#include <obd_support.h>
#include <lustre_handles.h>
+#include <lustre_lib.h>
+
+#if !defined(HAVE_RCU) || !defined(__KERNEL__)
+# define list_add_rcu list_add
+# define list_del_rcu list_del
+# define list_for_each_rcu list_for_each
+# define list_for_each_safe_rcu list_for_each_safe
+# define rcu_read_lock() spin_lock(&bucket->lock)
+# define rcu_read_unlock() spin_unlock(&bucket->lock)
+#endif /* ifndef HAVE_RCU */
-spinlock_t handle_lock;
static __u64 handle_base;
#define HANDLE_INCR 7
-static struct list_head *handle_hash = NULL;
-static int handle_count = 0;
+static spinlock_t handle_base_lock;
+
+static struct handle_bucket {
+ spinlock_t lock;
+ struct list_head head;
+} *handle_hash;
+
+static atomic_t handle_count = ATOMIC_INIT(0);
#define HANDLE_HASH_SIZE (1 << 14)
#define HANDLE_HASH_MASK (HANDLE_HASH_SIZE - 1)
*/
void class_handle_hash(struct portals_handle *h, portals_handle_addref_cb cb)
{
- struct list_head *bucket;
+ struct handle_bucket *bucket;
ENTRY;
LASSERT(h != NULL);
LASSERT(list_empty(&h->h_link));
- spin_lock(&handle_lock);
-
/*
* This is fast, but simplistic cookie generation algorithm, it will
* need a re-do at some point in the future for security.
*/
- h->h_cookie = handle_base;
+ spin_lock(&handle_base_lock);
handle_base += HANDLE_INCR;
- bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
- list_add(&h->h_link, bucket);
- handle_count++;
-
+ h->h_cookie = handle_base;
if (unlikely(handle_base == 0)) {
/*
* Cookie of zero is "dangerous", because in many places it's
CWARN("The universe has been exhausted: cookie wrap-around.\n");
handle_base += HANDLE_INCR;
}
+ spin_unlock(&handle_base_lock);
+
+ atomic_inc(&handle_count);
+ h->h_addref = cb;
+ spin_lock_init(&h->h_lock);
- spin_unlock(&handle_lock);
+ bucket = &handle_hash[h->h_cookie & HANDLE_HASH_MASK];
+ spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ spin_unlock(&bucket->lock);
- h->h_addref = cb;
CDEBUG(D_INFO, "added object %p with handle "LPX64" to hash\n",
h, h->h_cookie);
EXIT;
CDEBUG(D_INFO, "removing object %p with handle "LPX64" from hash\n",
h, h->h_cookie);
- handle_count--;
- list_del_init(&h->h_link);
+ spin_lock(&h->h_lock);
+ if (h->h_in == 0) {
+ spin_unlock(&h->h_lock);
+ return;
+ }
+ h->h_in = 0;
+ spin_unlock(&h->h_lock);
+ list_del_rcu(&h->h_link);
}
void class_handle_unhash(struct portals_handle *h)
{
- spin_lock(&handle_lock);
+ struct handle_bucket *bucket;
+ bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+
+ spin_lock(&bucket->lock);
class_handle_unhash_nolock(h);
- spin_unlock(&handle_lock);
+ spin_unlock(&bucket->lock);
+
+ atomic_dec(&handle_count);
+}
+
+void class_handle_hash_back(struct portals_handle *h)
+{
+ struct handle_bucket *bucket;
+ ENTRY;
+
+ bucket = handle_hash + (h->h_cookie & HANDLE_HASH_MASK);
+
+ atomic_inc(&handle_count);
+ spin_lock(&bucket->lock);
+ list_add_rcu(&h->h_link, &bucket->head);
+ h->h_in = 1;
+ spin_unlock(&bucket->lock);
+
+ EXIT;
}
void *class_handle2object(__u64 cookie)
{
- struct list_head *bucket, *tmp;
+ struct handle_bucket *bucket;
+ struct list_head *tmp;
void *retval = NULL;
ENTRY;
LASSERT(handle_hash != NULL);
+ /* Be careful when you want to change this code. See the
+ * rcu_read_lock() definition on top this file. - jxiong */
bucket = handle_hash + (cookie & HANDLE_HASH_MASK);
- spin_lock(&handle_lock);
- list_for_each(tmp, bucket) {
+ rcu_read_lock();
+ list_for_each_rcu(tmp, &bucket->head) {
struct portals_handle *h;
h = list_entry(tmp, struct portals_handle, h_link);
+ if (h->h_cookie != cookie)
+ continue;
- if (h->h_cookie == cookie) {
+ spin_lock(&h->h_lock);
+ if (likely(h->h_cookie != 0)) {
h->h_addref(h);
retval = h;
- break;
}
+ spin_unlock(&h->h_lock);
+ break;
}
- spin_unlock(&handle_lock);
+ rcu_read_unlock();
RETURN(retval);
}
+void class_handle_free_cb(struct rcu_head *rcu)
+{
+ struct portals_handle *h = RCU2HANDLE(rcu);
+ if (h->h_free_cb) {
+ h->h_free_cb(h->h_ptr, h->h_size);
+ } else {
+ void *ptr = h->h_ptr;
+ unsigned int size = h->h_size;
+ OBD_FREE(ptr, size);
+ }
+}
+
int class_handle_init(void)
{
- struct list_head *bucket;
+ struct handle_bucket *bucket;
LASSERT(handle_hash == NULL);
- OBD_VMALLOC(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
+ OBD_VMALLOC(handle_hash, sizeof(*bucket) * HANDLE_HASH_SIZE);
if (handle_hash == NULL)
return -ENOMEM;
+ spin_lock_init(&handle_base_lock);
for (bucket = handle_hash + HANDLE_HASH_SIZE - 1; bucket >= handle_hash;
- bucket--)
- CFS_INIT_LIST_HEAD(bucket);
-
- get_random_bytes(&handle_base, sizeof(handle_base));
+ bucket--) {
+ CFS_INIT_LIST_HEAD(&bucket->head);
+ spin_lock_init(&bucket->lock);
+ }
+ ll_get_random_bytes(&handle_base, sizeof(handle_base));
LASSERT(handle_base != 0ULL);
return 0;
{
int i;
- spin_lock(&handle_lock);
for (i = 0; i < HANDLE_HASH_SIZE; i++) {
struct list_head *tmp, *pos;
- list_for_each_safe(tmp, pos, &(handle_hash[i])) {
+ spin_lock(&handle_hash[i].lock);
+ list_for_each_safe_rcu(tmp, pos, &(handle_hash[i].head)) {
struct portals_handle *h;
h = list_entry(tmp, struct portals_handle, h_link);
class_handle_unhash_nolock(h);
}
+ spin_unlock(&handle_hash[i].lock);
}
- spin_unlock(&handle_lock);
}
void class_handle_cleanup(void)
{
+ int count;
LASSERT(handle_hash != NULL);
- if (handle_count != 0) {
- CERROR("handle_count at cleanup: %d\n", handle_count);
+ count = atomic_read(&handle_count);
+ if (count != 0) {
+ CERROR("handle_count at cleanup: %d\n", count);
cleanup_all_handles();
}
OBD_VFREE(handle_hash, sizeof(*handle_hash) * HANDLE_HASH_SIZE);
handle_hash = NULL;
- if (handle_count)
- CERROR("leaked %d handles\n", handle_count);
+ if (atomic_read(&handle_count))
+ CERROR("leaked %d handles\n", atomic_read(&handle_count));
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff