dm: always allow one page in dm_merge_bvec
Some callers assume they can always add at least one page to an empty bio,
so dm_merge_bvec should not return 0 in this case: we'll reject the I/O
later after the bio is submitted.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index bca448e..469cec5 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -837,10 +837,10 @@
struct dm_table *map = dm_get_table(md);
struct dm_target *ti;
sector_t max_sectors;
- int max_size;
+ int max_size = 0;
if (unlikely(!map))
- return 0;
+ goto out;
ti = dm_table_find_target(map, bvm->bi_sector);
@@ -861,14 +861,15 @@
if (max_size && ti->type->merge)
max_size = ti->type->merge(ti, bvm, biovec, max_size);
+ dm_table_put(map);
+
+out:
/*
* Always allow an entire first page
*/
if (max_size <= biovec->bv_len && !(bvm->bi_size >> SECTOR_SHIFT))
max_size = biovec->bv_len;
- dm_table_put(map);
-
return max_size;
}