Merge tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block
authorLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Aug 2021 01:52:11 +0000 (18:52 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 31 Aug 2021 01:52:11 +0000 (18:52 -0700)
Pull block updates from Jens Axboe:
 "Nothing major in here - lots of good cleanups and tech debt handling,
  which is also evident in the diffstats. In particular:

   - Add disk sequence numbers (Matteo)

   - Discard merge fix (Ming)

   - Relax disk zoned reporting restrictions (Niklas)

   - Bio error handling zoned leak fix (Pavel)

   - Start of proper add_disk() error handling (Luis, Christoph)

   - blk crypto fix (Eric)

   - Non-standard GPT location support (Dmitry)

   - IO priority improvements and cleanups (Damien)o

   - blk-throtl improvements (Chunguang)

   - diskstats_show() stack reduction (Abd-Alrhman)

   - Loop scheduler selection (Bart)

   - Switch block layer to use kmap_local_page() (Christoph)

   - Remove obsolete disk_name helper (Christoph)

   - block_device refcounting improvements (Christoph)

   - Ensure gendisk always has a request queue reference (Christoph)

   - Misc fixes/cleanups (Shaokun, Oliver, Guoqing)"

* tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block: (129 commits)
  sg: pass the device name to blk_trace_setup
  block, bfq: cleanup the repeated declaration
  blk-crypto: fix check for too-large dun_bytes
  blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN
  blk-zoned: allow zone management send operations without CAP_SYS_ADMIN
  block: mark blkdev_fsync static
  block: refine the disk_live check in del_gendisk
  mmc: sdhci-tegra: Enable MMC_CAP2_ALT_GPT_TEGRA
  mmc: block: Support alternative_gpt_sector() operation
  partitions/efi: Support non-standard GPT location
  block: Add alternative_gpt_sector() operation
  bio: fix page leak bio_add_hw_page failure
  block: remove CONFIG_DEBUG_BLOCK_EXT_DEVT
  block: remove a pointless call to MINOR() in device_add_disk
  null_blk: add error handling support for add_disk()
  virtio_blk: add error handling support for add_disk()
  block: add error handling for device_add_disk / add_disk
  block: return errors from disk_alloc_events
  block: return errors from blk_integrity_add
  block: call blk_register_queue earlier in device_add_disk
  ...

14 files changed:
1  2 
block/Makefile
block/blk-cgroup.c
block/blk-core.c
block/blk-iocost.c
block/blk-iolatency.c
block/blk-mq.c
block/blk.h
block/mq-deadline.c
block/partitions/ldm.c
drivers/block/virtio_blk.c
drivers/s390/block/dasd_eckd.c
drivers/scsi/sr.c
include/linux/fs.h
lib/Kconfig.debug

