X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=block%2Fll_rw_blk.c;h=ef42bb2b12b6dd89b0edc1734485e66147920759;hb=e8f3f6cad7e423253090887bc4afe7bc844162da;hp=74a567afb83069f1d666409c645107a2d78e516d;hpb=cabca0cb0d0e8579428d8f8c3f606e2f01d26d14;p=linux-2.6

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 74a567afb8..ef42bb2b12 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -340,6 +340,15 @@ unsigned blk_ordered_req_seq(struct request *rq)
 	if (rq == &q->post_flush_rq)
 		return QUEUE_ORDSEQ_POSTFLUSH;
 
+	/*
+	 * !fs requests don't need to follow barrier ordering.  Always
+	 * put them at the front.  This fixes the following deadlock.
+	 *
+	 * http://thread.gmane.org/gmane.linux.kernel/537473
+	 */
+	if (!blk_fs_request(rq))
+		return QUEUE_ORDSEQ_DRAIN;
+
 	if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
 	    (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
 		return QUEUE_ORDSEQ_DRAIN;
@@ -518,8 +527,6 @@ int blk_do_ordered(request_queue_t *q, struct request **rqp)
 static int flush_dry_bio_endio(struct bio *bio, unsigned int bytes, int error)
 {
 	request_queue_t *q = bio->bi_private;
-	struct bio_vec *bvec;
-	int i;
 
 	/*
 	 * This is dry run, restore bio_sector and size.  We'll finish
@@ -531,13 +538,6 @@ static int flush_dry_bio_endio(struct bio *bio, unsigned int bytes, int error)
 	if (bio->bi_size)
 		return 1;
 
-	/* Rewind bvec's */
-	bio->bi_idx = 0;
-	bio_for_each_segment(bvec, bio, i) {
-		bvec->bv_len += bvec->bv_offset;
-		bvec->bv_offset = 0;
-	}
-
 	/* Reset bio */
 	set_bit(BIO_UPTODATE, &bio->bi_flags);
 	bio->bi_size = q->bi_size;
@@ -1295,9 +1295,9 @@ static int blk_hw_contig_segment(request_queue_t *q, struct bio *bio,
 	if (unlikely(!bio_flagged(nxt, BIO_SEG_VALID)))
 		blk_recount_segments(q, nxt);
 	if (!BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)) ||
-	    BIOVEC_VIRT_OVERSIZE(bio->bi_hw_front_size + bio->bi_hw_back_size))
+	    BIOVEC_VIRT_OVERSIZE(bio->bi_hw_back_size + nxt->bi_hw_front_size))
 		return 0;
-	if (bio->bi_size + nxt->bi_size > q->max_segment_size)
+	if (bio->bi_hw_back_size + nxt->bi_hw_front_size > q->max_segment_size)
 		return 0;
 
 	return 1;
@@ -3802,7 +3802,6 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node)
 
 	return ret;
 }
-EXPORT_SYMBOL(current_io_context);
 
 /*
  * If the current task has no IO context then create one and initialise it.