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>
It's suitable not for info only but in debug purpose as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@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>
Introduce 3 states we will have to work with:
* alive for tasks sleeping or running
* dead for zombies
* stopped for stopped tasks. We cannot distinguish tasks in this state now,
but with freezer cgroup this will become possible
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Kill all the macros for reading/writing image parts. New API looks like
* write_img_buf/write_img
Write an object into an image. Reports 0 for OK, -1 for error. The _buf
version accepts object size as an argument, the other one uses sizeof()
* read_img_buf/read_img
Reads an object from image. Reports 0 for OK, -1 for error or EOF.
* read_img_buf_eof/read_img
Reads an object from image. Reports 1 for OK, 0 for EOF and -1 for error.
This is not symmetrical with the previous one, but it was done deliberately
to make it possible to write code like
ret = read_img_bug_eof();
if (ret <= 0)
return ret; /* 0 means OK, all is done, -1 means error was met */.
... /* 1 means object was read, can proceed */
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Keep task arch-independent fields in one struct (will be extended) in the
beginning of the image and make pads be located separately.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
* @xemul-mails:
crtools: Collect dumping fd parameters into one place
crtools: Toss dump_one_fd args around
crtools: Rename fd to lfd in dump_one_fd
crtools: Sanitize pstree construction
crtools: Remove unused printk_registers and co
crtools: Deduplicate file info showing code
crtools: Merge pstree collecting into showing
crtools: Remove unused and wrong arrays from pstree image
crtools: Remove lseeks after prep_cr_ calls
crtools: Cleanup collect_pstree in cr-show
Conflicts:
cr-show.c
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Print common info once, then append path if required.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
1. There's no need in collecting children list in shower
2. There's no need in reading file twice -- we can collect and
show everything in one go.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
The cr preparation functions to read magic from files and thus this
lseek is not required.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Rename this into read_pstree and remove unneeded 2nd argument.
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>
Remove unneeded path argument (we do know the file data is read from) and
actually bogus show_header boolean.
Also introduce two helpers for showing header and tail.
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>
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>
Also re-make image to be 2 pages in size
which should be enough for basic params we
need to restore tasks.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
We will need more options since the
tool should support both cgroups freezer
and a regular task stop/dump/restore/continue
transition.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
