// SPDX-License-Identifier: GPL-2.0/* * Simple file system for zoned block devices exposing zones as files. * * Copyright (C) 2022 Western Digital Corporation or its affiliates. */#include <linux/fs.h>#include <linux/seq_file.h>#include <linux/blkdev.h> #include "zonefs.h" struct zonefs_sysfs_attr {	struct attribute attr;	ssize_t (*show)(struct zonefs_sb_info *sbi, char *buf);}; #define ZONEFS_SYSFS_ATTR_RO(name) \static struct zonefs_sysfs_attr zonefs_sysfs_attr_##name = __ATTR_RO(name) #define ATTR_LIST(name) &zonefs_sysfs_attr_##name.attr static ssize_t zonefs_sysfs_attr_show(struct kobject *kobj,				      struct attribute *attr, char *buf){	struct zonefs_sb_info *sbi =		container_of(kobj, struct zonefs_sb_info, s_kobj);	struct zonefs_sysfs_attr *zonefs_attr =		container_of(attr, struct zonefs_sysfs_attr, attr); 	if (!zonefs_attr->show)		return 0; 	return zonefs_attr->show(sbi, buf);} static ssize_t max_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf){	return sysfs_emit(buf, "%u\n", sbi->s_max_wro_seq_files);}ZONEFS_SYSFS_ATTR_RO(max_wro_seq_files); static ssize_t nr_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf){	return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_wro_seq_files));}ZONEFS_SYSFS_ATTR_RO(nr_wro_seq_files); static ssize_t max_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf){	return sysfs_emit(buf, "%u\n", sbi->s_max_active_seq_files);}ZONEFS_SYSFS_ATTR_RO(max_active_seq_files); static ssize_t nr_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf){	return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_active_seq_files));}ZONEFS_SYSFS_ATTR_RO(nr_active_seq_files); static struct attribute *zonefs_sysfs_attrs[] = {	ATTR_LIST(max_wro_seq_files),	ATTR_LIST(nr_wro_seq_files),	ATTR_LIST(max_active_seq_files),	ATTR_LIST(nr_active_seq_files),	NULL,};ATTRIBUTE_GROUPS(zonefs_sysfs); static void zonefs_sysfs_sb_release(struct kobject *kobj){	struct zonefs_sb_info *sbi =		container_of(kobj, struct zonefs_sb_info, s_kobj); 	complete(&sbi->s_kobj_unregister);} static const struct sysfs_ops zonefs_sysfs_attr_ops = {	.show	= zonefs_sysfs_attr_show,}; static const struct kobj_type zonefs_sb_ktype = {	.default_groups = zonefs_sysfs_groups,	.sysfs_ops	= &zonefs_sysfs_attr_ops,	.release	= zonefs_sysfs_sb_release,}; static struct kobject *zonefs_sysfs_root; int zonefs_sysfs_register(struct super_block *sb){	struct zonefs_sb_info *sbi = ZONEFS_SB(sb);	int ret; 	super_set_sysfs_name_id(sb);	init_completion(&sbi->s_kobj_unregister);	ret = kobject_init_and_add(&sbi->s_kobj, &zonefs_sb_ktype,				   zonefs_sysfs_root, "%s", sb->s_id);	if (ret) {		kobject_put(&sbi->s_kobj);		wait_for_completion(&sbi->s_kobj_unregister);		return ret;	} 	sbi->s_sysfs_registered = true; 	return 0;} void zonefs_sysfs_unregister(struct super_block *sb){	struct zonefs_sb_info *sbi = ZONEFS_SB(sb); 	if (!sbi || !sbi->s_sysfs_registered)		return; 	kobject_del(&sbi->s_kobj);	kobject_put(&sbi->s_kobj);	wait_for_completion(&sbi->s_kobj_unregister);} int __init zonefs_sysfs_init(void){	zonefs_sysfs_root = kobject_create_and_add("zonefs", fs_kobj);	if (!zonefs_sysfs_root)		return -ENOMEM; 	return 0;} void zonefs_sysfs_exit(void){	kobject_put(zonefs_sysfs_root);	zonefs_sysfs_root = NULL;}