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=== Description (from pull-request) ===
From 9451eeffb0688b801034d963c455c8b31ccbf28c Mon Sep 17 00:00:00 2001
From: Tycho Andersen <tycho.ander...@canonical.com>
Date: Thu, 10 Mar 2016 10:54:19 -0700
Subject: [PATCH 1/2] criu: make exec_criu static
This is no longer needed outside of criu.c with the ->migrate API call, so
let's mark it that way.
Signed-off-by: Tycho Andersen <tycho.ander...@canonical.com>
---
src/lxc/criu.c | 2 +-
src/lxc/criu.h | 2 --
2 files changed, 1 insertion(+), 3 deletions(-)
diff --git a/src/lxc/criu.c b/src/lxc/criu.c
index 25e8d70..b4ebf42 100644
--- a/src/lxc/criu.c
+++ b/src/lxc/criu.c
@@ -47,7 +47,7 @@
lxc_log_define(lxc_criu, lxc);
-void exec_criu(struct lxc_handler *handler, struct criu_opts *opts)
+static void exec_criu(struct criu_opts *opts)
{
char **argv, log[PATH_MAX];
int static_args = 22, argc = 0, i, ret;
diff --git a/src/lxc/criu.h b/src/lxc/criu.h
index 75e6381..ed6dc81 100644
--- a/src/lxc/criu.h
+++ b/src/lxc/criu.h
@@ -58,8 +58,6 @@ struct criu_opts {
const char *cgroup_path;
};
-void exec_criu(struct lxc_handler *handler, struct criu_opts *opts);
-
/* Check and make sure the container has a configuration that we know CRIU can
* dump. */
bool criu_ok(struct lxc_container *c);
From 7103fe6f08cb04a498e3090d8416b4275a4a0d7e Mon Sep 17 00:00:00 2001
From: Tycho Andersen <tycho.ander...@canonical.com>
Date: Thu, 10 Mar 2016 11:10:14 -0700
Subject: [PATCH 2/2] cgroup: cgroup_escape takes no arguments
cgroup_escape() is a slight abuse of the cgroup code: what we really want
here is to escape the *current* process, whether it happens to be the LXC
monitor or not, into the / cgroups.
In the case of dump, we can't do an lxc_init(), because:
lxc 20160310103501.547 ERROR lxc_commands - commands.c:lxc_cmd_init:993 - ##
lxc 20160310103501.547 ERROR lxc_commands - commands.c:lxc_cmd_init:994 - #
The container appears to be already running!
lxc 20160310103501.547 ERROR lxc_commands - commands.c:lxc_cmd_init:995 - ##
We don't want to make this a command to send to the handler, because again,
cgroup_escape() is intended to escape the *current* task to the root
cgroups.
So, let's just have cgroup_escape() build its own handler when required.
Signed-off-by: Tycho Andersen <tycho.ander...@canonical.com>
---
src/lxc/cgfsng.c | 18 ++++++++++++++----
src/lxc/cgroup.h | 4 ++--
src/lxc/criu.c | 16 +++-------------
3 files changed, 19 insertions(+), 19 deletions(-)
diff --git a/src/lxc/cgfsng.c b/src/lxc/cgfsng.c
index 32213bf..90b8358 100644
--- a/src/lxc/cgfsng.c
+++ b/src/lxc/cgfsng.c
@@ -1280,14 +1280,21 @@ static int cgfsng_nrtasks(void *hdata) {
}
/* Only root needs to escape to the cgroup of its init */
-static bool cgfsng_escape(void *hdata)
+static bool cgfsng_escape()
{
- struct cgfsng_handler_data *d = hdata;
+ struct cgfsng_handler_data *d;
int i;
+ bool ret = false;
if (geteuid())
return true;
+ d = cgfsng_init("criu-temp-cgfsng");
+ if (!d) {
+ ERROR("cgfsng_init failed");
+ return false;
+ }
+
for (i = 0; d->hierarchies[i]; i++) {
char *fullpath = must_make_path(d->hierarchies[i]->mountpoint,
d->hierarchies[i]->base_cgroup,
@@ -1295,12 +1302,15 @@ static bool cgfsng_escape(void *hdata)
if (lxc_write_to_file(fullpath, "0", 2, false) != 0) {
SYSERROR("Failed to escape to %s", fullpath);
free(fullpath);
- return false;
+ goto out;
}
free(fullpath);
}
- return true;
+ ret = true;
+out:
+ free_handler_data(d);
+ return ret;
}
#define THAWED "THAWED"
diff --git a/src/lxc/cgroup.h b/src/lxc/cgroup.h
index ff3651e..e56a115 100644
--- a/src/lxc/cgroup.h
+++ b/src/lxc/cgroup.h
@@ -48,7 +48,7 @@ struct cgroup_ops {
bool (*create_legacy)(void *hdata, pid_t pid);
const char *(*get_cgroup)(void *hdata, const char *subsystem);
const char *(*canonical_path)(void *hdata);
- bool (*escape)(void *hdata);
+ bool (*escape)();
int (*set)(const char *filename, const char *value, const char *name,
const char *lxcpath);
int (*get)(const char *filename, char *value, size_t len, const char
*name, const char *lxcpath);
bool (*unfreeze)(void *hdata);
@@ -73,7 +73,7 @@ extern void cgroup_cleanup(struct lxc_handler *handler);
extern bool cgroup_create_legacy(struct lxc_handler *handler);
extern int cgroup_nrtasks(struct lxc_handler *handler);
extern const char *cgroup_get_cgroup(struct lxc_handler *handler, const char
*subsystem);
-extern bool cgroup_escape(struct lxc_handler *handler);
+extern bool cgroup_escape();
/*
* Currently, this call only makes sense for privileged containers.
diff --git a/src/lxc/criu.c b/src/lxc/criu.c
index b4ebf42..a683130 100644
--- a/src/lxc/criu.c
+++ b/src/lxc/criu.c
@@ -63,7 +63,7 @@ static void exec_criu(struct criu_opts *opts)
* /actual/ root cgroup so that lxcfs thinks criu has enough rights to
* see all cgroups.
*/
- if (!cgroup_escape(handler)) {
+ if (!cgroup_escape()) {
ERROR("failed to escape cgroups");
return;
}
@@ -517,7 +517,7 @@ void do_restore(struct lxc_container *c, int pipe, char
*directory, bool verbose
os.cgroup_path = cgroup_canonical_path(handler);
/* exec_criu() returning is an error */
- exec_criu(handler, &os);
+ exec_criu(&os);
umount(rootfs->mount);
rmdir(rootfs->mount);
goto out_fini_handler;
@@ -624,16 +624,6 @@ static bool do_dump(struct lxc_container *c, char *mode,
char *directory,
if (pid == 0) {
struct criu_opts os;
- struct lxc_handler *handler;
-
- handler = lxc_init(c->name, c->lxc_conf, c->config_path);
- if (!handler)
- exit(1);
-
- if (!cgroup_init(handler)) {
- ERROR("failed initing cgroups");
- exit(1);
- }
os.action = mode;
os.directory = directory;
@@ -643,7 +633,7 @@ static bool do_dump(struct lxc_container *c, char *mode,
char *directory,
os.predump_dir = predump_dir;
/* exec_criu() returning is an error */
- exec_criu(handler, &os);
+ exec_criu(&os);
exit(1);
} else {
int status;
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