locking/lockref: Use try_cmpxchg64 in CMPXCHG_LOOP macro

[sfrench/cifs-2.6.git] / lib / lockref.c

diff --git a/lib/lockref.c b/lib/lockref.c
index 5b34bbd3eba818563db89437eb267782e8c3a6c9..c6f0b183b937b0743f57104741110fbf995ceaf4 100644 (file)
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -14,12 +14,11 @@
        BUILD_BUG_ON(sizeof(old) != 8);                                         \
        old.lock_count = READ_ONCE(lockref->lock_count);                        \
        while (likely(arch_spin_value_unlocked(old.lock.rlock.raw_lock))) {     \
-               struct lockref new = old, prev = old;                           \
+               struct lockref new = old;                                       \
                CODE                                                            \
-               old.lock_count = cmpxchg64_relaxed(&lockref->lock_count,        \
-                                                  old.lock_count,              \
-                                                  new.lock_count);             \
-               if (likely(old.lock_count == prev.lock_count)) {                \
+               if (likely(try_cmpxchg64_relaxed(&lockref->lock_count,          \
+                                                &old.lock_count,               \
+                                                new.lock_count))) {            \
                        SUCCESS;                                                \
                }                                                               \
                if (!--retry)                                                   \