dm switch: simplify conditional in alloc_region_table()
The variable sctx->nr_regions has type unsigned long and the variable
nr_regions has type sector_t.
Thus the variables may be different when overflow happens.
Changed the conditional to "if (nr_regions >= ULONG_MAX)".
Also move the assignment of nr_regions after sector_div()
and the sanity check which looks more sane.
Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c
index b128575..871c18f 100644
--- a/drivers/md/dm-switch.c
+++ b/drivers/md/dm-switch.c
@@ -99,11 +99,11 @@
if (sector_div(nr_regions, sctx->region_size))
nr_regions++;
- sctx->nr_regions = nr_regions;
- if (sctx->nr_regions != nr_regions || sctx->nr_regions >= ULONG_MAX) {
+ if (nr_regions >= ULONG_MAX) {
ti->error = "Region table too large";
return -EINVAL;
}
+ sctx->nr_regions = nr_regions;
nr_slots = nr_regions;
if (sector_div(nr_slots, sctx->region_entries_per_slot))