On Mon, Jan 26, 2026 at 02:23:36PM -0800, Nicolin Chen wrote:

On Mon, Jan 26, 2026 at 05:06:40PM -0400, Jason Gunthorpe wrote:

quoted

On Wed, Jan 21, 2026 at 05:24:22PM -0800, Nicolin Chen wrote:

quoted

@@ -3220,6 +3241,9 @@ arm_smmu_master_build_inv(struct arm_smmu_master *master,
 		break;
 	}
 
+	/* Set a default users counter */
+	refcount_set(&cur->users, 1);

I think abusing users here is a little too hard to read..

Can we just keep track in the state somehow with a flag?

Or maybe union in a "bool needs_free" that is for the on-stack version
of this structure?

This doesn't only apply to the case when a tag is newly allocated
during the attach, but it can be used when an old tag has users=0
during a detach, right?

Oh, IDK, I didn't look so closely..

I though this was just about cleaning up the tag during attach, the
detach flow worked differently and did use users = 0?

Jason