X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=block%2Fblk-map.c;h=ddd96fb11a7d71638a32e3e9060aac1f1adac808;hb=5402a7349d26875f69c184badf87b88541b1cf6c;hp=0b1af5a3537ca0728407c8acfedfaba44338cd19;hpb=c36c804559d3a891a2e655ba8185b4fa7eaee156;p=linux-2.6

diff --git a/block/blk-map.c b/block/blk-map.c
index 0b1af5a353..ddd96fb11a 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -210,6 +210,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 	if (!bio_flagged(bio, BIO_USER_MAPPED))
 		rq->cmd_flags |= REQ_COPY_USER;
 
+	blk_queue_bounce(q, &bio);
 	bio_get(bio);
 	blk_rq_bio_prep(q, rq, bio);
 	rq->buffer = rq->data = NULL;
@@ -268,6 +269,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	int reading = rq_data_dir(rq) == READ;
 	int do_copy = 0;
 	struct bio *bio;
+	unsigned long stack_mask = ~(THREAD_SIZE - 1);
 
 	if (len > (q->max_hw_sectors << 9))
 		return -EINVAL;
@@ -278,6 +280,10 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
 	do_copy = ((kaddr & alignment) || (len & alignment));
 
+	if (!((kaddr & stack_mask) ^
+	      ((unsigned long)current->stack & stack_mask)))
+		do_copy = 1;
+
 	if (do_copy)
 		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
 	else