From patchwork Thu Aug 15 15:11:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Behrens X-Patchwork-Id: 2845203 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2CA23BF546 for ; Thu, 15 Aug 2013 15:11:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 466B520378 for ; Thu, 15 Aug 2013 15:11:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C13AF2018E for ; Thu, 15 Aug 2013 15:11:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757562Ab3HOPLh (ORCPT ); Thu, 15 Aug 2013 11:11:37 -0400 Received: from xp-ob.rzone.de ([81.169.146.139]:41357 "EHLO xp-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756958Ab3HOPLa (ORCPT ); Thu, 15 Aug 2013 11:11:30 -0400 X-RZG-CLASS-ID: xp Received: from pizpot.store ([192.168.43.236]) by josoe.store (RZmta 31.40 OK) with ESMTP id p04750p7FEfDLt for ; Thu, 15 Aug 2013 17:11:24 +0200 (CEST) From: Stefan Behrens To: linux-btrfs@vger.kernel.org Subject: [PATCH v8 5/8] Btrfs: fill UUID tree initially Date: Thu, 15 Aug 2013 17:11:21 +0200 Message-Id: <8dca359fd18ab34e242111542f48891a53124e58.1376575048.git.sbehrens@giantdisaster.de> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-9.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When the UUID tree is initially created, a task is spawned that walks through the root tree. For each found subvolume root_item, the uuid and received_uuid entries in the UUID tree are added. This is such a quick operation so that in case somebody wants to unmount the filesystem while the task is still running, the unmount is delayed until the UUID tree building task is finished. Signed-off-by: Stefan Behrens --- fs/btrfs/ctree.h | 3 ++ fs/btrfs/disk-io.c | 7 +++ fs/btrfs/volumes.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 160 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 9a99c66..e6b71ad 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -1647,6 +1648,8 @@ struct btrfs_fs_info { struct btrfs_dev_replace dev_replace; atomic_t mutually_exclusive_operation_running; + + struct semaphore uuid_tree_rescan_sem; }; /* diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index f75ccfc..d9ff76e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include "compat.h" #include "ctree.h" @@ -2295,6 +2296,7 @@ int open_ctree(struct super_block *sb, init_rwsem(&fs_info->extent_commit_sem); init_rwsem(&fs_info->cleanup_work_sem); init_rwsem(&fs_info->subvol_sem); + sema_init(&fs_info->uuid_tree_rescan_sem, 1); fs_info->dev_replace.lock_owner = 0; atomic_set(&fs_info->dev_replace.nesting_level, 0); mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount); @@ -3552,6 +3554,11 @@ int close_ctree(struct btrfs_root *root) fs_info->closing = 1; smp_mb(); + /* wait for the uuid_scan task to finish */ + down(&fs_info->uuid_tree_rescan_sem); + /* avoid complains from lockdep et al., set sem back to initial state */ + up(&fs_info->uuid_tree_rescan_sem); + /* pause restriper - we want to resume on mount */ btrfs_pause_balance(fs_info); diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b99d3f4..8e0aeef 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include "compat.h" #include "ctree.h" @@ -3432,11 +3433,146 @@ int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) return 0; } +static int btrfs_uuid_scan_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_key key; + struct btrfs_key max_key; + struct btrfs_path *path = NULL; + int ret = 0; + struct extent_buffer *eb; + int slot; + struct btrfs_root_item root_item; + u32 item_size; + struct btrfs_trans_handle *trans; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = 0; + + max_key.objectid = (u64)-1; + max_key.type = BTRFS_ROOT_ITEM_KEY; + max_key.offset = (u64)-1; + + path->keep_locks = 1; + + while (1) { + ret = btrfs_search_forward(root, &key, &max_key, path, 0); + if (ret) { + if (ret > 0) + ret = 0; + break; + } + + if (key.type != BTRFS_ROOT_ITEM_KEY || + (key.objectid < BTRFS_FIRST_FREE_OBJECTID && + key.objectid != BTRFS_FS_TREE_OBJECTID) || + key.objectid > BTRFS_LAST_FREE_OBJECTID) + goto skip; + + eb = path->nodes[0]; + slot = path->slots[0]; + item_size = btrfs_item_size_nr(eb, slot); + if (item_size < sizeof(root_item)) + goto skip; + + trans = NULL; + read_extent_buffer(eb, &root_item, + btrfs_item_ptr_offset(eb, slot), + (int)sizeof(root_item)); + if (btrfs_root_refs(&root_item) == 0) + goto skip; + if (!btrfs_is_empty_uuid(root_item.uuid)) { + /* + * 1 - subvol uuid item + * 1 - received_subvol uuid item + */ + trans = btrfs_start_transaction(fs_info->uuid_root, 2); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, + root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + key.objectid); + if (ret < 0) { + pr_warn("btrfs: uuid_tree_add failed %d\n", + ret); + btrfs_end_transaction(trans, + fs_info->uuid_root); + break; + } + } + + if (!btrfs_is_empty_uuid(root_item.received_uuid)) { + if (!trans) { + /* 1 - received_subvol uuid item */ + trans = btrfs_start_transaction( + fs_info->uuid_root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + } + ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, + root_item.received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + key.objectid); + if (ret < 0) { + pr_warn("btrfs: uuid_tree_add failed %d\n", + ret); + btrfs_end_transaction(trans, + fs_info->uuid_root); + break; + } + } + + if (trans) { + ret = btrfs_end_transaction(trans, fs_info->uuid_root); + if (ret) + break; + } + +skip: + btrfs_release_path(path); + if (key.offset < (u64)-1) { + key.offset++; + } else if (key.type < BTRFS_ROOT_ITEM_KEY) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + } else if (key.objectid < (u64)-1) { + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + key.objectid++; + } else { + break; + } + cond_resched(); + } + +out: + btrfs_free_path(path); + if (ret) + pr_warn("btrfs: btrfs_uuid_scan_kthread failed %d\n", ret); + up(&fs_info->uuid_tree_rescan_sem); + return 0; +} + int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info) { struct btrfs_trans_handle *trans; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *uuid_root; + struct task_struct *task; + int ret; /* * 1 - root node @@ -3456,8 +3592,21 @@ int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info) fs_info->uuid_root = uuid_root; - return btrfs_commit_transaction(trans, tree_root); + ret = btrfs_commit_transaction(trans, tree_root); + if (ret) + return ret; + + down(&fs_info->uuid_tree_rescan_sem); + task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid"); + if (IS_ERR(task)) { + pr_warn("btrfs: failed to start uuid_scan task\n"); + up(&fs_info->uuid_tree_rescan_sem); + return PTR_ERR(task); + } + + return 0; } + /* * shrinking a device means finding all of the device extents past * the new size, and then following the back refs to the chunks.