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1// SPDX-License-Identifier: GPL-2.02/*3 * Simple file system for zoned block devices exposing zones as files.4 *5 * Copyright (C) 2022 Western Digital Corporation or its affiliates.6 */7#include <linux/fs.h>8#include <linux/seq_file.h>9#include <linux/blkdev.h>10 11#include "zonefs.h"12 13struct zonefs_sysfs_attr {14 struct attribute attr;15 ssize_t (*show)(struct zonefs_sb_info *sbi, char *buf);16};17 18#define ZONEFS_SYSFS_ATTR_RO(name) \19static struct zonefs_sysfs_attr zonefs_sysfs_attr_##name = __ATTR_RO(name)20 21#define ATTR_LIST(name) &zonefs_sysfs_attr_##name.attr22 23static ssize_t zonefs_sysfs_attr_show(struct kobject *kobj,24 struct attribute *attr, char *buf)25{26 struct zonefs_sb_info *sbi =27 container_of(kobj, struct zonefs_sb_info, s_kobj);28 struct zonefs_sysfs_attr *zonefs_attr =29 container_of(attr, struct zonefs_sysfs_attr, attr);30 31 if (!zonefs_attr->show)32 return 0;33 34 return zonefs_attr->show(sbi, buf);35}36 37static ssize_t max_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf)38{39 return sysfs_emit(buf, "%u\n", sbi->s_max_wro_seq_files);40}41ZONEFS_SYSFS_ATTR_RO(max_wro_seq_files);42 43static ssize_t nr_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf)44{45 return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_wro_seq_files));46}47ZONEFS_SYSFS_ATTR_RO(nr_wro_seq_files);48 49static ssize_t max_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf)50{51 return sysfs_emit(buf, "%u\n", sbi->s_max_active_seq_files);52}53ZONEFS_SYSFS_ATTR_RO(max_active_seq_files);54 55static ssize_t nr_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf)56{57 return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_active_seq_files));58}59ZONEFS_SYSFS_ATTR_RO(nr_active_seq_files);60 61static struct attribute *zonefs_sysfs_attrs[] = {62 ATTR_LIST(max_wro_seq_files),63 ATTR_LIST(nr_wro_seq_files),64 ATTR_LIST(max_active_seq_files),65 ATTR_LIST(nr_active_seq_files),66 NULL,67};68ATTRIBUTE_GROUPS(zonefs_sysfs);69 70static void zonefs_sysfs_sb_release(struct kobject *kobj)71{72 struct zonefs_sb_info *sbi =73 container_of(kobj, struct zonefs_sb_info, s_kobj);74 75 complete(&sbi->s_kobj_unregister);76}77 78static const struct sysfs_ops zonefs_sysfs_attr_ops = {79 .show = zonefs_sysfs_attr_show,80};81 82static const struct kobj_type zonefs_sb_ktype = {83 .default_groups = zonefs_sysfs_groups,84 .sysfs_ops = &zonefs_sysfs_attr_ops,85 .release = zonefs_sysfs_sb_release,86};87 88static struct kobject *zonefs_sysfs_root;89 90int zonefs_sysfs_register(struct super_block *sb)91{92 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);93 int ret;94 95 super_set_sysfs_name_id(sb);96 init_completion(&sbi->s_kobj_unregister);97 ret = kobject_init_and_add(&sbi->s_kobj, &zonefs_sb_ktype,98 zonefs_sysfs_root, "%s", sb->s_id);99 if (ret) {100 kobject_put(&sbi->s_kobj);101 wait_for_completion(&sbi->s_kobj_unregister);102 return ret;103 }104 105 sbi->s_sysfs_registered = true;106 107 return 0;108}109 110void zonefs_sysfs_unregister(struct super_block *sb)111{112 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);113 114 if (!sbi || !sbi->s_sysfs_registered)115 return;116 117 kobject_del(&sbi->s_kobj);118 kobject_put(&sbi->s_kobj);119 wait_for_completion(&sbi->s_kobj_unregister);120}121 122int __init zonefs_sysfs_init(void)123{124 zonefs_sysfs_root = kobject_create_and_add("zonefs", fs_kobj);125 if (!zonefs_sysfs_root)126 return -ENOMEM;127 128 return 0;129}130 131void zonefs_sysfs_exit(void)132{133 kobject_put(zonefs_sysfs_root);134 zonefs_sysfs_root = NULL;135}136