From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 23 Dec 2008 11:44:19 +0000 (+0100)
Subject: bounce: don't rely on a zeroed bio_vec list
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=f735b5eeb9fcbb001e0cf2a5296b19c4bbaec55f;p=linux-beck.git

bounce: don't rely on a zeroed bio_vec list

__blk_queue_bounce() relies on a zeroed bio_vec list, since it looks
up arbitrary indexes in the allocated bio. The block layer only
guarentees that added entries are valid, so clear memory after alloc.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/mm/bounce.c b/mm/bounce.c
index bf0cf7c8387b..e590272fe7a8 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -198,8 +198,13 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
 		/*
 		 * irk, bounce it
 		 */
-		if (!bio)
-			bio = bio_alloc(GFP_NOIO, (*bio_orig)->bi_vcnt);
+		if (!bio) {
+			unsigned int cnt = (*bio_orig)->bi_vcnt;
+
+			bio = bio_alloc(GFP_NOIO, cnt);
+			memset(bio->bi_io_vec, 0, cnt * sizeof(struct bio_vec));
+		}
+			
 
 		to = bio->bi_io_vec + i;