/* 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