--- /dev/null
+// 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);
+};
+
+static inline struct zonefs_sysfs_attr *to_attr(struct attribute *attr)
+{
+ return container_of(attr, struct zonefs_sysfs_attr, attr);
+}
+
+#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 struct attribute *zonefs_sysfs_attrs[] = {
+ ATTR_LIST(max_wro_seq_files),
+ ATTR_LIST(nr_wro_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 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;
+
+ 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;
+}
#include <linux/uuid.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
+#include <linux/kobject.h>
/*
* Maximum length of file names: this only needs to be large enough to fit
unsigned int s_max_wro_seq_files;
atomic_t s_wro_seq_files;
+
+ bool s_sysfs_registered;
+ struct kobject s_kobj;
+ struct completion s_kobj_unregister;
};
static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
#define zonefs_warn(sb, format, args...) \
pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
+int zonefs_sysfs_register(struct super_block *sb);
+void zonefs_sysfs_unregister(struct super_block *sb);
+int zonefs_sysfs_init(void);
+void zonefs_sysfs_exit(void);
+
#endif