From a1897fddd28daf6b23d05a30dc2a18836f77f8e3 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Thu, 27 Dec 2012 09:01:23 +0000 Subject: [PATCH] Btrfs: record first logical byte in memory This'd save us a rbtree search which may become expensive in large filesystem. Signed-off-by: Liu Bo Signed-off-by: Josef Bacik --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 1 + fs/btrfs/extent-tree.c | 19 ++++++++++++++++++- 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 22f012d..9ee099f 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1250,6 +1250,7 @@ struct btrfs_fs_info { /* block group cache stuff */ spinlock_t block_group_cache_lock; + u64 first_logical_byte; struct rb_root block_group_cache_tree; /* keep track of unallocated space */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 1db8a99..04f98e3 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2130,6 +2130,7 @@ int open_ctree(struct super_block *sb, spin_lock_init(&fs_info->block_group_cache_lock); fs_info->block_group_cache_tree = RB_ROOT; + fs_info->first_logical_byte = (u64)-1; extent_io_tree_init(&fs_info->freed_extents[0], fs_info->btree_inode->i_mapping); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 825f23b..82400b2 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -161,6 +161,10 @@ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, rb_link_node(&block_group->cache_node, parent, p); rb_insert_color(&block_group->cache_node, &info->block_group_cache_tree); + + if (info->first_logical_byte > block_group->key.objectid) + info->first_logical_byte = block_group->key.objectid; + spin_unlock(&info->block_group_cache_lock); return 0; @@ -202,8 +206,11 @@ block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, break; } } - if (ret) + if (ret) { btrfs_get_block_group(ret); + if (bytenr == 0 && info->first_logical_byte > ret->key.objectid) + info->first_logical_byte = ret->key.objectid; + } spin_unlock(&info->block_group_cache_lock); return ret; @@ -4848,6 +4855,13 @@ static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) struct btrfs_block_group_cache *cache; u64 bytenr; + spin_lock(&root->fs_info->block_group_cache_lock); + bytenr = root->fs_info->first_logical_byte; + spin_unlock(&root->fs_info->block_group_cache_lock); + + if (bytenr < (u64)-1) + return bytenr; + cache = btrfs_lookup_first_block_group(root->fs_info, search_start); if (!cache) return 0; @@ -8059,6 +8073,9 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans, spin_lock(&root->fs_info->block_group_cache_lock); rb_erase(&block_group->cache_node, &root->fs_info->block_group_cache_tree); + + if (root->fs_info->first_logical_byte == block_group->key.objectid) + root->fs_info->first_logical_byte = (u64)-1; spin_unlock(&root->fs_info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); -- 2.7.4