[RFC 1/2] vhost: return error instead of NULL on create

[Keith Busch]

From: Keith Busch <kbu...@kernel.org>

Let callers distinguish why the vhost create failed.

Signed-off-by: Keith Busch <kbu...@kernel.org>
---
 arch/x86/kvm/mmu/mmu.c | 2 +-
 drivers/vhost/vhost.c  | 2 +-
 kernel/vhost_task.c    | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index d4ac4a1f8b81b..18ca1ea6dc240 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -7471,7 +7471,7 @@ static void kvm_mmu_start_lpage_recovery(struct once 
*once)
                                      kvm_nx_huge_page_recovery_worker_kill,
                                      kvm, "kvm-nx-lpage-recovery");
 
-       if (!nx_thread)
+       if (IS_ERR(nx_thread))
                return;
 
        vhost_task_start(nx_thread);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 9ac25d08f473e..61dd19c7f99f1 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -666,7 +666,7 @@ static struct vhost_worker *vhost_worker_create(struct 
vhost_dev *dev)
 
        vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed,
                                 worker, name);
-       if (!vtsk)
+       if (!IS_ERR(vtsk))
                goto free_worker;
 
        mutex_init(&worker->mutex);
diff --git a/kernel/vhost_task.c b/kernel/vhost_task.c
index 8800f5acc0071..2ef2e1b800916 100644
--- a/kernel/vhost_task.c
+++ b/kernel/vhost_task.c
@@ -133,7 +133,7 @@ struct vhost_task *vhost_task_create(bool (*fn)(void *),
 
        vtsk = kzalloc(sizeof(*vtsk), GFP_KERNEL);
        if (!vtsk)
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        init_completion(&vtsk->exited);
        mutex_init(&vtsk->exit_mutex);
        vtsk->data = arg;
@@ -145,7 +145,7 @@ struct vhost_task *vhost_task_create(bool (*fn)(void *),
        tsk = copy_process(NULL, 0, NUMA_NO_NODE, &args);
        if (IS_ERR(tsk)) {
                kfree(vtsk);
-               return NULL;
+               return ERR_PTR(PTR_ERR(tsk));
        }
 
        vtsk->task = tsk;
-- 
2.43.5