From patchwork Thu Dec 23 17:31:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12698555 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81D52C43219 for ; Thu, 23 Dec 2021 17:32:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244504AbhLWRcl (ORCPT ); Thu, 23 Dec 2021 12:32:41 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:54106 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244497AbhLWRcM (ORCPT ); Thu, 23 Dec 2021 12:32:12 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 621D4212C9; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QikYsI6tpiNvzhNII6O3hXNc22etDJ2ItyVUZR1gNys=; b=VT2ad/UjT099XlZF7zdYcybzukePJyF82QKcc2G292wOf+R8GkLm4htdTE6sRL0upXCBCm z64v4apnvlva9MRKU2Mv4eF0yQRb2ewfYn/6uvdNQvmeBS4VzHvRHhrOWT8GwdtDBnq3x8 I9OtatcBLWPpXzQn7if3G1lS1xt5JSw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QikYsI6tpiNvzhNII6O3hXNc22etDJ2ItyVUZR1gNys=; b=P5Sdi6RAEvl7zB9dQ6P6rQnPW3dtULdbTKLRqXcYsAA8gQYfDfaUfYEAkKCO3o77EOr/Fx it9cKo3fvTr1mLAg== Received: from quack2.suse.cz (unknown [10.163.28.18]) by relay2.suse.de (Postfix) with ESMTP id 518F5A3B8A; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 1D0071E0BCE; Thu, 23 Dec 2021 18:32:07 +0100 (CET) From: Jan Kara To: Cc: Jens Axboe , Paolo Valente , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 1/3] bfq: Avoid false marking of bic as stably merged Date: Thu, 23 Dec 2021 18:31:57 +0100 Message-Id: <20211223173207.15388-1-jack@suse.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20211223171425.3551-1-jack@suse.cz> References: <20211223171425.3551-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1119; h=from:subject; bh=s24YJhUV9PaVoF9XPonZ2DcL0PhzkDxy7int8Fo9bZ4=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBhxLKMrd3RDSYuLwevckUk1a2v9JbPj8JDz8xuizgR myDeYaeJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYcSyjAAKCRCcnaoHP2RA2Q45CA CnCKu3QEkRrX4zqwVBpVO7DE+XOqRv8ux5g3cLi2FRf5Heb6XRxdXjQpe0D1NQdgqCsb70rLiFJrgT HW38RIcUAo5A6qQJooZQbA7EconXhpCCXyYg+c+4UCp+7LlyRn739HHvkY0iP5gP5F2UIBd9B9s2tl L1GPEgz0ALzcP6rsW6Na4kVt4nqkDIFkmji2ZzWnYgnx3XSRRY/71N+KU/VA838Rl1CFcDBLvzkEUr Bb0b+0+j+TyF34e99qmnt/wTHs2xtaoI6jEDC+uWmhc5sfExmDvMtspVmGhjzsVbS0LXQXqO6TcyUg 23FwtDPWVl1b/F+gamoN2lcfPyZm11 X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org bfq_setup_cooperator() can mark bic as stably merged even though it decides to not merge its bfqqs (when bfq_setup_merge() returns NULL). Make sure to mark bic as stably merged only if we are really going to merge bfqqs. CC: stable@vger.kernel.org Fixes: 430a67f9d616 ("block, bfq: merge bursts of newly-created queues") Signed-off-by: Jan Kara --- block/bfq-iosched.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index fec18118dc30..056399185c2f 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2762,9 +2762,12 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, struct bfq_queue *new_bfqq = bfq_setup_merge(bfqq, stable_merge_bfqq); - bic->stably_merged = true; - if (new_bfqq && new_bfqq->bic) - new_bfqq->bic->stably_merged = true; + if (new_bfqq) { + bic->stably_merged = true; + if (new_bfqq->bic) + new_bfqq->bic->stably_merged = + true; + } return new_bfqq; } else return NULL; From patchwork Thu Dec 23 17:31:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12698556 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FAD3C43217 for ; Thu, 23 Dec 2021 17:32:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244516AbhLWRcm (ORCPT ); Thu, 23 Dec 2021 12:32:42 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:54102 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244572AbhLWRcM (ORCPT ); Thu, 23 Dec 2021 12:32:12 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 623A1212CB; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C9in//R3DjnsjNPtsLfO1o0yJgaA0KfNls+oEZb8Nno=; b=wrCbIbuGIF/kGiXuZGMk6tGp+LWmNMg9V0+L+64VVS1p8rEVZQtwWPK82E3sQZp8tuzzy0 