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 AF5A0C2BB85 for ; Fri, 10 Apr 2020 03:51:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87873206C0 for ; Fri, 10 Apr 2020 03:51:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490707; bh=ZfU77++yMcL770c3ZrBqDkny1zBJBG8/lLNTflP8DkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ru/Q5UVHy9otOoiXrydHxptYVZ162LjdbOAMqNdwYRzl9B1GDIEbxbiDXjZckL70T 79MU4vPrzzt9IBYjygvUEK4bvnACloIwQI7Afx80sb4HTYKt9YdaejiXUa6LIq9ubN wuHr8X8iJ63SDjYU+1/rog2QZjzULzJoKRjFRzOQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728476AbgDJDvp (ORCPT ); Thu, 9 Apr 2020 23:51:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:36864 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726819AbgDJDvb (ORCPT ); Thu, 9 Apr 2020 23:51:31 -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 76E7421556; Fri, 10 Apr 2020 03:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586490691; bh=ZfU77++yMcL770c3ZrBqDkny1zBJBG8/lLNTflP8DkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wGED3q+ftYwhcTWXD27P24x0K6Y5o09d2f1R34CKTQuKW0MIyF+uaJ2/PvqKjyHve Er0L1o6e3JgM/M9CFNpI6cw2Q1AWqTmv1EkeDsXfExTbeuwKp9VhvTUvP30p91jOTA HNn6Zw/Lg+6LFUC+MIENppoC7CyD5q3zVBqc2DYk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josef Bacik , David Sterba , Sasha Levin , linux-btrfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.4 8/8] btrfs: track reloc roots based on their commit root bytenr Date: Thu, 9 Apr 2020 23:51:21 -0400 Message-Id: <20200410035122.10065-8-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200410035122.10065-1-sashal@kernel.org> References: <20200410035122.10065-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@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 246754b31619e..df04309390bba 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1289,7 +1289,7 @@ 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); @@ -1321,10 +1321,11 @@ 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) @@ -1342,7 +1343,7 @@ 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 rb_node *rb_node; struct mapping_node *node = NULL; @@ -1350,7 +1351,7 @@ 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); @@ -1362,7 +1363,7 @@ 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); @@ -1503,6 +1504,7 @@ 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); @@ -4578,11 +4580,6 @@ 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