• Darrick J. Wong's avatar
    vfs: make remap_file_range functions take and return bytes completed · 42ec3d4c
    Darrick J. Wong authored
    Change the remap_file_range functions to take a number of bytes to
    operate upon and return the number of bytes they operated on.  This is a
    requirement for allowing fs implementations to return short clone/dedupe
    results to the user, which will enable us to obey resource limits in a
    graceful manner.
    
    A subsequent patch will enable copy_file_range to signal to the
    ->clone_file_range implementation that it can handle a short length,
    which will be returned in the function's return value.  For now the
    short return is not implemented anywhere so the behavior won't change --
    either copy_file_range manages to clone the entire range or it tries an
    alternative.
    
    Neither clone ioctl can take advantage of this, alas.
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Reviewed-by: default avatarAmir Goldstein <amir73il@gmail.com>
    Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    42ec3d4c
ioctl.c 17.6 KB