1 // SPDX-License-Identifier: GPL-2.0
3 * Simple file system for zoned block devices exposing zones as files.
5 * Copyright (C) 2022 Western Digital Corporation or its affiliates.
8 #include <linux/seq_file.h>
9 #include <linux/blkdev.h>
13 struct zonefs_sysfs_attr {
14 struct attribute attr;
15 ssize_t (*show)(struct zonefs_sb_info *sbi, char *buf);
18 static inline struct zonefs_sysfs_attr *to_attr(struct attribute *attr)
20 return container_of(attr, struct zonefs_sysfs_attr, attr);
23 #define ZONEFS_SYSFS_ATTR_RO(name) \
24 static struct zonefs_sysfs_attr zonefs_sysfs_attr_##name = __ATTR_RO(name)
26 #define ATTR_LIST(name) &zonefs_sysfs_attr_##name.attr
28 static ssize_t zonefs_sysfs_attr_show(struct kobject *kobj,
29 struct attribute *attr, char *buf)
31 struct zonefs_sb_info *sbi =
32 container_of(kobj, struct zonefs_sb_info, s_kobj);
33 struct zonefs_sysfs_attr *zonefs_attr =
34 container_of(attr, struct zonefs_sysfs_attr, attr);
36 if (!zonefs_attr->show)
39 return zonefs_attr->show(sbi, buf);
42 static ssize_t max_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf)
44 return sysfs_emit(buf, "%u\n", sbi->s_max_wro_seq_files);
46 ZONEFS_SYSFS_ATTR_RO(max_wro_seq_files);
48 static ssize_t nr_wro_seq_files_show(struct zonefs_sb_info *sbi, char *buf)
50 return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_wro_seq_files));
52 ZONEFS_SYSFS_ATTR_RO(nr_wro_seq_files);
54 static ssize_t max_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf)
56 return sysfs_emit(buf, "%u\n", sbi->s_max_active_seq_files);
58 ZONEFS_SYSFS_ATTR_RO(max_active_seq_files);
60 static ssize_t nr_active_seq_files_show(struct zonefs_sb_info *sbi, char *buf)
62 return sysfs_emit(buf, "%d\n", atomic_read(&sbi->s_active_seq_files));
64 ZONEFS_SYSFS_ATTR_RO(nr_active_seq_files);
66 static struct attribute *zonefs_sysfs_attrs[] = {
67 ATTR_LIST(max_wro_seq_files),
68 ATTR_LIST(nr_wro_seq_files),
69 ATTR_LIST(max_active_seq_files),
70 ATTR_LIST(nr_active_seq_files),
73 ATTRIBUTE_GROUPS(zonefs_sysfs);
75 static void zonefs_sysfs_sb_release(struct kobject *kobj)
77 struct zonefs_sb_info *sbi =
78 container_of(kobj, struct zonefs_sb_info, s_kobj);
80 complete(&sbi->s_kobj_unregister);
83 static const struct sysfs_ops zonefs_sysfs_attr_ops = {
84 .show = zonefs_sysfs_attr_show,
87 static struct kobj_type zonefs_sb_ktype = {
88 .default_groups = zonefs_sysfs_groups,
89 .sysfs_ops = &zonefs_sysfs_attr_ops,
90 .release = zonefs_sysfs_sb_release,
93 static struct kobject *zonefs_sysfs_root;
95 int zonefs_sysfs_register(struct super_block *sb)
97 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
100 init_completion(&sbi->s_kobj_unregister);
101 ret = kobject_init_and_add(&sbi->s_kobj, &zonefs_sb_ktype,
102 zonefs_sysfs_root, "%s", sb->s_id);
104 kobject_put(&sbi->s_kobj);
105 wait_for_completion(&sbi->s_kobj_unregister);
109 sbi->s_sysfs_registered = true;
114 void zonefs_sysfs_unregister(struct super_block *sb)
116 struct zonefs_sb_info *sbi = ZONEFS_SB(sb);
118 if (!sbi || !sbi->s_sysfs_registered)
121 kobject_del(&sbi->s_kobj);
122 kobject_put(&sbi->s_kobj);
123 wait_for_completion(&sbi->s_kobj_unregister);
126 int __init zonefs_sysfs_init(void)
128 zonefs_sysfs_root = kobject_create_and_add("zonefs", fs_kobj);
129 if (!zonefs_sysfs_root)
135 void zonefs_sysfs_exit(void)
137 kobject_put(zonefs_sysfs_root);
138 zonefs_sysfs_root = NULL;