diff --cc block/Makefile
Simple merge
Simple merge
Simple merge
Simple merge
Simple merge
diff --cc block/blk-mq.c
Simple merge
diff --cc block/blk.h
Simple merge
index 36920670dccc35f3c4d019423a53754400c3a40a,0000000000000000000000000000000000000000..3c3693c34f0615b301b81bbb25dcfd345dac54af
mode 100644,000000..100644
--- /dev/null
@@@ -1,1104 -1,0 +1,1106 @@@
 +// SPDX-License-Identifier: GPL-2.0
 +/*
 + *  MQ Deadline i/o scheduler - adaptation of the legacy deadline scheduler,
 + *  for the blk-mq scheduling framework
 + *
 + *  Copyright (C) 2016 Jens Axboe <axboe@kernel.dk>
 + */
 +#include <linux/kernel.h>
 +#include <linux/fs.h>
 +#include <linux/blkdev.h>
 +#include <linux/blk-mq.h>
 +#include <linux/elevator.h>
 +#include <linux/bio.h>
 +#include <linux/module.h>
 +#include <linux/slab.h>
 +#include <linux/init.h>
 +#include <linux/compiler.h>
 +#include <linux/rbtree.h>
 +#include <linux/sbitmap.h>
 +
 +#include <trace/events/block.h>
 +
 +#include "blk.h"
 +#include "blk-mq.h"
 +#include "blk-mq-debugfs.h"
 +#include "blk-mq-tag.h"
 +#include "blk-mq-sched.h"
 +
 +/*
 + * See Documentation/block/deadline-iosched.rst
 + */
 +static const int read_expire = HZ / 2;  /* max time before a read is submitted. */
 +static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
 +static const int writes_starved = 2;    /* max times reads can starve a write */
 +static const int fifo_batch = 16;       /* # of sequential requests treated as one
 +                                   by the above parameters. For throughput. */
 +
 +enum dd_data_dir {
 +      DD_READ         = READ,
 +      DD_WRITE        = WRITE,
 +};
 +
 +enum { DD_DIR_COUNT = 2 };
 +
 +enum dd_prio {
 +      DD_RT_PRIO      = 0,
 +      DD_BE_PRIO      = 1,
 +      DD_IDLE_PRIO    = 2,
 +      DD_PRIO_MAX     = 2,
 +};
 +
 +enum { DD_PRIO_COUNT = 3 };
 +
 +/* I/O statistics per I/O priority. */
 +struct io_stats_per_prio {
 +      local_t inserted;
 +      local_t merged;
 +      local_t dispatched;
 +      local_t completed;
 +};
 +
 +/* I/O statistics for all I/O priorities (enum dd_prio). */
 +struct io_stats {
 +      struct io_stats_per_prio stats[DD_PRIO_COUNT];
 +};
 +
 +/*
 + * Deadline scheduler data per I/O priority (enum dd_prio). Requests are
 + * present on both sort_list[] and fifo_list[].
 + */
 +struct dd_per_prio {
 +      struct list_head dispatch;
 +      struct rb_root sort_list[DD_DIR_COUNT];
 +      struct list_head fifo_list[DD_DIR_COUNT];
 +      /* Next request in FIFO order. Read, write or both are NULL. */
 +      struct request *next_rq[DD_DIR_COUNT];
 +};
 +
 +struct deadline_data {
 +      /*
 +       * run time data
 +       */
 +
 +      struct dd_per_prio per_prio[DD_PRIO_COUNT];
 +
 +      /* Data direction of latest dispatched request. */
 +      enum dd_data_dir last_dir;
 +      unsigned int batching;          /* number of sequential requests made */
 +      unsigned int starved;           /* times reads have starved writes */
 +
 +      struct io_stats __percpu *stats;
 +
 +      /*
 +       * settings that change how the i/o scheduler behaves
 +       */
 +      int fifo_expire[DD_DIR_COUNT];
 +      int fifo_batch;
 +      int writes_starved;
 +      int front_merges;
 +      u32 async_depth;
 +
 +      spinlock_t lock;
 +      spinlock_t zone_lock;
 +};
 +
 +/* Count one event of type 'event_type' and with I/O priority 'prio' */
 +#define dd_count(dd, event_type, prio) do {                           \
 +      struct io_stats *io_stats = get_cpu_ptr((dd)->stats);           \
 +                                                                      \
 +      BUILD_BUG_ON(!__same_type((dd), struct deadline_data *));       \
 +      BUILD_BUG_ON(!__same_type((prio), enum dd_prio));               \
 +      local_inc(&io_stats->stats[(prio)].event_type);                 \
 +      put_cpu_ptr(io_stats);                                          \
 +} while (0)
 +
 +/*
 + * Returns the total number of dd_count(dd, event_type, prio) calls across all
 + * CPUs. No locking or barriers since it is fine if the returned sum is slightly
 + * outdated.
 + */
 +#define dd_sum(dd, event_type, prio) ({                                       \
 +      unsigned int cpu;                                               \
 +      u32 sum = 0;                                                    \
 +                                                                      \
 +      BUILD_BUG_ON(!__same_type((dd), struct deadline_data *));       \
 +      BUILD_BUG_ON(!__same_type((prio), enum dd_prio));               \
 +      for_each_present_cpu(cpu)                                       \
 +              sum += local_read(&per_cpu_ptr((dd)->stats, cpu)->      \
 +                                stats[(prio)].event_type);            \
 +      sum;                                                            \
 +})
 +
 +/* Maps an I/O priority class to a deadline scheduler priority. */
 +static const enum dd_prio ioprio_class_to_prio[] = {
 +      [IOPRIO_CLASS_NONE]     = DD_BE_PRIO,
 +      [IOPRIO_CLASS_RT]       = DD_RT_PRIO,
 +      [IOPRIO_CLASS_BE]       = DD_BE_PRIO,
 +      [IOPRIO_CLASS_IDLE]     = DD_IDLE_PRIO,
 +};
 +
 +static inline struct rb_root *
 +deadline_rb_root(struct dd_per_prio *per_prio, struct request *rq)
 +{
 +      return &per_prio->sort_list[rq_data_dir(rq)];
 +}
 +
 +/*
 + * Returns the I/O priority class (IOPRIO_CLASS_*) that has been assigned to a
 + * request.
 + */
 +static u8 dd_rq_ioclass(struct request *rq)
 +{
 +      return IOPRIO_PRIO_CLASS(req_get_ioprio(rq));
 +}
 +
 +/*
 + * get the request after `rq' in sector-sorted order
 + */
 +static inline struct request *
 +deadline_latter_request(struct request *rq)
 +{
 +      struct rb_node *node = rb_next(&rq->rb_node);
 +
 +      if (node)
 +              return rb_entry_rq(node);
 +
 +      return NULL;
 +}
 +
 +static void
