Now we supports sub-mntns, so root_ns_mask sounds more correct than
current_ns_mask.
v2: typo fix
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Known issue:
* currently only namespaces with the same root is supported
* nested namespaces can be dumped and restored only if the root task
has own mount namespace.
All nested namespaces are restored in a root namespace in temporary
directories. All mount points restored in one tree and then they are
divided into namesaces.
The task with minimal pid for each namespaces unshared mntns and
then it makes pivot_root in a proper temporary directory. All other
tasks makes setns to enter into a mount namespace of the task with
minimal pid.
v2: clean up
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently ns_ids list is filled only on dump. Soon we'll need this
list for mount namespaces on restore, e.g. to know which tasks share
the namespaces.
v2: merge the patch "namespace: add a function to search an ns_id
item by id" into this one.
v3: add prefix rst_ to add_ns_id
v4: look up namespace by two values -- type AND ID
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's going to be used for restoring namespaces. For example we need to
enumirate the ns_ids list for restoring mount namespaces.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Well, we want to pre-dump files (fsnotifies), for that we
will need mountinfo-s and root, and for the latter -- the
current ns mask.
The problem with current ns mask is that its generation is
incorporated into ns IDs generation and dumping. And since
the ids dumping is not performed on pre-dump, let's just
provide a helper for ns-mask generation.
Strictly speaking, the whole ns-mask idea is not great, but
it's to be fixed later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We really have a mess of extern/non-extern declaration
of functions in our headers. Always use extern for
unification purpose.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Since *all* of them just call do_dump_gen_file with proper ops,
just call one directly. Compacts the code.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Based on work done by Cyrill Corcunov (many thanks for that).
In this commit we implement c/r for files which have opened
/proc/$pid/ns/$ids entries.
The idea is rather simple one
Checkpoint
==========
- Check if the file name is the one of known to be ns ref
- If match then write protobuf entry
Restore
=======
- Read all ns entries from the image
- When criu tries to open one we lookup over process
tree to figure out which PID should be used in path
and then just open it
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This will be needed for fast parsing of procfs ns references.
[ xemul: Add user_ns_desc here ]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I'll need to modify this header so before anything
else lets beautify it
- drop struct pstree_item declaration it's already in pstree.h
- move struct cr_options to top
- align members of struct ns_desc
- move externs to top
- add argument name to try_show_namespaces
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When we've read all pstree-items and their ids we
can get the desired clone-flags early and avoid all
these dances with flag calculations in fork_with_pid
and company.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Introduce the current_ns_mask variable, that collects info about
which namespaces tasks being dumped and to be restored live in.
For simlicity all tasks are supposed to live in one set of spaces.
This should be fixed eventually.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The recent kernels allow to get namespaces IDs by reading proc-ns links.
Use this to generate IDs for tasks' namespaces (I do generate them, since
IDs provided by kernel look ugly :( ).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
These are structs that (now) tie together ns string
and the CLONE_ flag. It's nice to have one (some code
becomes simpler) and will help us with auto-namespaces
detection.
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>
This will be required for parasite transport socket creation -- it will
have to be created in a net ns we're putting parasite in and then we'll
have to restore it back to original to go on dumping.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It uses pid for create image file and real_pid for dumping ns-s.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Each fdset item now has the callback which will show a contents of a magic-described
image file. Per-task and global show code is reworked to walk the respective fdsets
and calling ->show on each file.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
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>
Generic code will be used for other namespaces.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Acked-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>
