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authorTejun Heo <tj@kernel.org>2015-08-18 22:58:16 +0200
committerTejun Heo <tj@kernel.org>2015-08-18 22:58:16 +0200
commit3e1d2eed39d804e48282931835c7203fa47fe1d9 (patch)
treebb9fb11d59686da511a018f318d9d826727c009f
parentcgroup: don't print subsystems for the default hierarchy (diff)
downloadlinux-3e1d2eed39d804e48282931835c7203fa47fe1d9.tar.xz
linux-3e1d2eed39d804e48282931835c7203fa47fe1d9.zip
cgroup: introduce cgroup_subsys->legacy_name
This allows cgroup subsystems to use a different name on the unified hierarchy. cgroup_subsys->name is used on the unified hierarchy, ->legacy_name elsewhere. If ->legacy_name is not explicitly set, it's automatically set to ->name and the userland visible behavior remains unchanged. v2: Make parse_cgroupfs_options() only consider ->legacy_name as mount options are used only on legacy hierarchies. Suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: cgroups@vger.kernel.org
-rw-r--r--include/linux/cgroup-defs.h3
-rw-r--r--kernel/cgroup.c29
2 files changed, 21 insertions, 11 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 8f5770a7d85a..7d0bb53e4553 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -434,6 +434,9 @@ struct cgroup_subsys {
int id;
const char *name;
+ /* optional, initialized automatically during boot if not set */
+ const char *legacy_name;
+
/* link to parent, protected by cgroup_lock() */
struct cgroup_root *root;
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d9f854defa78..9c8eb17d593a 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1028,10 +1028,13 @@ static const struct file_operations proc_cgroupstats_operations;
static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
char *buf)
{
+ struct cgroup_subsys *ss = cft->ss;
+
if (cft->ss && !(cft->flags & CFTYPE_NO_PREFIX) &&
!(cgrp->root->flags & CGRP_ROOT_NOPREFIX))
snprintf(buf, CGROUP_FILE_NAME_MAX, "%s.%s",
- cft->ss->name, cft->name);
+ cgroup_on_dfl(cgrp) ? ss->name : ss->legacy_name,
+ cft->name);
else
strncpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
return buf;
@@ -1336,7 +1339,7 @@ static int cgroup_show_options(struct seq_file *seq,
if (root != &cgrp_dfl_root)
for_each_subsys(ss, ssid)
if (root->subsys_mask & (1 << ssid))
- seq_printf(seq, ",%s", ss->name);
+ seq_printf(seq, ",%s", ss->legacy_name);
if (root->flags & CGRP_ROOT_NOPREFIX)
seq_puts(seq, ",noprefix");
if (root->flags & CGRP_ROOT_XATTR)
@@ -1449,7 +1452,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
}
for_each_subsys(ss, i) {
- if (strcmp(token, ss->name))
+ if (strcmp(token, ss->legacy_name))
continue;
if (ss->disabled)
continue;
@@ -4995,6 +4998,8 @@ int __init cgroup_init_early(void)
ss->id = i;
ss->name = cgroup_subsys_name[i];
+ if (!ss->legacy_name)
+ ss->legacy_name = cgroup_subsys_name[i];
if (ss->early_init)
cgroup_init_subsys(ss, true);
@@ -5142,7 +5147,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
for_each_subsys(ss, ssid)
if (root->subsys_mask & (1 << ssid))
seq_printf(m, "%s%s", count++ ? "," : "",
- ss->name);
+ ss->legacy_name);
if (strlen(root->name))
seq_printf(m, "%sname=%s", count ? "," : "",
root->name);
@@ -5182,7 +5187,7 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
for_each_subsys(ss, i)
seq_printf(m, "%s\t%d\t%d\t%d\n",
- ss->name, ss->root->hierarchy_id,
+ ss->legacy_name, ss->root->hierarchy_id,
atomic_read(&ss->root->nr_cgrps), !ss->disabled);
mutex_unlock(&cgroup_mutex);
@@ -5404,12 +5409,14 @@ static int __init cgroup_disable(char *str)
continue;
for_each_subsys(ss, i) {
- if (!strcmp(token, ss->name)) {
- ss->disabled = 1;
- printk(KERN_INFO "Disabling %s control group"
- " subsystem\n", ss->name);
- break;
- }
+ if (strcmp(token, ss->name) &&
+ strcmp(token, ss->legacy_name))
+ continue;
+
+ ss->disabled = 1;
+ printk(KERN_INFO "Disabling %s control group subsystem\n",
+ ss->name);
+ break;
}
}
return 1;