[CRIU] [PATCH 3/3 v2] cg: Add rollback in get_cg_set

[Cyrill Gorcunov]

On Sat, Apr 02, 2016 at 12:17:18AM -0700, Andrew Vagin wrote:
> >  
> >  		if (collect && collect_cgroups(&cs->ctls)) {
> > -			put_ctls(ctls);
> > +			list_del(&cs->l);
> > +			n_sets--;
> 
> Can we call collect_cgroups() before filling cs?

We can, but I think it's more natural to splice here:
 - allocate new cg_set
 - splice existing data into it
 - now operate with @cg_set only

> 
> > +			put_ctls(&cs->ctls);
> >  			xfree(cs);
> > +			INIT_LIST_HEAD(ctls);
> 
> I think it's better to use list_splice_init() instead of
> list_splice()

yup, thanks. attached.
-------------- next part --------------
>From 34e71b48c4fe1f16cbd7ca34d5f5df335c8b5442 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov at virtuozzo.com>
Date: Thu, 31 Mar 2016 16:32:41 +0300
Subject: [PATCH] cg: Add rollback in get_cg_set

In case of error inside collect_cgroups we need

- @ctls list has been spliced into @cs->ctls so we cant just free it,
   but rather use put_ctls on @cs->ctls

- delete @cs->l from global @cg_sets list before free it

https://jira.sw.ru/browse/PSBM-45553

Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
---
 criu/cgroup.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/criu/cgroup.c b/criu/cgroup.c
index ccac9fa..bb76606 100644
--- a/criu/cgroup.c
+++ b/criu/cgroup.c
@@ -201,7 +201,7 @@ static struct cg_set *get_cg_set(struct list_head *ctls, unsigned int n_ctls, bo
 	if (cs) {
 		cs->id = cg_set_ids++;
 		INIT_LIST_HEAD(&cs->ctls);
-		list_splice(ctls, &cs->ctls);
+		list_splice_init(ctls, &cs->ctls);
 		cs->n_ctls = n_ctls;
 		list_add_tail(&cs->l, &cg_sets);
 		n_sets++;
@@ -214,7 +214,9 @@ static struct cg_set *get_cg_set(struct list_head *ctls, unsigned int n_ctls, bo
 		}
 
 		if (collect && collect_cgroups(&cs->ctls)) {
-			put_ctls(ctls);
+			list_del(&cs->l);
+			n_sets--;
+			put_ctls(&cs->ctls);
 			xfree(cs);
 			return NULL;
 		}
-- 
2.5.5