From 7328cb4feff36c03159241716caa5b72e18ead66 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 23 Oct 2007 09:49:25 +0200
Subject: [PATCH] --- yaml --- r: 72185 b: refs/heads/master c:
 7aeacf982203fb4dea2f3434eefdc268cfd5d6d9 h: refs/heads/master i:   72183:
 4e9a3e2f3cd8374a265fb8dc5db19ac181190f65 v: v3

---
 [refs]                  |  2 +-
 trunk/block/ll_rw_blk.c | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 1a3f6a110eb7..2cf9956d8b72 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ad0d4083e65d9f223275adbfb9a7927e2120dc6c
+refs/heads/master: 7aeacf982203fb4dea2f3434eefdc268cfd5d6d9
diff --git a/trunk/block/ll_rw_blk.c b/trunk/block/ll_rw_blk.c
index fb8fb8852c3b..de5ba479c224 100644
--- a/trunk/block/ll_rw_blk.c
+++ b/trunk/block/ll_rw_blk.c
@@ -1351,8 +1351,20 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
 new_segment:
 			if (!sg)
 				sg = sglist;
-			else
+			else {
+				/*
+				 * If the driver previously mapped a shorter
+				 * list, we could see a termination bit
+				 * prematurely unless it fully inits the sg
+				 * table on each mapping. We KNOW that there
+				 * must be more entries here or the driver
+				 * would be buggy, so force clear the
+				 * termination bit to avoid doing a full
+				 * sg_init_table() in drivers for each command.
+				 */
+				sg->page_link &= ~0x02;
 				sg = sg_next(sg);
+			}
 
 			sg_set_page(sg, bvec->bv_page);
 			sg->length = nbytes;