HHzmobteFYSUENzenZZ1OP0ywDn40KYSszCUH+kpe6EwUZVBsPewLMaKfvgQ1BeJHaCvJA ZLNqS/cfXzdC0iIgSeM1LtMA/rpUQmc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C9in//R3DjnsjNPtsLfO1o0yJgaA0KfNls+oEZb8Nno=; b=2TzP+zhVdt5Wlj3HS0HCnZ7F+p0lrmNfceZqm06cUvqYIzSZYdAa4qC36jFe45JijodLmj s1hVEx4widRSdfAQ== Received: from quack2.suse.cz (unknown [10.163.28.18]) by relay2.suse.de (Postfix) with ESMTP id 4AC57A3B84; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 2071D1F2B67; Thu, 23 Dec 2021 18:32:07 +0100 (CET) From: Jan Kara To: Cc: Jens Axboe , Paolo Valente , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 2/3] bfq: Avoid merging queues with different parents Date: Thu, 23 Dec 2021 18:31:58 +0100 Message-Id: <20211223173207.15388-2-jack@suse.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20211223171425.3551-1-jack@suse.cz> References: <20211223171425.3551-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2888; h=from:subject; bh=eGFgvBuuWOZ2reRV/MITzLHWA54wvIhnC2e5QiNO6Zg=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBhxLKNPk8nGYgSAqacDszgFhj2RuxwmU0kB25ebv0u 9l77m/+JATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYcSyjQAKCRCcnaoHP2RA2X3fB/ 4n4AJupAqDjkbcZJWyU5twKTTh0Qfdg0ECm9/kBx7BKDS8GrVIkabWx2jNrX5qvmIUtvUMrJ9moTCu cYXUYY9pZ+Z2gWwvSpeGOZbJmX69agg01qV2vVTFtU1fC4jheX+xh1yfS9AXNb3//0wTn3f2krhM1P w/lh/lMFv2btYVg+qyUc3nKWTfxu3qdZs/EO1Yho6s18TdyGV/fTdQMDHGoz0FOZFsQuPpQbcLaH7o 2xkZKxVnrmh03OgBJpQ6kXFW+SoXnCycfetCLxHpJXysRtlq4gTYEIZfsMV4Ualn6nNUxqqHFvHsVt 4SDtZeURd0u+hDOBnSn5ISI9Zm7vhg X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org It can happen that the parent of a bfqq changes between the moment we decide two queues are worth to merge (and set bic->stable_merge_bfqq) and the moment bfq_setup_merge() is called. This can happen e.g. because the process submitted IO for a different cgroup and thus bfqq got reparented. It can even happen that the bfqq we are merging with has parent cgroup that is already offline and going to be destroyed in which case the merge can lead to use-after-free issues such as: BUG: KASAN: use-after-free in __bfq_deactivate_entity+0x9cb/0xa50 Read of size 8 at addr ffff88800693c0c0 by task runc:[2:INIT]/10544 CPU: 0 PID: 10544 Comm: runc:[2:INIT] Tainted: G E 5.15.2-0.g5fb85fd-default #1 openSUSE Tumbleweed (unreleased) f1f3b891c72369aebecd2e43e4641a6358867c70 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014 Call Trace: dump_stack_lvl+0x46/0x5a print_address_description.constprop.0+0x1f/0x140 ? __bfq_deactivate_entity+0x9cb/0xa50 kasan_report.cold+0x7f/0x11b ? __bfq_deactivate_entity+0x9cb/0xa50 __bfq_deactivate_entity+0x9cb/0xa50 ? update_curr+0x32f/0x5d0 bfq_deactivate_entity+0xa0/0x1d0 bfq_del_bfqq_busy+0x28a/0x420 ? resched_curr+0x116/0x1d0 ? bfq_requeue_bfqq+0x70/0x70 ? check_preempt_wakeup+0x52b/0xbc0 __bfq_bfqq_expire+0x1a2/0x270 bfq_bfqq_expire+0xd16/0x2160 ? try_to_wake_up+0x4ee/0x1260 ? bfq_end_wr_async_queues+0xe0/0xe0 ? _raw_write_unlock_bh+0x60/0x60 ? _raw_spin_lock_irq+0x81/0xe0 bfq_idle_slice_timer+0x109/0x280 ? bfq_dispatch_request+0x4870/0x4870 __hrtimer_run_queues+0x37d/0x700 ? enqueue_hrtimer+0x1b0/0x1b0 ? kvm_clock_get_cycles+0xd/0x10 ? ktime_get_update_offsets_now+0x6f/0x280 hrtimer_interrupt+0x2c8/0x740 Fix the problem by checking that the parent of the two bfqqs we are merging in bfq_setup_merge() is the same. Link: https://lore.kernel.org/linux-block/20211125172809.GC19572@quack2.suse.cz/ CC: stable@vger.kernel.org Fixes: 430a67f9d616 ("block, bfq: merge bursts of newly-created queues") Signed-off-by: Jan Kara --- block/bfq-iosched.