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>
This commit is contained in:
Tomohiro Kusumi 2015-10-29 03:54:21 +09:00 committed by Mike Snitzer
parent f49e869a61
commit aad9ae4550

View File

@ -99,11 +99,11 @@ static int alloc_region_table(struct dm_target *ti, unsigned nr_paths)
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))