Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/cpufreq

[sfrench/cifs-2.6.git] / block / ll_rw_blk.c

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 6b5173ac81313d8adb5c1d7b521559f565bb209b..ef42bb2b12b6dd89b0edc1734485e66147920759 100644 (file)
--- 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;