Commit d27567a0 authored by Babu Moger's avatar Babu Moger Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Move default group file creation to mount 



The default resource group and its files are created during kernel init
time. Upcoming changes will make some resctrl files optional based on
a mount parameter. If optional files are to be added to the default
group based on the mount option, then each new file needs to be created
separately and call kernfs_activate() again.

Create all files of the default resource group during resctrl mount,
destroyed during unmount, to avoid scattering resctrl file addition
across two separate code flows.

Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarPeter Newman <peternewman@google.com>
Reviewed-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-6-babu.moger@amd.com
parent df5f3a1d

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+34 −24
Original line number Diff line number Diff line
@@ -54,6 +54,9 @@ static struct kernfs_node *kn_mondata; 
static struct seq_buf last_cmd_status;

static char last_cmd_status_buf[512];



static int rdtgroup_setup_root(struct rdt_fs_context *ctx);

static void rdtgroup_destroy_root(void);



struct dentry *debugfs_resctrl;



void rdt_last_cmd_clear(void)
@@ -2529,10 +2532,14 @@ static int rdt_get_tree(struct fs_context *fc) 
		goto out;

	}



	ret = rdt_enable_ctx(ctx);

	ret = rdtgroup_setup_root(ctx);

	if (ret)

		goto out;



	ret = rdt_enable_ctx(ctx);

	if (ret)

		goto out_root;



	ret = schemata_list_create();

	if (ret) {

		schemata_list_destroy();
@@ -2541,6 +2548,12 @@ static int rdt_get_tree(struct fs_context *fc) 


	closid_init();



	ret = rdtgroup_add_files(rdtgroup_default.kn, RFTYPE_CTRL_BASE);

	if (ret)

		goto out_schemata_free;



	kernfs_activate(rdtgroup_default.kn);



	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);

	if (ret < 0)

		goto out_schemata_free;
@@ -2597,6 +2610,8 @@ static int rdt_get_tree(struct fs_context *fc) 
	schemata_list_destroy();

out_ctx:

	rdt_disable_ctx();

out_root:

	rdtgroup_destroy_root();

out:

	rdt_last_cmd_clear();

	mutex_unlock(&rdtgroup_mutex);
@@ -2667,7 +2682,6 @@ static int rdt_init_fs_context(struct fs_context *fc) 
	if (!ctx)

		return -ENOMEM;



	ctx->kfc.root = rdt_root;

	ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;

	fc->fs_private = &ctx->kfc;

	fc->ops = &rdt_fs_context_ops;
@@ -2837,6 +2851,7 @@ static void rdt_kill_sb(struct super_block *sb) 
	rdt_pseudo_lock_release();

	rdtgroup_default.mode = RDT_MODE_SHAREABLE;

	schemata_list_destroy();

	rdtgroup_destroy_root();

	static_branch_disable_cpuslocked(&rdt_alloc_enable_key);

	static_branch_disable_cpuslocked(&rdt_mon_enable_key);

	static_branch_disable_cpuslocked(&rdt_enable_key);
@@ -3718,10 +3733,8 @@ static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { 
	.show_options	= rdtgroup_show_options,

};



static int __init rdtgroup_setup_root(void)

static int rdtgroup_setup_root(struct rdt_fs_context *ctx)

{

	int ret;



	rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,

				      KERNFS_ROOT_CREATE_DEACTIVATED |

				      KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
@@ -3729,6 +3742,20 @@ static int __init rdtgroup_setup_root(void) 
	if (IS_ERR(rdt_root))

		return PTR_ERR(rdt_root);



	ctx->kfc.root = rdt_root;

	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);



	return 0;

}



static void rdtgroup_destroy_root(void)

{

	kernfs_destroy_root(rdt_root);

	rdtgroup_default.kn = NULL;

}



static void __init rdtgroup_setup_default(void)

{

	mutex_lock(&rdtgroup_mutex);



	rdtgroup_default.closid = 0;
@@ -3738,19 +3765,7 @@ static int __init rdtgroup_setup_root(void) 


	list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);



	ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RFTYPE_CTRL_BASE);

	if (ret) {

		kernfs_destroy_root(rdt_root);

		goto out;

	}



	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);

	kernfs_activate(rdtgroup_default.kn);



out:

	mutex_unlock(&rdtgroup_mutex);



	return ret;

}



static void domain_destroy_mon_state(struct rdt_domain *d)
@@ -3872,13 +3887,11 @@ int __init rdtgroup_init(void) 
	seq_buf_init(&last_cmd_status, last_cmd_status_buf,

		     sizeof(last_cmd_status_buf));



	ret = rdtgroup_setup_root();

	if (ret)

		return ret;

	rdtgroup_setup_default();



	ret = sysfs_create_mount_point(fs_kobj, "resctrl");

	if (ret)

		goto cleanup_root;

		return ret;



	ret = register_filesystem(&rdt_fs_type);

	if (ret)
@@ -3911,8 +3924,6 @@ int __init rdtgroup_init(void) 


cleanup_mountpoint:

	sysfs_remove_mount_point(fs_kobj, "resctrl");

cleanup_root:

	kernfs_destroy_root(rdt_root);



	return ret;

}
@@ -3922,5 +3933,4 @@ void __exit rdtgroup_exit(void) 
	debugfs_remove_recursive(debugfs_resctrl);

	unregister_filesystem(&rdt_fs_type);

	sysfs_remove_mount_point(fs_kobj, "resctrl");

	kernfs_destroy_root(rdt_root);

}