cgroup: rename subsys_bits to subsys_mask

In a previous discussion, Tejun Heo suggested to rename references to
subsys_bits (added_bits, removed_bits, etc) by something more meaningful.

Cc: Li Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Lennart Poettering <lpoetter@redhat.com>
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 508b4a9..ced292d 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -111,13 +111,13 @@ struct cgroupfs_root {
         * The bitmask of subsystems intended to be attached to this
         * hierarchy
         */
-       unsigned long subsys_bits;
+       unsigned long subsys_mask;
 
        /* Unique id for this hierarchy. */
        int hierarchy_id;
 
        /* The bitmask of subsystems currently attached to this hierarchy */
-       unsigned long actual_subsys_bits;
+       unsigned long actual_subsys_mask;
 
        /* A list running through the attached subsystems */
        struct list_head subsys_list;
@@ -557,7 +557,7 @@ static struct css_set *find_existing_css_set(
         * won't change, so no need for locking.
         */
        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
-               if (root->subsys_bits & (1UL << i)) {
+               if (root->subsys_mask & (1UL << i)) {
                        /* Subsystem is in this hierarchy. So we want
                         * the subsystem state from the new
                         * cgroup */
@@ -1002,7 +1002,7 @@ static void cgroup_d_remove_dir(struct dentry *dentry)
        struct dentry *parent;
        struct cgroupfs_root *root = dentry->d_sb->s_fs_info;
 
-       cgroup_clear_directory(dentry, true, root->subsys_bits);
+       cgroup_clear_directory(dentry, true, root->subsys_mask);
 
        parent = dentry->d_parent;
        spin_lock(&parent->d_lock);
@@ -1046,22 +1046,22 @@ void cgroup_release_and_wakeup_rmdir(struct cgroup_subsys_state *css)
  * returns an error, no reference counts are touched.
  */
 static int rebind_subsystems(struct cgroupfs_root *root,
-                             unsigned long final_bits)
+                             unsigned long final_subsys_mask)
 {
-       unsigned long added_bits, removed_bits;
+       unsigned long added_mask, removed_mask;
        struct cgroup *cgrp = &root->top_cgroup;
        int i;
 
        BUG_ON(!mutex_is_locked(&cgroup_mutex));
        BUG_ON(!mutex_is_locked(&cgroup_root_mutex));
 
-       removed_bits = root->actual_subsys_bits & ~final_bits;
-       added_bits = final_bits & ~root->actual_subsys_bits;
+       removed_mask = root->actual_subsys_mask & ~final_subsys_mask;
+       added_mask = final_subsys_mask & ~root->actual_subsys_mask;
        /* Check that any added subsystems are currently free */
        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
                unsigned long bit = 1UL << i;
                struct cgroup_subsys *ss = subsys[i];
-               if (!(bit & added_bits))
+               if (!(bit & added_mask))
                        continue;
                /*
                 * Nobody should tell us to do a subsys that doesn't exist:
@@ -1086,7 +1086,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
        for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
                struct cgroup_subsys *ss = subsys[i];
                unsigned long bit = 1UL << i;
-               if (bit & added_bits) {
+               if (bit & added_mask) {
                        /* We're binding this subsystem to this hierarchy */
                        BUG_ON(ss == NULL);
                        BUG_ON(cgrp->subsys[i]);
@@ -1099,7 +1099,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
                        if (ss->bind)
                                ss->bind(cgrp);
                        /* refcount was already taken, and we're keeping it */
-               } else if (bit & removed_bits) {
+               } else if (bit & removed_mask) {
                        /* We're removing this subsystem */
                        BUG_ON(ss == NULL);
                        BUG_ON(cgrp->subsys[i] != dummytop->subsys[i]);
@@ -1112,7 +1112,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
                        list_move(&ss->sibling, &rootnode.subsys_list);
                        /* subsystem is now free - drop reference on module */
                        module_put(ss->module);
-               } else if (bit & final_bits) {
+               } else if (bit & final_subsys_mask) {
                        /* Subsystem state should already exist */
                        BUG_ON(ss == NULL);
                        BUG_ON(!cgrp->subsys[i]);
@@ -1129,7 +1129,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
                        BUG_ON(cgrp->subsys[i]);
                }
        }
-       root->subsys_bits = root->actual_subsys_bits = final_bits;
+       root->subsys_mask = root->actual_subsys_mask = final_subsys_mask;
        synchronize_rcu();
 
