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* [2.6.23 PATCH 07/18] dm io: fix panic on large request
@ 2007-07-11 20:58 Alasdair G Kergon
  2007-07-17 13:16 ` Patrick McHardy
  0 siblings, 1 reply; 8+ messages in thread
From: Alasdair G Kergon @ 2007-07-11 20:58 UTC (permalink / raw)
  To: Andrew Morton; +Cc: dm-devel, linux-kernel, Jun'ichi Nomura

From: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>

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: "Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

---
 drivers/md/dm-io.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletion(-)

Index: linux/drivers/md/dm-io.c
===================================================================
--- linux.orig/drivers/md/dm-io.c	2007-07-11 21:37:32.000000000 +0100
+++ linux/drivers/md/dm-io.c	2007-07-11 21:37:43.000000000 +0100
@@ -293,7 +293,10 @@ static void do_region(int rw, unsigned i
 		 * 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;

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2007-07-20 15:08 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-07-11 20:58 [2.6.23 PATCH 07/18] dm io: fix panic on large request Alasdair G Kergon
2007-07-17 13:16 ` Patrick McHardy
2007-07-17 16:39   ` Jun'ichi Nomura
2007-07-17 17:50     ` Patrick McHardy
2007-07-17 22:20       ` Jun'ichi Nomura
2007-07-18 10:08         ` Patrick McHardy
2007-07-18 15:23   ` Chuck Ebbert
2007-07-20 15:07     ` Milan Broz

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