[lxc-devel] [lxc/master] Avoid double lxc-freeze/unfreeze

[Rachid-Koucha on Github]

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From 2341916a0367130d5a084a89884c15c3a835a4b4 Mon Sep 17 00:00:00 2001
From: Rachid Koucha <47061324+Rachid-Koucha at users.noreply.github.com>
Date: Sat, 26 Jan 2019 23:46:34 +0100
Subject: [PATCH] Avoid double lxc-freeze/unfreeze

If we call lxc-freeze multiple times for an already frozen container, LXC
triggers useless freezing by writing into the "freezer.state" cgroup file.
This is the same when we call lxc-unfreeze multiple times.
Checking the current state with a LXC_CMD_GET_STATE
(calling c->state) would permit to check if the container is FROZEN
or not.

Signed-off-by: Rachid Koucha <rachid.koucha at gmail.com>
---
 src/lxc/lxccontainer.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index bee34db015..364c6c7a78 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -525,13 +525,17 @@ WRAP_API(bool, lxcapi_is_running)
 static bool do_lxcapi_freeze(struct lxc_container *c)
 {
 	int ret;
+	lxc_state_t s;
 
 	if (!c)
 		return false;
 
-	ret = lxc_freeze(c->lxc_conf, c->name, c->config_path);
-	if (ret < 0)
-		return false;
+	s = lxc_getstate(c->name, c->config_path);
+	if (s != FROZEN) {
+	  ret = lxc_freeze(c->lxc_conf, c->name, c->config_path);
+	  if (ret < 0)
+	    return false;
+	}
 
 	return true;
 }
@@ -541,13 +545,17 @@ WRAP_API(bool, lxcapi_freeze)
 static bool do_lxcapi_unfreeze(struct lxc_container *c)
 {
 	int ret;
+	lxc_state_t s;
 
 	if (!c)
 		return false;
 
-	ret = lxc_unfreeze(c->lxc_conf, c->name, c->config_path);
-	if (ret < 0)
-		return false;
+	s = lxc_getstate(c->name, c->config_path);
+	if (s == FROZEN) {
+	  ret = lxc_unfreeze(c->lxc_conf, c->name, c->config_path);
+	  if (ret < 0)
+	    return false;
+	}
 
 	return true;
 }