RDS: cleanup/fix rds_rdma_unuse
First, it looks to me like the atomic_inc is wrong.
We should be decrementing refcount only once here, no? It's
already being done by the mr_put() at the end.
Second, simplify the logic a bit by bailing early (with a warning)
if !mr.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 24274bb..5011efa 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -414,27 +414,30 @@
spin_lock_irqsave(&rs->rs_rdma_lock, flags);
mr = rds_mr_tree_walk(&rs->rs_rdma_keys, r_key, NULL);
- if (mr && (mr->r_use_once || force)) {
+ if (!mr) {
+ printk(KERN_ERR "rds: trying to unuse MR with unknown r_key %u!\n", r_key);
+ spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
+ return;
+ }
+
+ if (mr->r_use_once || force) {
rb_erase(&mr->r_rb_node, &rs->rs_rdma_keys);
RB_CLEAR_NODE(&mr->r_rb_node);
zot_me = 1;
- } else if (mr)
- atomic_inc(&mr->r_refcount);
+ }
spin_unlock_irqrestore(&rs->rs_rdma_lock, flags);
/* May have to issue a dma_sync on this memory region.
* Note we could avoid this if the operation was a RDMA READ,
* but at this point we can't tell. */
- if (mr) {
- if (mr->r_trans->sync_mr)
- mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
+ if (mr->r_trans->sync_mr)
+ mr->r_trans->sync_mr(mr->r_trans_private, DMA_FROM_DEVICE);
- /* If the MR was marked as invalidate, this will
- * trigger an async flush. */
- if (zot_me)
- rds_destroy_mr(mr);
- rds_mr_put(mr);
- }
+ /* If the MR was marked as invalidate, this will
+ * trigger an async flush. */
+ if (zot_me)
+ rds_destroy_mr(mr);
+ rds_mr_put(mr);
}
void rds_rdma_free_op(struct rds_rdma_op *ro)