 +deadline_add_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
 +{
 +      struct rb_root *root = deadline_rb_root(per_prio, rq);
 +
 +      elv_rb_add(root, rq);
 +}
 +
 +static inline void
 +deadline_del_rq_rb(struct dd_per_prio *per_prio, struct request *rq)
 +{
 +      const enum dd_data_dir data_dir = rq_data_dir(rq);
 +
 +      if (per_prio->next_rq[data_dir] == rq)
 +              per_prio->next_rq[data_dir] = deadline_latter_request(rq);
 +
 +      elv_rb_del(deadline_rb_root(per_prio, rq), rq);
 +}
 +
 +/*
 + * remove rq from rbtree and fifo.
 + */
 +static void deadline_remove_request(struct request_queue *q,
 +                                  struct dd_per_prio *per_prio,
 +                                  struct request *rq)
 +{
 +      list_del_init(&rq->queuelist);
 +
 +      /*
 +       * We might not be on the rbtree, if we are doing an insert merge
 +       */
 +      if (!RB_EMPTY_NODE(&rq->rb_node))
 +              deadline_del_rq_rb(per_prio, rq);
 +
 +      elv_rqhash_del(q, rq);
 +      if (q->last_merge == rq)
 +              q->last_merge = NULL;
 +}
 +
 +static void dd_request_merged(struct request_queue *q, struct request *req,
 +                            enum elv_merge type)
 +{
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      const u8 ioprio_class = dd_rq_ioclass(req);
 +      const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];
 +
 +      /*
 +       * if the merge was a front merge, we need to reposition request
 +       */
 +      if (type == ELEVATOR_FRONT_MERGE) {
 +              elv_rb_del(deadline_rb_root(per_prio, req), req);
 +              deadline_add_rq_rb(per_prio, req);
 +      }
 +}
 +
 +/*
 + * Callback function that is invoked after @next has been merged into @req.
 + */
 +static void dd_merged_requests(struct request_queue *q, struct request *req,
 +                             struct request *next)
 +{
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      const u8 ioprio_class = dd_rq_ioclass(next);
 +      const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
 +
 +      dd_count(dd, merged, prio);
 +
 +      /*
 +       * if next expires before rq, assign its expire time to rq
 +       * and move into next position (next will be deleted) in fifo
 +       */
 +      if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
 +              if (time_before((unsigned long)next->fifo_time,
 +                              (unsigned long)req->fifo_time)) {
 +                      list_move(&req->queuelist, &next->queuelist);
 +                      req->fifo_time = next->fifo_time;
 +              }
 +      }
 +
 +      /*
 +       * kill knowledge of next, this one is a goner
 +       */
 +      deadline_remove_request(q, &dd->per_prio[prio], next);
 +}
 +
 +/*
 + * move an entry to dispatch queue
 + */
 +static void
 +deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
 +                    struct request *rq)
 +{
 +      const enum dd_data_dir data_dir = rq_data_dir(rq);
 +
 +      per_prio->next_rq[data_dir] = deadline_latter_request(rq);
 +
 +      /*
 +       * take it off the sort and fifo list
 +       */
 +      deadline_remove_request(rq->q, per_prio, rq);
 +}
 +
 +/* Number of requests queued for a given priority level. */
 +static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio)
 +{
 +      return dd_sum(dd, inserted, prio) - dd_sum(dd, completed, prio);
 +}
 +
 +/*
 + * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
 + * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
 + */
 +static inline int deadline_check_fifo(struct dd_per_prio *per_prio,
 +                                    enum dd_data_dir data_dir)
 +{
 +      struct request *rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
 +
 +      /*
 +       * rq is expired!
 +       */
 +      if (time_after_eq(jiffies, (unsigned long)rq->fifo_time))
 +              return 1;
 +
 +      return 0;
 +}
 +
 +/*
 + * For the specified data direction, return the next request to
 + * dispatch using arrival ordered lists.
 + */
 +static struct request *
 +deadline_fifo_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
 +                    enum dd_data_dir data_dir)
 +{
 +      struct request *rq;
 +      unsigned long flags;
 +
 +      if (list_empty(&per_prio->fifo_list[data_dir]))
 +              return NULL;
 +
 +      rq = rq_entry_fifo(per_prio->fifo_list[data_dir].next);
 +      if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
 +              return rq;
 +
 +      /*
 +       * Look for a write request that can be dispatched, that is one with
 +       * an unlocked target zone.
 +       */
 +      spin_lock_irqsave(&dd->zone_lock, flags);
 +      list_for_each_entry(rq, &per_prio->fifo_list[DD_WRITE], queuelist) {
 +              if (blk_req_can_dispatch_to_zone(rq))
 +                      goto out;
 +      }
 +      rq = NULL;
 +out:
 +      spin_unlock_irqrestore(&dd->zone_lock, flags);
 +
 +      return rq;
 +}
 +
 +/*
 + * For the specified data direction, return the next request to
 + * dispatch using sector position sorted lists.
 + */
 +static struct request *
 +deadline_next_request(struct deadline_data *dd, struct dd_per_prio *per_prio,
 +                    enum dd_data_dir data_dir)
 +{
 +      struct request *rq;
 +      unsigned long flags;
 +
 +      rq = per_prio->next_rq[data_dir];
 +      if (!rq)
 +              return NULL;
 +
 +      if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q))
 +              return rq;
 +
 +      /*
 +       * Look for a write request that can be dispatched, that is one with
 +       * an unlocked target zone.
 +       */
 +      spin_lock_irqsave(&dd->zone_lock, flags);
 +      while (rq) {
 +              if (blk_req_can_dispatch_to_zone(rq))
 +                      break;
 +              rq = deadline_latter_request(rq);
 +      }
 +      spin_unlock_irqrestore(&dd->zone_lock, flags);
 +
 +      return rq;
 +}
 +
