[CRIU] [PATCH 1/6] tty: notify about orphan tty-s via rpc
Pavel Emelyanov
xemul at virtuozzo.com
Tue Feb 7 02:24:39 PST 2017
On 02/07/2017 08:51 AM, Andrei Vagin wrote:
> On Mon, Feb 06, 2017 at 01:01:12PM +0300, Pavel Emelyanov wrote:
>> On 01/04/2017 02:40 AM, Andrei Vagin wrote:
>>> From: Andrei Vagin <avagin at virtuozzo.com>
>>>
>>> Now Docker creates a pty pair from a container devpts to use is as console.
>>> A slave tty is set as a control tty for the init process and bind-mounted
>>> into /dev/console. The master tty is handled externelly.
>>>
>>> Now CRIU can handle external resources, but here we have internal resources
>>> which are used externaly.
>>>
>>> https://github.com/opencontainers/runc/issues/1202
>>> Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
>>> ---
>>> criu/action-scripts.c | 20 ++++++++++++++++++--
>>> criu/cr-restore.c | 1 +
>>> criu/cr-service.c | 27 +++++++++++++++++++++------
>>> criu/include/action-scripts.h | 6 +++++-
>>> criu/include/cr_options.h | 1 +
>>> criu/include/servicefd.h | 1 +
>>> criu/tty.c | 40 +++++++++++++++++++++++++++++++++++-----
>>> images/rpc.proto | 2 ++
>>> 8 files changed, 84 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/criu/action-scripts.c b/criu/action-scripts.c
>>> index bfa1f82..c18d1aa 100644
>>> --- a/criu/action-scripts.c
>>> +++ b/criu/action-scripts.c
>>> @@ -13,6 +13,9 @@
>>> #include "pstree.h"
>>> #include "common/bug.h"
>>> #include "util.h"
>>> +#include <sys/un.h>
>>> +#include <sys/socket.h>
>>> +#include "common/scm.h"
>>>
>>> static const char *action_names[ACT_MAX] = {
>>> [ ACT_PRE_DUMP ] = "pre-dump",
>>> @@ -24,6 +27,7 @@ static const char *action_names[ACT_MAX] = {
>>> [ ACT_SETUP_NS ] = "setup-namespaces",
>>> [ ACT_POST_SETUP_NS ] = "post-setup-namespaces",
>>> [ ACT_POST_RESUME ] = "post-resume",
>>> + [ ACT_ORPHAN_PTS_MASTER ] = "orphan-pts-master",
>>> };
>>>
>>> struct script {
>>> @@ -95,6 +99,17 @@ static int run_shell_scripts(const char *action)
>>> return retval;
>>> }
>>>
>>> +int rpc_send_fd(enum script_actions act, int fd)
>>> +{
>>> + const char *action = action_names[act];
>>> +
>>> + if (scripts_mode != SCRIPTS_RPC)
>>> + return -1;
>>> +
>>> + pr_debug("\tRPC\n");
>>> + return send_criu_rpc_script(act, (char *)action, rpc_sk, fd);
>>> +}
>>> +
>>> int run_scripts(enum script_actions act)
>>> {
>>> int ret = 0;
>>> @@ -107,7 +122,7 @@ int run_scripts(enum script_actions act)
>>>
>>> if (scripts_mode == SCRIPTS_RPC) {
>>> pr_debug("\tRPC\n");
>>> - ret = send_criu_rpc_script(act, (char *)action, rpc_sk);
>>> + ret = send_criu_rpc_script(act, (char *)action, rpc_sk, -1);
