block: Add fallthrough markers to switch statements

[karo-tx-linux.git] / block / blk-merge.c

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3990ae40634123b4e16b0398ae36d1f1b74dc205..5df13041b8513128c9e1e028e0711895b0ad365d 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -108,30 +108,8 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
        bool do_split = true;
        struct bio *new = NULL;
        const unsigned max_sectors = get_max_io_size(q, bio);
-       unsigned bvecs = 0;
 
        bio_for_each_segment(bv, bio, iter) {
-               /*
-                * With arbitrary bio size, the incoming bio may be very
-                * big. We have to split the bio into small bios so that
-                * each holds at most BIO_MAX_PAGES bvecs because
-                * bio_clone() can fail to allocate big bvecs.
-                *
-                * It should have been better to apply the limit per
-                * request queue in which bio_clone() is involved,
-                * instead of globally. The biggest blocker is the
-                * bio_clone() in bio bounce.
-                *
-                * If bio is splitted by this reason, we should have
-                * allowed to continue bios merging, but don't do
-                * that now for making the change simple.
-                *
-                * TODO: deal with bio bounce's bio_clone() gracefully
-                * and convert the global limit into per-queue limit.
-                */
-               if (bvecs++ >= BIO_MAX_PAGES)
-                       goto split;
-
                /*
                 * If the queue doesn't support SG gaps and adding this
                 * offset would create a gap, disallow it.
@@ -202,8 +180,7 @@ split:
        return do_split ? new : NULL;
 }
 
-void blk_queue_split(struct request_queue *q, struct bio **bio,
-                    struct bio_set *bs)
+void blk_queue_split(struct request_queue *q, struct bio **bio)
 {
        struct bio *split, *res;
        unsigned nsegs;
@@ -211,13 +188,13 @@ void blk_queue_split(struct request_queue *q, struct bio **bio,
        switch (bio_op(*bio)) {
        case REQ_OP_DISCARD:
        case REQ_OP_SECURE_ERASE:
-               split = blk_bio_discard_split(q, *bio, bs, &nsegs);
+               split = blk_bio_discard_split(q, *bio, q->bio_split, &nsegs);
                break;
        case REQ_OP_WRITE_ZEROES:
-               split = blk_bio_write_zeroes_split(q, *bio, bs, &nsegs);
+               split = blk_bio_write_zeroes_split(q, *bio, q->bio_split, &nsegs);
                break;
        case REQ_OP_WRITE_SAME:
-               split = blk_bio_write_same_split(q, *bio, bs, &nsegs);
+               split = blk_bio_write_same_split(q, *bio, q->bio_split, &nsegs);
                break;
        default:
                split = blk_bio_segment_split(q, *bio, q->bio_split, &nsegs);
@@ -671,6 +648,9 @@ static void blk_account_io_merge(struct request *req)
 static struct request *attempt_merge(struct request_queue *q,
                                     struct request *req, struct request *next)
 {
+       if (!q->mq_ops)
+               lockdep_assert_held(q->queue_lock);
+
        if (!rq_mergeable(req) || !rq_mergeable(next))
                return NULL;