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authorTejun Heo <tj@kernel.org>2013-04-14 10:32:19 -0700
committerTejun Heo <tj@kernel.org>2013-04-14 10:47:02 -0700
commitda1f296fd2bfd5ad3c53d72a1ece593e821cf374 (patch)
tree775d4cac346481dc310f2174f0a8a2c38ed60ccd /kernel/cgroup.c
parent26d5bbe5ba2073fc7ef9e69a55543b2376f5bad0 (diff)
cgroup: make cgroup_path() not print double slashes
While reimplementing cgroup_path(), 65dff759d2 ("cgroup: fix cgroup_path() vs rename() race") introduced a bug where the path of a non-root cgroup would have two slahses at the beginning, which is caused by treating the root cgroup which has the name '/' like non-root cgroups. $ grep systemd /proc/self/cgroup 1:name=systemd://user/root/1 Fix it by special casing root cgroup case and not looping over it in the normal path. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 678a22c75fdb..faf55f59646b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1811,11 +1811,17 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
int ret = -ENAMETOOLONG;
char *start;
+ if (!cgrp->parent) {
+ if (strlcpy(buf, "/", buflen) >= buflen)
+ return -ENAMETOOLONG;
+ return 0;
+ }
+
start = buf + buflen - 1;
*start = '\0';
rcu_read_lock();
- while (cgrp) {
+ do {
const char *name = cgroup_name(cgrp);
int len;
@@ -1824,15 +1830,12 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
goto out;
memcpy(start, name, len);
- if (!cgrp->parent)
- break;
-
if (--start < buf)
goto out;
*start = '/';
cgrp = cgrp->parent;
- }
+ } while (cgrp->parent);
ret = 0;
memmove(buf, start, buf + buflen - start);
out: