From b711d4eaf0c408a811311ee3e94d6e9e5a230a9a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 16 Aug 2020 08:23:05 -0700 Subject: [PATCH] io_uring: find and cancel head link async work on files exit Commit f254ac04c874 ("io_uring: enable lookup of links holding inflight files") only handled 2 out of the three head link cases we have, we also need to lookup and cancel work that is blocked in io-wq if that work has a link that's holding a reference to the files structure. Put the "cancel head links that hold this request pending" logic into io_attempt_cancel(), which will to through the motions of finding and canceling head links that hold the current inflight files stable request pending. Cc: stable@vger.kernel.org Reported-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index dc506b75659c..346a3eb84785 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8063,6 +8063,33 @@ static bool io_timeout_remove_link(struct io_ring_ctx *ctx, return found; } +static bool io_cancel_link_cb(struct io_wq_work *work, void *data) +{ + return io_match_link(container_of(work, struct io_kiocb, work), data); +} + +static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req) +{ + enum io_wq_cancel cret; + + /* cancel this particular work, if it's running */ + cret = io_wq_cancel_work(ctx->io_wq, &req->work); + if (cret != IO_WQ_CANCEL_NOTFOUND) + return; + + /* find links that hold this pending, cancel those */ + cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_link_cb, req, true); + if (cret != IO_WQ_CANCEL_NOTFOUND) + return; + + /* if we have a poll link holding this pending, cancel that */ + if (io_poll_remove_link(ctx, req)) + return; + + /* final option, timeout link is holding this req pending */ + io_timeout_remove_link(ctx, req); +} + static void io_uring_cancel_files(struct io_ring_ctx *ctx, struct files_struct *files) { @@ -8116,10 +8143,8 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, continue; } } else { - io_wq_cancel_work(ctx->io_wq, &cancel_req->work); - /* could be a link, check and remove if it is */ - if (!io_poll_remove_link(ctx, cancel_req)) - io_timeout_remove_link(ctx, cancel_req); + /* cancel this request, or head link requests */ + io_attempt_cancel(ctx, cancel_req); io_put_req(cancel_req); } -- 2.20.1