From bee550994f6b0c1179bd3ccea58dc5c2c4ccf842 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 28 Jun 2013 16:24:11 -0700 Subject: [PATCH] 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 Acked-by: Li Zefan --- kernel/cgroup.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 9835a097f3c0..6b7324431b99 100644 --- 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 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) -- GitLab