io_uring: fix OP_ASYNC_CANCEL across tasks

IORING_OP_ASYNC_CANCEL tries io-wq cancellation only for current task.
If it fails go over tctx_list and try it out for every single tctx.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 70286b3..a4bce17 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5667,8 +5667,47 @@ static int io_async_cancel_prep(struct io_kiocb *req,
 static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_ring_ctx *ctx = req->ctx;
+       u64 sqe_addr = req->cancel.addr;
+       struct io_tctx_node *node;
+       int ret;
 
-       io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
+       /* tasks should wait for their io-wq threads, so safe w/o sync */
+       ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx);
+       spin_lock_irq(&ctx->completion_lock);
+       if (ret != -ENOENT)
+               goto done;
+       ret = io_timeout_cancel(ctx, sqe_addr);
+       if (ret != -ENOENT)
+               goto done;
+       ret = io_poll_cancel(ctx, sqe_addr);
+       if (ret != -ENOENT)
+               goto done;
+       spin_unlock_irq(&ctx->completion_lock);
+
+       /* slow path, try all io-wq's */
+       io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+       ret = -ENOENT;
+       list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
+               struct io_uring_task *tctx = node->task->io_uring;
+
+               if (!tctx || !tctx->io_wq)
+                       continue;
+               ret = io_async_cancel_one(tctx, req->cancel.addr, ctx);
+               if (ret != -ENOENT)
+                       break;
+       }
+       io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+
+       spin_lock_irq(&ctx->completion_lock);
+done:
+       io_cqring_fill_event(req, ret);
+       io_commit_cqring(ctx);
+       spin_unlock_irq(&ctx->completion_lock);
+       io_cqring_ev_posted(ctx);
+
+       if (ret < 0)
+               req_set_fail_links(req);
+       io_put_req(req);
        return 0;
 }