Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:

 - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ
   was initially a fork of CFQ, but subsequently changed to implement
   fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant
   to be used on desktop type single drives, providing good fairness.
   From Paolo.

 - Add Kyber IO scheduler. This is a full multiqueue aware scheduler,
   using a scalable token based algorithm that throttles IO based on
   live completion IO stats, similary to blk-wbt. From Omar.

 - A series from Jan, moving users to separately allocated backing
   devices. This continues the work of separating backing device life
   times, solving various problems with hot removal.

 - A series of updates for lightnvm, mostly from Javier. Includes a
   'pblk' target that exposes an open channel SSD as a physical block
   device.

 - A series of fixes and improvements for nbd from Josef.

 - A series from Omar, removing queue sharing between devices on mostly
   legacy drivers. This helps us clean up other bits, if we know that a
   queue only has a single device backing. This has been overdue for
   more than a decade.

 - Fixes for the blk-stats, and improvements to unify the stats and user
   windows. This both improves blk-wbt, and enables other users to
   register a need to receive IO stats for a device. From Omar.

 - blk-throttle improvements from Shaohua. This provides a scalable
   framework for implementing scalable priotization - particularly for
   blk-mq, but applicable to any type of block device. The interface is
   marked experimental for now.

 - Bucketized IO stats for IO polling from Stephen Bates. This improves
   efficiency of polled workloads in the presence of mixed block size
   IO.

 - A few fixes for opal, from Scott.

 - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics.
   From a variety of folks, mostly Sagi and James Smart.

 - A series from Bart, improving our exposed info and capabilities from
   the blk-mq debugfs support.

 - A series from Christoph, cleaning up how handle WRITE_ZEROES.

 - A series from Christoph, cleaning up the block layer handling of how
   we track errors in a request. On top of being a nice cleanup, it also
   shrinks the size of struct request a bit.

 - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was
   never used by platforms, and the latter has outlived it's usefulness.

 - Various little bug fixes and cleanups from a wide variety of folks.

* 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits)
  block: hide badblocks attribute by default
  blk-mq: unify hctx delay_work and run_work
  block: add kblock_mod_delayed_work_on()
  blk-mq: unify hctx delayed_run_work and run_work
  nbd: fix use after free on module unload
  MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler
  blk-mq-sched: alloate reserved tags out of normal pool
  mtip32xx: use runtime tag to initialize command header
  scsi: Implement blk_mq_ops.show_rq()
  blk-mq: Add blk_mq_ops.show_rq()
  blk-mq: Show operation, cmd_flags and rq_flags names
  blk-mq: Make blk_flags_show() callers append a newline character
  blk-mq: Move the "state" debugfs attribute one level down
  blk-mq: Unregister debugfs attributes earlier
  blk-mq: Only unregister hctxs for which registration succeeded
  blk-mq-debugfs: Rename functions for registering and unregistering the mq directory
  blk-mq: Let blk_mq_debugfs_register() look up the queue name
  blk-mq: Register <dev>/queue/mq after having registered <dev>/queue
  ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset
  ide-pm: always pass 0 error to __blk_end_request_all
  ..

1 files changed, 19 insertions, 19 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 0ecb6461ed81..994403efee19 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -445,32 +445,27 @@ static int lo_req_flush(struct loop_device *lo, struct request *rq)
 	return ret;
 }
 
-static inline void handle_partial_read(struct loop_cmd *cmd, long bytes)
+static void lo_complete_rq(struct request *rq)
 {
-	if (bytes < 0 || op_is_write(req_op(cmd->rq)))
-		return;
+	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
-	if (unlikely(bytes < blk_rq_bytes(cmd->rq))) {
+	if (unlikely(req_op(cmd->rq) == REQ_OP_READ && cmd->use_aio &&
+		     cmd->ret >= 0 && cmd->ret < blk_rq_bytes(cmd->rq))) {
 		struct bio *bio = cmd->rq->bio;
 
-		bio_advance(bio, bytes);
+		bio_advance(bio, cmd->ret);
 		zero_fill_bio(bio);
 	}
+
+	blk_mq_end_request(rq, cmd->ret < 0 ? -EIO : 0);
 }
 
 static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 {
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
-	struct request *rq = cmd->rq;
-
-	handle_partial_read(cmd, ret);
 
-	if (ret > 0)
-		ret = 0;
-	else if (ret < 0)
-		ret = -EIO;
-
-	blk_mq_complete_request(rq, ret);
+	cmd->ret = ret;
+	blk_mq_complete_request(cmd->rq);
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
@@ -528,6 +523,7 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 	case REQ_OP_FLUSH:
 		return lo_req_flush(lo, rq);
 	case REQ_OP_DISCARD:
+	case REQ_OP_WRITE_ZEROES:
 		return lo_discard(lo, rq, pos);
 	case REQ_OP_WRITE:
 		if (lo->transfer)
@@ -826,7 +822,7 @@ static void loop_config_discard(struct loop_device *lo)
 		q->limits.discard_granularity = 0;
 		q->limits.discard_alignment = 0;
 		blk_queue_max_discard_sectors(q, 0);
-		q->limits.discard_zeroes_data = 0;
+		blk_queue_max_write_zeroes_sectors(q, 0);
 		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
 		return;
 	}
@@ -834,7 +830,7 @@ static void loop_config_discard(struct loop_device *lo)
 	q->limits.discard_granularity = inode->i_sb->s_blocksize;
 	q->limits.discard_alignment = 0;
 	blk_queue_max_discard_sectors(q, UINT_MAX >> 9);
-	q->limits.discard_zeroes_data = 1;
+	blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9);
 	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 }
 
@@ -1660,6 +1656,7 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	switch (req_op(cmd->rq)) {
 	case REQ_OP_FLUSH:
 	case REQ_OP_DISCARD:
+	case REQ_OP_WRITE_ZEROES:
 		cmd->use_aio = false;
 		break;
 	default:
@@ -1686,8 +1683,10 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	ret = do_req_filebacked(lo, cmd->rq);
  failed:
 	/* complete non-aio request */
-	if (!cmd->use_aio || ret)
-		blk_mq_complete_request(cmd->rq, ret ? -EIO : 0);
+	if (!cmd->use_aio || ret) {
+		cmd->ret = ret ? -EIO : 0;
+		blk_mq_complete_request(cmd->rq);
+	}
 }
 
 static void loop_queue_work(struct kthread_work *work)
@@ -1710,9 +1709,10 @@ static int loop_init_request(void *data, struct request *rq,
 	return 0;
 }
 
-static struct blk_mq_ops loop_mq_ops = {
+static const struct blk_mq_ops loop_mq_ops = {
 	.queue_rq       = loop_queue_rq,
 	.init_request	= loop_init_request,
+	.complete	= lo_complete_rq,
 };
 
 static int loop_add(struct loop_device **l, int i)