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Diffstat (limited to 'include/linux/ceph/string_table.h')
-rw-r--r--include/linux/ceph/string_table.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/include/linux/ceph/string_table.h b/include/linux/ceph/string_table.h
new file mode 100644
index 000000000000..1b02c96daf75
--- /dev/null
+++ b/include/linux/ceph/string_table.h
@@ -0,0 +1,62 @@
+#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