>From 4b5e65e0911690422a9b253b8ef68b14288e99c5 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@xxxxxxxxxx>
Date: Fri, 28 Jun 2013 16:24:11 -0700
cgroup_populate_dir() didn't use to check whether the actual file
creations were successful and could return success with only subset of
the requested files created, which is nasty.
This patch udpates cgroup_populate_dir() so that it either succeeds
with all files or fails with no file.
v2: The original patch also converted for_each_root_subsys() usages to
for_each_subsys() without explaining why. That part has been
moved to a separate patch.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
Li, I separated out the for_each_subsys() conversion to a separate
patch instead.
Thanks.
kernel/cgroup.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4171,10 +4171,13 @@ static struct cftype cgroup_base_files[]
* cgroup_populate_dir - create subsys files in a cgroup directory
* @cgrp: target cgroup
* @subsys_mask: mask of the subsystem ids whose files should be added
+ *
+ * On failure, no file is added.
*/
static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask)
{
struct cgroup_subsys *ss;
+ int ret = 0;
/* process cftsets of each subsystem */
for_each_root_subsys(cgrp->root, ss) {
@@ -4182,8 +4185,11 @@ static int cgroup_populate_dir(struct cg
if (!test_bit(ss->subsys_id, &subsys_mask))
continue;
- list_for_each_entry(set, &ss->cftsets, node)
- cgroup_addrm_files(cgrp, ss, set->cfts, true);
+ list_for_each_entry(set, &ss->cftsets, node) {
+ ret = cgroup_addrm_files(cgrp, ss, set->cfts, true);
+ if (ret < 0)
+ goto err;
+ }
}
/* This cgroup is ready now */
@@ -4201,6 +4207,9 @@ static int cgroup_populate_dir(struct cg
}
return 0;
+err:
+ cgroup_clear_dir(cgrp, subsys_mask);
+ return ret;
}
static void css_dput_fn(struct work_struct *work)
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