Commit 5528d17d authored Feb 16, 2010 by Mikulas Patocka Committed by Alasdair G Kergon Feb 16, 2010

dm raid1: fail writes if errors are not handled and log fails

If the mirror log fails when the handle_errors option was not selected
and there is no remaining valid mirror leg, writes return success even
though they weren't actually written to any device.  This patch
completes them with EIO instead.

This code path is taken:
do_writes:
	bio_list_merge(&ms->failures, &sync);
do_failures:
	if (!get_valid_mirror(ms)) (false)
	else if (errors_handled(ms)) (false)
	else bio_endio(bio, 0);

The logic in do_failures is based on presuming that the write was already
tried: if it succeeded at least on one leg (without handle_errors) it
is reported as success.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=555197



Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

parent ebfd32bb

drivers/md/dm-raid1.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -724,7 +724,7 @@ static void do_writes(struct mirror_set ms, struct bio_list writes)
		/*
		* Dispatch io.
		*/
		if (unlikely(ms->log_failure)) {
		if (unlikely(ms->log_failure) && errors_handled(ms)) {
		spin_lock_irq(&ms->lock);
		bio_list_merge(&ms->failures, &sync);
		spin_unlock_irq(&ms->lock);

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