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, 14 insertions, 11 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 15c9fe766071..1c3e87d6c48f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -34,6 +34,7 @@
 
 #include <trace/events/scsi.h>
 
+#include "scsi_debugfs.h"
 #include "scsi_priv.h"
 #include "scsi_logging.h"
 
@@ -229,8 +230,8 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @rq_flags:	flags for ->rq_flags
  * @resid:	optional residual length
  *
- * returns the req->errors value which is the scsi_cmnd result
- * field.
+ * Returns the scsi_cmnd result field if a command was executed, or a negative
+ * Linux error code if we didn't get that far.
  */
 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		 int data_direction, void *buffer, unsigned bufflen,
@@ -256,7 +257,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 
 	rq->cmd_len = COMMAND_SIZE(cmd[0]);
 	memcpy(rq->cmd, cmd, rq->cmd_len);
-	req->retries = retries;
+	rq->retries = retries;
 	req->timeout = timeout;
 	req->cmd_flags |= flags;
 	req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
@@ -281,7 +282,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 	if (sshdr)
 		scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
-	ret = req->errors;
+	ret = rq->result;
  out:
 	blk_put_request(req);
 
@@ -797,8 +798,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		/*
 		 * __scsi_error_from_host_byte may have reset the host_byte
 		 */
-		req->errors = cmd->result;
-
+		scsi_req(req)->result = cmd->result;
 		scsi_req(req)->resid_len = scsi_get_resid(cmd);
 
 		if (scsi_bidi_cmnd(cmd)) {
@@ -835,7 +835,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 	/*
 	 * Recovered errors need reporting, but they're always treated as
 	 * success, so fiddle the result code here.  For passthrough requests
-	 * we already took a copy of the original into rq->errors which
+	 * we already took a copy of the original into sreq->result which
 	 * is what gets returned to the user
 	 */
 	if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
@@ -1177,7 +1177,7 @@ static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
 	cmd->cmd_len = scsi_req(req)->cmd_len;
 	cmd->cmnd = scsi_req(req)->cmd;
 	cmd->transfersize = blk_rq_bytes(req);
-	cmd->allowed = req->retries;
+	cmd->allowed = scsi_req(req)->retries;
 	return BLKPREP_OK;
 }
 
@@ -1281,7 +1281,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 	switch (ret) {
 	case BLKPREP_KILL:
 	case BLKPREP_INVALID:
-		req->errors = DID_NO_CONNECT << 16;
+		scsi_req(req)->result = DID_NO_CONNECT << 16;
 		/* release the command and kill it */
 		if (req->special) {
 			struct scsi_cmnd *cmd = req->special;
@@ -1905,7 +1905,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, cmd->request->errors);
+	blk_mq_complete_request(cmd->request);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
@@ -2154,10 +2154,13 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
 	return q;
 }
 
-static struct blk_mq_ops scsi_mq_ops = {
+static const struct blk_mq_ops scsi_mq_ops = {
 	.queue_rq	= scsi_queue_rq,
 	.complete	= scsi_softirq_done,
 	.timeout	= scsi_timeout,
+#ifdef CONFIG_BLK_DEBUG_FS
+	.show_rq	= scsi_show_rq,
+#endif
 	.init_request	= scsi_init_request,
 	.exit_request	= scsi_exit_request,
 	.map_queues	= scsi_map_queues,