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

commit 5528d17de1 upstream.

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>
Cc: maximilian attems <max@stro.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Mikulas Patocka 2010-02-16 18:42:55 +00:00 committed by Willy Tarreau
parent a6a215cbde
commit 7404ccad11

View File

@ -1198,7 +1198,7 @@ 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);