It is a test for convert_path_from_another_mp fix, it is a bit tricky as
we don't fully support ghosts on readonly fs, but only if the ghost can
be remaped on some _other_ bindmount (luckily we have same ghost on other
bind). Moreover wrong absolute path generated with old convert_path_from
_another_mp for lnkat don't always fail, only in case we want to do
linkat on mount in _other_ mountns and absolute path makes us do it in
local mountns and local path is readonly and we fail. =)
v2: remove unused headers
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
If dmi->ns_mountpoint is "/" then in dst we will return "/..." -
absolute path but we want here path relative to dmi mount. Adding "./"
before the path guaranties that it will be always relative.
https://jira.sw.ru/browse/PSBM-72351
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Fork tasks and create fds with different numbers.
Some children share file with parent (CLONE_FILES).
Check, than we can suspend and resume in this case.
v2: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Currently, we set rlim(RLIMIT_NOFILE) unlimited
and service_fd_rlim_cur to place service fds.
This leads to a signify problem: every task uses
the biggest possible files_struct in kernel, and
it consumes excess memory after restore
in comparation to dump. In some situations this
may end in restore fail as there is no enough
memory in memory cgroup of on node.
The patch fixes the problem by introducing
task-measured service_fd_base. It's calculated
in dependence of max used file fd and is placed
near the right border of kernel-allocated memory
hunk for task's fds (see alloc_fdtable() for
details). This reduces kernel-allocated files_struct
to 512 fds for the most process in standard linux
system (I've analysed the processes in my work system).
Also, since the "standard processes" will have the same
service_fd_base, clone_service_fd() won't have to
actualy dup() their service fds for them like we
have at the moment. This is the one of reasons why
we still keep service fds as a range of fds,
and do not try to use unused holes in task fds.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
v2: Add a handle for very big fd numbers near service_fd_rlim_cur.
v3: Fix excess accounting for nr equal to pow 2 minus 1.
In normal life this is impossible. But in case of big
fdt::nr number (many processes, sharing the same files),
and custom service_fd_base, normal (!CLONE_FILES) child
of such process may have overlaping service fds with
parent's fdt. This patch introduces "memmove()" behavior
(currently there is "memcpy()" behavior) and this will
be used in next patch.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
This patch just moves part of clone_service_fd()
to separate function, that change readability of the code.
There are no functional changes, only refactoring.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
This patch makes the call of service fds relocation after
root_prepare_shared()->prepare_fd_pid(). Next patches
will make service_fd_base depend on task's max fd used,
and for root_item we need to read all fles to know
the maximum of them.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Next patches will make service_fd_base not contant.
It will be "floating" and change from task to task.
This patch makes preparation for that: it closes
old service fd after it's duplicated.
Currently the code is unused as in case of
!(rsti(me)->clone_flags & CLONE_FILES), the child
has the same id as its parent, and the duplication
just does not occur.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Next patches will make service fds numbers not connected
not rlimit. Change the name to better fit its goal.
Also, leave service_fd_rlim_cur variable to have cached
access to rlimit value.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
v2: More comments
This patch populates/occupies PROC_FD_OFF fd number,
which is goint to be replaced atomically in next patches.
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
This patch populates and occupies ROOT_FD_OFF fd,
which guarantees it won't be reused by ordinary fds.
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
This patch introduces sfds_protected, which allows
to mask areas, where modifications of sfds are prohibited.
That guarantees, that populated sfds won't be reused.
v4: New
v5: Add comment and print sfd type before BUG().
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Function to print call trace of a process.
Borrowed from this fm:
https://www.gnu.org/software/libc/manual/html_node/Backtraces.html
backtrace() and backtrace_symbols() are not implemented in alpine,
so we use __GLIBC__ ifdef to do not compile this function there.
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
1)Further mntns_set_root_fd() calls install_service_fd(),
which silently closes already open fd. So, kill close_service_fd()
and make __mntns_get_root_fd() atomical in ROOT_FD_OFF modifications.
2)close_pid_proc() is not need here, as it's about root_item's
/proc directory and __mntns_get_root_fd() actions don't act on it.
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Here we need to close proc self fd only, as it's not
a service fd, and it can occupy real task fd number.
Closing of PROC_PID_FD_OFF is useless action here,
because it's already occupy a service fd number.
