• Bob Peterson's avatar
    GFS2: Withdraw for IO errors writing to the journal or statfs · 942b0cdd
    Bob Peterson authored
    Before this patch, if GFS2 encountered IO errors while writing to
    the journal, it would not report the problem, so they would go
    unnoticed, sometimes for many hours. Sometimes this would only be
    noticed later, when recovery tried to do journal replay and failed
    due to invalid metadata at the blocks that resulted in IO errors.
    
    This patch makes GFS2's log daemon check for IO errors. If it
    encounters one, it withdraws from the file system and reports
    why in dmesg. A similar action is taken when IO errors occur when
    writing to the system statfs file.
    
    These errors are also reported back to any callers of fsync, since
    that requires the journal to be flushed. Therefore, any IO errors
    that would previously go unnoticed are now noticed and the file
    system is withdrawn as early as possible, thus preventing further
    file system damage.
    
    Also note that this reintroduces superblock variable sd_log_error,
    which Christoph removed with commit f729b66f.
    Signed-off-by: 's avatarBob Peterson <rpeterso@redhat.com>
    942b0cdd