• Joe Thornber's avatar
    dm cache: add fail io mode and needs_check flag · 028ae9f7
    Joe Thornber authored
    If a cache metadata operation fails (e.g. transaction commit) the
    cache's metadata device will abort the current transaction, set a new
    needs_check flag, and the cache will transition to "read-only" mode.  If
    aborting the transaction or setting the needs_check flag fails the cache
    will transition to "fail-io" mode.
    
    Once needs_check is set the cache device will not be allowed to
    activate.  Activation requires write access to metadata.  Future work is
    needed to add proper support for running the cache in read-only mode.
    
    Once in fail-io mode the cache will report a status of "Fail".
    
    Also, add commit() wrapper that will disallow commits if in read_only or
    fail mode.
    Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    028ae9f7
cache.txt 12.1 KB