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-rw-r--r--io_uring/io_uring.h397
1 files changed, 397 insertions, 0 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
new file mode 100644
index 0000000000..d2bad1df34
--- /dev/null
+++ b/io_uring/io_uring.h
@@ -0,0 +1,397 @@
+#ifndef IOU_CORE_H
+#define IOU_CORE_H
+
+#include <linux/errno.h>
+#include <linux/lockdep.h>
+#include <linux/resume_user_mode.h>
+#include <linux/kasan.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 {
+ /*
+ * A hint to not wake right away but delay until there are enough of
+ * tw's queued to match the number of CQEs the task is waiting for.
+ *
+ * Must not be used wirh requests generating more than one CQE.
+ * It's also ignored unless IORING_SETUP_DEFER_TASKRUN is set.
+ */
+ IOU_F_TWQ_LAZY_WAKE = 1,
+};
+
+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,
+};
+
+bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow);
+void io_req_cqe_overflow(struct io_kiocb *req);
+int io_run_task_work_sig(struct io_ring_ctx *ctx);
+void io_req_defer_failed(struct io_kiocb *req, s32 res);
+void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags);
+bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags);
+bool io_fill_cqe_req_aux(struct io_kiocb *req, bool defer, s32 res, u32 cflags);
+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);
+
+void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
+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, struct io_tw_state *ts_dont_use);
+void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts);
+void io_req_task_queue_fail(struct io_kiocb *req, int ret);
+void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts);
+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_ring_add_registered_file(struct io_uring_task *tctx, struct file *file,
+ int start, int end);
+
+int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts);
+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_submit_flush_completions(struct io_ring_ctx *ctx);
+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_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);
+
+void *io_mem_alloc(size_t size);
+void io_mem_free(void *ptr);
+
+#if defined(CONFIG_PROVE_LOCKING)
+static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx)
+{
+ lockdep_assert(in_task());
+
+ if (ctx->flags & IORING_SETUP_IOPOLL) {
+ lockdep_assert_held(&ctx->uring_lock);
+ } else if (!ctx->task_complete) {
+ lockdep_assert_held(&ctx->completion_lock);
+ } else if (ctx->submitter_task) {
+ /*
+ * ->submitter_task may be NULL and we can still post a CQE,
+ * if the ring has been setup with IORING_SETUP_R_DISABLED.
+ * Not from an SQE, as those cannot be submitted, but via
+ * updating tagged resources.
+ */
+ if (ctx->submitter_task->flags & PF_EXITING)
+ lockdep_assert(current_work());
+ else
+ lockdep_assert(current == ctx->submitter_task);
+ }
+}
+#else
+static inline void io_lockdep_assert_cq_locked(struct io_ring_ctx *ctx)
+{
+}
+#endif
+
+static inline void io_req_task_work_add(struct io_kiocb *req)
+{
+ __io_req_task_work_add(req, 0);
+}
+
+#define io_for_each_link(pos, head) \
+ for (pos = (head); pos; pos = pos->link)
+
+static inline bool io_get_cqe_overflow(struct io_ring_ctx *ctx,
+ struct io_uring_cqe **ret,
+ bool overflow)
+{
+ io_lockdep_assert_cq_locked(ctx);
+
+ if (unlikely(ctx->cqe_cached >= ctx->cqe_sentinel)) {
+ if (unlikely(!io_cqe_cache_refill(ctx, overflow)))
+ return false;
+ }
+ *ret = ctx->cqe_cached;
+ ctx->cached_cq_tail++;
+ ctx->cqe_cached++;
+ if (ctx->flags & IORING_SETUP_CQE32)
+ ctx->cqe_cached++;
+ return true;
+}
+
+static inline bool io_get_cqe(struct io_ring_ctx *ctx, struct io_uring_cqe **ret)
+{
+ return io_get_cqe_overflow(ctx, ret, false);
+}
+
+static __always_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.
+ */
+ if (unlikely(!io_get_cqe(ctx, &cqe)))
+ return false;
+
+ if (trace_io_uring_complete_enabled())
+ trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
+ req->cqe.res, req->cqe.flags,
+ req->big_cqe.extra1, req->big_cqe.extra2);
+
+ memcpy(cqe, &req->cqe, sizeof(*cqe));
+ if (ctx->flags & IORING_SETUP_CQE32) {
+ memcpy(cqe->big_cqe, &req->big_cqe, sizeof(*cqe));
+ memset(&req->big_cqe, 0, sizeof(req->big_cqe));
+ }
+ 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 io_kiocb *req)
+{
+ if (!(req->flags & REQ_F_FIXED_FILE) && req->file)
+ fput(req->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);
+}
+
+static inline void io_poll_wq_wake(struct io_ring_ctx *ctx)
+{
+ if (wq_has_sleeper(&ctx->poll_wq))
+ __wake_up(&ctx->poll_wq, TASK_NORMAL, 0,
+ poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
+}
+
+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 (wq_has_sleeper(&ctx->cq_wait))
+ __wake_up(&ctx->cq_wait, TASK_NORMAL, 0,
+ poll_to_key(EPOLL_URING_WAKE | EPOLLIN));
+}
+
+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;
+ unsigned int entries;
+
+ /* make sure SQ entry isn't read before tail */
+ entries = smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
+ return min(entries, ctx->sq_entries);
+}
+
+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 task_work_pending(current) || !wq_list_empty(&ctx->work_llist);
+}
+
+static inline void io_tw_lock(struct io_ring_ctx *ctx, struct io_tw_state *ts)
+{
+ if (!ts->locked) {
+ mutex_lock(&ctx->uring_lock);
+ ts->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 || ctx->poll_activated))
+ __io_commit_cqring_flush(ctx);
+}
+
+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;
+}
+
+extern struct kmem_cache *req_cachep;
+
+static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx)
+{
+ struct io_kiocb *req;
+
+ req = container_of(ctx->submit_state.free_list.next, struct io_kiocb, comp_list);
+ wq_stack_extract(&ctx->submit_state.free_list);
+ return req;
+}
+
+static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req)
+{
+ if (unlikely(io_req_cache_empty(ctx))) {
+ if (!__io_alloc_req_refill(ctx))
+ return false;
+ }
+ *req = io_extract_req(ctx);
+ return true;
+}
+
+static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx)
+{
+ return likely(ctx->submitter_task == current);
+}
+
+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);
+}
+
+/*
+ * IORING_SETUP_SQE128 contexts allocate twice the normal SQE size for each
+ * slot.
+ */
+static inline size_t uring_sqe_size(struct io_ring_ctx *ctx)
+{
+ if (ctx->flags & IORING_SETUP_SQE128)
+ return 2 * sizeof(struct io_uring_sqe);
+ return sizeof(struct io_uring_sqe);
+}
+#endif