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| author | Jun'ichi Nomura <j-nomura@ce.jp.nec.com> | 2007-07-12 17:27:45 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-08-09 14:27:42 -0700 |
| commit | 3bca2f557175e72b20f76d7489695f4c76ca0bf4 (patch) | |
| tree | 75c079f2df9dad2d306e7a7378c3dea7b70d4980 | |
| parent | 74ff092c258313747791da5d82054027167d1a79 (diff) | |
| download | lwn-3bca2f557175e72b20f76d7489695f4c76ca0bf4.tar.gz lwn-3bca2f557175e72b20f76d7489695f4c76ca0bf4.zip | |
dm io: fix another 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.
Signed-off-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -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; |