>>> goto out;
>>> }
>>>
>>> @@ -145,6 +160,7 @@ int add_rpc_notify(int sk)
>>> BUG_ON(scripts_mode == SCRIPTS_SHELL);
>>> scripts_mode = SCRIPTS_RPC;
>>>
>>> - rpc_sk = sk;
>>> + rpc_sk = install_service_fd(RPC_SK_OFF, sk);
>>> +
>>> return 0;
>>> }
>>> diff --git a/criu/cr-restore.c b/criu/cr-restore.c
>>> index 1c87c6e..db296c6 100644
>>> --- a/criu/cr-restore.c
>>> +++ b/criu/cr-restore.c
>>> @@ -3192,6 +3192,7 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
>>> close_proc();
>>> close_service_fd(ROOT_FD_OFF);
>>> close_service_fd(USERNSD_SK);
>>> + close_service_fd(RPC_SK_OFF);
>>>
>>> __gcov_flush();
>>>
>>> diff --git a/criu/cr-service.c b/criu/cr-service.c
>>> index 00a2d07..97195b2 100644
>>> --- a/criu/cr-service.c
>>> +++ b/criu/cr-service.c
>>> @@ -36,6 +36,9 @@
>>> #include "irmap.h"
>>> #include "kerndat.h"
>>> #include "proc_parse.h"
>>> +#include <sys/un.h>
>>> +#include <sys/socket.h>
>>> +#include "common/scm.h"
>>>
>>> #include "setproctitle.h"
>>>
>>> @@ -84,10 +87,10 @@ err:
>>> return -1;
>>> }
>>>
>>> -static int send_criu_msg(int socket_fd, CriuResp *msg)
>>> +static int send_criu_msg_with_fd(int socket_fd, CriuResp *msg, int fd)
>>> {
>>> unsigned char *buf;
>>> - int len;
>>> + int len, ret;
>>>
>>> len = criu_resp__get_packed_size(msg);
>>>
>>> @@ -100,7 +103,11 @@ static int send_criu_msg(int socket_fd, CriuResp *msg)
>>> goto err;
>>> }
>>>
>>> - if (write(socket_fd, buf, len) == -1) {
>>> + if (fd >= 0) {
>>> + ret = send_fds(socket_fd, NULL, 0, &fd, 1, buf, len);
>>> + } else
>>> + ret = write(socket_fd, buf, len);
>>
>> O_O How about the message itself? How will client know what was just sent to him?
>
> I don't understand a question. This part isn't changed.
>
> As for the whole function, we add an ability to attach a file destriptor to a message.
I mean -- when I call send_criu_msg_with_fd and set fd != -1 _only_ the
descriptor is sent, while the message itself is created and initialized,
but is NOT sent.
Is that intentional? Are callers supposed to call this routine twice -- first
time for the message itself and the 2nd time for the descriptor to be sent?
>>
>>> + if (ret < 0) {
>>> pr_perror("Can't send response");
>>> goto err;
>>> }
>>> @@ -112,6 +119,11 @@ err:
>>> return -1;
>>> }
>>>
>>> +static int send_criu_msg(int socket_fd, CriuResp *msg)
>>> +{
>>> + return send_criu_msg_with_fd(socket_fd, msg, -1);
>>> +}
>>> +
>>> static void set_resp_err(CriuResp *resp)
>>> {
>>> resp->cr_errno = get_cr_errno();
>>> @@ -174,7 +186,7 @@ int send_criu_restore_resp(int socket_fd, bool success, int pid)
>>> return send_criu_msg(socket_fd, &msg);
>>> }
>>>
>>> -int send_criu_rpc_script(enum script_actions act, char *name, int fd)
>>> +int send_criu_rpc_script(enum script_actions act, char *name, int sk, int fd)
>>> {
>>> int ret;
>>> CriuResp msg = CRIU_RESP__INIT;
>>> @@ -201,11 +213,11 @@ int send_criu_rpc_script(enum script_actions act, char *name, int fd)
>>> break;
>>> }
>>>
>>> - ret = send_criu_msg(fd, &msg);
>>> + ret = send_criu_msg_with_fd(sk, &msg, fd);
>>> if (ret < 0)
>>> return ret;
>>>
>>> - ret = recv_criu_msg(fd, &req);
>>> + ret = recv_criu_msg(sk, &req);
>>> if (ret < 0)
>>> return ret;
>>>
>>> @@ -504,6 +516,9 @@ static int setup_opts_from_req(int sk, CriuOpts *req)
>>> }
>>> }
>>>
>>> + if (req->orphan_pts_master)
>>> + opts.orphan_pts_master = true;
>>> +
>>> if (check_namespace_opts())
>>> goto err;
>>>
>>> diff --git a/criu/include/action-scripts.h b/criu/include/action-scripts.h
>>> index 2e3b25e..9161621 100644
>>> --- a/criu/include/action-scripts.h
>>> +++ b/criu/include/action-scripts.h
>>> @@ -1,6 +1,8 @@
>>> #ifndef __CR_ACTION_SCRIPTS_H__
>>> #define __CR_ACTION_SCRIPTS_H__
>>>
>>> +#include "asm/int.h"
>>> +
>>> enum script_actions {
>>> ACT_PRE_DUMP,
>>> ACT_POST_DUMP,
>>> @@ -11,6 +13,7 @@ enum script_actions {
>>> ACT_SETUP_NS,
>>> ACT_POST_SETUP_NS,
>>> ACT_POST_RESUME,
>>> + ACT_ORPHAN_PTS_MASTER,
>>>
>>> ACT_MAX
>>> };
>>> @@ -18,6 +21,7 @@ enum script_actions {
>>> extern int add_script(char *path);
>>> extern int add_rpc_notify(int sk);
>>> extern int run_scripts(enum script_actions);
>>> -extern int send_criu_rpc_script(enum script_actions act, char *name, int arg);
>>> +extern int rpc_send_fd(enum script_actions, int fd);
>>> +extern int send_criu_rpc_script(enum script_actions act, char *name, int sk, int fd);
>>>
>>> #endif /* __CR_ACTION_SCRIPTS_H__ */
>>> diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
>>> index 4f70b41..ee16573 100644
>>> --- a/criu/include/cr_options.h
>>> +++ b/criu/include/cr_options.h
>>> @@ -119,6 +119,7 @@ struct cr_options {
>>> bool display_stats;
>>> bool weak_sysctls;
>>> bool check_only;
>>> + bool orphan_pts_master;
>>> };
>>>
>>> extern struct cr_options opts;
>>> diff --git a/criu/include/servicefd.h b/criu/include/servicefd.h
>>> index 5152fb6..1b48e90 100644
>>> --- a/criu/include/servicefd.h
>>> +++ b/criu/include/servicefd.h
>>> @@ -21,6 +21,7 @@ enum sfd_type {
>>> NS_FD_OFF, /* Node's net namespace fd */
>>> TRANSPORT_FD_OFF, /* to transfer file descriptors */
>>> LAZY_PAGES_SK_OFF, /* socket for communication with lazy-pages daemon */
>>> + RPC_SK_OFF,
>>
>> Unused in the set.
