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-rw-r--r--io_uring/io_uring.h399
1 files changed, 399 insertions, 0 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
new file mode 100644
index 000000000..019600570
--- /dev/null
+++ b/io_uring/io_uring.h
@@ -0,0 +1,399 @@
+#ifndef IOU_CORE_H
+#define IOU_CORE_H
+
+#include <linux/errno.h>
+#include <linux/lockdep.h>
+#include <linux/resume_user_mode.h>
+#include <linux/io_uring_types.h>
+#include <uapi/linux/eventpoll.h>
+#include "io-wq.h"
+#include "slist.h"
+#include "filetable.h"
+
+#ifndef CREATE_TRACE_POINTS
+#include <trace/events/io_uring.h>
+#endif
+
+enum {
+ IOU_OK = 0,
+ IOU_ISSUE_SKIP_COMPLETE = -EIOCBQUEUED,
+
+ /*
+ * Intended only when both IO_URING_F_MULTISHOT is passed
+ * to indicate to the poll runner that multishot should be
+ * removed and the result is set on req->cqe.res.
+ */
+ IOU_STOP_MULTISHOT = -ECANCELED,
+};
+
+struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow);
+bool io_req_cqe_overflow(struct io_kiocb *req);
+int io_run_task_work_sig(struct io_ring_ctx *ctx);
+int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked);
+int io_run_local_work(struct io_ring_ctx *ctx);
+void io_req_complete_failed(struct io_kiocb *req, s32 res);
+void __io_req_complete(struct io_kiocb *req, unsigned issue_flags);
+void io_req_complete_post(struct io_kiocb *req);
+bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
+ bool allow_overflow);
+bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
+ bool allow_overflow);
+void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
+
+struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages);
+
+struct file *io_file_get_normal(struct io_kiocb *req, int fd);
+struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
+ unsigned issue_flags);
+
+static inline bool io_req_ffs_set(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_FIXED_FILE;
+}
+
+void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
+bool io_is_uring_fops(struct file *file);
+bool io_alloc_async_data(struct io_kiocb *req);
+void io_req_task_queue(struct io_kiocb *req);
+void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
+void io_req_task_complete(struct io_kiocb *req, bool *locked);
+void io_req_task_queue_fail(struct io_kiocb *req, int ret);
+void io_req_task_submit(struct io_kiocb *req, bool *locked);
+void tctx_task_work(struct callback_head *cb);
+__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
+int io_uring_alloc_task_context(struct task_struct *task,
+ struct io_ring_ctx *ctx);
+
+int io_poll_issue(struct io_kiocb *req, bool *locked);
+int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr);
+int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin);
+void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node);
+int io_req_prep_async(struct io_kiocb *req);
+
+struct io_wq_work *io_wq_free_work(struct io_wq_work *work);
+void io_wq_submit_work(struct io_wq_work *work);
+
+void io_free_req(struct io_kiocb *req);
+void io_queue_next(struct io_kiocb *req);
+void __io_put_task(struct task_struct *task, int nr);
+void io_task_refs_refill(struct io_uring_task *tctx);
+bool __io_alloc_req_refill(struct io_ring_ctx *ctx);
+
+bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all);
+
+static inline void io_req_task_work_add(struct io_kiocb *req)
+{
+ __io_req_task_work_add(req, true);
+}
+
+#define io_for_each_link(pos, head) \
+ for (pos = (head); pos; pos = pos->link)
+
+static inline void io_cq_lock(struct io_ring_ctx *ctx)
+ __acquires(ctx->completion_lock)
+{
+ spin_lock(&ctx->completion_lock);
+}
+
+void io_cq_unlock_post(struct io_ring_ctx *ctx);
+
+static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
+ bool overflow)
+{
+ if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
+ struct io_uring_cqe *cqe = ctx->cqe_cached;
+
+ ctx->cached_cq_tail++;
+ ctx->cqe_cached++;
+ if (ctx->flags & IORING_SETUP_CQE32)
+ ctx->cqe_cached++;
+ return cqe;
+ }
+
+ return __io_get_cqe(ctx, overflow);
+}
+
+static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
+{
+ return io_get_cqe_overflow(ctx, false);
+}
+
+static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
+ struct io_kiocb *req)
+{
+ struct io_uring_cqe *cqe;
+
+ /*
+ * If we can't get a cq entry, userspace overflowed the
+ * submission (by quite a lot). Increment the overflow count in
+ * the ring.
