• Yan Zheng's avatar
    Btrfs: fix tree logs parallel sync · 7237f183
    Yan Zheng authored
    
    
    To improve performance, btrfs_sync_log merges tree log sync
    requests. But it wrongly merges sync requests for different
    tree logs. If multiple tree logs are synced at the same time,
    only one of them actually gets synced.
    
    This patch has following changes to fix the bug:
    
    Move most tree log related fields in btrfs_fs_info to
    btrfs_root. This allows merging sync requests separately
    for each tree log.
    
    Don't insert root item into the log root tree immediately
    after log tree is allocated. Root item for log tree is
    inserted when log tree get synced for the first time. This
    allows syncing the log root tree without first syncing all
    log trees.
    
    At tree-log sync, btrfs_sync_log first sync the log tree;
    then updates corresponding root item in the log root tree;
    sync the log root tree; then update the super block.
    Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
    7237f183