From patchwork Thu Apr 16 13:22:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 227710 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 70AB7C2BB55 for ; Thu, 16 Apr 2020 15:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4742620771 for ; Thu, 16 Apr 2020 15:00:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587049212; bh=KaRnqimdJK2+YakApchmRvSrJLlaObdWFeRaxC/MGBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=n/Bjn6eFcZ7vjisZJt/Qt4d7j5mxhEMih8+KdiMkoon1ylJ3In602asRtsBq/yih9 pSC3amYmtqpWm6Oej4TNK1gNB+c3BKmxRxri9HR76bGCsx3HFbtbrD3xiRdS4S81FK H9ezoY4qtZ8pELcQE0ABM+uKlmRsv1aUg7cwYKQE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394868AbgDPO7y (ORCPT ); Thu, 16 Apr 2020 10:59:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:41044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2898839AbgDPNy2 (ORCPT ); Thu, 16 Apr 2020 09:54:28 -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 C281F2076D; Thu, 16 Apr 2020 13:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587045266; bh=KaRnqimdJK2+YakApchmRvSrJLlaObdWFeRaxC/MGBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WFamU6cbRBTvZdRZijjpJ9F676j387PqAa2QB3Mfg1/1ViW9v3Ps4fVLaU42rjaUI d0XDC+VfUiFN73kIO4qj3qRqxfN4M1xy5Koj8Inf8e81eRcS+umsc60Lurg/ZZg+2t oTUNXK5ZLhuykjbGj9H0RfOmrlNiDdVXDbB4GMIc= 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 5.6 065/254] btrfs: track reloc roots based on their commit root bytenr Date: Thu, 16 Apr 2020 15:22:34 +0200 Message-Id: <20200416131334.029587084@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.804095985@linuxfoundation.org> References: <20200416131325.804095985@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 d7e8839048d71..8e86934a17c35 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1298,7 +1298,7 @@ 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); @@ -1329,10 +1329,11 @@ 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) @@ -1350,7 +1351,7 @@ 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; @@ -1359,7 +1360,7 @@ 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); @@ -1371,7 +1372,7 @@ 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); @@ -1529,6 +1530,7 @@ 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); @@ -4727,11 +4729,6 @@ 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))