From d659e6cc98766a1a61d6bdd283f95d149abd7719 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 16 Mar 2009 17:44:30 +0000 Subject: [PATCH] dm io: respect BIO_MAX_PAGES limit dm-io calls bio_get_nr_vecs to get the maximum number of pages to use for a given device. It allocates one additional bio_vec to use internally but failed to respect BIO_MAX_PAGES, so fix this. This was the likely cause of: https://bugzilla.redhat.com/show_bug.cgi?id=173153 Cc: stable@kernel.org Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-io.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index f14813be4eff..36e2b5e46a6b 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -292,6 +292,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, (PAGE_SIZE >> SECTOR_SHIFT)); num_bvecs = 1 + min_t(int, bio_get_nr_vecs(where->bdev), num_bvecs); + if (unlikely(num_bvecs > BIO_MAX_PAGES)) + num_bvecs = BIO_MAX_PAGES; bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios); bio->bi_sector = where->sector + (where->count - remaining); bio->bi_bdev = where->bdev; -- 2.20.1