From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:1370 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755708Ab3DWMA7 (ORCPT ); Tue, 23 Apr 2013 08:00:59 -0400 Message-ID: <5176791D.9030209@cn.fujitsu.com> Date: Tue, 23 Apr 2013 20:05:49 +0800 From: Wang Shilong MIME-Version: 1.0 To: Jan Schmidt CC: chris.mason@fusionio.com, linux-btrfs@vger.kernel.org, wangshilong1991@gmail.com, dsterba@suse.cz Subject: Re: [PATCH v3 2/3] Btrfs: rescan for qgroups References: <1366716411-9750-1-git-send-email-list.btrfs@jan-o-sch.net> <1366716411-9750-3-git-send-email-list.btrfs@jan-o-sch.net> In-Reply-To: <1366716411-9750-3-git-send-email-list.btrfs@jan-o-sch.net> Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hello Jan, [..snip..] > /* > * the delayed ref sequence number we pass depends on the direction of > * the operation. for add operations, we pass (node->seq - 1) to skip > @@ -1401,7 +1428,17 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, > if (ret < 0) > return ret; > > + mutex_lock(&fs_info->qgroup_rescan_lock); > spin_lock(&fs_info->qgroup_lock); > + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { > + if (fs_info->qgroup_rescan_progress.objectid <= node->bytenr) { > + ret = 0; > + mutex_unlock(&fs_info->qgroup_rescan_lock); > + goto unlock; > + } > + } > + mutex_unlock(&fs_info->qgroup_rescan_lock); > + > quota_root = fs_info->quota_root; > if (!quota_root) > goto unlock; > @@ -1820,3 +1857,250 @@ void assert_qgroups_uptodate(struct btrfs_trans_handle *trans) > trans->delayed_ref_elem.seq); > BUG(); > } > + > +/* > + * returns < 0 on error, 0 when more leafs are to be scanned. > + * returns 1 when done, 2 when done and FLAG_INCONSISTENT was cleared. > + */ > +static int > +qgroup_rescan_leaf(struct qgroup_rescan *qscan, struct btrfs_path *path, > + struct btrfs_trans_handle *trans, struct ulist *tmp, > + struct extent_buffer *scratch_leaf) > +{ > + struct btrfs_key found; > + struct btrfs_fs_info *fs_info = qscan->fs_info; > + struct ulist *roots = NULL; > + struct ulist_node *unode; > + struct ulist_iterator uiter; > + struct seq_list tree_mod_seq_elem = {}; > + u64 seq; > + int slot; > + int ret; > + > + path->leave_spinning = 1; > + mutex_lock(&fs_info->qgroup_rescan_lock); > + ret = btrfs_search_slot_for_read(fs_info->extent_root, > + &fs_info->qgroup_rescan_progress, > + path, 1, 0); > + > + pr_debug("current progress key (%llu %u %llu), search_slot ret %d\n", > + (unsigned long long)fs_info->qgroup_rescan_progress.objectid, > + fs_info->qgroup_rescan_progress.type, > + (unsigned long long)fs_info->qgroup_rescan_progress.offset, > + ret); > + > + if (ret) { > + /* > + * The rescan is about to end, we will not be scanning any > + * further blocks. We cannot unset the RESCAN flag here, because > + * we want to commit the transaction if everything went well. > + * To make the live accounting work in this phase, we set our > + * scan progress pointer such that every real extent objectid > + * will be smaller. > + */ > + fs_info->qgroup_rescan_progress.objectid = (u64)-1; > + btrfs_release_path(path); > + mutex_unlock(&fs_info->qgroup_rescan_lock); > + return ret; > + } > + > + btrfs_item_key_to_cpu(path->nodes[0], &found, > + btrfs_header_nritems(path->nodes[0]) - 1); > + fs_info->qgroup_rescan_progress.objectid = found.objectid + 1; > + > + btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem); > + memcpy(scratch_leaf, path->nodes[0], sizeof(*scratch_leaf)); > + slot = path->slots[0]; > + btrfs_release_path(path); > + mutex_unlock(&fs_info->qgroup_rescan_lock); > + > + for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) { > + btrfs_item_key_to_cpu(scratch_leaf, &found, slot); > + if (found.type != BTRFS_EXTENT_ITEM_KEY) > + continue; > + ret = btrfs_find_all_roots(trans, fs_info, found.objectid, > + tree_mod_seq_elem.seq, &roots); > + if (ret < 0) > + break; > + spin_lock(&fs_info->qgroup_lock); > + seq = fs_info->qgroup_seq; > + fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */ > + > + ulist_reinit(tmp); > + ULIST_ITER_INIT(&uiter); > + while ((unode = ulist_next(roots, &uiter))) { > + struct btrfs_qgroup *qg; > + > + qg = find_qgroup_rb(fs_info, unode->val); > + if (!qg) > + continue; > + > + ret = ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, > + GFP_ATOMIC); If ulist_add() fails, we still need to call ulist_free(roots).. > + if (ret < 0) { > + spin_unlock(&fs_info->qgroup_lock); > + goto out; > + } > + } > + > + /* this is similar to step 2 of btrfs_qgroup_account_ref */ > + ULIST_ITER_INIT(&uiter); > + while ((unode = ulist_next(tmp, &uiter))) { > + struct btrfs_qgroup *qg; > + struct btrfs_qgroup_list *glist; > + > + qg = (struct btrfs_qgroup *)(uintptr_t) unode->aux; > + qg->rfer += found.offset; > + qg->rfer_cmpr += found.offset; > + WARN_ON(qg->tag >= seq); > + WARN_ON(qg->refcnt >= seq); > + if (qg->refcnt < seq) > + qg->refcnt = seq + 1; > + else > + qg->refcnt = qg->refcnt + 1; > + qgroup_dirty(fs_info, qg); > + > + list_for_each_entry(glist, &qg->groups, next_group) { > + ret = ulist_add(tmp, glist->group->qgroupid, > + (uintptr_t)glist->group, > + GFP_ATOMIC); If ulist_add() fails, we still need to call ulist_free(roots).. > + if (ret < 0) { > + spin_unlock(&fs_info->qgroup_lock); > + goto out; > + } > + } > + } > + > + qgroup_account_ref_step3(fs_info, roots, tmp, seq, -1, > + found.offset); please check return value of qgroup_account_ref_step3()... As -ENOMEM may happen. > + > + spin_unlock(&fs_info->qgroup_lock); > + ulist_free(roots); > + ret = 0; > + } > + > +out: > + btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem); > + > + return ret; > +} > + > [..snip..]