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 13 struct 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) \ 19 static struct zonefs_sysfs_attr zonefs_sysfs_attr_##name = __ATTR_RO(name) 20 21 #define ATTR_LIST(name) &zonefs_sysfs_attr_##name.attr 22 23 static 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 37 static 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 } 41 ZONEFS_SYSFS_ATTR_RO(max_wro_seq_files); 42 43 static 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 } 47 ZONEFS_SYSFS_ATTR_RO(nr_wro_seq_files); 48 49 static 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 } 53 ZONEFS_SYSFS_ATTR_RO(max_active_seq_files); 54 55 static 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 } 59 ZONEFS_SYSFS_ATTR_RO(nr_active_seq_files); 60 61 static 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 }; 68 ATTRIBUTE_GROUPS(zonefs_sysfs); 69 70 static 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 78 static const struct sysfs_ops zonefs_sysfs_attr_ops = { 79 .show = zonefs_sysfs_attr_show, 80 }; 81 82 static 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 88 static struct kobject *zonefs_sysfs_root; 89 90 int zonefs_sysfs_register(struct super_block *sb) 91 { 92 struct zonefs_sb_info *sbi = ZONEFS_SB(sb); 93 int ret; 94 95 init_completion(&sbi->s_kobj_unregister); 96 ret = kobject_init_and_add(&sbi->s_kobj, &zonefs_sb_ktype, 97 zonefs_sysfs_root, "%s", sb->s_id); 98 if (ret) { 99 kobject_put(&sbi->s_kobj); 100 wait_for_completion(&sbi->s_kobj_unregister); 101 return ret; 102 } 103 104 sbi->s_sysfs_registered = true; 105 106 return 0; 107 } 108 109 void zonefs_sysfs_unregister(struct super_block *sb) 110 { 111 struct zonefs_sb_info *sbi = ZONEFS_SB(sb); 112 113 if (!sbi || !sbi->s_sysfs_registered) 114 return; 115 116 kobject_del(&sbi->s_kobj); 117 kobject_put(&sbi->s_kobj); 118 wait_for_completion(&sbi->s_kobj_unregister); 119 } 120 121 int __init zonefs_sysfs_init(void) 122 { 123 zonefs_sysfs_root = kobject_create_and_add("zonefs", fs_kobj); 124 if (!zonefs_sysfs_root) 125 return -ENOMEM; 126 127 return 0; 128 } 129 130 void zonefs_sysfs_exit(void) 131 { 132 kobject_put(zonefs_sysfs_root); 133 zonefs_sysfs_root = NULL; 134 } 135