 +/*
 + * deadline_dispatch_requests selects the best request according to
 + * read/write expire, fifo_batch, etc
 + */
 +static struct request *__dd_dispatch_request(struct deadline_data *dd,
 +                                           struct dd_per_prio *per_prio)
 +{
 +      struct request *rq, *next_rq;
 +      enum dd_data_dir data_dir;
 +      enum dd_prio prio;
 +      u8 ioprio_class;
 +
 +      lockdep_assert_held(&dd->lock);
 +
 +      if (!list_empty(&per_prio->dispatch)) {
 +              rq = list_first_entry(&per_prio->dispatch, struct request,
 +                                    queuelist);
 +              list_del_init(&rq->queuelist);
 +              goto done;
 +      }
 +
 +      /*
 +       * batches are currently reads XOR writes
 +       */
 +      rq = deadline_next_request(dd, per_prio, dd->last_dir);
 +      if (rq && dd->batching < dd->fifo_batch)
 +              /* we have a next request are still entitled to batch */
 +              goto dispatch_request;
 +
 +      /*
 +       * at this point we are not running a batch. select the appropriate
 +       * data direction (read / write)
 +       */
 +
 +      if (!list_empty(&per_prio->fifo_list[DD_READ])) {
 +              BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_READ]));
 +
 +              if (deadline_fifo_request(dd, per_prio, DD_WRITE) &&
 +                  (dd->starved++ >= dd->writes_starved))
 +                      goto dispatch_writes;
 +
 +              data_dir = DD_READ;
 +
 +              goto dispatch_find_request;
 +      }
 +
 +      /*
 +       * there are either no reads or writes have been starved
 +       */
 +
 +      if (!list_empty(&per_prio->fifo_list[DD_WRITE])) {
 +dispatch_writes:
 +              BUG_ON(RB_EMPTY_ROOT(&per_prio->sort_list[DD_WRITE]));
 +
 +              dd->starved = 0;
 +
 +              data_dir = DD_WRITE;
 +
 +              goto dispatch_find_request;
 +      }
 +
 +      return NULL;
 +
 +dispatch_find_request:
 +      /*
 +       * we are not running a batch, find best request for selected data_dir
 +       */
 +      next_rq = deadline_next_request(dd, per_prio, data_dir);
 +      if (deadline_check_fifo(per_prio, data_dir) || !next_rq) {
 +              /*
 +               * A deadline has expired, the last request was in the other
 +               * direction, or we have run out of higher-sectored requests.
 +               * Start again from the request with the earliest expiry time.
 +               */
 +              rq = deadline_fifo_request(dd, per_prio, data_dir);
 +      } else {
 +              /*
 +               * The last req was the same dir and we have a next request in
 +               * sort order. No expired requests so continue on from here.
 +               */
 +              rq = next_rq;
 +      }
 +
 +      /*
 +       * For a zoned block device, if we only have writes queued and none of
 +       * them can be dispatched, rq will be NULL.
 +       */
 +      if (!rq)
 +              return NULL;
 +
 +      dd->last_dir = data_dir;
 +      dd->batching = 0;
 +
 +dispatch_request:
 +      /*
 +       * rq is the selected appropriate request.
 +       */
 +      dd->batching++;
 +      deadline_move_request(dd, per_prio, rq);
 +done:
 +      ioprio_class = dd_rq_ioclass(rq);
 +      prio = ioprio_class_to_prio[ioprio_class];
 +      dd_count(dd, dispatched, prio);
 +      /*
 +       * If the request needs its target zone locked, do it.
 +       */
 +      blk_req_zone_write_lock(rq);
 +      rq->rq_flags |= RQF_STARTED;
 +      return rq;
 +}
 +
 +/*
 + * Called from blk_mq_run_hw_queue() -> __blk_mq_sched_dispatch_requests().
 + *
 + * One confusing aspect here is that we get called for a specific
 + * hardware queue, but we may return a request that is for a
 + * different hardware queue. This is because mq-deadline has shared
 + * state for all hardware queues, in terms of sorting, FIFOs, etc.
 + */
 +static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx)
 +{
 +      struct deadline_data *dd = hctx->queue->elevator->elevator_data;
 +      struct request *rq;
 +      enum dd_prio prio;
 +
 +      spin_lock(&dd->lock);
 +      for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
 +              rq = __dd_dispatch_request(dd, &dd->per_prio[prio]);
 +              if (rq)
 +                      break;
 +      }
 +      spin_unlock(&dd->lock);
 +
 +      return rq;
 +}
 +
 +/*
 + * Called by __blk_mq_alloc_request(). The shallow_depth value set by this
 + * function is used by __blk_mq_get_tag().
 + */
 +static void dd_limit_depth(unsigned int op, struct blk_mq_alloc_data *data)
 +{
 +      struct deadline_data *dd = data->q->elevator->elevator_data;
 +
 +      /* Do not throttle synchronous reads. */
 +      if (op_is_sync(op) && !op_is_write(op))
 +              return;
 +
 +      /*
 +       * Throttle asynchronous requests and writes such that these requests
 +       * do not block the allocation of synchronous requests.
 +       */
 +      data->shallow_depth = dd->async_depth;
 +}
 +
 +/* Called by blk_mq_update_nr_requests(). */
 +static void dd_depth_updated(struct blk_mq_hw_ctx *hctx)
 +{
 +      struct request_queue *q = hctx->queue;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      struct blk_mq_tags *tags = hctx->sched_tags;
 +
 +      dd->async_depth = max(1UL, 3 * q->nr_requests / 4);
 +
 +      sbitmap_queue_min_shallow_depth(tags->bitmap_tags, dd->async_depth);
 +}
 +
 +/* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */
 +static int dd_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
 +{
 +      dd_depth_updated(hctx);
 +      return 0;
 +}
 +
 +static void dd_exit_sched(struct elevator_queue *e)
 +{
 +      struct deadline_data *dd = e->elevator_data;
 +      enum dd_prio prio;
 +
 +      for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
 +              struct dd_per_prio *per_prio = &dd->per_prio[prio];
