets, which have no skbs in queues
(listening or established -- both work OK).
The cpt part uses the sock_diag engine that was merged to Dave recently to
collect sockets. Then it dumps sockets by checking the filesystem ID of a
failed-to-open through /proc/pid/fd descriptors (sockets do not allow for
such tricks with opens through proc) against SOCKFS_TYPE.
The rst part is more tricky. Listen sockets are just restored, this is simple.
Connected sockets are restored like this:
1. One end establishes a listening anon socket at the desired descriptor;
2. The other end just creates a socket at the desired descriptor;
3. All sockets, that are to be connect()-ed call connect. Unix sockets
do not block connect() till the accept() time and thus we continue with...
4. ... all listening sockets call accept() and ... dup2 the new fd into the
accepting end.
There's a problem with this approach -- socket names are not preserved, but
looking into our OpenVZ implementation I think this is OK for existing apps.
What should be done next is:
1. Need to merge the file IDs patches in our tree and make Andrey to
support files sharing. This will solve the
sk = socket();
fork();
case. Currently it simply doesn't work :(
2. Need to add support for DGRAM sockets -- I wrote comment how to do it
in the can_dump_unix_sk()
3. Need to add support for in-flight connections
4. Implement support for UDP sockets (quite simple)
5. Implement support for listening TCP sockets (also not very complex)
6. Implement support for connected TCP scokets (hard one, Tejun's patches are not
very good for this from my POV)
Cyrill, plz, apply this patch and put the above descriptions onto wiki docs (do we
have the plans page yet?).
Andrey, plz, take care of unix sockets tests in zdtm. Most likely it won't work till
you do the shared files support for sockets.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This as well implies we change paths to PATH_MAX size.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelianov <xemul@parallels.com>
Now I try to restore CWD and a relative path will be invalid.
Add new options -D to set image files directory.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Added
- ability to parse every single file crtools
understands via magic number
- dumped memory pages can be rendered in two
modes -- as a simple set of pages' virtual addresses
or in hexdummp fashion (via -c command line key).
For example
./crtools -s -c -f pages-2557.img
CR_FD_PAGES: pages-2557.img
----------------------------------------
7fffb44ace20: 00 00 00 00 00 00 00 00 00 00 00 74 65 73 74 2f |. . . . . . . . . . . t e s t / |
7fffb44ace30: 74 65 73 74 2d 73 69 67 61 63 74 69 6f 6e 00 48 |t e s t - s i g a c t i o n . H |
7fffb44ace40: 4f 53 54 4e 41 4d 45 3d 6c 6f 63 61 6c 68 6f 73 |O S T N A M E = l o c a l h o s |
7fffb44ace50: 74 2e 6c 6f 63 61 6c 64 6f 6d 61 69 6e 00 54 45 |t . l o c a l d o m a i n . T E |
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
v2:
- Pavel reported there is no need to lock/unlock
last-pid file in cycle, just lock it once before
threads creation and unlock at the end.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
A parasite code dumps all sigactions in sigact.pid.
v2: remove hard code for sizeof(sigset_t)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
