/* SPDX-License-Identifier: GPL-2.0 */#ifndef _FS_CEPH_STRING_TABLE_H#define _FS_CEPH_STRING_TABLE_H #include <linux/types.h>#include <linux/kref.h>#include <linux/rbtree.h>#include <linux/rcupdate.h> struct ceph_string {	struct kref kref;	union {		struct rb_node node;		struct rcu_head rcu;	};	size_t len;	char str[];}; extern void ceph_release_string(struct kref *ref);extern struct ceph_string *ceph_find_or_create_string(const char *str,						      size_t len);extern bool ceph_strings_empty(void); static inline struct ceph_string *ceph_get_string(struct ceph_string *str){	kref_get(&str->kref);	return str;} static inline void ceph_put_string(struct ceph_string *str){	if (!str)		return;	kref_put(&str->kref, ceph_release_string);} static inline int ceph_compare_string(struct ceph_string *cs,				      const char* str, size_t len){	size_t cs_len = cs ? cs->len : 0;	if (cs_len != len)		return cs_len - len;	if (len == 0)		return 0;	return strncmp(cs->str, str, len);} #define ceph_try_get_string(x)					\({								\	struct ceph_string *___str;				\	rcu_read_lock();					\	for (;;) {						\		___str = rcu_dereference(x);			\		if (!___str ||					\		    kref_get_unless_zero(&___str->kref))	\			break;					\	}							\	rcu_read_unlock();					\	(___str);						\}) #endif