From: Christophe Saout <christophe@saout.de>

We should never access a bio after generic_make_request - there's no guarantee
it still exists.

Signed-off-by: Olaf Kirch <olaf.kirch@oracle.com>
Acked-by: Christophe Saout <christophe@saout.de>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

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

Index: linux-2.6.21-rc5/drivers/md/dm-crypt.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/md/dm-crypt.c	2007-04-03 17:13:56.000000000 +0100
+++ linux-2.6.21-rc5/drivers/md/dm-crypt.c	2007-04-03 17:14:06.000000000 +0100
@@ -669,9 +669,12 @@ static void process_write(struct crypt_i
 
 		generic_make_request(clone);
 
+		/* Do not reference clone after this - it
+		 * may be gone already. */
+
 		/* out of memory -> run queues */
 		if (remaining)
-			congestion_wait(bio_data_dir(clone), HZ/100);
+			congestion_wait(WRITE, HZ/100);
 	}
 }