This is a note to let you know that I've just added the patch titled io_uring: refactor poll update to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-refactor-poll-update.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Sep 1 11:59:31 AM CEST 2022 From: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Mon, 29 Aug 2022 14:30:14 +0100 Subject: io_uring: refactor poll update To: stable@xxxxxxxxxxxxxxx Cc: Jens Axboe <axboe@xxxxxxxxx>, asml.silence@xxxxxxxxx Message-ID: <decb6e4ea41a43485fcdd1853cca4af0bd3ed526.1661594698.git.asml.silence@xxxxxxxxx> From: Pavel Begunkov <asml.silence@xxxxxxxxx> [ upstream commmit 2bbb146d96f4b45e17d6aeede300796bc1a96d68 ] Clean up io_poll_update() and unify cancellation paths for remove and update. Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Link: https://lore.kernel.org/r/5937138b6265a1285220e2fab1b28132c1d73ce3.1639605189.git.asml.silence@xxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> [pavel: backport] Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 62 ++++++++++++++++++++++++---------------------------------- 1 file changed, 26 insertions(+), 36 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5931,61 +5931,51 @@ static int io_poll_update(struct io_kioc struct io_ring_ctx *ctx = req->ctx; struct io_kiocb *preq; bool completing; - int ret; + int ret2, ret = 0; spin_lock(&ctx->completion_lock); preq = io_poll_find(ctx, req->poll_update.old_user_data, true); if (!preq) { ret = -ENOENT; - goto err; - } - - if (!req->poll_update.update_events && !req->poll_update.update_user_data) { - completing = true; - ret = io_poll_remove_one(preq) ? 0 : -EALREADY; - goto err; +fail: + spin_unlock(&ctx->completion_lock); + goto out; } - + io_poll_remove_double(preq); /* * Don't allow racy completion with singleshot, as we cannot safely * update those. For multishot, if we're racing with completion, just * let completion re-add it. */ - io_poll_remove_double(preq); completing = !__io_poll_remove_one(preq, &preq->poll, false); if (completing && (preq->poll.events & EPOLLONESHOT)) { ret = -EALREADY; - goto err; - } - /* we now have a detached poll request. reissue. */ - ret = 0; -err: - if (ret < 0) { - spin_unlock(&ctx->completion_lock); - req_set_fail(req); - io_req_complete(req, ret); - return 0; - } - /* only mask one event flags, keep behavior flags */ - if (req->poll_update.update_events) { - preq->poll.events &= ~0xffff; - preq->poll.events |= req->poll_update.events & 0xffff; - preq->poll.events |= IO_POLL_UNMASK; + goto fail; } - if (req->poll_update.update_user_data) - preq->user_data = req->poll_update.new_user_data; spin_unlock(&ctx->completion_lock); + if (req->poll_update.update_events || req->poll_update.update_user_data) { + /* only mask one event flags, keep behavior flags */ + if (req->poll_update.update_events) { + preq->poll.events &= ~0xffff; + preq->poll.events |= req->poll_update.events & 0xffff; + preq->poll.events |= IO_POLL_UNMASK; + } + if (req->poll_update.update_user_data) + preq->user_data = req->poll_update.new_user_data; + + ret2 = io_poll_add(preq, issue_flags); + /* successfully updated, don't complete poll request */ + if (!ret2) + goto out; + } + req_set_fail(preq); + io_req_complete(preq, -ECANCELED); +out: + if (ret < 0) + req_set_fail(req); /* complete update request, we're done with it */ io_req_complete(req, ret); - - if (!completing) { - ret = io_poll_add(preq, issue_flags); - if (ret < 0) { - req_set_fail(preq); - io_req_complete(preq, ret); - } - } return 0; } Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are queue-5.15/io_uring-fix-wrong-arm_poll-error-handling.patch queue-5.15/io_uring-poll-rework.patch queue-5.15/io_uring-remove-unused-function-req_ref_put.patch queue-5.15/io_uring-fail-links-when-poll-fails.patch queue-5.15/io_uring-inline-io_poll_complete.patch queue-5.15/io_uring-bump-poll-refs-to-full-31-bits.patch queue-5.15/io_uring-clean-cqe-filling-functions.patch queue-5.15/io_uring-fix-uaf-due-to-missing-pollfree-handling.patch queue-5.15/io_uring-correct-fill-events-helpers-types.patch queue-5.15/io_uring-refactor-poll-update.patch queue-5.15/io_uring-kill-poll-linking-optimisation.patch queue-5.15/io_uring-remove-poll-entry-from-list-when-canceling-all.patch queue-5.15/io_uring-move-common-poll-bits.patch