From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.cn.fujitsu.com ([183.91.158.132]:29303 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751130AbeBHDXH (ORCPT ); Wed, 7 Feb 2018 22:23:07 -0500 Received: from G08CNEXCHPEKD03.g08.fujitsu.local (unknown [10.167.33.85]) by cn.fujitsu.com (Postfix) with ESMTP id BB4C848AE767 for ; Thu, 8 Feb 2018 11:23:02 +0800 (CST) From: Su Yue To: CC: Subject: [PATCH v4 05/18] btrfs-progs: lowmem check: introduce mark/clear_block_groups_full() Date: Thu, 8 Feb 2018 11:27:24 +0800 Message-ID: <20180208032737.31561-6-suy.fnst@cn.fujitsu.com> In-Reply-To: <20180208032737.31561-1-suy.fnst@cn.fujitsu.com> References: <20180208032737.31561-1-suy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-btrfs-owner@vger.kernel.org List-ID: Excluding or pining all metadata blocks is not time-efficient for large storage filesystems. Here is another way to mark all metadata block groups full and allocate a new chunk for CoW. So new reservered extents never overwrite extents. Introduce modify_block_groups_cache() to modify all blocks groups cache state and set all extents in block groups unfree in free space cache. mark/clear_block_groups_full() wraps above function. Suggested-by: Qu Wenruo Signed-off-by: Su Yue --- check/mode-lowmem.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index 1fc84f1e8c44..a200c28a9cf7 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -233,6 +233,99 @@ static int update_nodes_refs(struct btrfs_root *root, u64 bytenr, return 0; } +/* + * Mark all extents unfree in the block group. And set @block_group->cached + * according to @cache. + */ +static int modify_block_group_cache(struct btrfs_fs_info *fs_info, + struct btrfs_block_group_cache *block_group, int cache) +{ + struct extent_io_tree *free_space_cache = &fs_info->free_space_cache; + u64 start = block_group->key.objectid; + u64 end = start + block_group->key.offset; + + if (cache && !block_group->cached) { + block_group->cached = 1; + clear_extent_dirty(free_space_cache, start, end - 1); + } + + if (!cache && block_group->cached) { + block_group->cached = 0; + clear_extent_dirty(free_space_cache, start, end - 1); + } + return 0; +} + +/* + * Modify block groups which have @flags unfree in free space cache. + * + * @cache: if 0, clear block groups cache state; + * not 0, mark blocks groups cached. + */ +static int modify_block_groups_cache(struct btrfs_fs_info *fs_info, u64 flags, + int cache) +{ + struct btrfs_root *root = fs_info->extent_root; + struct btrfs_key key; + struct btrfs_path path; + struct btrfs_block_group_cache *bg_cache; + struct btrfs_block_group_item *bi; + struct btrfs_block_group_item bg_item; + struct extent_buffer *eb; + int slot; + int ret; + + key.objectid = 0; + key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; + key.offset = 0; + + btrfs_init_path(&path); + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (ret < 0) { + error("fail to search block groups due to %s", strerror(-ret)); + goto out; + } + + while (1) { + eb = path.nodes[0]; + slot = path.slots[0]; + btrfs_item_key_to_cpu(eb, &key, slot); + bg_cache = btrfs_lookup_block_group(fs_info, key.objectid); + if (!bg_cache) { + ret = -ENOENT; + goto out; + } + + bi = btrfs_item_ptr(eb, slot, struct btrfs_block_group_item); + read_extent_buffer(eb, &bg_item, (unsigned long)bi, + sizeof(bg_item)); + if (btrfs_block_group_flags(&bg_item) & flags) + modify_block_group_cache(fs_info, bg_cache, cache); + + ret = btrfs_next_item(root, &path); + if (ret > 0) { + ret = 0; + goto out; + } + if (ret < 0) + goto out; + } + +out: + btrfs_release_path(&path); + return ret; +} + +static int mark_block_groups_full(struct btrfs_fs_info *fs_info, u64 flags) +{ + return modify_block_groups_cache(fs_info, flags, 1); +} + +static int clear_block_groups_full(struct btrfs_fs_info *fs_info, u64 flags) +{ + return modify_block_groups_cache(fs_info, flags, 0); +} + /* * This function only handles BACKREF_MISSING, * If corresponding extent item exists, increase the ref, else insert an extent -- 2.16.1