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| author | Tejun Heo <tj@kernel.org> | 2013-04-14 19:32:19 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-04-14 19:47:02 +0200 |
| commit | da1f296fd2bfd5ad3c53d72a1ece593e821cf374 (patch) | |
| tree | 775d4cac346481dc310f2174f0a8a2c38ed60ccd /kernel/cgroup.c | |
| parent | Revert "cgroup: remove bind() method from cgroup_subsys." (diff) | |
| download | linux-da1f296fd2bfd5ad3c53d72a1ece593e821cf374.tar.xz linux-da1f296fd2bfd5ad3c53d72a1ece593e821cf374.zip | |
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.c | 13 |
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: |