        return 0;
@@ -1158,7 +1158,7 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry)
 }
 
 struct cgroup_sb_opts {
-       unsigned long subsys_bits;
+       unsigned long subsys_mask;
        unsigned long flags;
        char *release_agent;
        bool clone_children;
@@ -1267,7 +1267,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                        /* Mutually exclusive option 'all' + subsystem name */
                        if (all_ss)
                                return -EINVAL;
-                       set_bit(i, &opts->subsys_bits);
+                       set_bit(i, &opts->subsys_mask);
                        one_ss = true;
 
                        break;
@@ -1288,7 +1288,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                                continue;
                        if (ss->disabled)
                                continue;
-                       set_bit(i, &opts->subsys_bits);
+                       set_bit(i, &opts->subsys_mask);
                }
        }
 
@@ -1300,19 +1300,19 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
         * the cpuset subsystem.
         */
        if (test_bit(ROOT_NOPREFIX, &opts->flags) &&
-           (opts->subsys_bits & mask))
+           (opts->subsys_mask & mask))
                return -EINVAL;
 
 
        /* Can't specify "none" and some subsystems */
-       if (opts->subsys_bits && opts->none)
+       if (opts->subsys_mask && opts->none)
                return -EINVAL;
 
        /*
         * We either have to specify by name or by subsystems. (So all
         * empty hierarchies must have a name).
         */
-       if (!opts->subsys_bits && !opts->name)
+       if (!opts->subsys_mask && !opts->name)
                return -EINVAL;
 
        /*
@@ -1324,7 +1324,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) {
                unsigned long bit = 1UL << i;
 
-               if (!(bit & opts->subsys_bits))
+               if (!(bit & opts->subsys_mask))
                        continue;
                if (!try_module_get(subsys[i]->module)) {
                        module_pin_failed = true;
@@ -1341,7 +1341,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
                        /* drop refcounts only on the ones we took */
                        unsigned long bit = 1UL << i;
 
-                       if (!(bit & opts->subsys_bits))
+                       if (!(bit & opts->subsys_mask))
                                continue;
                        module_put(subsys[i]->module);
                }
@@ -1351,13 +1351,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
        return 0;
 }
 
-static void drop_parsed_module_refcounts(unsigned long subsys_bits)
+static void drop_parsed_module_refcounts(unsigned long subsys_mask)
 {
        int i;
        for (i = CGROUP_BUILTIN_SUBSYS_COUNT; i < CGROUP_SUBSYS_COUNT; i++) {
                unsigned long bit = 1UL << i;
 
-               if (!(bit & subsys_bits))
+               if (!(bit & subsys_mask))
                        continue;
                module_put(subsys[i]->module);
        }
@@ -1369,7 +1369,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
        struct cgroupfs_root *root = sb->s_fs_info;
        struct cgroup *cgrp = &root->top_cgroup;
        struct cgroup_sb_opts opts;
-       unsigned long added_bits, removed_bits;
+       unsigned long added_mask, removed_mask;
 
        mutex_lock(&cgrp->dentry->d_inode->i_mutex);
        mutex_lock(&cgroup_mutex);
@@ -1381,31 +1381,31 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data)
                goto out_unlock;
 
        /* See feature-removal-schedule.txt */
-       if (opts.subsys_bits != root->actual_subsys_bits || opts.release_agent)
+       if (opts.subsys_mask != root->actual_subsys_mask || opts.release_agent)
                pr_warning("cgroup: option changes via remount are deprecated (pid=%d comm=%s)\n",
                           task_tgid_nr(current), current->comm);
 
-       added_bits = opts.subsys_bits & ~root->subsys_bits;
-       removed_bits = root->subsys_bits & ~opts.subsys_bits;
+       added_mask = opts.subsys_mask & ~root->subsys_mask;
+       removed_mask = root->subsys_mask & ~opts.subsys_mask;
 
        /* Don't allow flags or name to change at remount */
        if (opts.flags != root->flags ||
            (opts.name && strcmp(opts.name, root->name))) {
                ret = -EINVAL;
-               drop_parsed_module_refcounts(opts.subsys_bits);
+               drop_parsed_module_refcounts(opts.subsys_mask);
                goto out_unlock;
        }
 
