cgroup: clean up sane_behavior handling

[mirror_ubuntu-bionic-kernel.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index fb07c6d43aff968c385b8ea8f4e077769937314e..28f7d47c1d4a06153489c014186efb9693192b60 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1289,8 +1289,6 @@ static int cgroup_show_options(struct seq_file *seq,
        for_each_subsys(ss, ssid)
                if (root->subsys_mask & (1 << ssid))
                        seq_printf(seq, ",%s", ss->name);
-       if (root->flags & CGRP_ROOT_SANE_BEHAVIOR)
-               seq_puts(seq, ",sane_behavior");
        if (root->flags & CGRP_ROOT_NOPREFIX)
                seq_puts(seq, ",noprefix");
        if (root->flags & CGRP_ROOT_XATTR)
@@ -1324,6 +1322,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        bool all_ss = false, one_ss = false;
        unsigned int mask = -1U;
        struct cgroup_subsys *ss;
+       int nr_opts = 0;
        int i;
 
 #ifdef CONFIG_CPUSETS
@@ -1333,6 +1332,8 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        memset(opts, 0, sizeof(*opts));
 
        while ((token = strsep(&o, ",")) != NULL) {
+               nr_opts++;
+
                if (!*token)
                        return -EINVAL;
                if (!strcmp(token, "none")) {
@@ -1417,36 +1418,32 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                        return -ENOENT;
        }
 
-       /* Consistency checks */
-
        if (opts->flags & CGRP_ROOT_SANE_BEHAVIOR) {
                pr_warn("sane_behavior: this is still under development and its behaviors will change, proceed at your own risk\n");
-
-               if ((opts->flags & (CGRP_ROOT_NOPREFIX | CGRP_ROOT_XATTR)) ||
-                   opts->cpuset_clone_children || opts->release_agent ||
-                   opts->name) {
-                       pr_err("sane_behavior: noprefix, xattr, clone_children, release_agent and name are not allowed\n");
+               if (nr_opts != 1) {
+                       pr_err("sane_behavior: no other mount options allowed\n");
                        return -EINVAL;
                }
-       } else {
-               /*
-                * If the 'all' option was specified select all the
-                * subsystems, otherwise if 'none', 'name=' and a subsystem
-                * name options were not specified, let's default to 'all'
-                */
-               if (all_ss || (!one_ss && !opts->none && !opts->name))
-                       for_each_subsys(ss, i)
-                               if (!ss->disabled)
-                                       opts->subsys_mask |= (1 << i);
-
-               /*
-                * We either have to specify by name or by subsystems. (So
-                * all empty hierarchies must have a name).
-                */
-               if (!opts->subsys_mask && !opts->name)
-                       return -EINVAL;
+               return 0;
        }
 
+       /*
+        * If the 'all' option was specified select all the subsystems,
+        * otherwise if 'none', 'name=' and a subsystem name options were
+        * not specified, let's default to 'all'
+        */
+       if (all_ss || (!one_ss && !opts->none && !opts->name))
+               for_each_subsys(ss, i)
+                       if (!ss->disabled)
+                               opts->subsys_mask |= (1 << i);
+
+       /*
+        * We either have to specify by name or by subsystems. (So all
+        * empty hierarchies must have a name).
+        */
+       if (!opts->subsys_mask && !opts->name)
+               return -EINVAL;
+
        /*
         * Option noprefix was introduced just for backward compatibility
         * with the old cpuset, so we allow noprefix only if mounting just
@@ -1455,7 +1452,6 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        if ((opts->flags & CGRP_ROOT_NOPREFIX) && (opts->subsys_mask & mask))
                return -EINVAL;
 
-
        /* Can't specify "none" and some subsystems */
        if (opts->subsys_mask && opts->none)
                return -EINVAL;
@@ -1724,7 +1720,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
                goto out_unlock;
 
        /* look for a matching existing root */
-       if (!opts.subsys_mask && !opts.none && !opts.name) {
+       if (opts.flags & CGRP_ROOT_SANE_BEHAVIOR) {
                cgrp_dfl_root_visible = true;
                root = &cgrp_dfl_root;
                cgroup_get(&root->cgrp);
@@ -1761,15 +1757,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
                        goto out_unlock;
                }
 
-               if (root->flags ^ opts.flags) {
-                       if ((root->flags | opts.flags) & CGRP_ROOT_SANE_BEHAVIOR) {
-                               pr_err("sane_behavior: new mount options should match the existing superblock\n");
-                               ret = -EINVAL;
-                               goto out_unlock;
-                       } else {
-                               pr_warn("new mount options do not match the existing superblock, will be ignored\n");
-                       }
-               }
+               if (root->flags ^ opts.flags)
+                       pr_warn("new mount options do not match the existing superblock, will be ignored\n");
 
                /*
                 * A root's lifetime is governed by its root cgroup.
@@ -4809,8 +4798,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
  */
 int __init cgroup_init_early(void)
 {
-       static struct cgroup_sb_opts __initdata opts =
-               { .flags = CGRP_ROOT_SANE_BEHAVIOR };
+       static struct cgroup_sb_opts __initdata opts;
        struct cgroup_subsys *ss;
        int i;