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Commit aad9ae45 authored by Tomohiro Kusumi's avatar Tomohiro Kusumi Committed by Mike Snitzer
Browse files

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: default avatarTomohiro Kusumi <kusumi.tomohiro@gmail.com>
Reviewed-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent f49e869a

drivers/md/dm-switch.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -99,11 +99,11 @@ static int alloc_region_table(struct dm_target *ti, unsigned nr_paths) 
	if (sector_div(nr_regions, sctx->region_size))

	if (sector_div(nr_regions, sctx->region_size))

		nr_regions++;

		nr_regions++;





	sctx->nr_regions = nr_regions;

	if (nr_regions >= ULONG_MAX) {

	if (sctx->nr_regions != nr_regions || sctx->nr_regions >= ULONG_MAX) {

		ti->error = "Region table too large";

		ti->error = "Region table too large";

		return -EINVAL;

		return -EINVAL;

	}

	}

	sctx->nr_regions = nr_regions;





	nr_slots = nr_regions;

	nr_slots = nr_regions;

	if (sector_div(nr_slots, sctx->region_entries_per_slot))

	if (sector_div(nr_slots, sctx->region_entries_per_slot))