From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Subject: [PATCH 02/13] io_uring: avoid taking ctx refs for task-cancel
Date: Tue, 23 Feb 2021 01:55:37 +0000 [thread overview]
Message-ID: <bba359aab588d4df3433331c71c0801713323fe5.1614045169.git.asml.silence@gmail.com> (raw)
In-Reply-To: <[email protected]>
Don't bother to take a ctx->refs for io_req_task_cancel() because it
take uring_lock before putting a request, and the context is promised to
stay alive until unlock happens.
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io_uring.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 6e781c064e74..2d66d0afc6c0 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2010,10 +2010,10 @@ static void io_req_task_cancel(struct callback_head *cb)
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
struct io_ring_ctx *ctx = req->ctx;
+ /* ctx is guaranteed to stay alive while we hold uring_lock */
mutex_lock(&ctx->uring_lock);
__io_req_task_cancel(req, req->result);
mutex_unlock(&ctx->uring_lock);
- percpu_ref_put(&ctx->refs);
}
static void __io_req_task_submit(struct io_kiocb *req)
@@ -2044,14 +2044,12 @@ static void io_req_task_queue(struct io_kiocb *req)
ret = io_req_task_work_add(req);
if (unlikely(ret)) {
req->result = -ECANCELED;
- percpu_ref_get(&req->ctx->refs);
io_req_task_work_add_fallback(req, io_req_task_cancel);
}
}
static void io_req_task_queue_fail(struct io_kiocb *req, int ret)
{
- percpu_ref_get(&req->ctx->refs);
req->result = ret;
req->task_work.func = io_req_task_cancel;
--
2.24.0
next prev parent reply other threads:[~2021-02-23 2:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 1:55 [PATCH for-next 00/13] simple 5.13 cleanups Pavel Begunkov
2021-02-23 1:55 ` [PATCH 01/13] io_uring: introduce a new helper for ctx quiesce Pavel Begunkov
2021-02-23 1:55 ` Pavel Begunkov [this message]
2021-02-23 1:55 ` [PATCH 03/13] io_uring: reuse io_req_task_queue_fail() Pavel Begunkov
2021-02-23 1:55 ` [PATCH 04/13] io_uring: further deduplicate file slot selection Pavel Begunkov
2021-02-23 1:55 ` [PATCH 05/13] io_uring: add a helper failing not issued requests Pavel Begunkov
2021-02-23 1:55 ` [PATCH 06/13] io_uring: refactor provide/remove buffer locking Pavel Begunkov
2021-02-23 1:55 ` [PATCH 07/13] io_uring: don't restirct issue_flags for io_openat Pavel Begunkov
2021-02-23 1:55 ` [PATCH 08/13] io_uring: use better types for cflags Pavel Begunkov
2021-02-23 1:55 ` [PATCH 09/13] io_uring: refactor out send/recv async setup Pavel Begunkov
2021-02-23 1:55 ` [PATCH 10/13] io_uring: untie alloc_async_data and needs_async_data Pavel Begunkov
2021-02-23 1:55 ` [PATCH 11/13] io_uring: rethink def->needs_async_data Pavel Begunkov
2021-02-23 1:55 ` [PATCH 12/13] io_uring: merge defer_prep() and prep_async() Pavel Begunkov
2021-02-23 1:55 ` [PATCH 13/13] io_uring: simplify io_resubmit_prep() Pavel Begunkov
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