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()

4 files changed, 11 insertions, 8 deletions

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 63521cd36ce5..1de8695c264b 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1029,7 +1029,7 @@ All time durations are in microseconds.
 	one number is written, $MAX is updated.
 
   cpu.pressure
-	A read-only nested-key file which exists on non-root cgroups.
+	A read-write nested-keyed file.
 
 	Shows pressure stall information for CPU. See
 	:ref:`Documentation/accounting/psi.rst <psi>` for details.
@@ -1475,7 +1475,7 @@ PAGE_SIZE multiple when read back.
 	reduces the impact on the workload and memory management.
 
   memory.pressure
-	A read-only nested-key file which exists on non-root cgroups.
+	A read-only nested-keyed file.
 
 	Shows pressure stall information for memory. See
 	:ref:`Documentation/accounting/psi.rst <psi>` for details.
@@ -1714,7 +1714,7 @@ IO Interface Files
 	  8:16 rbps=2097152 wbps=max riops=max wiops=max
 
   io.pressure
-	A read-only nested-key file which exists on non-root cgroups.
+	A read-only nested-keyed file.
 
 	Shows pressure stall information for IO. See
 	:ref:`Documentation/accounting/psi.rst <psi>` for details.
diff --git a/MAINTAINERS b/MAINTAINERS
index e9fccfb27e2d..bfc1b86e3e73 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4468,7 +4468,7 @@ F:	include/linux/console*
 
 CONTROL GROUP (CGROUP)
 M:	Tejun Heo <tj@kernel.org>
-M:	Li Zefan <lizefan@huawei.com>
+M:	Zefan Li <lizefan.x@bytedance.com>
 M:	Johannes Weiner <hannes@cmpxchg.org>
 L:	cgroups@vger.kernel.org
 S:	Maintained
@@ -4492,11 +4492,9 @@ F:	block/blk-throttle.c
 F:	include/linux/blk-cgroup.h
 
 CONTROL GROUP - CPUSET
-M:	Li Zefan <lizefan@huawei.com>
+M:	Zefan Li <lizefan.x@bytedance.com>
 L:	cgroups@vger.kernel.org
 S:	Maintained
-W:	http://www.bullopensource.org/cpuset/
-W:	http://oss.sgi.com/projects/cpusets/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git
 F:	Documentation/admin-guide/cgroup-v1/cpusets.rst
 F:	include/linux/cpuset.h
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);