2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: NeilBrown commit 5bf295975416f8e97117bbbcfb0191c00bc3e2b4 upstream. 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. This avoids a race that can be triggered with mdadm-3.0 and external metadata, so it suitable for -stable. Reported-by: Rafal Marszewski Acked-by: Dan Williams Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2772,11 +2772,8 @@ array_state_store(mddev_t *mddev, const } else err = -EBUSY; spin_unlock_irq(&mddev->write_lock); - } else { - mddev->ro = 0; - mddev->recovery_cp = MaxSector; - err = do_md_run(mddev); - } + } else + err = -EINVAL; break; case active: if (mddev->pers) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/