4.18-stable review patch. If anyone has any objections, please let me know.
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From: Greg Edwards gedwards@ddn.com
[ Upstream commit d6c02a9beb67f13d5f14f23e72fa9981e8b84477 ]
In commit ed996a52c868 ("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: ed996a52c868 ("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 --- block/bio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/block/bio.c +++ b/block/bio.c @@ -156,7 +156,7 @@ out:
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)