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authorMikulas Patocka <mpatocka@redhat.com>2009-12-10 23:52:06 +0000
committerAlasdair G Kergon <agk@redhat.com>2009-12-10 23:52:06 +0000
commit929be8fcb4b4b65d038e73d3bb34715851a95ca2 (patch)
tree7c008317d90232b5b2d3869b9fa68c1ec023d7f6
parent60f355ead31e2be8d06ac8acb163df91a1c64e3b (diff)
downloadlinux-929be8fcb4b4b65d038e73d3bb34715851a95ca2.tar.bz2
dm raid1: hold all write bios when leg fails
Hold all write bios when leg fails and errors are handled When using a userspace daemon such as dmeventd to handle errors, we must delay completing bios until it has done its job. This patch prevents the following race: - primary leg fails - write "1" fail, the write is held, secondary leg is set default - write "2" goes straight to the secondary leg Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r--drivers/md/dm-raid1.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index e363335e8d81..f8d7b3aa46c6 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -69,6 +69,7 @@ struct mirror_set {
region_t nr_regions;
int in_sync;
int log_failure;
+ int leg_failure;
atomic_t suspend;
atomic_t default_mirror; /* Default mirror */
@@ -211,6 +212,8 @@ static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)
struct mirror_set *ms = m->ms;
struct mirror *new;
+ ms->leg_failure = 1;
+
/*
* error_count is used for nothing more than a
* simple way to tell if a device has encountered
@@ -734,8 +737,12 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
dm_rh_delay(ms->rh, bio);
while ((bio = bio_list_pop(&nosync))) {
- map_bio(get_default_mirror(ms), bio);
- generic_make_request(bio);
+ if (unlikely(ms->leg_failure) && errors_handled(ms))
+ hold_bio(ms, bio);
+ else {
+ map_bio(get_default_mirror(ms), bio);
+ generic_make_request(bio);
+ }
}
}
@@ -848,6 +855,7 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
ms->nr_regions = dm_sector_div_up(ti->len, region_size);
ms->in_sync = 0;
ms->log_failure = 0;
+ ms->leg_failure = 0;
atomic_set(&ms->suspend, 0);
atomic_set(&ms->default_mirror, DEFAULT_MIRROR);