[CRIU] [PATCH 1/6] tty: notify about orphan tty-s via rpc

Andrei Vagin avagin at virtuozzo.com
Mon Feb 6 21:51:48 PST 2017


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.
> 
> > +	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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