diff options
| -rw-r--r-- | include/linux/ceph/libceph.h | 1 | ||||
| -rw-r--r-- | include/linux/ceph/string_table.h | 62 | ||||
| -rw-r--r-- | net/ceph/Makefile | 2 | ||||
| -rw-r--r-- | net/ceph/ceph_common.c | 2 | ||||
| -rw-r--r-- | net/ceph/string_table.c | 111 |
5 files changed, 177 insertions, 1 deletions
diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h index 690985daad1c..6afc5d98fad1 100644 --- a/include/linux/ceph/libceph.h +++ b/include/linux/ceph/libceph.h @@ -21,6 +21,7 @@ #include <linux/ceph/mon_client.h> #include <linux/ceph/osd_client.h> #include <linux/ceph/ceph_fs.h> +#include <linux/ceph/string_table.h> /* * mount options 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 diff --git a/net/ceph/Makefile b/net/ceph/Makefile index 958d9856912c..84cbed630c4b 100644 --- a/net/ceph/Makefile +++ b/net/ceph/Makefile @@ -11,5 +11,5 @@ libceph-y := ceph_common.o messenger.o msgpool.o buffer.o pagelist.o \ crypto.o armor.o \ auth_x.o \ ceph_fs.o ceph_strings.o ceph_hash.o \ - pagevec.o snapshot.o + pagevec.o snapshot.o string_table.o diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c index 55d2bfee16d7..bddfcf6f09c2 100644 --- a/net/ceph/ceph_common.c +++ b/net/ceph/ceph_common.c @@ -747,6 +747,8 @@ out: static void __exit exit_ceph_lib(void) { dout("exit_ceph_lib\n"); + WARN_ON(!ceph_strings_empty()); + ceph_osdc_cleanup(); ceph_msgr_exit(); ceph_crypto_shutdown(); diff --git a/net/ceph/string_table.c b/net/ceph/string_table.c new file mode 100644 index 000000000000..ca53c8319209 --- /dev/null +++ b/net/ceph/string_table.c @@ -0,0 +1,111 @@ +#include <linux/slab.h> +#include <linux/gfp.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/ceph/string_table.h> + +static DEFINE_SPINLOCK(string_tree_lock); +static struct rb_root string_tree = RB_ROOT; + +struct ceph_string *ceph_find_or_create_string(const char* str, size_t len) +{ + struct ceph_string *cs, *exist; + struct rb_node **p, *parent; + int ret; + + exist = NULL; + spin_lock(&string_tree_lock); + p = &string_tree.rb_node; + while (*p) { + exist = rb_entry(*p, struct ceph_string, node); + ret = ceph_compare_string(exist, str, len); + if (ret > 0) + p = &(*p)->rb_left; + else if (ret < 0) + p = &(*p)->rb_right; + else + break; + exist = NULL; + } + if (exist && !kref_get_unless_zero(&exist->kref)) { + rb_erase(&exist->node, &string_tree); + RB_CLEAR_NODE(&exist->node); + exist = NULL; + } + spin_unlock(&string_tree_lock); + if (exist) + return exist; + + cs = kmalloc(sizeof(*cs) + len + 1, GFP_NOFS); + if (!cs) + return NULL; + + kref_init(&cs->kref); + cs->len = len; + memcpy(cs->str, str, len); + cs->str[len] = 0; + +retry: + exist = NULL; + parent = NULL; + p = &string_tree.rb_node; + spin_lock(&string_tree_lock); + while (*p) { + parent = *p; + exist = rb_entry(*p, struct ceph_string, node); + ret = ceph_compare_string(exist, str, len); + if (ret > 0) + p = &(*p)->rb_left; + else if (ret < 0) + p = &(*p)->rb_right; + else + break; + exist = NULL; + } + ret = 0; + if (!exist) { + rb_link_node(&cs->node, parent, p); + rb_insert_color(&cs->node, &string_tree); + } else if (!kref_get_unless_zero(&exist->kref)) { + rb_erase(&exist->node, &string_tree); + RB_CLEAR_NODE(&exist->node); + ret = -EAGAIN; + } + spin_unlock(&string_tree_lock); + if (ret == -EAGAIN) + goto retry; + + if (exist) { + kfree(cs); + cs = exist; + } + + return cs; +} +EXPORT_SYMBOL(ceph_find_or_create_string); + +static void ceph_free_string(struct rcu_head *head) +{ + struct ceph_string *cs = container_of(head, struct ceph_string, rcu); + kfree(cs); +} + +void ceph_release_string(struct kref *ref) +{ + struct ceph_string *cs = container_of(ref, struct ceph_string, kref); + + spin_lock(&string_tree_lock); + if (!RB_EMPTY_NODE(&cs->node)) { + rb_erase(&cs->node, &string_tree); + RB_CLEAR_NODE(&cs->node); + } + spin_unlock(&string_tree_lock); + + call_rcu(&cs->rcu, ceph_free_string); +} +EXPORT_SYMBOL(ceph_release_string); + +bool ceph_strings_empty(void) +{ + return RB_EMPTY_ROOT(&string_tree); +} |