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| author | Jun'ichi Nomura <j-nomura@ce.jp.nec.com> | 2007-07-12 20:27:45 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-13 02:01:08 +0400 |
| commit | 596f138eede0c113aa655937c8be85fc15ccd61c (patch) | |
| tree | efd4e3d67b759b84bb1e72f9d50897d275085f7c | |
| parent | c95bc206da4bc9838bad826883f8f461a972e441 (diff) | |
| download | linux-596f138eede0c113aa655937c8be85fc15ccd61c.tar.xz | |
dm io: fix panic on large request
bio_alloc_bioset() will return NULL if 'num_vecs' is too large.
Use bio_get_nr_vecs() to get estimation of maximum number.
Cc: stable@kernel.org
Signed-off-by: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/md/dm-io.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index 352c6fbeac53..f3a772486437 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -293,7 +293,10 @@ static void do_region(int rw, unsigned int region, struct io_region *where, * bvec for bio_get/set_region() and decrement bi_max_vecs * to hide it from bio_add_page(). */ - num_bvecs = (remaining / (PAGE_SIZE >> SECTOR_SHIFT)) + 2; + num_bvecs = dm_sector_div_up(remaining, + (PAGE_SIZE >> SECTOR_SHIFT)); + num_bvecs = 1 + min_t(int, bio_get_nr_vecs(where->bdev), + num_bvecs); bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios); bio->bi_sector = where->sector + (where->count - remaining); bio->bi_bdev = where->bdev; |