BUG/MAJOR: memory: Don't forget to unlock the rwlock if the pool is empty.

In __pool_get_first(), don't forget to unlock the pool lock if the pool is
empty, otherwise no writer will be able to take the lock, and as it is done
when reloading, it leads to an infinite loop on reload.

This should be backported with commit 04f5fe87d3d3a222b89420f8c1231461f55ebdeb

(cherry picked from commit 1c7c0d6b97513e79c304aaf834f83843f32a674d)
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/include/common/memory.h b/include/common/memory.h
index cafe03a..5071989 100644 (file)
--- a/include/common/memory.h
+++ b/include/common/memory.h
@@ -225,8 +225,10 @@ static inline void *__pool_get_first(struct pool_head *pool)
        HA_RWLOCK_RDLOCK(POOL_LOCK, &pool->flush_lock);
        cmp.free_list = pool->free_list;
        do {
-               if (cmp.free_list == NULL)
+               if (cmp.free_list == NULL) {
+                       HA_RWLOCK_RDUNLOCK(POOL_LOCK, &pool->flush_lock);
                        return NULL;
+               }
                new.seq = cmp.seq + 1;
                __ha_barrier_load();
                new.free_list = *POOL_LINK(pool, cmp.free_list);