+ */
+ cqe = io_get_cqe(ctx);
+ if (unlikely(!cqe))
+ return io_req_cqe_overflow(req);
+
+ trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
+ req->cqe.res, req->cqe.flags,
+ (req->flags & REQ_F_CQE32_INIT) ? req->extra1 : 0,
+ (req->flags & REQ_F_CQE32_INIT) ? req->extra2 : 0);
+
+ memcpy(cqe, &req->cqe, sizeof(*cqe));
+
+ if (ctx->flags & IORING_SETUP_CQE32) {
+ u64 extra1 = 0, extra2 = 0;
+
+ if (req->flags & REQ_F_CQE32_INIT) {
+ extra1 = req->extra1;
+ extra2 = req->extra2;
+ }
+
+ WRITE_ONCE(cqe->big_cqe[0], extra1);
+ WRITE_ONCE(cqe->big_cqe[1], extra2);
+ }
+ return true;
+}
+
+static inline void req_set_fail(struct io_kiocb *req)
+{
+ req->flags |= REQ_F_FAIL;
+ if (req->flags & REQ_F_CQE_SKIP) {
+ req->flags &= ~REQ_F_CQE_SKIP;
+ req->flags |= REQ_F_SKIP_LINK_CQES;
+ }
+}
+
+static inline void io_req_set_res(struct io_kiocb *req, s32 res, u32 cflags)
+{
+ req->cqe.res = res;
+ req->cqe.flags = cflags;
+}
+
+static inline bool req_has_async_data(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_ASYNC_DATA;
+}
+
+static inline void io_put_file(struct file *file)
+{
+ if (file)
+ fput(file);
+}
+
+static inline void io_ring_submit_unlock(struct io_ring_ctx *ctx,
+ unsigned issue_flags)
+{
+ lockdep_assert_held(&ctx->uring_lock);
+ if (issue_flags & IO_URING_F_UNLOCKED)
+ mutex_unlock(&ctx->uring_lock);
+}
+
+static inline void io_ring_submit_lock(struct io_ring_ctx *ctx,
+ unsigned issue_flags)
+{
+ /*
+ * "Normal" inline submissions always hold the uring_lock, since we
+ * grab it from the system call. Same is true for the SQPOLL offload.
+ * The only exception is when we've detached the request and issue it
+ * from an async worker thread, grab the lock for that case.
+ */
+ if (issue_flags & IO_URING_F_UNLOCKED)
+ mutex_lock(&ctx->uring_lock);
+ lockdep_assert_held(&ctx->uring_lock);
+}
+
+static inline void io_commit_cqring(struct io_ring_ctx *ctx)
+{
+ /* order cqe stores with ring update */
+ smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
+}
+
+/* requires smb_mb() prior, see wq_has_sleeper() */
+static inline void __io_cqring_wake(struct io_ring_ctx *ctx)
+{
+ /*
+ * Trigger waitqueue handler on all waiters on our waitqueue. This
+ * won't necessarily wake up all the tasks, io_should_wake() will make
+ * that decision.
+ *
+ * Pass in EPOLLIN|EPOLL_URING_WAKE as the poll wakeup key. The latter
+ * set in the mask so that if we recurse back into our own poll
+ * waitqueue handlers, we know we have a dependency between eventfd or
+ * epoll and should terminate multishot poll at that point.
+ */
+ if (waitqueue_active(&ctx->cq_wait))
+ __wake_up(&ctx->cq_wait, TASK_NORMAL, 0,
+ poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
+}
+
+static inline void io_cqring_wake(struct io_ring_ctx *ctx)
+{
+ smp_mb();
+ __io_cqring_wake(ctx);
+}
+
+static inline bool io_sqring_full(struct io_ring_ctx *ctx)
+{
+ struct io_rings *r = ctx->rings;
+
+ return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
+}
+
+static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
+{
+ struct io_rings *rings = ctx->rings;
+
+ /* make sure SQ entry isn't read before tail */
+ return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
+}
+
+static inline int io_run_task_work(void)
+{
+ /*
+ * Always check-and-clear the task_work notification signal. With how
+ * signaling works for task_work, we can find it set with nothing to
+ * run. We need to clear it for that case, like get_signal() does.
