diff options
Diffstat (limited to 'io_uring/io_uring.h')
| -rw-r--r-- | io_uring/io_uring.h | 397 |
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 |