 +
 +              WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_READ]));
 +              WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE]));
 +      }
 +
 +      free_percpu(dd->stats);
 +
 +      kfree(dd);
 +}
 +
 +/*
 + * initialize elevator private data (deadline_data).
 + */
 +static int dd_init_sched(struct request_queue *q, struct elevator_type *e)
 +{
 +      struct deadline_data *dd;
 +      struct elevator_queue *eq;
 +      enum dd_prio prio;
 +      int ret = -ENOMEM;
 +
 +      eq = elevator_alloc(q, e);
 +      if (!eq)
 +              return ret;
 +
 +      dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
 +      if (!dd)
 +              goto put_eq;
 +
 +      eq->elevator_data = dd;
 +
 +      dd->stats = alloc_percpu_gfp(typeof(*dd->stats),
 +                                   GFP_KERNEL | __GFP_ZERO);
 +      if (!dd->stats)
 +              goto free_dd;
 +
 +      for (prio = 0; prio <= DD_PRIO_MAX; prio++) {
 +              struct dd_per_prio *per_prio = &dd->per_prio[prio];
 +
 +              INIT_LIST_HEAD(&per_prio->dispatch);
 +              INIT_LIST_HEAD(&per_prio->fifo_list[DD_READ]);
 +              INIT_LIST_HEAD(&per_prio->fifo_list[DD_WRITE]);
 +              per_prio->sort_list[DD_READ] = RB_ROOT;
 +              per_prio->sort_list[DD_WRITE] = RB_ROOT;
 +      }
 +      dd->fifo_expire[DD_READ] = read_expire;
 +      dd->fifo_expire[DD_WRITE] = write_expire;
 +      dd->writes_starved = writes_starved;
 +      dd->front_merges = 1;
 +      dd->last_dir = DD_WRITE;
 +      dd->fifo_batch = fifo_batch;
 +      spin_lock_init(&dd->lock);
 +      spin_lock_init(&dd->zone_lock);
 +
 +      q->elevator = eq;
 +      return 0;
 +
 +free_dd:
 +      kfree(dd);
 +
 +put_eq:
 +      kobject_put(&eq->kobj);
 +      return ret;
 +}
 +
 +/*
 + * Try to merge @bio into an existing request. If @bio has been merged into
 + * an existing request, store the pointer to that request into *@rq.
 + */
 +static int dd_request_merge(struct request_queue *q, struct request **rq,
 +                          struct bio *bio)
 +{
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      const u8 ioprio_class = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
 +      const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];
 +      sector_t sector = bio_end_sector(bio);
 +      struct request *__rq;
 +
 +      if (!dd->front_merges)
 +              return ELEVATOR_NO_MERGE;
 +
 +      __rq = elv_rb_find(&per_prio->sort_list[bio_data_dir(bio)], sector);
 +      if (__rq) {
 +              BUG_ON(sector != blk_rq_pos(__rq));
 +
 +              if (elv_bio_merge_ok(__rq, bio)) {
 +                      *rq = __rq;
++                      if (blk_discard_mergable(__rq))
++                              return ELEVATOR_DISCARD_MERGE;
 +                      return ELEVATOR_FRONT_MERGE;
 +              }
 +      }
 +
 +      return ELEVATOR_NO_MERGE;
 +}
 +
 +/*
 + * Attempt to merge a bio into an existing request. This function is called
 + * before @bio is associated with a request.
 + */
 +static bool dd_bio_merge(struct request_queue *q, struct bio *bio,
 +              unsigned int nr_segs)
 +{
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      struct request *free = NULL;
 +      bool ret;
 +
 +      spin_lock(&dd->lock);
 +      ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
 +      spin_unlock(&dd->lock);
 +
 +      if (free)
 +              blk_mq_free_request(free);
 +
 +      return ret;
 +}
 +
 +/*
 + * add rq to rbtree and fifo
 + */
 +static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
 +                            bool at_head)
 +{
 +      struct request_queue *q = hctx->queue;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      const enum dd_data_dir data_dir = rq_data_dir(rq);
 +      u16 ioprio = req_get_ioprio(rq);
 +      u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio);
 +      struct dd_per_prio *per_prio;
 +      enum dd_prio prio;
 +      LIST_HEAD(free);
 +
 +      lockdep_assert_held(&dd->lock);
 +
 +      /*
 +       * This may be a requeue of a write request that has locked its
 +       * target zone. If it is the case, this releases the zone lock.
 +       */
 +      blk_req_zone_write_unlock(rq);
 +
 +      prio = ioprio_class_to_prio[ioprio_class];
 +      dd_count(dd, inserted, prio);
 +      rq->elv.priv[0] = (void *)(uintptr_t)1;
 +
 +      if (blk_mq_sched_try_insert_merge(q, rq, &free)) {
 +              blk_mq_free_requests(&free);
 +              return;
 +      }
 +
 +      trace_block_rq_insert(rq);
 +
 +      per_prio = &dd->per_prio[prio];
 +      if (at_head) {
 +              list_add(&rq->queuelist, &per_prio->dispatch);
 +      } else {
 +              deadline_add_rq_rb(per_prio, rq);
 +
 +              if (rq_mergeable(rq)) {
 +                      elv_rqhash_add(q, rq);
 +                      if (!q->last_merge)
 +                              q->last_merge = rq;
 +              }
 +
 +              /*
 +               * set expire time and add to fifo list
 +               */
 +              rq->fifo_time = jiffies + dd->fifo_expire[data_dir];
 +              list_add_tail(&rq->queuelist, &per_prio->fifo_list[data_dir]);
 +      }
 +}
 +
 +/*
 + * Called from blk_mq_sched_insert_request() or blk_mq_sched_insert_requests().
 + */
 +static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
 +                             struct list_head *list, bool at_head)
 +{
 +      struct request_queue *q = hctx->queue;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      spin_lock(&dd->lock);
 +      while (!list_empty(list)) {
 +              struct request *rq;
 +
 +              rq = list_first_entry(list, struct request, queuelist);
 +              list_del_init(&rq->queuelist);
 +              dd_insert_request(hctx, rq, at_head);
 +      }
 +      spin_unlock(&dd->lock);
 +}
 +
