Merge tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - clean up how we pass around gfp_t and
   blk_mq_req_flags_t (Christoph)

 - prepare us to defer scheduler attach (Christoph)

 - clean up drivers handling of bounce buffers (Christoph)

 - fix timeout handling corner cases (Christoph/Bart/Keith)

 - bcache fixes (Coly)

 - prep work for bcachefs and some block layer optimizations (Kent).

 - convert users of bio_sets to using embedded structs (Kent).

 - fixes for the BFQ io scheduler (Paolo/Davide/Filippo)

 - lightnvm fixes and improvements (Matias, with contributions from Hans
   and Javier)

 - adding discard throttling to blk-wbt (me)

 - sbitmap blk-mq-tag handling (me/Omar/Ming).

 - remove the sparc jsflash block driver, acked by DaveM.

 - Kyber scheduler improvement from Jianchao, making it more friendly
   wrt merging.

 - conversion of symbolic proc permissions to octal, from Joe Perches.
   Previously the block parts were a mix of both.

 - nbd fixes (Josef and Kevin Vigor)

 - unify how we handle the various kinds of timestamps that the block
   core and utility code uses (Omar)

 - three NVMe pull requests from Keith and Christoph, bringing AEN to
   feature completeness, file backed namespaces, cq/sq lock split, and
   various fixes

 - various little fixes and improvements all over the map

* tag 'for-4.18/block-20180603' of git://git.kernel.dk/linux-block: (196 commits)
  blk-mq: update nr_requests when switching to 'none' scheduler
  block: don't use blocking queue entered for recursive bio submits
  dm-crypt: fix warning in shutdown path
  lightnvm: pblk: take bitmap alloc. out of critical section
  lightnvm: pblk: kick writer on new flush points
  lightnvm: pblk: only try to recover lines with written smeta
  lightnvm: pblk: remove unnecessary bio_get/put
  lightnvm: pblk: add possibility to set write buffer size manually
  lightnvm: fix partial read error path
  lightnvm: proper error handling for pblk_bio_add_pages
  lightnvm: pblk: fix smeta write error path
  lightnvm: pblk: garbage collect lines with failed writes
  lightnvm: pblk: rework write error recovery path
  lightnvm: pblk: remove dead function
  lightnvm: pass flag on graceful teardown to targets
  lightnvm: pblk: check for chunk size before allocating it
  lightnvm: pblk: remove unnecessary argument
  lightnvm: pblk: remove unnecessary indirection
  lightnvm: pblk: return NVM_ error on failed submission
  lightnvm: pblk: warn in case of corrupted write buffer
  ...

1 files changed, 25 insertions, 21 deletions

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 25c14c58385c..56c493c6cd90 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -268,19 +268,16 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
 EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge);
 
 /*
- * Reverse check our software queue for entries that we could potentially
- * merge with. Currently includes a hand-wavy stop count of 8, to not spend
- * too much time checking for merges.
+ * Iterate list of requests and see if we can merge this bio with any
+ * of them.
  */
-static bool blk_mq_attempt_merge(struct request_queue *q,
-				 struct blk_mq_ctx *ctx, struct bio *bio)
+bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
+			   struct bio *bio)
 {
 	struct request *rq;
 	int checked = 8;
 
-	lockdep_assert_held(&ctx->lock);
-
-	list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
+	list_for_each_entry_reverse(rq, list, queuelist) {
 		bool merged = false;
 
 		if (!checked--)
@@ -305,13 +302,30 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
 			continue;
 		}
 
-		if (merged)
-			ctx->rq_merged++;
 		return merged;
 	}
 
 	return false;
 }
+EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge);
+
+/*
+ * Reverse check our software queue for entries that we could potentially
+ * merge with. Currently includes a hand-wavy stop count of 8, to not spend
+ * too much time checking for merges.
+ */
+static bool blk_mq_attempt_merge(struct request_queue *q,
+				 struct blk_mq_ctx *ctx, struct bio *bio)
+{
+	lockdep_assert_held(&ctx->lock);
+
+	if (blk_mq_bio_list_merge(q, &ctx->rq_list, bio)) {
+		ctx->rq_merged++;
+		return true;
+	}
+
+	return false;
+}
 
 bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
 {
@@ -571,6 +585,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 
 	if (!e) {
 		q->elevator = NULL;
+		q->nr_requests = q->tag_set->queue_depth;
 		return 0;
 	}
 
@@ -633,14 +648,3 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
 	blk_mq_sched_tags_teardown(q);
 	q->elevator = NULL;
 }
-
-int blk_mq_sched_init(struct request_queue *q)
-{
-	int ret;
-
-	mutex_lock(&q->sysfs_lock);
-	ret = elevator_init(q, NULL);
-	mutex_unlock(&q->sysfs_lock);
-
-	return ret;
-}