Instead of passing self-vma file path to restorer
code simply open it before restore_task call and
pass descriptor instead. This saves some memory.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
We will later need other fields of this file, so let's parse it right
now in a way, that allows to easily get new fields.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
* @xemul:
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-dump.c
include/sockets.h
sockets.c
The conflicts are mostly because of commit
995ef5eca3
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
No need to track in a weird way. It's small structure.
Moreover, the rest of parasite code doesn't count for
space allocated _after_ the main control block. We simply
had happened to not hit any problems before.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
This allows us to get rid of open-coded "/proc/pid/X".
Based-on-patch-from: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
It basically reverts e189efc176
which was overdone one.
Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
* @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>
Make the dump_one_fd fn accept local fd and integer target fd values
instead of target fd dir and target fd string name.
This saves couple of atoi-s (done once) and makes the next patch simpler.
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>
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>
Some process can share one struct file-s, we may find them by "object IDs".
A file descriptor is opened in one process and send to other via unix socket.
The procedure of restoring files contains four stages.
* Collect data about all file's descriptors
On this stage we find process which will restore a file descriptor and
create a list of processes, who should get this descriptor.
* Create datagrams unix sockets
If a file descriptor should be received, a unix socket is created
instead of it.
* Open file descriptors
A process with the least pid opens a file and sends this file
descriptors to all one who wait it.
* Receive file descriptors.
When we were thinking up this algoritm, we wanted to minimize a number
of context switches. A number of context switches is proportional of a
number of processes.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Remove excessive checks and keep it a pointer.
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>
Restorer does really restore shared memory (including page
contents restore) only on master process, while all other
processes do open such memory area via map_files/ procfs entry
so that we might have a situation when shared VMA is present
in some particular core-%d.img file but it's not listed in
collected shmems array and find_shmem_by_pid will return NULL.
This is perfectly fine, be ready for that.
Another issue is that shared memory might look like
CR_FD_SHMEM: /home/cyrill/projects/kernel/crtools/shmem-2641.img
----------------------------------------
0x7f2200775000-0x7f2200776000 id 19664
0x7f2200776000-0x7f2200777000 id 19663
----------------------------------------
So vma area is [x;y) range and we should distinguish two
shmem lookup cases
- one when we search for page in shmem area
- second when we lookup shmem area in collected ranges
They both have a different lookup conditions so single
find_shmem splitted into two helpers find_shmem and
find_shmem_page as appropriate.
This patch finally fixes the three process asynchronious
shared memory updates test-case.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
The remapping of /proc path to shmem should be
done with pid of process which did mmap() call
initially.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Since we're not system library
- no underscopes in functions name until really needed
and known to not clash with posix namespace
- empty line between system headers and own headers
for readability
- extern for function prototypes
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Otherwise getting errors like
| CC libnetlink.o
| In file included from libnetlink.c:4:0:
| ./include/libnetlink.h:34:0: error: "NLMSG_LENGTH" redefined [-Werror]
And make macros a bit more readable.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
The next patch will remap shmems region and will use it in restorer.
Actually this patch moves shmem_nr to struct shmems.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
[gorcunov: Various tuneups]
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>
