Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
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.attr
22
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}