On Sun, May 3, 2009 at 11:58 PM, NeilBrown <neilb@xxxxxxx> wrote: > Being able to write 'clean' to an 'array_state' of an inactive array > to activate it in 'clean' mode is both unnecessary and inconvenient. > > It is unnecessary because the same can be achieved by writing > 'active'. This activates and array, but it still remains 'clean' > until the first write. > > It is inconvenient because writing 'clean' is more often used to > cause an 'active' array to revert to 'clean' mode (thus blocking > any writes until a 'write-pending' is promoted to 'active'). > > Allowing 'clean' to both activate an array and mark an active array as > clean can lead to races: One program writes 'clean' to mark the > active array as clean at the same time as another program writes > 'inactive' to deactivate (stop) and active array. Depending on which > writes first, the array could be deactivated and immediately > reactivated which isn't what was desired. > > So just disable the use of 'clean' to activate an array. > > Signed-off-by: NeilBrown <neilb@xxxxxxx> Reported-by: Rafal Marszewski <rafal.marszewski@xxxxxxxxx> Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx> Thanks, Dan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
