ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
 EXPORT_SYMBOL(scsi_sd_pm_domain);
 
-struct scsi_host_cmd_pool {
-       struct kmem_cache       *cmd_slab;
-       unsigned int            users;
-       char                    *cmd_name;
-};
-
-static struct scsi_host_cmd_pool scsi_cmd_pool = {
-       .cmd_name       = "scsi_cmd_cache",
-};
-
-static DEFINE_MUTEX(host_cmd_pool_mutex);
-
-/**
- * scsi_host_free_command - internal function to release a command
- * @shost:     host to free the command for
- * @cmd:       command to release
- *
- * the command must previously have been allocated by
- * scsi_host_alloc_command.
- */
-static void
-scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
-{
-       struct scsi_host_cmd_pool *pool = shost->cmd_pool;
-
-       if (cmd->prot_sdb)
-               kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
-       scsi_free_sense_buffer(shost, cmd->sense_buffer);
-       kmem_cache_free(pool->cmd_slab, cmd);
-}
-
-/**
- * scsi_host_alloc_command - internal function to allocate command
- * @shost:     SCSI host whose pool to allocate from
- * @gfp_mask:  mask for the allocation
- *
- * Returns a fully allocated command with sense buffer and protection
- * data buffer (where applicable) or NULL on failure
- */
-static struct scsi_cmnd *
-scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
-{
-       struct scsi_host_cmd_pool *pool = shost->cmd_pool;
-       struct scsi_cmnd *cmd;
-
-       cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask);
-       if (!cmd)
-               goto fail;
-
-       cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp_mask,
-                       NUMA_NO_NODE);
-       if (!cmd->sense_buffer)
-               goto fail_free_cmd;
-
-       if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
-               cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
-               if (!cmd->prot_sdb)
-                       goto fail_free_sense;
-       }
-
-       return cmd;
-
-fail_free_sense:
-       scsi_free_sense_buffer(shost, cmd->sense_buffer);
-fail_free_cmd:
-       kmem_cache_free(pool->cmd_slab, cmd);
-fail:
-       return NULL;
-}
-
-/**
- * __scsi_get_command - Allocate a struct scsi_cmnd
- * @shost: host to transmit command
- * @gfp_mask: allocation mask
- *
- * Description: allocate a struct scsi_cmd from host's slab, recycling from the
- *              host's free_list if necessary.
- */
-static struct scsi_cmnd *
-__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
-{
-       struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
-
-       if (unlikely(!cmd)) {
-               unsigned long flags;
-
-               spin_lock_irqsave(&shost->free_list_lock, flags);
-               if (likely(!list_empty(&shost->free_list))) {
-                       cmd = list_entry(shost->free_list.next,
-                                        struct scsi_cmnd, list);
-                       list_del_init(&cmd->list);
-               }
-               spin_unlock_irqrestore(&shost->free_list_lock, flags);
-
-               if (cmd) {
-                       void *buf, *prot;
-
-                       buf = cmd->sense_buffer;
-                       prot = cmd->prot_sdb;
-
-                       memset(cmd, 0, sizeof(*cmd));
-
-                       cmd->sense_buffer = buf;
-                       cmd->prot_sdb = prot;
-               }
-       }
-
-       return cmd;
-}
-
-/**
- * scsi_get_command - Allocate and setup a scsi command block
- * @dev: parent scsi device
- * @gfp_mask: allocator flags
- *
- * Returns:    The allocated scsi command structure.
- */
-struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
-{
-       struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
-       unsigned long flags;
-
-       if (unlikely(cmd == NULL))
-               return NULL;
-
-       cmd->device = dev;
-       INIT_LIST_HEAD(&cmd->list);
-       INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
-       spin_lock_irqsave(&dev->list_lock, flags);
-       list_add_tail(&cmd->list, &dev->cmd_list);
-       spin_unlock_irqrestore(&dev->list_lock, flags);
-       cmd->jiffies_at_alloc = jiffies;
-       return cmd;
-}
-
-/**
- * __scsi_put_command - Free a struct scsi_cmnd
- * @shost: dev->host
- * @cmd: Command to free
- */
-static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
-{
-       unsigned long flags;
-
-       if (unlikely(list_empty(&shost->free_list))) {
-               spin_lock_irqsave(&shost->free_list_lock, flags);
-               if (list_empty(&shost->free_list)) {
-                       list_add(&cmd->list, &shost->free_list);
-                       cmd = NULL;
-               }
-               spin_unlock_irqrestore(&shost->free_list_lock, flags);
-       }
-
-       if (likely(cmd != NULL))
-               scsi_host_free_command(shost, cmd);
-}
-
 /**
  * scsi_put_command - Free a scsi command block
  * @cmd: command block to free
        spin_unlock_irqrestore(&cmd->device->list_lock, flags);
 
