/* 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