So, we skip this excess syscall, and leave PROC_PID_FD_OFF
open.
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Next patch will move SELF_STDIN_OFF sfd to fdstore.
This patch moves fdstore_init() before tty_prep_fds().
v4: New
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Create a zombie with specific pgid and check that
pgid remains the same after restore.
This test hangs criu restore without any of two previous patches:
1)without "restore: Call prepare_fds() in restore_one_zombie()"
in 100% cases;
2)without "restore: Split restore_one_helper() and wait exiting
zombie children" fail is racy, but you can add something like
criu/cr-restore.c:
## -1130,6 +1130,8 @@ static int restore_one_zombie(CoreEntry *core)
if (task_entries != NULL) {
restore_finish_stage(task_entries, CR_STATE_RESTORE);
+ if (current->parent->pid->state == TASK_ALIVE)
+ sleep(2);
zombie_prepare_signals();
}
and it will fail with almost 100% probability.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Zombie is also can be choosen as a parent for task helper like
any other task.
If the task helper exits between restore_finish_stage(CR_STATE_RESTORE)
and zombie_prepare_signals()->SIG_UNBLOCK, the standard criu SIGCHLD
handler is called, and the restore fails:
(00.057762) 41: Error (criu/cr-restore.c:1557): 40 exited, status=0
(00.057815) Error (criu/cr-restore.c:2465): Restoring FAILED.
This patch makes restore_one_zombie() behave as restore_one_helper()
and to wait children exits before allowing SIGCHLD. This makes us
safe against races with exiting children.
See next patch for test details.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Zombie may be choosen as parent for task helper
during solving pgid dependences. In this situation,
it becomes to share fdt with the helper and it has
to call prepare_fds() to decrement fdt->nr.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
There are two problems. The first is CTL_TTY_OFF occupies
one of the biggest available fds in the system. It's a number
near service_fd_rlim_cur. Next patches want to allocate
service fds lower, than service_fd_rlim_cur, and they want
to know max used fd from file fles after the image reading.
But since one of fds is already set very big (CTL_TTY_OFF)
on a stage of collection fles, the only availabe service
fds are near service_fd_rlim_cur. It's vicious circle,
and the only way is to change ctl tty fd allocation way.
The second problem is ctl tty is ugly out of generic file
engine fixup (see open_fd()). This is made because ctl tty
is the only slave fle, which needs additional actions
(see tty_restore_ctl_terminal()). Another file types just
receive their slave fle, and do not do anything else.
This patch moves ctl tty to generic engine and solves all
the above problems. To do that, we implement new CTL_TTY
file type, which open method waits till slave tty is received
and then calls tty_restore_ctl_terminal() for that. It fits
to generic engine well, and allocates fd via find_unused_fd(),
and do not polute file table by big fd numbers.
Next patch will kill currently unneed CTL_TTY leftovers
and will remove CTL_TTY_OFF service fd from criu.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Move the function and reduce its arguments number.
This is cleanup needed to keep all tty code together.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Unchanged test provided by Andrew.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
In case we have mounts:
1 /mnt/
2 /mnt/a with parent 1
3 /mnt/a/b with parent 1
4 /mnt/a with parent 2
We determine 2 as needing remap with does_mnt_overmount() and remap it.
Next we mount 4 on top of 2. Next in fixup_remap_mounts() we want to
move 2 back to it's parent 1, but instead move 4 there. So in these case
children-overmounts need to be remapped too.
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Remaps in mnt_remap_list should follow same descending order which was
setup in mnt_resort_siblings(), so don't reorder them.
For instance if we have sibling mounts with mountpoints:
1) /dir1/dir2/dir3
2) /dir1/dir2
3) /dir1
Here (2) is sibling-overmount for (1). Mount (3) is sibling-overmount
for both (1) and (2). So when we move overmounts back in
fixup_remap_mounts() we should first move (2) and only then (3).
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
We should add new entry _before_ first entry with less depth to sort in
descending order.
e.g: entries in list have depths [7,5,3], adding new entry m with depth
4 we would break list_for_each_entry loop on p with depth 3, before
patch we would get [7,5,3,4] after list_add, which is wrong.
Also we can relax "<=" check to "<" to avoid unnecessary reordering.
