Commit aad9ae45 authored Oct 29, 2015 by Tomohiro Kusumi Committed by Mike Snitzer Oct 31, 2015

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>

parent f49e869a

drivers/md/dm-switch.c

+2 −2

Original line number	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))
		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))

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