From: Jens Axboe <jens.axboe@oracle.com>
Date: Wed, 17 Oct 2007 11:02:33 +0000 (+0200)
Subject: [BLOCK] Clear sg entry before filling in blk_rq_map_sg()
X-Git-Tag: v2.6.24-rc1~490^2~3
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=60573b874b03d22678614ca1e73f6b15c1b53b40;p=linux-2.6

[BLOCK] Clear sg entry before filling in blk_rq_map_sg()

The memset() of the sg entry was originally removed, because it could
overwrite a chain pointer. But it's quite OK to memset() it when we know
it's a valid entry, since it can't contain a chain pointer.

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

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 9eabac95fb..1014d349a3 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1352,6 +1352,7 @@ new_segment:
 			sg = next_sg;
 			next_sg = sg_next(sg);
 
+			memset(sg, 0, sizeof(*sg));
 			sg->page = bvec->bv_page;
 			sg->length = nbytes;
 			sg->offset = bvec->bv_offset;