[no subject]

Finally, the dead lock appears.

[  296.806097]        CPU0
[  296.808550]        ----
[  296.811003]   lock(&xa->xa_lock#15);  <----- __rxe_add_to_pool
[  296.814583]   <Interrupt>
[  296.817209]     lock(&xa->xa_lock#15); <---- rxe_pool_get_index
[  296.820961]
                 *** DEADLOCK ***

Fixes: 3225717f6dfa ("RDMA/rxe: Replace red-black trees by carrays")
Reported-and-tested-by: Yi Zhang <yi.zhang@xxxxxxxxxx>
Signed-off-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 87066d04ed18..eb76ca185303 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -121,6 +121,7 @@ void *rxe_alloc(struct rxe_pool *pool)
 	struct rxe_pool_elem *elem;
 	void *obj;
 	int err;
+	unsigned long flags;
 
 	if (WARN_ON(!(pool->flags & RXE_POOL_ALLOC)))
 		return NULL;
@@ -138,8 +139,10 @@ void *rxe_alloc(struct rxe_pool *pool)
 	elem->obj = obj;
 	kref_init(&elem->ref_cnt);
 
-	err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
-			      &pool->next, GFP_KERNEL);
+	xa_lock_irqsave(&pool->xa, flags);
+	err = __xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
+				&pool->next, GFP_KERNEL);
+	xa_unlock_irqrestore(&pool->xa, flags);
 	if (err)
 		goto err_free;
 
@@ -155,6 +158,7 @@ void *rxe_alloc(struct rxe_pool *pool)
 int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
 {
 	int err;
+	unsigned long flags;
 
 	if (WARN_ON(pool->flags & RXE_POOL_ALLOC))
 		return -EINVAL;
@@ -166,8 +170,10 @@ int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
 	elem->obj = (u8 *)elem - pool->elem_offset;
 	kref_init(&elem->ref_cnt);
 
-	err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
-			      &pool->next, GFP_KERNEL);
+	xa_lock_irqsave(&pool->xa, flags);
+	err = __xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
+				&pool->next, GFP_KERNEL);
+	xa_unlock_irqrestore(&pool->xa, flags);
 	if (err)
 		goto err_cnt;
 
@@ -200,8 +206,11 @@ static void rxe_elem_release(struct kref *kref)
 {
 	struct rxe_pool_elem *elem = container_of(kref, typeof(*elem), ref_cnt);
 	struct rxe_pool *pool = elem->pool;
+	unsigned long flags;
 
-	xa_erase(&pool->xa, elem->index);
+	xa_lock_irqsave(&pool->xa, flags);
+	__xa_erase(&pool->xa, elem->index);
+	xa_unlock_irqrestore(&pool->xa, flags);
 
 	if (pool->cleanup)
 		pool->cleanup(elem);
-- 
2.27.0