From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE287C4338F for ; Mon, 26 Jul 2021 16:13:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAD5260240 for ; Mon, 26 Jul 2021 16:13:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233318AbhGZPcd (ORCPT ); Mon, 26 Jul 2021 11:32:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:43054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231687AbhGZP2I (ORCPT ); Mon, 26 Jul 2021 11:28:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9568560F93; Mon, 26 Jul 2021 16:07:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627315628; bh=ee601JuA1ThonTN8QLunCwZp1Yk/X4xbxu0WgNGSHYA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CMFgDeUA8J6i2axXSP+3idsIHL2BDC9YEMVMzOw9m/fQJIdZ3y8pdrLV28Tn0h9PA V9AOChYJe3a2DHeB+VtS+ZMt7K7BxOVBJztg+rR9BFfPISVkQNk4uI2RPJG6WB0yMz 3AHcwT44Q8ukZEYBPz5NybeduWOcDJOfoDi+FuXk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilya Dryomov , Robin Geuze Subject: [PATCH 5.10 150/167] rbd: always kick acquire on "acquired" and "released" notifications Date: Mon, 26 Jul 2021 17:39:43 +0200 Message-Id: <20210726153844.454372196@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153839.371771838@linuxfoundation.org> References: <20210726153839.371771838@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ilya Dryomov commit 8798d070d416d18a75770fc19787e96705073f43 upstream. Skipping the "lock has been released" notification if the lock owner is not what we expect based on owner_cid can lead to I/O hangs. One example is our own notifications: because owner_cid is cleared in rbd_unlock(), when we get our own notification it is processed as unexpected/duplicate and maybe_kick_acquire() isn't called. If a peer that requested the lock then doesn't go through with acquiring it, I/O requests that came in while the lock was being quiesced would be stalled until another I/O request is submitted and kicks acquire from rbd_img_exclusive_lock(). This makes the comment in rbd_release_lock() actually true: prior to this change the canceled work was being requeued in response to the "lock has been acquired" notification from rbd_handle_acquired_lock(). Cc: stable@vger.kernel.org # 5.3+ Signed-off-by: Ilya Dryomov Tested-by: Robin Geuze Signed-off-by: Greg Kroah-Hartman --- drivers/block/rbd.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4248,15 +4248,11 @@ static void rbd_handle_acquired_lock(str if (!rbd_cid_equal(&cid, &rbd_empty_cid)) { down_write(&rbd_dev->lock_rwsem); if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) { - /* - * we already know that the remote client is - * the owner - */ - up_write(&rbd_dev->lock_rwsem); - return; + dout("%s rbd_dev %p cid %llu-%llu == owner_cid\n", + __func__, rbd_dev, cid.gid, cid.handle); + } else { + rbd_set_owner_cid(rbd_dev, &cid); } - - rbd_set_owner_cid(rbd_dev, &cid); downgrade_write(&rbd_dev->lock_rwsem); } else { down_read(&rbd_dev->lock_rwsem); @@ -4281,14 +4277,12 @@ static void rbd_handle_released_lock(str if (!rbd_cid_equal(&cid, &rbd_empty_cid)) { down_write(&rbd_dev->lock_rwsem); if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) { - dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n", + dout("%s rbd_dev %p cid %llu-%llu != owner_cid %llu-%llu\n", __func__, rbd_dev, cid.gid, cid.handle, rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle); - up_write(&rbd_dev->lock_rwsem); - return; + } else { + rbd_set_owner_cid(rbd_dev, &rbd_empty_cid); } - - rbd_set_owner_cid(rbd_dev, &rbd_empty_cid); downgrade_write(&rbd_dev->lock_rwsem); } else { down_read(&rbd_dev->lock_rwsem);