Commit d67c7c9d authored Aug 08, 2018 by Greg Edwards Committed by Greg Kroah-Hartman Sep 15, 2018

block: bvec_nr_vecs() returns value for wrong slab



[ Upstream commit d6c02a9beb67f13d5f14f23e72fa9981e8b84477 ]

In commit ed996a52 ("block: simplify and cleanup bvec pool
handling"), the value of the slab index is incremented by one in
bvec_alloc() after the allocation is done to indicate an index value of
0 does not need to be later freed.

bvec_nr_vecs() was not updated accordingly, and thus returns the wrong
value.  Decrement idx before performing the lookup.

Fixes: ed996a52 ("block: simplify and cleanup bvec pool handling")
Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 6952b4ed

block/bio.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -156,7 +156,7 @@ static void bio_put_slab(struct bio_set *bs)

		unsigned int bvec_nr_vecs(unsigned short idx)
		{
		return bvec_slabs[idx].nr_vecs;
		return bvec_slabs[--idx].nr_vecs;
		}

		void bvec_free(mempool_t pool, struct bio_vec bv, unsigned int idx)