Merge tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block

Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...

1 files changed, 8 insertions, 7 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 22467f475ab4..1c9d4f0f96ea 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -180,7 +180,7 @@ static unsigned get_max_segment_size(struct request_queue *q,
  */
 static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv,
 		unsigned *nsegs, unsigned *last_seg_size,
-		unsigned *front_seg_size, unsigned *sectors)
+		unsigned *front_seg_size, unsigned *sectors, unsigned max_segs)
 {
 	unsigned len = bv->bv_len;
 	unsigned total_len = 0;
@@ -190,7 +190,7 @@ static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv,
 	 * Multi-page bvec may be too big to hold in one segment, so the
 	 * current bvec has to be splitted as multiple segments.
 	 */
-	while (len && new_nsegs + *nsegs < queue_max_segments(q)) {
+	while (len && new_nsegs + *nsegs < max_segs) {
 		seg_size = get_max_segment_size(q, bv->bv_offset + total_len);
 		seg_size = min(seg_size, len);
 
@@ -240,6 +240,7 @@ 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);
+	const unsigned max_segs = queue_max_segments(q);
 
 	bio_for_each_bvec(bv, bio, iter) {
 		/*
@@ -254,14 +255,14 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 			 * Consider this a new segment if we're splitting in
 			 * the middle of this vector.
 			 */
-			if (nsegs < queue_max_segments(q) &&
+			if (nsegs < max_segs &&
 			    sectors < max_sectors) {
 				/* split in the middle of bvec */
 				bv.bv_len = (max_sectors - sectors) << 9;
 				bvec_split_segs(q, &bv, &nsegs,
 						&seg_size,
 						&front_seg_size,
-						&sectors);
+						&sectors, max_segs);
 			}
 			goto split;
 		}
@@ -283,7 +284,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 			continue;
 		}
 new_segment:
-		if (nsegs == queue_max_segments(q))
+		if (nsegs == max_segs)
 			goto split;
 
 		bvprv = bv;
@@ -296,7 +297,7 @@ new_segment:
 			if (nsegs == 1 && seg_size > front_seg_size)
 				front_seg_size = seg_size;
 		} else if (bvec_split_segs(q, &bv, &nsegs, &seg_size,
-				    &front_seg_size, &sectors)) {
+				    &front_seg_size, &sectors, max_segs)) {
 			goto split;
 		}
 	}
@@ -415,7 +416,7 @@ new_segment:
 			bvprv = bv;
 			prev = 1;
 			bvec_split_segs(q, &bv, &nr_phys_segs, &seg_size,
-					&front_seg_size, NULL);
+					&front_seg_size, NULL, UINT_MAX);
 		}
 		bbio = bio;
 	}