diff options
| -rw-r--r-- | drivers/md/dm.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index f1db689667ea..59806e67a175 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -925,6 +925,16 @@ static int dm_merge_bvec(struct request_queue *q, */ if (max_size && ti->type->merge) max_size = ti->type->merge(ti, bvm, biovec, max_size); + /* + * If the target doesn't support merge method and some of the devices + * provided their merge_bvec method (we know this by looking at + * queue_max_hw_sectors), then we can't allow bios with multiple vector + * entries. So always set max_size to 0, and the code below allows + * just one page. + */ + else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9) + + max_size = 0; out_table: dm_table_put(map); |