This is a note to let you know that I've just added the patch titled md: protect against crash upon fsync on ro array to the 3.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: md-protect-against-crash-upon-fsync-on-ro-array.patch and it can be found in the queue-3.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bbfa57c0f2243a7c31fd248d22e9861a2802cad5 Mon Sep 17 00:00:00 2001 From: Sebastian Riemer <sebastian.riemer@xxxxxxxxxxxxxxxx> Date: Thu, 21 Feb 2013 13:28:09 +1100 Subject: md: protect against crash upon fsync on ro array From: Sebastian Riemer <sebastian.riemer@xxxxxxxxxxxxxxxx> commit bbfa57c0f2243a7c31fd248d22e9861a2802cad5 upstream. If an fsync occurs on a read-only array, we need to send a completion for the IO and may not increment the active IO count. Otherwise, we hit a bug trace and can't stop the MD array anymore. By advice of Christoph Hellwig we return success upon a flush request but we return -EROFS for other writes. We detect flush requests by checking if the bio has zero sectors. This patch is suitable to any -stable kernel to which it applies. Signed-off-by: Sebastian Riemer <sebastian.riemer@xxxxxxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx> Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Cc: NeilBrown <neilb@xxxxxxx> Reported-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Acked-by: Paul Menzel <paulepanter@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: NeilBrown <neilb@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/md.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -307,6 +307,10 @@ static void md_make_request(struct reque bio_io_error(bio); return; } + if (mddev->ro == 1 && unlikely(rw == WRITE)) { + bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS); + return; + } smp_rmb(); /* Ensure implications of 'active' are visible */ rcu_read_lock(); if (mddev->suspended) { Patches currently in stable-queue which might be from sebastian.riemer@xxxxxxxxxxxxxxxx are queue-3.8/md-protect-against-crash-upon-fsync-on-ro-array.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html