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>
We allocate only one page for fdinfo_list_entries.
In the future we will be able to resize this memory.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Yet again -- this makes code easier to understand from my POV.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
open_fdinfo calls move_img_fd, so other functions should not care about it
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-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>
