Same as with previous patch -- we have to pull image-independent entry out of the victim
task to be able to use protobuf library for encoding.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Checkpoint and restore of fifo is similar to
pipes c/r except the pipe end-points are named
file.
Because the fifo has a name we use regular files
facility for fifo path c/r.
Still there is a trick used to "open" fifo:
the opening procedure migh sleep if a fifo's peer
is not yet opened, so before doing a real open
we yield a fake open procedure (with O_RDWR flag)
which prevents us from sleeping even if peer
is not yet ready. Also we need writable fifo
end to restore data queued.
v2:
- add open/priv members to reg_file_info
- make open_fifo_fd to use open_fe_fd
- comment on pipe_id
- make sure the fifo data is not restored twice
v3:
- drop useless fixme comment and add sane one
v4:
- Use restore_data flag to escape data restore duplication
- Use S_ISREG for file contents copying
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now crtools can restore sid in all cases.
A restore of pgid will be added soon and now it will fail on restore.
It's prevent testing of restoring SIDs.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's sign, that a parent has been changed sid after forking a child.
We should know a sid with which a process was born, because in a processes
chain, more then one process might change SID.
v2: fix names of variables
v3: prevent rewriting of born_sid
v4: Abort the restorer with error message if a born_sid can't be determing.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
to require dumping pid namespace. Dump and restore will be failed if
a tress doesn't contain a process init.
pid namespace will be created implicitly if a process init in the tree.
v2: fix comments from Pavel
v3: Restore of pidns should be approved by user
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Instead of spreading regular files handling code over
files.c and cr-dump.c move it to files-reg.c.
This allows to extend regular file handling code in
future without disturbing other source files and
make code logically coupled, where files.c is mostly
a place for general file handling code unrelated to
file type specifics.
While mostly it was code tossing there is some change
I have to notice -- the structure ghost_file was previously
declared in two paces cr-dump.c and files.c, in cr-dump.c
it was used for dumping while in files.c it was used
for restore. The structure had different members.
So to resolve this conflict the ghost_file structure
was renamed to ghost_file_dumpee.
Nothing else is changed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's only required for making pipe_id, but making it is better to
be done in place and using the st_ino only.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now pid is dumped from pid ns, it's gotted from parasite.
v2: fail if a zombie is in PIDNS
Signed-off-by: Andrey Vagin <avagin@openvz.org>
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>
because in collect_pstree we don't know pid-s of processes inside pidns
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
because a pid in a target pid ns is got from parasite.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When we dump pid ns, dump_pstree is called after dump_tasks
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
If we try to dump a process from another pid ns,
we have not another way to get its pid.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Add struct pid and use it everywhere. This struct contains
two fields: pid and real_pid.
real_pid is a pid outside of the target pid namespace.
pid is in the target pid namespace
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
There is no need to make it xmalloc'ed, it's
global for all processes dumped.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2: Synchronize the argument type of __alloc_pstree_item and the
values you put into it. I.e. int-int or bool-bool, not bool-int.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
because they describes a process TREE.
It's usefull, when we dump tasks from another pid namespace,
because a real pid is got from parasite. In previous version
we need to update pid in two places one is in a pstree_item and
one is in a children array.
A process tree will be necessery to restore sid and pgid,
because we should add fake tasks in a tree. For example if
a sesion leader is absent.
v2: fix rollback actions
v3: fix comments from Pavel Emelyanov
* add macros for_each_pstree_item
* and a few bugs
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The task is not complete - this is just a part of what have to be done. I.e.
looks like a lot of excessive deps can be fixed.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Otherwise I see output like
| Dumping path for 1536412160 fd via self 27 [/usr/bin/screen]
where fd is taken from stack and what is worse -- we work
with root privilegues, thus dumping _anything_ from stack
is very bad idea.
With explicitly cleared stack data and FD_DESC_INVALID the
log file will have an entry like
| Dumping path for -3 fd via self 27 [/usr/bin/screen]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This will allow to implement tty dumping
in future.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will fall through all the other checks, but let's do it
explicitly for better code understanding.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
No functional changes, just a code move.
TODO:
* need to write personal make_gen_id implementations for special
files (device and pos is const for them effectively)
* need to merge dump ops with restore ones (file_desc_ops)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Reg files are those obtained by open() syscall on restore.
Pipes should be checked to belong to pipefs (fifos are not supported
yet).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2:
- open_mount is cleaned up
- byte-stream hex conversion remains untouched since
strtol is flipping numbers to LE manner
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2:
- Pass initial counter value to eventfd call
(can't pass flags here since they are obtained
with fcntl and must be restored same way or
restore will fail)
- Use rst_file_params for flags and owner restore
- Use eventfd.[ch] instead of eventfs.[ch]
- Move show funcs to eventfd.c
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is also a code move plus two changes:
* shmems renamed to dump_shmems
* shmem area size is shared with restorer (it's one page for both for now)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We use mincore to check which pages we should take with us into
the image. The anonymour present or swapped should go, file present
but not cow-ed should not.
The mincore syscall wasn't very helpful with this -- it didn't detect
swap, but did detect some non present pages (pagecache). Plus it
didn't know anything about cow-ing filemaps.
Andrey Morton suggested to use the pagemap file in proc, but it lacked
the importaint stuff -- the cow filemap bit. Now it's there and we
can switch to using it.
The mincore usage for shared memory is still there, as for _that_ case
it's correct.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When dump finished with error we should unlock all locked
previously connections.
When restoring we should collect connctions and unlock them
all at the end.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
printf() has standard flag for adding "0x" prefix before hexadecimal integer.
MOD='[-+]\?[0-9]*.\?[0-9]*[lL]*'
git grep -l "0x%${MOD}x" | xargs -n1 sed -e "s/0x%\(${MOD}\)x/%#\1x/g" -i
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In case if dgram socket peer is not connected back
we can try to resolve peer by name.
For security reason this happens only if '-x' option
is passed at checkpoint and restore time.
In particular this is needed for programs which do
use dgram socket to send messages to /dev/log.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Command below was executed several times:
sed 's/\(pr_.*[^%,x,X]\)\(\%[0-9,l,L]*x\)/\10x\2/g' -i *.c
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Completely unlinked file is the one with n_link count being zero.
Such files only allow to read their contents and carry with us.
In order to dump this thing I introduce the "path remap" technology.
For reg file a remapping entry is dumped which describes, that at
restore stage before opening a regfile->path this path should be
linked to some other name and then (after open) unlinked.
For completely unlinked files the remap path would be a path to
a "ghost" file, i.e. a file which is created only at the time of
restore and which is removed completely at the end of it.
Partially unlinked files (i.e. those having n_link != 0, but a
path by which we see them in someone's fd is not accessible) should
be handled in another way.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is preriquisity for terminals handling and just a good
practice to save and restore everything we can :)
Not all combinations are supported. All the problems we still
have come from the inability to attach to group/session with
ID no tasks own as its PID.
This can be workarounded by fork()-ing this pid temporarily,
but we'd rather think in the direction of modifying the kernel
to give us direct syscall for this (oh my...)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I store them on _entry since sids can only be inherited or
set to current's pid. Thus the best we can do it restore sids
at fork time, thus save them in the image we use to fork.
Maybe when we submit patches that will give us ability to set
arbitrary pgid and sid we'll change this, but this is in the
future.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
