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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 6EDC8C2BB85 for ; Thu, 16 Apr 2020 13:34:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47E41221F4 for ; Thu, 16 Apr 2020 13:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587044053; bh=XrouFqZS6mZ+Z8554TiJfY6X/+zSy01uAd4I+qet6vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IKYst92z62nDIdOVE0EYVjE+x4ahV0OoEMphn3HyS1h3leszg2R2AYD6Tt01kmHi9 0256aVz0uz3NhCbN/XmxUbUWC7hn29TnynmHTkaOa5orC7Kew1vBZ9JwZ++PFEFXkf gRnqacZvSBy5+ZK/MqSlhgYNoxLhks7SKnpSBnv0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2896893AbgDPNeK (ORCPT ); Thu, 16 Apr 2020 09:34:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:38462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2895914AbgDPN3C (ORCPT ); Thu, 16 Apr 2020 09:29:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6F67321D79; Thu, 16 Apr 2020 13:29:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587043741; bh=XrouFqZS6mZ+Z8554TiJfY6X/+zSy01uAd4I+qet6vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zB4u2PmioXpQcsoC8/Ofd2RuBnk9J5dnBOo3zE5eDvYRmGKqO2OFCdlap/aLRjQCw a9omi05d6j8rmiRIBfM5fyONWgnrm4epple8FvqFj+zUwAC9nvbNs94GyuUoTl5NUV A+MvgP4GFh5IT4cQZcUlPRNXv4WE40aZdA1VuR28= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , David Sterba , Sasha Levin Subject: [PATCH 4.19 040/146] btrfs: track reloc roots based on their commit root bytenr Date: Thu, 16 Apr 2020 15:23:01 +0200 Message-Id: <20200416131248.037531160@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131242.353444678@linuxfoundation.org> References: <20200416131242.353444678@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josef Bacik [ Upstream commit ea287ab157c2816bf12aad4cece41372f9d146b4 ] We always search the commit root of the extent tree for looking up back references, however we track the reloc roots based on their current bytenr. This is wrong, if we commit the transaction between relocating tree blocks we could end up in this code in build_backref_tree if (key.objectid == key.offset) { /* * Only root blocks of reloc trees use backref * pointing to itself. */ root = find_reloc_root(rc, cur->bytenr); ASSERT(root); cur->root = root; break; } find_reloc_root() is looking based on the bytenr we had in the commit root, but if we've COWed this reloc root we will not find that bytenr, and we will trip over the ASSERT(root). Fix this by using the commit_root->start bytenr for indexing the commit root. Then we change the __update_reloc_root() caller to be used when we switch the commit root for the reloc root during commit. This fixes the panic I was seeing when we started throttling relocation for delayed refs. Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/relocation.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 6f4cb2db3b1a0..a7f9aa5f05aa5 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1253,7 +1253,7 @@ static int __must_check __add_reloc_root(struct btrfs_root *root) if (!node) return -ENOMEM; - node->bytenr = root->node->start; + node->bytenr = root->commit_root->start; node->data = root; spin_lock(&rc->reloc_root_tree.lock); @@ -1284,10 +1284,11 @@ static void __del_reloc_root(struct btrfs_root *root) if (rc && root->node) { spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_search(&rc->reloc_root_tree.rb_root, - root->node->start); + root->commit_root->start); if (rb_node) { node = rb_entry(rb_node, struct mapping_node, rb_node); rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); + RB_CLEAR_NODE(&node->rb_node); } spin_unlock(&rc->reloc_root_tree.lock); if (!node) @@ -1305,7 +1306,7 @@ static void __del_reloc_root(struct btrfs_root *root) * helper to update the 'address of tree root -> reloc tree' * mapping */ -static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr) +static int __update_reloc_root(struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; struct rb_node *rb_node; @@ -1314,7 +1315,7 @@ static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr) spin_lock(&rc->reloc_root_tree.lock); rb_node = tree_search(&rc->reloc_root_tree.rb_root, - root->node->start); + root->commit_root->start); if (rb_node) { node = rb_entry(rb_node, struct mapping_node, rb_node); rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); @@ -1326,7 +1327,7 @@ static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr) BUG_ON((struct btrfs_root *)node->data != root); spin_lock(&rc->reloc_root_tree.lock); - node->bytenr = new_bytenr; + node->bytenr = root->node->start; rb_node = tree_insert(&rc->reloc_root_tree.rb_root, node->bytenr, &node->rb_node); spin_unlock(&rc->reloc_root_tree.lock); @@ -1471,6 +1472,7 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, } if (reloc_root->commit_root != reloc_root->node) { + __update_reloc_root(reloc_root); btrfs_set_root_node(root_item, reloc_root->node); free_extent_buffer(reloc_root->commit_root); reloc_root->commit_root = btrfs_root_node(reloc_root); @@ -4599,11 +4601,6 @@ int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, BUG_ON(rc->stage == UPDATE_DATA_PTRS && root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); - if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { - if (buf == root->node) - __update_reloc_root(root, cow->start); - } - level = btrfs_header_level(buf); if (btrfs_header_generation(buf) <= btrfs_root_last_snapshot(&root->root_item)) -- 2.20.1