• Yan Zheng's avatar
    Btrfs: improve async block group caching · 11833d66
    Yan Zheng authored
    This patch gets rid of two limitations of async block group caching.
    The old code delays handling pinned extents when block group is in
    caching. To allocate logged file extents, the old code need wait
    until block group is fully cached. To get rid of the limitations,
    This patch introduces a data structure to track the progress of
    caching. Base on the caching progress, we know which extents should
    be added to the free space cache when handling the pinned extents.
    The logged file extents are also handled in a similar way.
    
    This patch also changes how pinned extents are tracked. The old
    code uses one tree to track pinned extents, and copy the pinned
    extents tree at transaction commit time. This patch makes it use
    two trees to track pinned extents. One tree for extents that are
    pinned in the running transaction, one tree for extents that can
    be unpinned. At transaction commit time, we swap the two trees.
    Signed-off-by: default avatarYan Zheng <zheng.yan@oracle.com>
    Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
    11833d66
disk-io.c 66.8 KB