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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 02065C282C3 for ; Tue, 22 Jan 2019 17:05:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C904C20866 for ; Tue, 22 Jan 2019 17:05:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729380AbfAVRFk (ORCPT ); Tue, 22 Jan 2019 12:05:40 -0500 Received: from mx2.suse.de ([195.135.220.15]:50112 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729316AbfAVRFk (ORCPT ); Tue, 22 Jan 2019 12:05:40 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 891ECABCB for ; Tue, 22 Jan 2019 17:05:39 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 713FADA84A; Tue, 22 Jan 2019 18:05:07 +0100 (CET) Date: Tue, 22 Jan 2019 18:05:07 +0100 From: David Sterba To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v4 6/7] btrfs: qgroup: Use delayed subtree rescan for balance Message-ID: <20190122170506.GP2900@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: <20190115081604.785-1-wqu@suse.com> <20190115081604.785-7-wqu@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190115081604.785-7-wqu@suse.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Jan 15, 2019 at 04:16:03PM +0800, Qu Wenruo wrote: > +int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, > + struct btrfs_root *root, > + struct extent_buffer *subv_eb) > +{ > + struct btrfs_fs_info *fs_info = root->fs_info; > + struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks; > + struct btrfs_qgroup_swapped_block *block; > + struct extent_buffer *reloc_eb = NULL; > + struct rb_node *n; Please don't use single letter variable here > + bool found = false; > + bool swapped = false; > + int level = btrfs_header_level(subv_eb); > + int ret = 0; > + int i; > + > + if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) > + return 0; > + if (!is_fstree(root->root_key.objectid) || !root->reloc_root) > + return 0; > + > + spin_lock(&blocks->lock); > + if (!blocks->swapped) { > + spin_unlock(&blocks->lock); > + goto out; I think you can return here directly, as this is a shortcut and there's no state that would need to be cleaned up (ret is still 0). > + } > + n = blocks->blocks[level].rb_node; > + > + while (n) { > + block = rb_entry(n, struct btrfs_qgroup_swapped_block, node); > + if (block->subv_bytenr < subv_eb->start) > + n = n->rb_left; > + else if (block->subv_bytenr > subv_eb->start) > + n = n->rb_right; > + else { > + found = true; > + break; > + } > + } > + if (!found) { > + spin_unlock(&blocks->lock); > + goto out; > + } > + /* Found one, remove it from @blocks first and update blocks->swapped */ > + rb_erase(&block->node, &blocks->blocks[level]); > + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { > + if (RB_EMPTY_ROOT(&blocks->blocks[i])) { > + swapped = true; > + break; > + } > + } > + blocks->swapped = swapped; > + spin_unlock(&blocks->lock); > + > + /* Read out reloc subtree root */ > + reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, > + block->reloc_generation, block->level, > + &block->first_key); > + if (IS_ERR(reloc_eb)) { > + ret = PTR_ERR(subv_eb); > + reloc_eb = NULL; > + goto free_out; > + } > + if (!extent_buffer_uptodate(reloc_eb)) { > + ret = -EIO; > + goto free_out; > + } > + > + ret = qgroup_trace_subtree_swap(trans, reloc_eb, subv_eb, > + block->last_snapshot, block->trace_leaf); > +free_out: > + kfree(block); > + free_extent_buffer(reloc_eb); > +out: > + if (ret < 0) { > + btrfs_err_rl(fs_info, > + "failed to account subtree at bytenr %llu: %d", > + subv_eb->start, ret); > + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; > + } > + return ret; > +}