Commit d659e6cc authored Mar 16, 2009 by Mikulas Patocka Committed by Alasdair G Kergon Mar 16, 2009

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 <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

parent f80a5570

drivers/md/dm-io.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;

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