 +/* Callback from inside blk_mq_rq_ctx_init(). */
 +static void dd_prepare_request(struct request *rq)
 +{
 +      rq->elv.priv[0] = NULL;
 +}
 +
 +/*
 + * Callback from inside blk_mq_free_request().
 + *
 + * For zoned block devices, write unlock the target zone of
 + * completed write requests. Do this while holding the zone lock
 + * spinlock so that the zone is never unlocked while deadline_fifo_request()
 + * or deadline_next_request() are executing. This function is called for
 + * all requests, whether or not these requests complete successfully.
 + *
 + * For a zoned block device, __dd_dispatch_request() may have stopped
 + * dispatching requests if all the queued requests are write requests directed
 + * at zones that are already locked due to on-going write requests. To ensure
 + * write request dispatch progress in this case, mark the queue as needing a
 + * restart to ensure that the queue is run again after completion of the
 + * request and zones being unlocked.
 + */
 +static void dd_finish_request(struct request *rq)
 +{
 +      struct request_queue *q = rq->q;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +      const u8 ioprio_class = dd_rq_ioclass(rq);
 +      const enum dd_prio prio = ioprio_class_to_prio[ioprio_class];
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];
 +
 +      /*
 +       * The block layer core may call dd_finish_request() without having
 +       * called dd_insert_requests(). Hence only update statistics for
 +       * requests for which dd_insert_requests() has been called. See also
 +       * blk_mq_request_bypass_insert().
 +       */
 +      if (rq->elv.priv[0])
 +              dd_count(dd, completed, prio);
 +
 +      if (blk_queue_is_zoned(q)) {
 +              unsigned long flags;
 +
 +              spin_lock_irqsave(&dd->zone_lock, flags);
 +              blk_req_zone_write_unlock(rq);
 +              if (!list_empty(&per_prio->fifo_list[DD_WRITE]))
 +                      blk_mq_sched_mark_restart_hctx(rq->mq_hctx);
 +              spin_unlock_irqrestore(&dd->zone_lock, flags);
 +      }
 +}
 +
 +static bool dd_has_work_for_prio(struct dd_per_prio *per_prio)
 +{
 +      return !list_empty_careful(&per_prio->dispatch) ||
 +              !list_empty_careful(&per_prio->fifo_list[DD_READ]) ||
 +              !list_empty_careful(&per_prio->fifo_list[DD_WRITE]);
 +}
 +
 +static bool dd_has_work(struct blk_mq_hw_ctx *hctx)
 +{
 +      struct deadline_data *dd = hctx->queue->elevator->elevator_data;
 +      enum dd_prio prio;
 +
 +      for (prio = 0; prio <= DD_PRIO_MAX; prio++)
 +              if (dd_has_work_for_prio(&dd->per_prio[prio]))
 +                      return true;
 +
 +      return false;
 +}
 +
 +/*
 + * sysfs parts below
 + */
 +#define SHOW_INT(__FUNC, __VAR)                                               \
 +static ssize_t __FUNC(struct elevator_queue *e, char *page)           \
 +{                                                                     \
 +      struct deadline_data *dd = e->elevator_data;                    \
 +                                                                      \
 +      return sysfs_emit(page, "%d\n", __VAR);                         \
 +}
 +#define SHOW_JIFFIES(__FUNC, __VAR) SHOW_INT(__FUNC, jiffies_to_msecs(__VAR))
 +SHOW_JIFFIES(deadline_read_expire_show, dd->fifo_expire[DD_READ]);
 +SHOW_JIFFIES(deadline_write_expire_show, dd->fifo_expire[DD_WRITE]);
 +SHOW_INT(deadline_writes_starved_show, dd->writes_starved);
 +SHOW_INT(deadline_front_merges_show, dd->front_merges);
 +SHOW_INT(deadline_async_depth_show, dd->front_merges);
 +SHOW_INT(deadline_fifo_batch_show, dd->fifo_batch);
 +#undef SHOW_INT
 +#undef SHOW_JIFFIES
 +
 +#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)                       \
 +static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)       \
 +{                                                                     \
 +      struct deadline_data *dd = e->elevator_data;                    \
 +      int __data, __ret;                                              \
 +                                                                      \
 +      __ret = kstrtoint(page, 0, &__data);                            \
 +      if (__ret < 0)                                                  \
 +              return __ret;                                           \
 +      if (__data < (MIN))                                             \
 +              __data = (MIN);                                         \
 +      else if (__data > (MAX))                                        \
 +              __data = (MAX);                                         \
 +      *(__PTR) = __CONV(__data);                                      \
 +      return count;                                                   \
 +}
 +#define STORE_INT(__FUNC, __PTR, MIN, MAX)                            \
 +      STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, )
 +#define STORE_JIFFIES(__FUNC, __PTR, MIN, MAX)                                \
 +      STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, msecs_to_jiffies)
 +STORE_JIFFIES(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX);
 +STORE_JIFFIES(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX);
 +STORE_INT(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX);
 +STORE_INT(deadline_front_merges_store, &dd->front_merges, 0, 1);
 +STORE_INT(deadline_async_depth_store, &dd->front_merges, 1, INT_MAX);
 +STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
 +#undef STORE_FUNCTION
 +#undef STORE_INT
 +#undef STORE_JIFFIES
 +
 +#define DD_ATTR(name) \
 +      __ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)
 +
 +static struct elv_fs_entry deadline_attrs[] = {
 +      DD_ATTR(read_expire),
 +      DD_ATTR(write_expire),
 +      DD_ATTR(writes_starved),
 +      DD_ATTR(front_merges),
 +      DD_ATTR(async_depth),
 +      DD_ATTR(fifo_batch),