>
> It will be used in the next patches. Will move. Thanks
>>
>>>
>>> SERVICE_FD_MAX
>>> };
>>> diff --git a/criu/tty.c b/criu/tty.c
>>> index 0f3d1c9..ae2d463 100644
>>> --- a/criu/tty.c
>>> +++ b/criu/tty.c
>>> @@ -28,6 +28,7 @@
>>> #include "files-reg.h"
>>> #include "namespaces.h"
>>> #include "external.h"
>>> +#include "action-scripts.h"
>>>
>>> #include "protobuf.h"
>>> #include "util.h"
>>> @@ -376,7 +377,7 @@ static int tty_verify_active_pairs(void * unused)
>>> continue;
>>> }
>>>
>>> - if (!opts.shell_job) {
>>> + if (!opts.shell_job && !opts.orphan_pts_master) {
>>> pr_err("Found slave peer index %d without "
>>> "correspond master peer\n",
>>> tty_get_index(i));
>>> @@ -681,7 +682,7 @@ static int tty_restore_ctl_terminal(struct file_desc *d, int fd)
>>> else
>>> index = driver->index;
>>>
>>> - if (is_pty(info->driver)) {
>>> + if (is_pty(info->driver) && tty_is_master(info)) {
>>> fake = pty_alloc_fake_slave(info);
>>> if (!fake)
>>> goto err;
>>> @@ -947,6 +948,32 @@ static int pty_open_unpaired_slave(struct file_desc *d, struct tty_info *slave)
>>> */
>>>
>>> if (likely(slave->inherit)) {
>>> + if (opts.orphan_pts_master) {
>>> + fake = pty_alloc_fake_master(slave);
>>> + if (!fake)
>>> + goto err;
>>> + master = pty_open_ptmx_index(&fake->d, slave->tie->pty->index, O_RDWR);
>>> + if (master < 0) {
>>> + pr_err("Can't open master pty %x (index %d)\n",
>>> + slave->tfe->id, slave->tie->pty->index);
>>> + goto err;
>>> + }
>>> +
>>> + unlock_pty(master);
>>> +
>>> + if (opts.orphan_pts_master &&
>>> + rpc_send_fd(ACT_ORPHAN_PTS_MASTER, master) == 0) {
>>> +
>>> + fd = open_tty_reg(slave->reg_d, slave->tfe->flags);
>>> + if (fd < 0) {
>>> + pr_err("Can't open slave pty %s\n", path_from_reg(slave->reg_d));
>>> + goto err;
>>> + }
>>> +
>>> + goto out;
>>> + }
>>> + }
>>> +
>>> if (!stdin_isatty) {
>>> pr_err("Don't have tty to inherit session from, aborting\n");
>>> return -1;
>>> @@ -981,6 +1008,7 @@ static int pty_open_unpaired_slave(struct file_desc *d, struct tty_info *slave)
>>>
>>> }
>>>
>>> +out:
>>> if (restore_tty_params(fd, slave))
>>> goto err;
>>>
>>> @@ -993,7 +1021,7 @@ static int pty_open_unpaired_slave(struct file_desc *d, struct tty_info *slave)
>>> * be already restored properly thus we can simply
>>> * use syscalls instead of lookup via process tree.
>>> */
>>> - if (likely(slave->inherit)) {
>>> + if (slave->inherit && opts.shell_job) {
>>> /*
>>> * The restoration procedure only works if we're
>>> * migrating not a session leader, otherwise it's
>>> @@ -1224,8 +1252,10 @@ static int tty_find_restoring_task(struct tty_info *info)
>>> if (!tty_is_master(info)) {
>>> if (tty_has_active_pair(info))
>>> return 0;
>>> - else
>>> + else if (!opts.orphan_pts_master)
>>> goto shell_job;
>>> + else
>>> + info->inherit = true;
>>> }
>>>
>>> /*
>>> @@ -1349,7 +1379,7 @@ static int tty_setup_slavery(void * unused)
>>> info->driver->type == TTY_TYPE__CTTY)
>>> continue;
>>>
>>> - if (!tty_is_master(info))
>>> + if (!tty_is_master(info) && info->link)
>>> continue;
>>>
>>> info->ctl_tty = info;
>>> diff --git a/images/rpc.proto b/images/rpc.proto
>>> index 7cf958c..832800c 100644
>>> --- a/images/rpc.proto
>>> +++ b/images/rpc.proto
>>> @@ -108,6 +108,8 @@ message criu_opts {
>>> optional uint32 timeout = 45;
>>> optional bool tcp_skip_in_flight = 46;
>>> optional bool weak_sysctls = 47;
>>> +
>>> + optional bool orphan_pts_master = 48;
>>> }
>>>
>>> message criu_dump_resp {
>>>
>>
> .
>
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