We want to have buffered images to speed up dump and,
slightly, restore. Right now we use plan file descriptors
to write and read images to/from. Making them buffered
cannot be gracefully done on plain fds, so introduce
a new class.
This will also help if (when?) we will want to do more
complex changes with images, e.g. store them all in one
file or send them directly to the network.
For now the cr_img just contains one int _fd variable.
This patch chages the prototype of open_image() to
return struct cr_img *, pb_(read|write)* to accept one
and fixes the compilation of the rest of the code :)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Since we're going to switch from int-fd-s to class-image
soon the fdset name will not fit into the new terminology.
This patch is
sed -e 's/fdset/imgset/g' -i *
sed -e 's/imgset_fd/img_from_set/g' -i *
git mv include/fdset.h include/imgset.h
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Here we define new api to be used in plugins.
- Plugin should provide a descriptor with help of
CR_PLUGIN_REGISTER macro, or in case if plugin require
no init/exit functions -- with CR_PLUGIN_REGISTER_DUMMY.
- Plugin should define a plugin hook with help of
CR_PLUGIN_REGISTER_HOOK macro.
- Now init/exit functions of plugins takes @stage
argument which tells plugin which stage of criu
it's been called on dump/restore. For exit it
also takes @ret which allows plugin to know if
something went wrong and it needs to cleanup
own resources.
The idea behind is to not limit plugins authors with names
of functions they might need to use for particular hook.
Such new API deprecates olds plugins structure but to keep
backward compatibility we will provide a tiny layer of
additional code to support old plugins for at least a couple
of release cycles.
For example a trivial plugin might look like
| #include <sys/types.h>
| #include <sys/stat.h>
| #include <fcntl.h>
| #include <libgen.h>
| #include <errno.h>
|
| #include <sys/socket.h>
| #include <linux/un.h>
|
| #include <stdio.h>
| #include <stdlib.h>
| #include <string.h>
| #include <unistd.h>
|
| #include "criu-plugin.h"
| #include "criu-log.h"
|
| static int dump_ext_file(int fd, int id)
| {
| pr_info("dump_ext_file: fd %d id %d\n", fd, id);
| return 0;
| }
|
| CR_PLUGIN_REGISTER_DUMMY("trivial")
| CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__DUMP_EXT_FILE, dump_ext_file)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Here is nothing interecting. If a file can't be dumped by criu,
plugins are called. If one of plugins knows how to dump the file,
the file entry is marked as need_callback. On restore if we see
this mark, we execute plugins for restoring the file.
v2: Callbacks are called for all files, which are not supported by CRIU.
v3: Call plugins for a file instead of file descriptor. A few file
descriptors can be associated with one file.
v4: A file descriptor is opened in a callback. It's required for
restoring anon vmas.
v5: Add a separate type for unsupported files
v6: define FD_TYPES__UNSUPP
v7: s/unsupp/ext (external)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
