Revert "block, dm: don't copy bios for request clones"
This reverts commit 5f1b670d0bef508a5554d92525f5f6d00d640b38.
Justification for revert as reported in this dm-devel post:
https://www.redhat.com/archives/dm-devel/2015-June/msg00160.html
this change should not be pushed to mainline yet.
Firstly, Christoph has a newer version of the patch that fixes silent
data corruption problem:
https://www.redhat.com/archives/dm-devel/2015-May/msg00229.html
And the new version still depends on LLDDs to always complete requests
to the end when error happens, while block API doesn't enforce such a
requirement. If the assumption is ever broken, the inconsistency between
request and bio (e.g. rq->__sector and rq->bio) will cause silent data
corruption:
https://www.redhat.com/archives/dm-devel/2015-June/msg00022.html
Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index a5f9412..16ba55a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -942,28 +942,21 @@
{
unsigned type = dm_table_get_type(t);
unsigned per_bio_data_size = 0;
+ struct dm_target *tgt;
unsigned i;
- switch (type) {
- case DM_TYPE_BIO_BASED:
- for (i = 0; i < t->num_targets; i++) {
- struct dm_target *tgt = t->targets + i;
-
- per_bio_data_size = max(per_bio_data_size,
- tgt->per_bio_data_size);
- }
- t->mempools = dm_alloc_bio_mempools(t->integrity_supported,
- per_bio_data_size);
- break;
- case DM_TYPE_REQUEST_BASED:
- case DM_TYPE_MQ_REQUEST_BASED:
- t->mempools = dm_alloc_rq_mempools(md, type);
- break;
- default:
+ if (unlikely(type == DM_TYPE_NONE)) {
DMWARN("no table type is set, can't allocate mempools");
return -EINVAL;
}
+ if (type == DM_TYPE_BIO_BASED)
+ for (i = 0; i < t->num_targets; i++) {
+ tgt = t->targets + i;
+ per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
+ }
+
+ t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported, per_bio_data_size);
if (!t->mempools)
return -ENOMEM;