From 8e5b3b89ecaf6d9295e561c225b35c574a5e0fe7 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 18 Mar 2024 22:00:30 +0000 Subject: [PATCH] io_uring: remove struct io_tw_state::locked ctx is always locked for task_work now, so get rid of struct io_tw_state::locked. Note I'm stopping one step before removing io_tw_state altogether, which is not empty, because it still serves the purpose of indicating which function is a tw callback and forcing users not to invoke them carelessly out of a wrong context. The removal can always be done later. Signed-off-by: Pavel Begunkov Tested-by: Ming Lei Link: https://lore.kernel.org/r/e95e1ea116d0bfa54b656076e6a977bc221392a4.1710799188.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 2 -- io_uring/io_uring.c | 31 ++++++++----------------------- io_uring/io_uring.h | 5 +---- io_uring/poll.c | 2 +- io_uring/rw.c | 6 ++---- io_uring/timeout.c | 8 ++------ io_uring/uring_cmd.c | 8 ++------ io_uring/waitid.c | 2 +- 8 files changed, 17 insertions(+), 47 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index ac333ea81d31..90e5af401800 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -438,8 +438,6 @@ struct io_ring_ctx { }; struct io_tw_state { - /* ->uring_lock is taken, callbacks can use io_tw_lock to lock it */ - bool locked; }; enum { diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 13fb5958454f..ecb59bb2418b 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -247,14 +247,12 @@ static __cold void io_fallback_req_func(struct work_struct *work) fallback_work.work); struct llist_node *node = llist_del_all(&ctx->fallback_llist); struct io_kiocb *req, *tmp; - struct io_tw_state ts = { .locked = true, }; + struct io_tw_state ts = {}; percpu_ref_get(&ctx->refs); mutex_lock(&ctx->uring_lock); llist_for_each_entry_safe(req, tmp, node, io_task_work.node) req->io_task_work.func(req, &ts); - if (WARN_ON_ONCE(!ts.locked)) - return; io_submit_flush_completions(ctx); mutex_unlock(&ctx->uring_lock); percpu_ref_put(&ctx->refs); @@ -1157,11 +1155,9 @@ static void ctx_flush_and_put(struct io_ring_ctx *ctx, struct io_tw_state *ts) return; if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); - if (ts->locked) { - io_submit_flush_completions(ctx); - mutex_unlock(&ctx->uring_lock); - ts->locked = false; - } + + io_submit_flush_completions(ctx); + mutex_unlock(&ctx->uring_lock); percpu_ref_put(&ctx->refs); } @@ -1185,8 +1181,6 @@ struct llist_node *io_handle_tw_list(struct llist_node *node, if (req->ctx != ctx) { ctx_flush_and_put(ctx, &ts); ctx = req->ctx; - - ts.locked = true; mutex_lock(&ctx->uring_lock); percpu_ref_get(&ctx->refs); } @@ -1459,22 +1453,16 @@ static int __io_run_local_work(struct io_ring_ctx *ctx, struct io_tw_state *ts, static inline int io_run_local_work_locked(struct io_ring_ctx *ctx, int min_events) { - struct io_tw_state ts = { .locked = true, }; - int ret; + struct io_tw_state ts = {}; if (llist_empty(&ctx->work_llist)) return 0; - - ret = __io_run_local_work(ctx, &ts, min_events); - /* shouldn't happen! */ - if (WARN_ON_ONCE(!ts.locked)) - mutex_lock(&ctx->uring_lock); - return ret; + return __io_run_local_work(ctx, &ts, min_events); } static int io_run_local_work(struct io_ring_ctx *ctx, int min_events) { - struct io_tw_state ts = { .locked = true }; + struct io_tw_state ts = {}; int ret; mutex_lock(&ctx->uring_lock); @@ -1702,10 +1690,7 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts) { - if (ts->locked) - io_req_complete_defer(req); - else - io_req_complete_post(req, IO_URING_F_UNLOCKED); + io_req_complete_defer(req); } /* diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 0861d49e83de..7f921daae9c3 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -351,10 +351,7 @@ static inline bool io_task_work_pending(struct io_ring_ctx *ctx) 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; - } + lockdep_assert_held(&ctx->uring_lock); } /* diff --git a/io_uring/poll.c b/io_uring/poll.c index 6db1dcb2c797..8901dd118e50 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -322,7 +322,7 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts) __poll_t mask = mangle_poll(req->cqe.res & req->apoll_events); - if (!io_fill_cqe_req_aux(req, ts->locked, mask, + if (!io_fill_cqe_req_aux(req, true, mask, IORING_CQE_F_MORE)) { io_req_set_res(req, mask, 0); return IOU_POLL_REMOVE_POLL_USE_RES; diff --git a/io_uring/rw.c b/io_uring/rw.c index 0afe4f9e0e3f..674581bda8d7 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -305,11 +305,9 @@ void io_req_rw_complete(struct io_kiocb *req, struct io_tw_state *ts) io_req_io_end(req); - if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) { - unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; + if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) + req->cqe.flags |= io_put_kbuf(req, 0); - req->cqe.flags |= io_put_kbuf(req, issue_flags); - } io_req_task_complete(req, ts); } diff --git a/io_uring/timeout.c b/io_uring/timeout.c index 7fd7dbb211d6..0a48e6acd0b2 100644 --- a/io_uring/timeout.c +++ b/io_uring/timeout.c @@ -72,10 +72,7 @@ static void io_timeout_complete(struct io_kiocb *req, struct io_tw_state *ts) struct io_ring_ctx *ctx = req->ctx; if (!io_timeout_finish(timeout, data)) { - bool filled; - filled = io_fill_cqe_req_aux(req, ts->locked, -ETIME, - IORING_CQE_F_MORE); - if (filled) { + if (io_fill_cqe_req_aux(req, true, -ETIME, IORING_CQE_F_MORE)) { /* re-arm timer */ spin_lock_irq(&ctx->timeout_lock); list_add(&timeout->list, ctx->timeout_list.prev); @@ -301,7 +298,6 @@ int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd) static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *ts) { - unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED; struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); struct io_kiocb *prev = timeout->prev; int ret = -ENOENT; @@ -313,7 +309,7 @@ static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *t .data = prev->cqe.user_data, }; - ret = io_try_cancel(req->task->io_uring, &cd, issue_flags); + ret = io_try_cancel(req->task->io_uring, &cd, 0); } io_req_set_res(req, ret ?: -ETIME, 0); io_req_task_complete(req, ts); diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 759f919b14a9..4614ce734fee 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -87,13 +87,9 @@ EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable); static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); - unsigned issue_flags = IO_URING_F_UNLOCKED; - /* locked task_work executor checks the deffered list completion */ - if (ts->locked) - issue_flags = IO_URING_F_COMPLETE_DEFER; - - ioucmd->task_work_cb(ioucmd, issue_flags); + /* task_work executor checks the deffered list completion */ + ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER); } void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, diff --git a/io_uring/waitid.c b/io_uring/waitid.c index 77d340666cb9..6362ec20abc0 100644 --- a/io_uring/waitid.c +++ b/io_uring/waitid.c @@ -118,7 +118,7 @@ static int io_waitid_finish(struct io_kiocb *req, int ret) static void io_waitid_complete(struct io_kiocb *req, int ret) { struct io_waitid *iw = io_kiocb_to_cmd(req, struct io_waitid); - struct io_tw_state ts = { .locked = true }; + struct io_tw_state ts = {}; /* anyone completing better be holding a reference */ WARN_ON_ONCE(!(atomic_read(&iw->refs) & IO_WAITID_REF_MASK));