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Commit a1a71b45 authored by Aristeu Rozanski's avatar Aristeu Rozanski Committed by Tejun Heo
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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: default avatarAristeu Rozanski <aris@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 03b1cde6

kernel/cgroup.c

+42 −42
Original line number Diff line number Diff line
@@ -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);