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.
Signed-off-by: Tejun Heo
Cc: Li Zefan
Cc: Johannes Weiner
Cc: cgro...@vger.kernel.org
---
include/linux/cgroup-defs.h | 3 +++
kernel/cgroup.c | 30 +++---
2 files changed, 22 insertions(+), 11 deletions(-)
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 8f5770a..7d0bb53 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 6c85e6d..0da2efa 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1027,10 +1027,13 @@ 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;
@@ -1335,7 +1338,7 @@ 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)
@@ -1448,7 +1451,8 @@ 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->name) &&
+ strcmp(token, ss->legacy_name))
continue;
if (ss->disabled)
continue;
@@ -4994,6 +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);
@@ -5141,7 +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);
@@ -5181,7 +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);
@@ -5403,12 +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;
--
2.4.3
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