 +      __ATTR_NULL
 +};
 +
 +#ifdef CONFIG_BLK_DEBUG_FS
 +#define DEADLINE_DEBUGFS_DDIR_ATTRS(prio, data_dir, name)             \
 +static void *deadline_##name##_fifo_start(struct seq_file *m,         \
 +                                        loff_t *pos)                  \
 +      __acquires(&dd->lock)                                           \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];             \
 +                                                                      \
 +      spin_lock(&dd->lock);                                           \
 +      return seq_list_start(&per_prio->fifo_list[data_dir], *pos);    \
 +}                                                                     \
 +                                                                      \
 +static void *deadline_##name##_fifo_next(struct seq_file *m, void *v, \
 +                                       loff_t *pos)                   \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];             \
 +                                                                      \
 +      return seq_list_next(v, &per_prio->fifo_list[data_dir], pos);   \
 +}                                                                     \
 +                                                                      \
 +static void deadline_##name##_fifo_stop(struct seq_file *m, void *v)  \
 +      __releases(&dd->lock)                                           \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +                                                                      \
 +      spin_unlock(&dd->lock);                                         \
 +}                                                                     \
 +                                                                      \
 +static const struct seq_operations deadline_##name##_fifo_seq_ops = { \
 +      .start  = deadline_##name##_fifo_start,                         \
 +      .next   = deadline_##name##_fifo_next,                          \
 +      .stop   = deadline_##name##_fifo_stop,                          \
 +      .show   = blk_mq_debugfs_rq_show,                               \
 +};                                                                    \
 +                                                                      \
 +static int deadline_##name##_next_rq_show(void *data,                 \
 +                                        struct seq_file *m)           \
 +{                                                                     \
 +      struct request_queue *q = data;                                 \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];             \
 +      struct request *rq = per_prio->next_rq[data_dir];               \
 +                                                                      \
 +      if (rq)                                                         \
 +              __blk_mq_debugfs_rq_show(m, rq);                        \
 +      return 0;                                                       \
 +}
 +
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_READ, read0);
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_RT_PRIO, DD_WRITE, write0);
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_READ, read1);
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_BE_PRIO, DD_WRITE, write1);
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_READ, read2);
 +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_IDLE_PRIO, DD_WRITE, write2);
 +#undef DEADLINE_DEBUGFS_DDIR_ATTRS
 +
 +static int deadline_batching_show(void *data, struct seq_file *m)
 +{
 +      struct request_queue *q = data;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      seq_printf(m, "%u\n", dd->batching);
 +      return 0;
 +}
 +
 +static int deadline_starved_show(void *data, struct seq_file *m)
 +{
 +      struct request_queue *q = data;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      seq_printf(m, "%u\n", dd->starved);
 +      return 0;
 +}
 +
 +static int dd_async_depth_show(void *data, struct seq_file *m)
 +{
 +      struct request_queue *q = data;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      seq_printf(m, "%u\n", dd->async_depth);
 +      return 0;
 +}
 +
 +static int dd_queued_show(void *data, struct seq_file *m)
 +{
 +      struct request_queue *q = data;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      seq_printf(m, "%u %u %u\n", dd_queued(dd, DD_RT_PRIO),
 +                 dd_queued(dd, DD_BE_PRIO),
 +                 dd_queued(dd, DD_IDLE_PRIO));
 +      return 0;
 +}
 +
 +/* Number of requests owned by the block driver for a given priority. */
 +static u32 dd_owned_by_driver(struct deadline_data *dd, enum dd_prio prio)
 +{
 +      return dd_sum(dd, dispatched, prio) + dd_sum(dd, merged, prio)
 +              - dd_sum(dd, completed, prio);
 +}
 +
 +static int dd_owned_by_driver_show(void *data, struct seq_file *m)
 +{
 +      struct request_queue *q = data;
 +      struct deadline_data *dd = q->elevator->elevator_data;
 +
 +      seq_printf(m, "%u %u %u\n", dd_owned_by_driver(dd, DD_RT_PRIO),
 +                 dd_owned_by_driver(dd, DD_BE_PRIO),
 +                 dd_owned_by_driver(dd, DD_IDLE_PRIO));
 +      return 0;
 +}
 +
 +#define DEADLINE_DISPATCH_ATTR(prio)                                  \
 +static void *deadline_dispatch##prio##_start(struct seq_file *m,      \
 +                                           loff_t *pos)               \
 +      __acquires(&dd->lock)                                           \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];             \
 +                                                                      \
 +      spin_lock(&dd->lock);                                           \
 +      return seq_list_start(&per_prio->dispatch, *pos);               \
 +}                                                                     \
