Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "This is the main pull request for block/storage for 4.21.

  Larger than usual, it was a busy round with lots of goodies queued up.
  Most notable is the removal of the old IO stack, which has been a long
  time coming. No new features for a while, everything coming in this
  week has all been fixes for things that were previously merged.

  This contains:

   - Use atomic counters instead of semaphores for mtip32xx (Arnd)

   - Cleanup of the mtip32xx request setup (Christoph)

   - Fix for circular locking dependency in loop (Jan, Tetsuo)

   - bcache (Coly, Guoju, Shenghui)
      * Optimizations for writeback caching
      * Various fixes and improvements

   - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith)
      * host and target support for NVMe over TCP
      * Error log page support
      * Support for separate read/write/poll queues
      * Much improved polling
      * discard OOM fallback
      * Tracepoint improvements

   - lightnvm (Hans, Hua, Igor, Matias, Javier)
      * Igor added packed metadata to pblk. Now drives without metadata
        per LBA can be used as well.
      * Fix from Geert on uninitialized value on chunk metadata reads.
      * Fixes from Hans and Javier to pblk recovery and write path.
      * Fix from Hua Su to fix a race condition in the pblk recovery
        code.
      * Scan optimization added to pblk recovery from Zhoujie.
      * Small geometry cleanup from me.

   - Conversion of the last few drivers that used the legacy path to
     blk-mq (me)

   - Removal of legacy IO path in SCSI (me, Christoph)

   - Removal of legacy IO stack and schedulers (me)

   - Support for much better polling, now without interrupts at all.
     blk-mq adds support for multiple queue maps, which enables us to
     have a map per type. This in turn enables nvme to have separate
     completion queues for polling, which can then be interrupt-less.
     Also means we're ready for async polled IO, which is hopefully
     coming in the next release.

   - Killing of (now) unused block exports (Christoph)

   - Unification of the blk-rq-qos and blk-wbt wait handling (Josef)

   - Support for zoned testing with null_blk (Masato)

   - sx8 conversion to per-host tag sets (Christoph)

   - IO priority improvements (Damien)

   - mq-deadline zoned fix (Damien)

   - Ref count blkcg series (Dennis)

   - Lots of blk-mq improvements and speedups (me)

   - sbitmap scalability improvements (me)

   - Make core inflight IO accounting per-cpu (Mikulas)

   - Export timeout setting in sysfs (Weiping)

   - Cleanup the direct issue path (Jianchao)

   - Export blk-wbt internals in block debugfs for easier debugging
     (Ming)

   - Lots of other fixes and improvements"

* tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits)
  kyber: use sbitmap add_wait_queue/list_del wait helpers
  sbitmap: add helpers for add/del wait queue handling
  block: save irq state in blkg_lookup_create()
  dm: don't reuse bio for flushes
  nvme-pci: trace SQ status on completions
  nvme-rdma: implement polling queue map
  nvme-fabrics: allow user to pass in nr_poll_queues
  nvme-fabrics: allow nvmf_connect_io_queue to poll
  nvme-core: optionally poll sync commands
  block: make request_to_qc_t public
  nvme-tcp: fix spelling mistake "attepmpt" -> "attempt"
  nvme-tcp: fix endianess annotations
  nvmet-tcp: fix endianess annotations
  nvme-pci: refactor nvme_poll_irqdisable to make sparse happy
  nvme-pci: only set nr_maps to 2 if poll queues are supported
  nvmet: use a macro for default error location
  nvmet: fix comparison of a u16 with -1
  blk-mq: enable IO poll if .nr_queues of type poll > 0
  blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight()
  blk-mq: skip zero-queue maps in blk_mq_map_swqueue
  ...

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index d2b9fdbc8994..6a743d3bb338 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -5,12 +5,17 @@
 #define CUTOFF_WRITEBACK	40
 #define CUTOFF_WRITEBACK_SYNC	70
 
+#define CUTOFF_WRITEBACK_MAX		70
+#define CUTOFF_WRITEBACK_SYNC_MAX	90
+
 #define MAX_WRITEBACKS_IN_PASS  5
 #define MAX_WRITESIZE_IN_PASS   5000	/* *512b */
 
 #define WRITEBACK_RATE_UPDATE_SECS_MAX		60
 #define WRITEBACK_RATE_UPDATE_SECS_DEFAULT	5
 
+#define BCH_AUTO_GC_DIRTY_THRESHOLD	50
+
 /*
  * 14 (16384ths) is chosen here as something that each backing device
  * should be a reasonable fraction of the share, and not to blow up
@@ -53,6 +58,9 @@ static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
 	}
 }
 
+extern unsigned int bch_cutoff_writeback;
+extern unsigned int bch_cutoff_writeback_sync;
+
 static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
 				    unsigned int cache_mode, bool would_skip)
 {
@@ -60,7 +68,7 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
 
 	if (cache_mode != CACHE_MODE_WRITEBACK ||
 	    test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
-	    in_use > CUTOFF_WRITEBACK_SYNC)
+	    in_use > bch_cutoff_writeback_sync)
 		return false;
 
 	if (dc->partial_stripes_expensive &&
@@ -73,7 +81,7 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
 
 	return (op_is_sync(bio->bi_opf) ||
 		bio->bi_opf & (REQ_META|REQ_PRIO) ||
-		in_use <= CUTOFF_WRITEBACK);
+		in_use <= bch_cutoff_writeback);
 }
 
 static inline void bch_writeback_queue(struct cached_dev *dc)