In the early draft of kcmp syscall it has been returning
[-1|0|1] values but finally [0|1|2] were merged into the
kernel, but I forgot to update the criu code. The good
thing is that because we're using rbtree the kcmp results
are still sorted and tree is balanced but sometime we may
take a wrong branch generating new ID even if the object
is present in the tree which eventually may lead to dump
faulure.
Reported-by: Deyan Doychev <deyan@1h.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When we don't know mnt_id, we don't know to which namespace a file
belongs.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch removes the global mntinfo_tree and collect_mount_info where
it was constructed. The mntinfo list is filled from dump_mnt_ns,
rst_collect_local_mntns, collect_mnt_namespaces and read_mnt_ns_img.
A mountinfo entry contains a reference on a proper ns_id entry, so
we cau use mnt_id to look up a proper mount namespace.
v2: remove trash after rebasing.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On restore all namespaces are restored as one tree and
a pointer on the root of this tree will be set on each namespace.
Below you can find a call trace, where it's used:
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Kernels before 3.15 doesn't show mnt_id and mnt_id isn't saved in
images, if mntns isn't dumped.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to dump nested mount namespaces, so we move the mountinfo
list on the namespace structure.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On restore all mount namespaces are restored in the root mntns and
sub-namecpeaces are restored in temorary places.
This function allows to get paths to these places.
It will be used in open_remap_ghost(), because it's called in the root
task, when other tasks are not forked yet.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to support nested mount namespaces,
file descriptors can be from different namespaces,
so a namespace root must be updated for each of them.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to support nested mntns, so the global mntinfo_tree
variable are useless and information about tree should be connected
to a proper namespace.
But when we don't dump mntns, we need to collect mounts for the current
mntns.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will fill mntinfo list and this is internal logic of mount.c
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to support nested mount namespaces and each NS has own
tree. The mount tree is used for checking that a file is reachable.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to support nested mount namespaces, so files can be opened
from more than one namespace and a root must be collect for each file.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
mntns_collect_root() uses PROC_FD_OFF, so we need to close it.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
One device can be mounted a few times, so files are identical only,
if they have the same mnt_id.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Otherwise it will have external files (from another namespace,
which isn't dumped).
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
because we want to check, that all files are reachable.
For that we need to collect all mounts from all namespaces.
v2: dump mntns separately
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
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>
v2: another attempt to write readable code:)
v3: clean up
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>
All non-root namespaces will be restored as sub-trees of the root tree.
This patch adds helpers to create a temporary directory and mount tmpfs
in it, then create directories for each non-root mount namespace.
tmpfs is quite useful here to simplify destroying this construction,
we don't need to unmount each namespace separately.
v2: add a comment why MNT_DETACH is not dangerous here
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
read_mnt_ns_img() is splited on two parts. The first part enumirates all
namespaces and call the second part, which read a proper image file.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
