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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-02-28 22:35:09 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-04-11 17:41:57 -0600 |
| commit | e83acd7d37d83035f2fe078f656f87418ea2a687 (patch) | |
| tree | 0f0dc9006b0a54854aeb948a80239b3bb2110726 /fs/io_uring.c | |
| parent | d434405aaab7d0ebc516b68a8fc4100922d7f5ef (diff) | |
| download | lwn-e83acd7d37d83035f2fe078f656f87418ea2a687.tar.gz lwn-e83acd7d37d83035f2fe078f656f87418ea2a687.zip | |
io_uring: avoid taking ctx refs for task-cancel
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 <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index bd14327c8e7e..db0c4b2dd141 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1985,10 +1985,10 @@ 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) @@ -2019,14 +2019,12 @@ 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; |