-static void io_sq_thread_drop_mm_files(void)
-{
- struct files_struct *files = current->files;
- struct mm_struct *mm = current->mm;
-
- if (mm) {
- kthread_unuse_mm(mm);
- mmput(mm);
- current->mm = NULL;
- }
- if (files) {
- struct nsproxy *nsproxy = current->nsproxy;
-
- task_lock(current);
- current->files = NULL;
- current->nsproxy = NULL;
- task_unlock(current);
- put_files_struct(files);
- put_nsproxy(nsproxy);
- }
-}
-
-static int __io_sq_thread_acquire_files(struct io_ring_ctx *ctx)
-{
- if (!current->files) {
- struct files_struct *files;
- struct nsproxy *nsproxy;
-
- task_lock(ctx->sqo_task);
- files = ctx->sqo_task->files;
- if (!files) {
- task_unlock(ctx->sqo_task);
- return -EOWNERDEAD;
- }
- atomic_inc(&files->count);
- get_nsproxy(ctx->sqo_task->nsproxy);
- nsproxy = ctx->sqo_task->nsproxy;
- task_unlock(ctx->sqo_task);
-
- task_lock(current);
- current->files = files;
- current->nsproxy = nsproxy;
- task_unlock(current);
- }
- return 0;
-}
-
-static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
-{
- struct mm_struct *mm;
-
- if (current->mm)
- return 0;
-
- task_lock(ctx->sqo_task);
- mm = ctx->sqo_task->mm;
- if (unlikely(!mm || !mmget_not_zero(mm)))
- mm = NULL;
- task_unlock(ctx->sqo_task);
-
- if (mm) {
- kthread_use_mm(mm);
- return 0;
- }
-
- return -EFAULT;
-}
-
-static int __io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx,
- struct io_kiocb *req)
-{
- const struct io_op_def *def = &io_op_defs[req->opcode];
- int ret;
-
- if (def->work_flags & IO_WQ_WORK_MM) {
- ret = __io_sq_thread_acquire_mm(ctx);
- if (unlikely(ret))
- return ret;
- }
-
- if (def->needs_file || (def->work_flags & IO_WQ_WORK_FILES)) {
- ret = __io_sq_thread_acquire_files(ctx);
- if (unlikely(ret))
- return ret;
- }
-
- return 0;
-}
-
-static inline int io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx,
- struct io_kiocb *req)
-{
- if (!(ctx->flags & IORING_SETUP_SQPOLL))
- return 0;
- return __io_sq_thread_acquire_mm_files(ctx, req);
-}
-
-static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx,
- struct cgroup_subsys_state **cur_css)
-
-{
-#ifdef CONFIG_BLK_CGROUP
- /* puts the old one when swapping */
- if (*cur_css != ctx->sqo_blkcg_css) {
- kthread_associate_blkcg(ctx->sqo_blkcg_css);
- *cur_css = ctx->sqo_blkcg_css;
- }
-#endif
-}
-
-static void io_sq_thread_unassociate_blkcg(void)
-{
-#ifdef CONFIG_BLK_CGROUP
- kthread_associate_blkcg(NULL);
-#endif
-}
-