From ce5f91bdfa3b47356b35661f84173eeef05d1299 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 28 Dec 2018 10:31:07 -0800 Subject: [PATCH] UPSTREAM: cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param It can be useful to inhibit all cgroup1 hierarchies especially during transition and for debugging. cgroup_no_v1 can block hierarchies with controllers which leaves out the named hierarchies. Expand it to cover the named hierarchies so that "cgroup_no_v1=all,named" disables all cgroup1 hierarchies. Signed-off-by: Tejun Heo Suggested-by: Marcin Pawlowski Signed-off-by: Tejun Heo Change-Id: Ibd093dd9b70d15402a21db3c1ef56005ebc7f99e (cherry picked from commit 3fc9c12d27b4ded4f1f761a800558dab2e6bbac5) Bug: 154548692 Signed-off-by: Marco Ballesio --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++-- kernel/cgroup/cgroup-v1.c | 14 +++++++++++++- 2 files changed, 19 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b2678cf459e4..af3044330cce 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -490,10 +490,14 @@ cut the overhead, others just disable the usage. So only cgroup_disable=memory is actually worthy} - cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1 - Format: { controller[,controller...] | "all" } + cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1 + Format: { { controller | "all" | "named" } + [,{ controller | "all" | "named" }...] } Like cgroup_disable, but only applies to cgroup v1; the blacklisted controllers remain available in cgroup2. + "all" blacklists all controllers and "named" disables + named mounts. Specifying both "all" and "named" disables + all v1 hierarchies. cgroup.memory= [KNL] Pass options to the cgroup memory controller. Format: diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 405167715d52..7b47cb0a82e9 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -27,6 +27,9 @@ /* Controllers blocked by the commandline in v1 */ static u16 cgroup_no_v1_mask; +/* disable named v1 mounts */ +static bool cgroup_no_v1_named; + /* * pidlist destructions need to be flushed on cgroup destruction. Use a * separate workqueue as flush domain. @@ -965,6 +968,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) } if (!strncmp(token, "name=", 5)) { const char *name = token + 5; + + /* blocked by boot param? */ + if (cgroup_no_v1_named) + return -ENOENT; /* Can't specify an empty name */ if (!strlen(name)) return -EINVAL; @@ -1294,7 +1301,12 @@ static int __init cgroup_no_v1(char *str) if (!strcmp(token, "all")) { cgroup_no_v1_mask = U16_MAX; - break; + continue; + } + + if (!strcmp(token, "named")) { + cgroup_no_v1_named = true; + continue; } for_each_subsys(ss, i) {