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-rw-r--r--kernel/fork.c36
1 files changed, 32 insertions, 4 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 37720a6d04ea..d3171e8e88e5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -819,9 +819,8 @@ void __init fork_init(void)
init_task.signal->rlim[RLIMIT_SIGPENDING] =
init_task.signal->rlim[RLIMIT_NPROC];
- for (i = 0; i < UCOUNT_COUNTS; i++) {
+ for (i = 0; i < UCOUNT_COUNTS; i++)
init_user_ns.ucount_max[i] = max_threads/2;
- }
#ifdef CONFIG_VMAP_STACK
cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "fork:vm_stack_cache",
@@ -1654,9 +1653,8 @@ static inline void init_task_pid_links(struct task_struct *task)
{
enum pid_type type;
- for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type) {
+ for (type = PIDTYPE_PID; type < PIDTYPE_MAX; ++type)
INIT_HLIST_NODE(&task->pid_links[type]);
- }
}
static inline void
@@ -1942,6 +1940,8 @@ static __latent_entropy struct task_struct *copy_process(
p = dup_task_struct(current, node);
if (!p)
goto fork_out;
+ if (args->io_thread)
+ p->flags |= PF_IO_WORKER;
/*
* This _must_ happen before we call free_task(), i.e. before we jump
@@ -2413,6 +2413,34 @@ struct mm_struct *copy_init_mm(void)
}
/*
+ * This is like kernel_clone(), but shaved down and tailored to just
+ * creating io_uring workers. It returns a created task, or an error pointer.
+ * The returned task is inactive, and the caller must fire it up through
+ * wake_up_new_task(p). All signals are blocked in the created task.
+ */
+struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
+{
+ unsigned long flags = CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|
+ CLONE_IO;
+ struct kernel_clone_args args = {
+ .flags = ((lower_32_bits(flags) | CLONE_VM |
+ CLONE_UNTRACED) & ~CSIGNAL),
+ .exit_signal = (lower_32_bits(flags) & CSIGNAL),
+ .stack = (unsigned long)fn,
+ .stack_size = (unsigned long)arg,
+ .io_thread = 1,
+ };
+ struct task_struct *tsk;
+
+ tsk = copy_process(NULL, 0, node, &args);
+ if (!IS_ERR(tsk)) {
+ sigfillset(&tsk->blocked);
+ sigdelsetmask(&tsk->blocked, sigmask(SIGKILL));
+ }
+ return tsk;
+}
+
+/*
* Ok, this is the main fork-routine.
*
* It copies the process, and if successful kick-starts