Introduce btrfs_update_block_group_priority() to update block_groups::priority. It will move block group from old tree to new tree if need.
Signed-off-by: Su Yue <suy.f...@cn.fujitsu.com> --- fs/btrfs/extent-tree.c | 76 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index b559c9a9afc6..5ea1f2e40701 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -11466,3 +11466,79 @@ void btrfs_remove_block_group_priority(struct btrfs_block_group_cache *cache) spin_unlock(&cache->lock); up_write(&pt->groups_sem); } + +static inline struct btrfs_priority_tree * +find_priority_tree(struct btrfs_space_info *sinfo, u64 flags, int level) +{ + int index = btrfs_bg_flags_to_raid_index(flags); + + return search_priority_tree(&sinfo->priority_trees[index], level); +} + +void btrfs_update_block_group_priority(struct btrfs_block_group_cache *cache) +{ + struct btrfs_priority_tree *old_tree, *new_tree; + struct rw_semaphore *front_sem, *back_sem; + long priority; + int old_level, new_level; + + if (!is_priority_alloc_enabled(cache->fs_info)) + return; + + spin_lock(&cache->lock); + if (cache->priority != PRIORITY_BG_UPDATING) { + spin_unlock(&cache->lock); + return; + } + + old_level = cache->priority_tree->level; + priority = compute_block_group_priority(cache); + new_level = compute_priority_level(cache->fs_info, priority); + + /* no need to move the block group */ + if (old_level == new_level) { + cache->priority = priority; + spin_unlock(&cache->lock); + return; + } + spin_unlock(&cache->lock); + + old_tree = cache->priority_tree; + new_tree = find_priority_tree(cache->space_info, cache->flags, + new_level); + + if (!old_tree || !new_tree) { + btrfs_err(cache->fs_info, +"can't found priority tree %d for block_group %llu old level %d new priority %ld", + old_tree ? new_level : old_level, + cache->key.objectid, old_level, priority); + BUG(); + } + + if (old_level > new_level) { + front_sem = &old_tree->groups_sem; + back_sem = &new_tree->groups_sem; + } else { + front_sem = &new_tree->groups_sem; + back_sem = &old_tree->groups_sem; + } + + down_write(front_sem); + down_write(back_sem); + spin_lock(&cache->lock); + + /* the block group was removed/is removing */ + if (cache->priority != PRIORITY_BG_UPDATING || + priority != compute_block_group_priority(cache) || + old_tree != cache->priority_tree) + goto out; + + unlink_block_group_priority(old_tree, cache); + cache->priority = priority; + link_block_group_priority(new_tree, cache); + cache->priority_tree = new_tree; +out: + spin_unlock(&cache->lock); + up_write(front_sem); + up_write(back_sem); +} -- 2.19.1