cgroup: remove "no" prefixed mount options

30312730bd02 ("cgroup: Add "no" prefixed mount options") added "no" prefixed
mount options to allow turning them off and 6a010a49b63a ("cgroup: Make
!percpu threadgroup_rwsem operations optional") added one more "no" prefixed
mount option. However, Michal pointed out that the "no" prefixed options
aren't necessary in allowing mount options to be turned off:

  # grep group /proc/mounts
  cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,relatime,nsdelegate,memory_recursiveprot 0 0
  # mount -o remount,nsdelegate,memory_recursiveprot none /sys/fs/cgroup
  # grep cgroup /proc/mounts
  cgroup2 /sys/fs/cgroup cgroup2 rw,relatime,nsdelegate,memory_recursiveprot 0 0

Note that this is different from the remount behavior when the mount(1) is
invoked without the device argument - "none":

 # grep cgroup /proc/mounts
 cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0
 # mount -o remount,nsdelegate,memory_recursiveprot /sys/fs/cgroup
 # grep cgroup /proc/mounts
 cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0

While a bit confusing, given that there is a way to turn off the options,
there's no reason to have the explicit "no" prefixed options. Let's remove
them.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 4 insertions, 20 deletions

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 7d023d42a6a5..c85dadf0d53b 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1872,22 +1872,18 @@ int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
 }
 
 enum cgroup2_param {
-	Opt_nsdelegate, Opt_nonsdelegate,
-	Opt_favordynmods, Opt_nofavordynmods,
-	Opt_memory_localevents, Opt_memory_nolocalevents,
-	Opt_memory_recursiveprot, Opt_memory_norecursiveprot,
+	Opt_nsdelegate,
+	Opt_favordynmods,
+	Opt_memory_localevents,
+	Opt_memory_recursiveprot,
 	nr__cgroup2_params
 };
 
 static const struct fs_parameter_spec cgroup2_fs_parameters[] = {
 	fsparam_flag("nsdelegate",		Opt_nsdelegate),
-	fsparam_flag("nonsdelegate",		Opt_nonsdelegate),
 	fsparam_flag("favordynmods",		Opt_favordynmods),
-	fsparam_flag("nofavordynmods",		Opt_nofavordynmods),
 	fsparam_flag("memory_localevents",	Opt_memory_localevents),
-	fsparam_flag("memory_nolocalevents",	Opt_memory_nolocalevents),
 	fsparam_flag("memory_recursiveprot",	Opt_memory_recursiveprot),
-	fsparam_flag("memory_norecursiveprot",	Opt_memory_norecursiveprot),
 	{}
 };
 
@@ -1905,27 +1901,15 @@ static int cgroup2_parse_param(struct fs_context *fc, struct fs_parameter *param
 	case Opt_nsdelegate:
 		ctx->flags |= CGRP_ROOT_NS_DELEGATE;
 		return 0;
-	case Opt_nonsdelegate:
-		ctx->flags &= ~CGRP_ROOT_NS_DELEGATE;
-		return 0;
 	case Opt_favordynmods:
 		ctx->flags |= CGRP_ROOT_FAVOR_DYNMODS;
 		return 0;
-	case Opt_nofavordynmods:
-		ctx->flags &= ~CGRP_ROOT_FAVOR_DYNMODS;
-		return 0;
 	case Opt_memory_localevents:
 		ctx->flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS;
 		return 0;
-	case Opt_memory_nolocalevents:
-		ctx->flags &= ~CGRP_ROOT_MEMORY_LOCAL_EVENTS;
-		return 0;
 	case Opt_memory_recursiveprot:
 		ctx->flags |= CGRP_ROOT_MEMORY_RECURSIVE_PROT;
 		return 0;
-	case Opt_memory_norecursiveprot:
-		ctx->flags &= ~CGRP_ROOT_MEMORY_RECURSIVE_PROT;
-		return 0;
 	}
 	return -EINVAL;
 }