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 056399185c2f..0da47f2ca781 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2638,6 +2638,14 @@ bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) if (process_refs == 0 || new_process_refs == 0) return NULL; + /* + * Make sure merged queues belong to the same parent. Parents could + * have changed since the time we decided the two queues are suitable + * for merging. + */ + if (new_bfqq->entity.parent != bfqq->entity.parent) + return NULL; + bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d", new_bfqq->pid); From patchwork Thu Dec 23 17:31:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 12698557 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FE2FC433F5 for ; Thu, 23 Dec 2021 17:32:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235248AbhLWRcn (ORCPT ); Thu, 23 Dec 2021 12:32:43 -0500 Received: from smtp-out2.suse.de ([195.135.220.29]:58400 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349656AbhLWRcM (ORCPT ); Thu, 23 Dec 2021 12:32:12 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 629591F387; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CLdWcUxslRhox4mbm09PAaOqxikabSZEH3WG0zJ7e6A=; b=rCWy6ph0y8Qy20nsINIYj4FMVg60gb7b9Xp2KdO2he3LzKbZ8D9LatSmmQstfasCiUSKxe zLRz4s75Fo4Wy5TK14YoFdwtjsMAa7BbKn96Vf7iy60AQQ35Ddch9s88sdYSrdfrXeutdc 7pKQWW9Q5+/P3Nk7KcDFhAHirao9/TY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1640280730; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CLdWcUxslRhox4mbm09PAaOqxikabSZEH3WG0zJ7e6A=; b=D9r75/tervm3m0BWnq9artqnfHn/PB/iEmViJqWGR+1pEDlSfTUXax/u8eKDGmlPfvW+LH VO1nhTdFl4H/qTCw== Received: from quack2.suse.cz (unknown [10.163.28.18]) by relay2.suse.de (Postfix) with ESMTP id 4EA69A3B89; Thu, 23 Dec 2021 17:32:10 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 244661F2BB6; Thu, 23 Dec 2021 18:32:07 +0100 (CET) From: Jan Kara To: Cc: Jens Axboe , Paolo Valente , "yukuai (C)" , Jan Kara , stable@vger.kernel.org Subject: [PATCH 3/3] bfq: Split shared queues on move between cgroups Date: Thu, 23 Dec 2021 18:31:59 +0100 Message-Id: <20211223173207.15388-3-jack@suse.cz> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20211223171425.3551-1-jack@suse.cz> References: <20211223171425.3551-1-jack@suse.cz> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1386; h=from:subject; bh=TGBjtt0Grb1Fs/1iAI39LWcQyjfnAr/HP/ZQxo/mPQw=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBhxLKOGMtYejmo8KCKQGoP/YL7qSr3m0V8J4bziX39 GJO/H3OJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYcSyjgAKCRCcnaoHP2RA2eDCB/ 0dFwPJoP3LEhfO7/cT2HwG6W0Spt/GeFpDckwZfCli+CxFVVgqZOrj23KW8mKb+/ORT81+6PGZ8Zjt jBBfl/qDjj+BGlQOVj1AZhzh+N8ZwRFzUhrBf3X5i1X/Wb1i8trx9fetuqO/sSNAo5KpPgA15fBqO9 UOJNL7/je/e0cf3JdhvosD9TM7m6dvzyiono4K/kEHib3gXrz93J9sCsUv3GHt9bIrsZE5kT8+TLEq FUDkvYpbRUiqWau4OWstVNd9AEBQk8vM5L+SVKtvpf89DLMDm4LFz0jEUc6gjKJjobitGHQQpH1hC3 g1qyuRM9SE2qr4HQiSx3fw4A8+Nkf9 X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When bfqq is shared by multiple processes it can happen that one of the processes gets moved to a different cgroup (or just starts submitting IO for different cgroup). In case that happens we need to split the merged bfqq as otherwise we will have IO for multiple cgroups in one bfqq and we will just account IO time to wrong entities etc. CC: stable@vger.kernel.org Fixes: e21b7a0b9887 ("block, bfq: add full hierarchical scheduling and cgroups support") Signed-off-by: Jan Kara --- block/bfq-cgroup.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 24a5c5329bcd..1f5fb723bed7 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -730,8 +730,18 @@ static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd, if (sync_bfqq) { entity = &sync_bfqq->entity; - if (entity->sched_data != &bfqg->sched_data) + if (entity->sched_data != &bfqg->sched_data) { + /* + * Moving bfqq that is shared with another process? + * Split the queues at the nearest occasion as the + * processes can be in different cgroups now. + */ + if (bfq_bfqq_coop(sync_bfqq)) { + bic->stably_merged = false; + bfq_mark_bfqq_split_coop(sync_bfqq); + } bfq_bfqq_move(bfqd, sync_bfqq, bfqg); + } } return bfqg;