Commit b01cd5ac authored Oct 01, 2008 by Mikulas Patocka Committed by Alasdair G Kergon Oct 01, 2008

dm: cope with access beyond end of device in dm_merge_bvec

If for any reason dm_merge_bvec() is given an offset beyond the end of the
device, avoid an oops and always allow one page to be added to an empty bio.
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>

parent 5037108a

drivers/md/dm.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -843,6 +843,8 @@ static int dm_merge_bvec(struct request_queue *q,
		goto out;

		ti = dm_table_find_target(map, bvm->bi_sector);
		if (!dm_target_is_valid(ti))
		goto out_table;

		/*
		* Find maximum amount of I/O that won't need splitting
		@@ -861,6 +863,7 @@ static int dm_merge_bvec(struct request_queue *q,
		if (max_size && ti->type->merge)
		max_size = ti->type->merge(ti, bvm, biovec, max_size);

		out_table:
		dm_table_put(map);

		out: