cgroup: update error handling in cgroup_populate_dir()

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@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2013-06-28 16:24:11 -07:00
parent 628f7cd47a
commit bee550994f

View File

@ -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 cgroup *cgrp, unsigned long subsys_mask)
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 cgroup *cgrp, unsigned long subsys_mask)
}
return 0;
err:
cgroup_clear_dir(cgrp, subsys_mask);
return ret;
}
static void css_dput_fn(struct work_struct *work)