From fc1ff9588a6d56258ff9576a31aa34f17757c666 Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 12 Jul 2007 17:29:15 +0100 Subject: dm raid1: handle log failure When writing to a mirror, the log must be updated first. Failure to update the log could result in the log not properly reflecting the state of the mirror if the machine should crash. We change the return type of the rh_flush function to give us the ability to check if a log write was successful. If the log write was unsuccessful, we fail the writes to avoid the case where the log does not properly reflect the state of the mirror. A follow-up patch - which is dependent on the ability to requeue I/O's to core device-mapper - will requeue the I/O's for retry (allowing the mirror to be reconfigured.) Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon Signed-off-by: Linus Torvalds --- drivers/md/dm-raid1.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index dee4221caa73..1a876f9965e0 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -134,6 +134,7 @@ struct mirror_set { /* recovery */ region_t nr_regions; int in_sync; + int log_failure; struct mirror *default_mirror; /* Default mirror */ @@ -589,9 +590,9 @@ static void rh_recovery_end(struct region *reg, int success) wake(rh->ms); } -static void rh_flush(struct region_hash *rh) +static int rh_flush(struct region_hash *rh) { - rh->log->type->flush(rh->log); + return rh->log->type->flush(rh->log); } static void rh_delay(struct region_hash *rh, struct bio *bio) @@ -892,12 +893,15 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes) */ rh_inc_pending(&ms->rh, &sync); rh_inc_pending(&ms->rh, &nosync); - rh_flush(&ms->rh); + ms->log_failure = rh_flush(&ms->rh) ? 1 : 0; /* * Dispatch io. */ - while ((bio = bio_list_pop(&sync))) + if (unlikely(ms->log_failure)) + while ((bio = bio_list_pop(&sync))) + bio_endio(bio, bio->bi_size, -EIO); + else while ((bio = bio_list_pop(&sync))) do_write(ms, bio); while ((bio = bio_list_pop(&recover))) -- cgit v1.2.3