| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
|---|---|
| 2 | #ifndef _FS_CEPH_STRING_TABLE_H |
| 3 | #define _FS_CEPH_STRING_TABLE_H |
| 4 | |
| 5 | #include <linux/types.h> |
| 6 | #include <linux/kref.h> |
| 7 | #include <linux/rbtree.h> |
| 8 | #include <linux/rcupdate.h> |
| 9 | |
| 10 | struct ceph_string { |
| 11 | struct kref kref; |
| 12 | union { |
| 13 | struct rb_node node; |
| 14 | struct rcu_head rcu; |
| 15 | }; |
| 16 | size_t len; |
| 17 | char str[]; |
| 18 | }; |
| 19 | |
| 20 | extern void ceph_release_string(struct kref *ref); |
| 21 | extern struct ceph_string *ceph_find_or_create_string(const char *str, |
| 22 | size_t len); |
| 23 | extern bool ceph_strings_empty(void); |
| 24 | |
| 25 | static inline struct ceph_string *ceph_get_string(struct ceph_string *str) |
| 26 | { |
| 27 | kref_get(kref: &str->kref); |
| 28 | return str; |
| 29 | } |
| 30 | |
| 31 | static inline void ceph_put_string(struct ceph_string *str) |
| 32 | { |
| 33 | if (!str) |
| 34 | return; |
| 35 | kref_put(kref: &str->kref, release: ceph_release_string); |
| 36 | } |
| 37 | |
| 38 | static inline int ceph_compare_string(struct ceph_string *cs, |
| 39 | const char* str, size_t len) |
| 40 | { |
| 41 | size_t cs_len = cs ? cs->len : 0; |
| 42 | if (cs_len != len) |
| 43 | return cs_len - len; |
| 44 | if (len == 0) |
| 45 | return 0; |
| 46 | return strncmp(cs->str, str, len); |
| 47 | } |
| 48 | |
| 49 | #define ceph_try_get_string(x) \ |
| 50 | ({ \ |
| 51 | struct ceph_string *___str; \ |
| 52 | rcu_read_lock(); \ |
| 53 | for (;;) { \ |
| 54 | ___str = rcu_dereference(x); \ |
| 55 | if (!___str || \ |
| 56 | kref_get_unless_zero(&___str->kref)) \ |
| 57 | break; \ |
| 58 | } \ |
| 59 | rcu_read_unlock(); \ |
| 60 | (___str); \ |
| 61 | }) |
| 62 | |
| 63 | #endif |
| 64 |