kthread: Pass in the thread's name during creation

This has us pass in the thread's name during creation in kernel_thread.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

diff --git a/kernel/kthread.c b/kernel/kthread.c
index fa4a12d..4bc6e09 100644 (file)
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -38,6 +38,7 @@ struct task_struct *kthreadd_task;
 struct kthread_create_info
 {
        /* Information passed to kthread() from kthreadd. */
+       char *full_name;
        int (*threadfn)(void *data);
        void *data;
        int node;
@@ -343,10 +344,12 @@ static int kthread(void *_create)
        /* Release the structure when caller killed by a fatal signal. */
        done = xchg(&create->done, NULL);
        if (!done) {
+               kfree(create->full_name);
                kfree(create);
                kthread_exit(-EINTR);
        }
 
+       self->full_name = create->full_name;
        self->threadfn = threadfn;
        self->data = data;
 
@@ -396,12 +399,13 @@ static void create_kthread(struct kthread_create_info *create)
        current->pref_node_fork = create->node;
 #endif
        /* We want our own signal handler (we take no signals by default). */
-       pid = kernel_thread(kthread, create, NULL,
+       pid = kernel_thread(kthread, create, create->full_name,
                            CLONE_FS | CLONE_FILES | SIGCHLD);
        if (pid < 0) {
                /* Release the structure when caller killed by a fatal signal. */
                struct completion *done = xchg(&create->done, NULL);
 
+               kfree(create->full_name);
                if (!done) {
                        kfree(create);
                        return;
@@ -428,6 +432,11 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
        create->data = data;
        create->node = node;
        create->done = &done;
+       create->full_name = kvasprintf(GFP_KERNEL, namefmt, args);
+       if (!create->full_name) {
+               task = ERR_PTR(-ENOMEM);
+               goto free_create;
+       }
 
        spin_lock(&kthread_create_lock);
        list_add_tail(&create->list, &kthread_create_list);
@@ -454,26 +463,7 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
                wait_for_completion(&done);
        }
        task = create->result;
-       if (!IS_ERR(task)) {
-               char name[TASK_COMM_LEN];
-               va_list aq;
-               int len;
-
-               /*
-                * task is already visible to other tasks, so updating
-                * COMM must be protected.
-                */
-               va_copy(aq, args);
-               len = vsnprintf(name, sizeof(name), namefmt, aq);
-               va_end(aq);
-               if (len >= TASK_COMM_LEN) {
-                       struct kthread *kthread = to_kthread(task);
-
-                       /* leave it truncated when out of memory. */
-                       kthread->full_name = kvasprintf(GFP_KERNEL, namefmt, args);
-               }
-               set_task_comm(task, name);
-       }
+free_create:
        kfree(create);
        return task;
 }