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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 D4557C282C0 for ; Wed, 23 Jan 2019 07:15:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A106B21019 for ; Wed, 23 Jan 2019 07:15:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726647AbfAWHPg (ORCPT ); Wed, 23 Jan 2019 02:15:36 -0500 Received: from mx2.suse.de ([195.135.220.15]:47380 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726435AbfAWHPg (ORCPT ); Wed, 23 Jan 2019 02:15:36 -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 68007B06D for ; Wed, 23 Jan 2019 07:15:33 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz Subject: [Patch v5 3/7] btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots() Date: Wed, 23 Jan 2019 15:15:14 +0800 Message-Id: <20190123071518.2528-4-wqu@suse.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190123071518.2528-1-wqu@suse.com> References: <20190123071518.2528-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Relocation code will drop btrfs_root::reloc_root as soon as merge_reloc_root() finishes. However later qgroup code will need to access btrfs_root::reloc_root after merge_reloc_root() for delayed subtree rescan. So alter the timming of resetting btrfs_root:::reloc_root, make it happens after transaction commit. With this patch, we will introduce a new btrfs_root::state, BTRFS_ROOT_DEAD_RELOC_TREE, to info part of btrfs_root::reloc_tree user that although btrfs_root::reloc_tree is still non-NULL, but still it's not used any more. The lifespan of btrfs_root::reloc tree will become: Old behavior | New ------------------------------------------------------------------------ btrfs_init_reloc_root() --- | btrfs_init_reloc_root() --- set reloc_root | | set reloc_root | | | | | | | merge_reloc_root() | | merge_reloc_root() | |- btrfs_update_reloc_root() --- | |- btrfs_update_reloc_root() -+- clear btrfs_root::reloc_root | set ROOT_DEAD_RELOC_TREE | | record root into dirty | | roots rbtree | | | | reloc_block_group() Or | | btrfs_recover_relocation() | | | After transaction commit | | |- clean_dirty_subvols() --- | clear btrfs_root::reloc_root During ROOT_DEAD_RELOC_TREE set lifespan, the only user of btrfs_root::reloc_tree should be qgroup. Since reloc root needs a longer life-span, this patch will also delay btrfs_drop_snapshot() call. Now btrfs_drop_snapshot() is called in clean_dirty_subvols(). This patch will increase the size of btrfs_root by 16 bytes. Signed-off-by: Qu Wenruo --- fs/btrfs/ctree.h | 15 ++++++++ fs/btrfs/disk-io.c | 1 + fs/btrfs/relocation.c | 86 ++++++++++++++++++++++++++++++++++--------- 3 files changed, 85 insertions(+), 17 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 0a68cf7032f5..865ce9531d96 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1195,6 +1195,13 @@ enum { BTRFS_ROOT_MULTI_LOG_TASKS, BTRFS_ROOT_DIRTY, BTRFS_ROOT_DELETING, + + /* + * Reloc tree is orphan, only kept here for qgroup delayed subtree scan + * + * Set for the subvolume tree owning the reloc tree. + */ + BTRFS_ROOT_DEAD_RELOC_TREE, }; /* @@ -1307,6 +1314,14 @@ struct btrfs_root { struct list_head ordered_root; u64 nr_ordered_extents; + /* + * Not empty if this subvolume root has gone through tree block swap + * (relocation) + * + * Will be used by reloc_control::dirty_subvol_roots. + */ + struct list_head reloc_dirty_list; + /* * Number of currently running SEND ioctls to prevent * manipulation with the read-only status via SUBVOL_SETFLAGS diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8da2f380d3c0..bfefa1de0455 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1175,6 +1175,7 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info, INIT_LIST_HEAD(&root->delalloc_root); INIT_LIST_HEAD(&root->ordered_extents); INIT_LIST_HEAD(&root->ordered_root); + INIT_LIST_HEAD(&root->reloc_dirty_list); INIT_LIST_HEAD(&root->logged_list[0]); INIT_LIST_HEAD(&root->logged_list[1]); spin_lock_init(&root->inode_lock); diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 272b287f8cf0..70a3e1170e8a 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -162,6 +162,8 @@ struct reloc_control { struct mapping_tree reloc_root_tree; /* list of reloc trees */ struct list_head reloc_roots; + /* list of subvolume trees who get relocated */ + struct list_head dirty_subvol_roots; /* size of metadata reservation for merging reloc trees */ u64 merging_rsv_size; /* size of relocated tree nodes */ @@ -1467,15 +1469,17 @@ int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root_item *root_item; int ret; - if (!root->reloc_root) + if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state) || + !root->reloc_root) goto out; reloc_root = root->reloc_root; root_item = &reloc_root->root_item; + /* root->reloc_root will stay until current relocation finished */ if (fs_info->reloc_ctl->merge_reloc_tree && btrfs_root_refs(root_item) == 0) { - root->reloc_root = NULL; + set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); __del_reloc_root(reloc_root); } @@ -2120,6 +2124,59 @@ static int find_next_key(struct btrfs_path *path, int level, return 1; } +/* + * Helper to insert current subvolume into reloc_control::dirty_subvol_roots + */ +static void insert_dirty_subvol(struct btrfs_trans_handle *trans, + struct reloc_control *rc, + struct btrfs_root *root) +{ + struct btrfs_root *reloc_root = root->reloc_root; + struct btrfs_root_item *reloc_root_item; + u64 root_objectid = root->root_key.objectid; + + /* @root must be a subvolume tree root with a valid reloc tree */ + ASSERT(root_objectid != BTRFS_TREE_RELOC_OBJECTID); + ASSERT(reloc_root); + + reloc_root_item = &reloc_root->root_item; + memset(&reloc_root_item->drop_progress, 0, + sizeof(reloc_root_item->drop_progress)); + reloc_root_item->drop_level = 0; + btrfs_set_root_refs(reloc_root_item, 0); + btrfs_update_reloc_root(trans, root); + + if (list_empty(&root->reloc_dirty_list)) { + btrfs_grab_fs_root(root); + list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots); + } + return; +} + +static int clean_dirty_subvols(struct reloc_control *rc) +{ + struct btrfs_root *root; + struct btrfs_root *next; + int ret = 0; + int tmp_ret; + + list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots, + reloc_dirty_list) { + struct btrfs_root *reloc_root = root->reloc_root; + + clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); + list_del_init(&root->reloc_dirty_list); + root->reloc_root = NULL; + if (reloc_root) { + tmp_ret = btrfs_drop_snapshot(reloc_root, NULL, 0, 1); + if (tmp_ret < 0 && !ret) + ret = tmp_ret; + } + btrfs_put_fs_root(root); + } + return ret; +} + /* * merge the relocated tree blocks in reloc tree with corresponding * fs tree. @@ -2259,13 +2316,8 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, out: btrfs_free_path(path); - if (err == 0) { - memset(&root_item->drop_progress, 0, - sizeof(root_item->drop_progress)); - root_item->drop_level = 0; - btrfs_set_root_refs(root_item, 0); - btrfs_update_reloc_root(trans, root); - } + if (err == 0) + insert_dirty_subvol(trans, rc, root); if (trans) btrfs_end_transaction_throttle(trans); @@ -2410,14 +2462,6 @@ void merge_reloc_roots(struct reloc_control *rc) } else { list_del_init(&reloc_root->root_list); } - - ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1); - if (ret < 0) { - if (list_empty(&reloc_root->root_list)) - list_add_tail(&reloc_root->root_list, - &reloc_roots); - goto out; - } } if (found) { @@ -4079,6 +4123,9 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) goto out_free; } btrfs_commit_transaction(trans); + ret = clean_dirty_subvols(rc); + if (ret < 0 && !err) + err = ret; out_free: btrfs_free_block_rsv(fs_info, rc->block_rsv); btrfs_free_path(path); @@ -4173,6 +4220,7 @@ static struct reloc_control *alloc_reloc_control(void) return NULL; INIT_LIST_HEAD(&rc->reloc_roots); + INIT_LIST_HEAD(&rc->dirty_subvol_roots); backref_cache_init(&rc->backref_cache); mapping_tree_init(&rc->reloc_root_tree); extent_io_tree_init(&rc->processed_blocks, NULL); @@ -4468,6 +4516,10 @@ int btrfs_recover_relocation(struct btrfs_root *root) goto out_free; } err = btrfs_commit_transaction(trans); + + ret = clean_dirty_subvols(rc); + if (ret < 0 && !err) + err = ret; out_free: kfree(rc); out: -- 2.20.1