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
dump of VZ7 ct fails, if we have overmounted tmpfs inside:
[root@silo ~]# prlctl enter su-test-2
entered into CT
CT-829e7b28 /# mkdir /mnt/overmntedtmp
CT-829e7b28 /# mount -t tmpfs tmpfs /mnt/overmntedtmp/
CT-829e7b28 /# mount -t tmpfs tmpfs /mnt
CT-829e7b28 /# logout
[root@silo ~]# prlctl suspend su-test-2
Suspending the CT...
Failed to suspend the CT: PRL_ERR_VZCTL_OPERATION_FAILED (Details: Will skip in-flight TCP connections
(01.657913) Error (criu/mount.c:1202): mnt: Can't open ./mnt/overmntedtmp: No such file or directory
(01.662528) Error (criu/util.c:709): exited, status=1
(01.664329) Error (criu/util.c:709): exited, status=1
(01.664694) Error (criu/cr-dump.c:2005): Dumping FAILED.
Failed to checkpoint the Container
All dump files and logs were saved to /vz/private/829e7b28-f204-4bce-b09f-d203b99befd4/dump/Dump.fail
Checkpointing failed
)
Criu wants to dump the contents of /mnt/overmntedtmp/ mount but it is
unavailable. So we copy the mount namespace in such a case and unmount
overmounts to access what we want to dump.
Actual usecase here is dumping CT with active mariadb and ssh
connection. Together they happen to create such overmount. As by default
systemd creates a separate mount namespace for mysql and also mounts
tmpfs to /run/user in it, and when ssh(root) is connected - systemd also
mounts tmpfs in container root mount namespace to /run/user/0 for user
files. As /run is slave mount /run/user/0 also propagates to mysql's
mount namespace and initially becomes overmounted by /run/user.
https://jira.sw.ru/browse/PSBM-57362
remove __maybe_unused for mnt_is_overmounted and umount_overmounts
changes in v2:
1) Use clone not fork, share resources with parent same as in
call_in_child_process.
2) Do not enter userns (create helper) for non-overmounted mounts. Thus
return back setns/resorens logic.
3) Helper opens fd for parent directly due to CLONE_FILES, remove futex.
4) Check helper exit status properly.
5) Add get_clean_fd helper.
6) Add better comments.
changes in v3:
1) Pass fd from helper through args instead of ret code, fix ret code
checking.
2) Add \n to pr_err in open_mountpoint
changes in v5:
Make comments even better.
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
also remove __maybe_unused for __umount_children_overmounts
note: leave it __maybe_unused yet
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
It has two arguments "pos_l and "pos_h" instead of one "off". It is used
to handle 64-bit offsets on 32-bit kernels.
SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
https://github.com/checkpoint-restore/criu/issues/424
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Due to way CRIU handles paths (as relative to workdir), there's a case,
where migration would fail. Simple example is a ghost file in filesystem
root (with root being cwd). For example, "/unlinked" becomes "unlinked".
And original code piece scans path for other slashes, which would be
missing in this case. But it's still a perfectly valid case, and there's
no need to fail. So if there's no parent dir - we just don't need to
create one and we can just return 0 here instead of failing.
Signed-off-by: Vitaly Ostrosablin <vostrosablin@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
The kernel doesn't have an interface to get a sent queue for udp
sockets, so currently we can't dump them and criu dump has to fail in
such cases.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Now we block all sockets with non-zero idiag_wqueue, but it doesn't mean
that a CORK option is enabled for a socket. A packet can be in a network
stack and it is accounted into idiag_wqueue.
https://github.com/checkpoint-restore/criu/issues/409
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Now it's probably one valide use case, because there is no way to commit
a container when a container is being checkpointed.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
All static tests has to stop any activity before C/R.
./tempfs_subns --pidfile=tempfs_subns.pid --outfile=tempfs_subns.out --dirname=tempfs_subns.test
Run criu dump
Unable to kill 128: [Errno 3] No such process
Run criu restore
7: Old mounts lost: []
7: New mounts appeared: [('/rootfs/criu/test', '/'), ('/', '/proc'), ('/', '/dev/pts')]
:
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Except for several false positives done by:
find -type f -name "*.c" -not -path "./test/*" -exec sed -i
's/\(\<pr_err.*[^\][^n]\)\("[,)]\)/\1\\n\2/g' {} \;
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Currently we use an additional pipe to steal data from a pipe, but we
don't check that we steal all data. And the additional pipe can have a
smaller size.
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
