mlx5_core: Fix possible race between mr tree insert/delete
In mlx5_core_destroy_mkey(), we must first remove the mr from the
radix tree and then destroy it. Otherwise we might hit a race if the
key was reallocated and we attempted to insert it to the radix tree.
Also handle radix tree insert/delete failures.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Eli Cohen <elic@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mr.c b/drivers/net/ethernet/mellanox/mlx5/core/mr.c
index ba0401d4..184c361 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mr.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mr.c
@@ -94,6 +94,11 @@
write_lock_irq(&table->lock);
err = radix_tree_insert(&table->tree, mlx5_base_mkey(mr->key), mr);
write_unlock_irq(&table->lock);
+ if (err) {
+ mlx5_core_warn(dev, "failed radix tree insert of mr 0x%x, %d\n",
+ mlx5_base_mkey(mr->key), err);
+ mlx5_core_destroy_mkey(dev, mr);
+ }
return err;
}
@@ -104,12 +109,22 @@
struct mlx5_mr_table *table = &dev->priv.mr_table;
struct mlx5_destroy_mkey_mbox_in in;
struct mlx5_destroy_mkey_mbox_out out;
+ struct mlx5_core_mr *deleted_mr;
unsigned long flags;
int err;
memset(&in, 0, sizeof(in));
memset(&out, 0, sizeof(out));
+ write_lock_irqsave(&table->lock, flags);
+ deleted_mr = radix_tree_delete(&table->tree, mlx5_base_mkey(mr->key));
+ write_unlock_irqrestore(&table->lock, flags);
+ if (!deleted_mr) {
+ mlx5_core_warn(dev, "failed radix tree delete of mr 0x%x\n",
+ mlx5_base_mkey(mr->key));
+ return -ENOENT;
+ }
+
in.hdr.opcode = cpu_to_be16(MLX5_CMD_OP_DESTROY_MKEY);
in.mkey = cpu_to_be32(mlx5_mkey_to_idx(mr->key));
err = mlx5_cmd_exec(dev, &in, sizeof(in), &out, sizeof(out));
@@ -119,10 +134,6 @@
if (out.hdr.status)
return mlx5_cmd_status_to_err(&out.hdr);
- write_lock_irqsave(&table->lock, flags);
- radix_tree_delete(&table->tree, mlx5_base_mkey(mr->key));
- write_unlock_irqrestore(&table->lock, flags);
-
return err;
}
EXPORT_SYMBOL(mlx5_core_destroy_mkey);