Merge branch 'for-5.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:
 "Two cgroup fixes:

   - fix a NULL deref when trying to poll PSI in the root cgroup

   - fix confusing controller parsing corner case when mounting cgroup
     v1 hierarchies

  And doc / maintainer file updates"

* 'for-5.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: update PSI file description in docs
  cgroup: fix psi monitor for root cgroup
  MAINTAINERS: Update my email address
  MAINTAINERS: Remove stale URLs for cpuset
  cgroup-v1: add disabled controller check in cgroup1_parse_param()

2 files changed, 6 insertions, 1 deletions

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 32596fdbcd5b..a5751784ad74 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -917,6 +917,9 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		for_each_subsys(ss, i) {
 			if (strcmp(param->key, ss->legacy_name))
 				continue;
+			if (!cgroup_ssid_enabled(i) || cgroup1_ssid_disabled(i))
+				return invalfc(fc, "Disabled controller '%s'",
+					       param->key);
 			ctx->subsys_mask |= (1 << i);
 			return 0;
 		}
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 613845769103..1ea995f801ec 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3564,6 +3564,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
 {
 	struct psi_trigger *new;
 	struct cgroup *cgrp;
+	struct psi_group *psi;
 
 	cgrp = cgroup_kn_lock_live(of->kn, false);
 	if (!cgrp)
@@ -3572,7 +3573,8 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
 	cgroup_get(cgrp);
 	cgroup_kn_unlock(of->kn);
 
-	new = psi_trigger_create(&cgrp->psi, buf, nbytes, res);
+	psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
+	new = psi_trigger_create(psi, buf, nbytes, res);
 	if (IS_ERR(new)) {
 		cgroup_put(cgrp);
 		return PTR_ERR(new);