 +                                                                      \
 +static void *deadline_dispatch##prio##_next(struct seq_file *m,               \
 +                                          void *v, loff_t *pos)       \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +      struct dd_per_prio *per_prio = &dd->per_prio[prio];             \
 +                                                                      \
 +      return seq_list_next(v, &per_prio->dispatch, pos);              \
 +}                                                                     \
 +                                                                      \
 +static void deadline_dispatch##prio##_stop(struct seq_file *m, void *v)       \
 +      __releases(&dd->lock)                                           \
 +{                                                                     \
 +      struct request_queue *q = m->private;                           \
 +      struct deadline_data *dd = q->elevator->elevator_data;          \
 +                                                                      \
 +      spin_unlock(&dd->lock);                                         \
 +}                                                                     \
 +                                                                      \
 +static const struct seq_operations deadline_dispatch##prio##_seq_ops = { \
 +      .start  = deadline_dispatch##prio##_start,                      \
 +      .next   = deadline_dispatch##prio##_next,                       \
 +      .stop   = deadline_dispatch##prio##_stop,                       \
 +      .show   = blk_mq_debugfs_rq_show,                               \
 +}
 +
 +DEADLINE_DISPATCH_ATTR(0);
 +DEADLINE_DISPATCH_ATTR(1);
 +DEADLINE_DISPATCH_ATTR(2);
 +#undef DEADLINE_DISPATCH_ATTR
 +
 +#define DEADLINE_QUEUE_DDIR_ATTRS(name)                                       \
 +      {#name "_fifo_list", 0400,                                      \
 +                      .seq_ops = &deadline_##name##_fifo_seq_ops}
 +#define DEADLINE_NEXT_RQ_ATTR(name)                                   \
 +      {#name "_next_rq", 0400, deadline_##name##_next_rq_show}
 +static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
 +      DEADLINE_QUEUE_DDIR_ATTRS(read0),
 +      DEADLINE_QUEUE_DDIR_ATTRS(write0),
 +      DEADLINE_QUEUE_DDIR_ATTRS(read1),
 +      DEADLINE_QUEUE_DDIR_ATTRS(write1),
 +      DEADLINE_QUEUE_DDIR_ATTRS(read2),
 +      DEADLINE_QUEUE_DDIR_ATTRS(write2),
 +      DEADLINE_NEXT_RQ_ATTR(read0),
 +      DEADLINE_NEXT_RQ_ATTR(write0),
 +      DEADLINE_NEXT_RQ_ATTR(read1),
 +      DEADLINE_NEXT_RQ_ATTR(write1),
 +      DEADLINE_NEXT_RQ_ATTR(read2),
 +      DEADLINE_NEXT_RQ_ATTR(write2),
 +      {"batching", 0400, deadline_batching_show},
 +      {"starved", 0400, deadline_starved_show},
 +      {"async_depth", 0400, dd_async_depth_show},
 +      {"dispatch0", 0400, .seq_ops = &deadline_dispatch0_seq_ops},
 +      {"dispatch1", 0400, .seq_ops = &deadline_dispatch1_seq_ops},
 +      {"dispatch2", 0400, .seq_ops = &deadline_dispatch2_seq_ops},
 +      {"owned_by_driver", 0400, dd_owned_by_driver_show},
 +      {"queued", 0400, dd_queued_show},
 +      {},
 +};
 +#undef DEADLINE_QUEUE_DDIR_ATTRS
 +#endif
 +
 +static struct elevator_type mq_deadline = {
 +      .ops = {
 +              .depth_updated          = dd_depth_updated,
 +              .limit_depth            = dd_limit_depth,
 +              .insert_requests        = dd_insert_requests,
 +              .dispatch_request       = dd_dispatch_request,
 +              .prepare_request        = dd_prepare_request,
 +              .finish_request         = dd_finish_request,
 +              .next_request           = elv_rb_latter_request,
 +              .former_request         = elv_rb_former_request,
 +              .bio_merge              = dd_bio_merge,
 +              .request_merge          = dd_request_merge,
 +              .requests_merged        = dd_merged_requests,
 +              .request_merged         = dd_request_merged,
 +              .has_work               = dd_has_work,
 +              .init_sched             = dd_init_sched,
 +              .exit_sched             = dd_exit_sched,
 +              .init_hctx              = dd_init_hctx,
 +      },
 +
 +#ifdef CONFIG_BLK_DEBUG_FS
 +      .queue_debugfs_attrs = deadline_queue_debugfs_attrs,
 +#endif
 +      .elevator_attrs = deadline_attrs,
 +      .elevator_name = "mq-deadline",
 +      .elevator_alias = "deadline",
 +      .elevator_features = ELEVATOR_F_ZBD_SEQ_WRITE,
 +      .elevator_owner = THIS_MODULE,
 +};
 +MODULE_ALIAS("mq-deadline-iosched");
 +
 +static int __init deadline_init(void)
 +{
 +      return elv_register(&mq_deadline);
 +}
 +
 +static void __exit deadline_exit(void)
 +{
 +      elv_unregister(&mq_deadline);
 +}
 +
 +module_init(deadline_init);
 +module_exit(deadline_exit);
 +
 +MODULE_AUTHOR("Jens Axboe, Damien Le Moal and Bart Van Assche");
 +MODULE_LICENSE("GPL");
 +MODULE_DESCRIPTION("MQ deadline IO scheduler");
Simple merge
index afb37aac09e88896050061c379b5a5a8c31f1149,63dc121a4c43b9d29370d4f1401579b05da45b78..57c6ae7debd97536fe75168bb04cd539ca186e24
@@@ -839,14 -820,6 +836,14 @@@ static int virtblk_probe(struct virtio_
        else
                blk_size = queue_logical_block_size(q);
  
-               goto err_cleanup_disk;
 +      if (unlikely(blk_size < SECTOR_SIZE || blk_size > PAGE_SIZE)) {
 +              dev_err(&vdev->dev,
 +                      "block size is changed unexpectedly, now is %u\n",
 +                      blk_size);
 +              err = -EINVAL;
++              goto out_cleanup_disk;
 +      }
 +
        /* Use topology information if available */
        err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
                                   struct virtio_blk_config, physical_block_exp,
Simple merge
Simple merge
Simple merge
Simple merge