+ */
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL))
+ clear_notify_signal();
+ /*
+ * PF_IO_WORKER never returns to userspace, so check here if we have
+ * notify work that needs processing.
+ */
+ if (current->flags & PF_IO_WORKER &&
+ test_thread_flag(TIF_NOTIFY_RESUME)) {
+ __set_current_state(TASK_RUNNING);
+ resume_user_mode_work(NULL);
+ }
+ if (task_work_pending(current)) {
+ __set_current_state(TASK_RUNNING);
+ task_work_run();
+ return 1;
+ }
+
+ return 0;
+}
+
+static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
+{
+ return test_thread_flag(TIF_NOTIFY_SIGNAL) ||
+ !wq_list_empty(&ctx->work_llist);
+}
+
+static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx)
+{
+ int ret = 0;
+ int ret2;
+
+ if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
+ ret = io_run_local_work(ctx);
+
+ /* want to run this after in case more is added */
+ ret2 = io_run_task_work();
+
+ /* Try propagate error in favour of if tasks were run,
+ * but still make sure to run them if requested
+ */
+ if (ret >= 0)
+ ret += ret2;
+
+ return ret;
+}
+
+static inline int io_run_local_work_locked(struct io_ring_ctx *ctx)
+{
+ bool locked;
+ int ret;
+
+ if (llist_empty(&ctx->work_llist))
+ return 0;
+
+ locked = true;
+ ret = __io_run_local_work(ctx, &locked);
+ /* shouldn't happen! */
+ if (WARN_ON_ONCE(!locked))
+ mutex_lock(&ctx->uring_lock);
+ return ret;
+}
+
+static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
+{
+ if (!*locked) {
+ mutex_lock(&ctx->uring_lock);
+ *locked = true;
+ }
+}
+
+/*
+ * Don't complete immediately but use deferred completion infrastructure.
+ * Protected by ->uring_lock and can only be used either with
+ * IO_URING_F_COMPLETE_DEFER or inside a tw handler holding the mutex.
+ */
+static inline void io_req_complete_defer(struct io_kiocb *req)
+ __must_hold(&req->ctx->uring_lock)
+{
+ struct io_submit_state *state = &req->ctx->submit_state;
+
+ lockdep_assert_held(&req->ctx->uring_lock);
+
+ wq_list_add_tail(&req->comp_list, &state->compl_reqs);
+}
+
+static inline void io_commit_cqring_flush(struct io_ring_ctx *ctx)
+{
+ if (unlikely(ctx->off_timeout_used || ctx->drain_active || ctx->has_evfd))
+ __io_commit_cqring_flush(ctx);
+}
+
+/* must to be called somewhat shortly after putting a request */
+static inline void io_put_task(struct task_struct *task, int nr)
+{
+ if (likely(task == current))
+ task->io_uring->cached_refs += nr;
+ else
+ __io_put_task(task, nr);
+}
+
+static inline void io_get_task_refs(int nr)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ tctx->cached_refs -= nr;
+ if (unlikely(tctx->cached_refs < 0))
+ io_task_refs_refill(tctx);
+}
+
+static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
+{
+ return !ctx->submit_state.free_list.next;
+}
+
+static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
+{
+ if (unlikely(io_req_cache_empty(ctx)))
+ return __io_alloc_req_refill(ctx);
+ return true;
+}
+
+static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
+{
+ struct io_wq_work_node *node;
+
+ node = wq_stack_extract(&ctx->submit_state.free_list);
+ return container_of(node, struct io_kiocb, comp_list);
+}
+
+static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
+{
+ return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
+ ctx->submitter_task == current);
+}
+
+static inline void io_req_queue_tw_complete(struct io_kiocb *req, s32 res)
+{
+ io_req_set_res(req, res, 0);
+ req->io_task_work.func = io_req_task_complete;
+ io_req_task_work_add(req);
+}
+
+#endif