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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 E4EACC3A5A5 for ; Tue, 3 Sep 2019 16:36:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA1522339D for ; Tue, 3 Sep 2019 16:36:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528587; bh=tllepvZJRZs1qOdtJ/BX20/5Z2C4FVcCNaCrspFb104=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ILsRD/1c1cSdjCeUo73xUhEaP8pvxnypfWRMBZFHup6FnaPAssNK/DPkphSDrojKL rhKfOLwtSrg6gpntYcxpEEK7HqLwv8U1+DLGFwfdVCdAP4nUwusKfQOXItT6osxllm hF4XaEE6baDhYMV9tCRWIxbMj0j1Bh22mhsARcxY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730894AbfICQg0 (ORCPT ); Tue, 3 Sep 2019 12:36:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:48550 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730806AbfICQ1P (ORCPT ); Tue, 3 Sep 2019 12:27:15 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 78B4D23431; Tue, 3 Sep 2019 16:27:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528034; bh=tllepvZJRZs1qOdtJ/BX20/5Z2C4FVcCNaCrspFb104=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GKX07FTHVmat85oEe467HVJnSncOIrTJ2AV7LknDVQVIL7b2C6BdFbDFGeT0zO3dB RUtxAlPvi1rbIfEKSd9zRZrAq5vdYRJVK2mKdMhcHL/klInkJt4zlAdGtLvcjqQSdR umloiqBvEGOrPVzOQKEZdWdmA7xG5vYL0XlLplJg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tang Junhui , Coly Li , Jens Axboe , Sasha Levin , linux-bcache@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 064/167] bcache: treat stale && dirty keys as bad keys Date: Tue, 3 Sep 2019 12:23:36 -0400 Message-Id: <20190903162519.7136-64-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903162519.7136-1-sashal@kernel.org> References: <20190903162519.7136-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tang Junhui [ Upstream commit 58ac323084ebf44f8470eeb8b82660f9d0ee3689 ] Stale && dirty keys can be produced in the follow way: After writeback in write_dirty_finish(), dirty keys k1 will replace by clean keys k2 ==>ret = bch_btree_insert(dc->disk.c, &keys, NULL, &w->key); ==>btree_insert_fn(struct btree_op *b_op, struct btree *b) ==>static int bch_btree_insert_node(struct btree *b, struct btree_op *op, struct keylist *insert_keys, atomic_t *journal_ref, Then two steps: A) update k1 to k2 in btree node memory; bch_btree_insert_keys(b, op, insert_keys, replace_key) B) Write the bset(contains k2) to cache disk by a 30s delay work bch_btree_leaf_dirty(b, journal_ref). But before the 30s delay work write the bset to cache device, these things happened: A) GC works, and reclaim the bucket k2 point to; B) Allocator works, and invalidate the bucket k2 point to, and increase the gen of the bucket, and place it into free_inc fifo; C) Until now, the 30s delay work still does not finish work, so in the disk, the key still is k1, it is dirty and stale (its gen is smaller than the gen of the bucket). and then the machine power off suddenly happens; D) When the machine power on again, after the btree reconstruction, the stale dirty key appear. In bch_extent_bad(), when expensive_debug_checks is off, it would treat the dirty key as good even it is stale keys, and it would cause bellow probelms: A) In read_dirty() it would cause machine crash: BUG_ON(ptr_stale(dc->disk.c, &w->key, 0)); B) It could be worse when reads hits stale dirty keys, it would read old incorrect data. This patch tolerate the existence of these stale && dirty keys, and treat them as bad key in bch_extent_bad(). (Coly Li: fix indent which was modified by sender's email client) Signed-off-by: Tang Junhui Cc: stable@vger.kernel.org Signed-off-by: Coly Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/md/bcache/extents.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/md/bcache/extents.c b/drivers/md/bcache/extents.c index 9560043666999..886710043025f 100644 --- a/drivers/md/bcache/extents.c +++ b/drivers/md/bcache/extents.c @@ -538,6 +538,7 @@ static bool bch_extent_bad(struct btree_keys *bk, const struct bkey *k) { struct btree *b = container_of(bk, struct btree, keys); unsigned int i, stale; + char buf[80]; if (!KEY_PTRS(k) || bch_extent_invalid(bk, k)) @@ -547,19 +548,19 @@ static bool bch_extent_bad(struct btree_keys *bk, const struct bkey *k) if (!ptr_available(b->c, k, i)) return true; - if (!expensive_debug_checks(b->c) && KEY_DIRTY(k)) - return false; - for (i = 0; i < KEY_PTRS(k); i++) { stale = ptr_stale(b->c, k, i); + if (stale && KEY_DIRTY(k)) { + bch_extent_to_text(buf, sizeof(buf), k); + pr_info("stale dirty pointer, stale %u, key: %s", + stale, buf); + } + btree_bug_on(stale > BUCKET_GC_GEN_MAX, b, "key too stale: %i, need_gc %u", stale, b->c->need_gc); - btree_bug_on(stale && KEY_DIRTY(k) && KEY_SIZE(k), - b, "stale dirty pointer"); - if (stale) return true; -- 2.20.1