• Liu Bo's avatar
    Btrfs: fix warning of free_extent_map · 3b277594
    Liu Bo authored
    
    
    Users report that an extent map's list is still linked when it's actually
    going to be freed from cache.
    
    The story is that
    
    a) when we're going to drop an extent map and may split this large one into
    smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means
    that it's on the list to be logged, then the smaller ems split from it will also
    be flagged as EXTENT_FLAG_LOGGING, and this is _not_ expected.
    
    b) we'll keep ems from unlinking the list and freeing when they are flagged with
    EXTENT_FLAG_LOGGING, because the log code holds one reference.
    
    The end result is the warning, but the truth is that we set the flag
    EXTENT_FLAG_LOGGING only during fsync.
    
    So clear flag EXTENT_FLAG_LOGGING for extent maps split from a large one.
    Reported-by: default avatarJohannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
    Reported-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
    Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
    3b277594
file.c 63.4 KB