-       ret = rebind_subsystems(root, opts.subsys_bits);
+       ret = rebind_subsystems(root, opts.subsys_mask);
        if (ret) {
-               drop_parsed_module_refcounts(opts.subsys_bits);
+               drop_parsed_module_refcounts(opts.subsys_mask);
                goto out_unlock;
        }
 
        /* clear out any existing files and repopulate subsystem files */
-       cgroup_clear_directory(cgrp->dentry, false, removed_bits);
+       cgroup_clear_directory(cgrp->dentry, false, removed_mask);
        /* re-populate subsystem files */
-       cgroup_populate_dir(cgrp, false, added_bits);
+       cgroup_populate_dir(cgrp, false, added_mask);
 
        if (opts.release_agent)
                strcpy(root->release_agent_path, opts.release_agent);
@@ -1491,8 +1491,8 @@ static int cgroup_test_super(struct super_block *sb, void *data)
         * If we asked for subsystems (or explicitly for no
         * subsystems) then they must match
         */
-       if ((opts->subsys_bits || opts->none)
-           && (opts->subsys_bits != root->subsys_bits))
+       if ((opts->subsys_mask || opts->none)
+           && (opts->subsys_mask != root->subsys_mask))
                return 0;
 
        return 1;
@@ -1502,7 +1502,7 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
 {
        struct cgroupfs_root *root;
 
-       if (!opts->subsys_bits && !opts->none)
+       if (!opts->subsys_mask && !opts->none)
                return NULL;
 
        root = kzalloc(sizeof(*root), GFP_KERNEL);
@@ -1515,7 +1515,7 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts)
        }
        init_cgroup_root(root);
 
-       root->subsys_bits = opts->subsys_bits;
+       root->subsys_mask = opts->subsys_mask;
        root->flags = opts->flags;
        if (opts->release_agent)
                strcpy(root->release_agent_path, opts->release_agent);
@@ -1547,7 +1547,7 @@ static int cgroup_set_super(struct super_block *sb, void *data)
        if (!opts->new_root)
                return -EINVAL;
 
-       BUG_ON(!opts->subsys_bits && !opts->none);
+       BUG_ON(!opts->subsys_mask && !opts->none);
 
        ret = set_anon_super(sb, NULL);
        if (ret)
@@ -1665,7 +1665,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
                if (ret)
                        goto unlock_drop;
 
-               ret = rebind_subsystems(root, root->subsys_bits);
+               ret = rebind_subsystems(root, root->subsys_mask);
                if (ret == -EBUSY) {
                        free_cg_links(&tmp_cg_links);
                        goto unlock_drop;
@@ -1705,7 +1705,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
                BUG_ON(root->number_of_cgroups != 1);
 
                cred = override_creds(&init_cred);
-               cgroup_populate_dir(root_cgrp, true, root->subsys_bits);
+               cgroup_populate_dir(root_cgrp, true, root->subsys_mask);
                revert_creds(cred);
                mutex_unlock(&cgroup_root_mutex);
                mutex_unlock(&cgroup_mutex);
@@ -1717,7 +1717,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
                 */
                cgroup_drop_root(opts.new_root);
                /* no subsys rebinding, so refcounts don't change */
-               drop_parsed_module_refcounts(opts.subsys_bits);
+               drop_parsed_module_refcounts(opts.subsys_mask);
        }
 
        kfree(opts.release_agent);
@@ -1731,7 +1731,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
  drop_new_super:
        deactivate_locked_super(sb);
  drop_modules:
-       drop_parsed_module_refcounts(opts.subsys_bits);
+       drop_parsed_module_refcounts(opts.subsys_mask);
  out_err:
        kfree(opts.release_agent);
        kfree(opts.name);
@@ -4109,7 +4109,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 
        list_add_tail(&cgrp->allcg_node, &root->allcg_list);
 
-       err = cgroup_populate_dir(cgrp, true, root->subsys_bits);
+       err = cgroup_populate_dir(cgrp, true, root->subsys_mask);
        /* If err < 0, we have a half-filled directory - oh well ;) */
 
        mutex_unlock(&cgroup_mutex);