• Steven Rostedt (Red Hat)'s avatar
    tracing: Do not return EINVAL in snapshot when not allocated · c9960e48
    Steven Rostedt (Red Hat) authored
    
    
    To use the tracing snapshot feature, writing a '1' into the snapshot
    file causes the snapshot buffer to be allocated if it has not already
    been allocated and dose a 'swap' with the main buffer, so that the
    snapshot now contains what was in the main buffer, and the main buffer
    now writes to what was the snapshot buffer.
    
    To free the snapshot buffer, a '0' is written into the snapshot file.
    
    To clear the snapshot buffer, any number but a '0' or '1' is written
    into the snapshot file. But if the file is not allocated it returns
    -EINVAL error code. This is rather pointless. It is better just to
    do nothing and return success.
    
    Acked-by: default avatarHiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    c9960e48