Shaohua Li <shli@xxxxxx> writes:
> There are 3 places the raid5-cache dispatches IO. The discard IO error
> doesn't matter, so we ignore it. The superblock write IO error can be
> handled in MD core. The remaining are log write and flush. When the IO
> error happens, we simply fail all raid disks and continue the stripe
> state machine. The MD/raid5 core can handle it (for example, mark all
> disks faulty, report bio error and so on).
>
> Signed-off-by: Shaohua Li <shli@xxxxxx>
> ---
> drivers/md/raid5-cache.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
> index afc3b6b..430ce5c 100644
> --- a/drivers/md/raid5-cache.c
> +++ b/drivers/md/raid5-cache.c
> @@ -223,7 +223,16 @@ static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
> io->state = state;
> }
>
> -/* XXX: totally ignores I/O errors */
> +static void r5l_log_io_error(struct r5l_log *log)
> +{
> + struct md_rdev *rdev;
> +
> + rcu_read_lock();
> + rdev_for_each_rcu(rdev, log->rdev->mddev)
> + md_error(log->rdev->mddev, rdev);
> + rcu_read_unlock();
> +}
This fails spare devices too... seems a bit heavy handed.
If the journal device fails we should still be able to read from the
array, just not write.
So can we just enhance the
if (s.failed > conf->max_degraded) {
test in handle_stripe(), and probably improve has_failed() too??
Thanks,
NeilBrown
> +
> static void r5l_log_endio(struct bio *bio)
> {
> struct r5l_io_unit *io = bio->bi_private;
> @@ -232,6 +241,9 @@ static void r5l_log_endio(struct bio *bio)
>
> bio_put(bio);
>
> + if (bio->bi_error)
> + r5l_log_io_error(log);
> +
> if (!atomic_dec_and_test(&io->pending_io))
> return;
>
> @@ -594,6 +606,9 @@ static void r5l_log_flush_endio(struct bio *bio)
> struct r5l_io_unit *io;
> struct stripe_head *sh;
>
> + if (bio->bi_error)
> + r5l_log_io_error(log);
> +
> spin_lock_irqsave(&log->io_list_lock, flags);
> list_for_each_entry(io, &log->flushing_ios, log_sibling) {
> while (!list_empty(&io->stripe_list)) {
> @@ -681,6 +696,7 @@ static void r5l_write_super_and_discard_space(struct r5l_log *log,
> !test_bit(MD_CHANGE_PENDING, &mddev->flags));
> }
>
> + /* discard IO error really doesn't matter, ignore it */
> if (log->last_checkpoint < end) {
> blkdev_issue_discard(bdev,
> log->last_checkpoint + log->rdev->data_offset,
> --
> 2.4.6
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