        BUG_ON(delayed_work_pending(&cmd->abort_work));
-
-       __scsi_put_command(cmd->device->host, cmd);
-}
-
-static struct scsi_host_cmd_pool *
-scsi_find_host_cmd_pool(struct Scsi_Host *shost)
-{
-       if (shost->hostt->cmd_size)
-               return shost->hostt->cmd_pool;
-       return &scsi_cmd_pool;
-}
-
-static void
-scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
-{
-       kfree(pool->cmd_name);
-       kfree(pool);
-}
-
-static struct scsi_host_cmd_pool *
-scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
-{
-       struct scsi_host_template *hostt = shost->hostt;
-       struct scsi_host_cmd_pool *pool;
-
-       pool = kzalloc(sizeof(*pool), GFP_KERNEL);
-       if (!pool)
-               return NULL;
-
-       pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->proc_name);
-       if (!pool->cmd_name) {
-               scsi_free_host_cmd_pool(pool);
-               return NULL;
-       }
-
-       if (hostt->cmd_size)
-               hostt->cmd_pool = pool;
-
-       return pool;
-}
-
-static struct scsi_host_cmd_pool *
-scsi_get_host_cmd_pool(struct Scsi_Host *shost)
-{
-       struct scsi_host_template *hostt = shost->hostt;
-       struct scsi_host_cmd_pool *retval = NULL, *pool;
-       size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
-
-       /*
-        * Select a command slab for this host and create it if not
-        * yet existent.
-        */
-       mutex_lock(&host_cmd_pool_mutex);
-       pool = scsi_find_host_cmd_pool(shost);
-       if (!pool) {
-               pool = scsi_alloc_host_cmd_pool(shost);
-               if (!pool)
-                       goto out;
-       }
-
-       if (!pool->users) {
-               pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
-                                                  SLAB_HWCACHE_ALIGN, NULL);
-               if (!pool->cmd_slab)
-                       goto out_free_pool;
-       }
-
-       pool->users++;
-       retval = pool;
-out:
-       mutex_unlock(&host_cmd_pool_mutex);
-       return retval;
-
-out_free_pool:
-       if (hostt->cmd_size) {
-               scsi_free_host_cmd_pool(pool);
-               hostt->cmd_pool = NULL;
-       }
-       goto out;
-}
-
-static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
-{
-       struct scsi_host_template *hostt = shost->hostt;
-       struct scsi_host_cmd_pool *pool;
-
-       mutex_lock(&host_cmd_pool_mutex);
-       pool = scsi_find_host_cmd_pool(shost);
-
-       /*
-        * This may happen if a driver has a mismatched get and put
-        * of the command pool; the driver should be implicated in
-        * the stack trace
-        */
-       BUG_ON(pool->users == 0);
-
-       if (!--pool->users) {
-               kmem_cache_destroy(pool->cmd_slab);
-               if (hostt->cmd_size) {
-                       scsi_free_host_cmd_pool(pool);
-                       hostt->cmd_pool = NULL;
-               }
-       }
-       mutex_unlock(&host_cmd_pool_mutex);
-}
-
-/**
- * scsi_setup_command_freelist - Setup the command freelist for a scsi host.
- * @shost: host to allocate the freelist for.
- *
- * Description: The command freelist protects against system-wide out of memory
- * deadlock by preallocating one SCSI command structure for each host, so the
- * system can always write to a swap file on a device associated with that host.
- *
- * Returns:    Nothing.
- */
-int scsi_setup_command_freelist(struct Scsi_Host *shost)
-{
-       struct scsi_cmnd *cmd;
-
-       spin_lock_init(&shost->free_list_lock);
-       INIT_LIST_HEAD(&shost->free_list);
-
-       shost->cmd_pool = scsi_get_host_cmd_pool(shost);
-       if (!shost->cmd_pool)
-               return -ENOMEM;
-
-       /*
-        * Get one backup command for this host.
-        */
-       cmd = scsi_host_alloc_command(shost, GFP_KERNEL);
-       if (!cmd) {
-               scsi_put_host_cmd_pool(shost);
-               shost->cmd_pool = NULL;
-               return -ENOMEM;
-       }
-       list_add(&cmd->list, &shost->free_list);
-       return 0;
-}
-
-/**
- * scsi_destroy_command_freelist - Release the command freelist for a scsi host.
- * @shost: host whose freelist is going to be destroyed
- */
-void scsi_destroy_command_freelist(struct Scsi_Host *shost)
-{
-       /*
-        * If cmd_pool is NULL the free list was not initialized, so
-        * do not attempt to release resources.
-        */
-       if (!shost->cmd_pool)
-               return;
-
-       while (!list_empty(&shost->free_list)) {
-               struct scsi_cmnd *cmd;
-
-               cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
-               list_del_init(&cmd->list);
-               scsi_host_free_command(shost, cmd);
-       }
-       shost->cmd_pool = NULL;
-       scsi_put_host_cmd_pool(shost);
 }
 
 #ifdef CONFIG_SCSI_LOGGING
 
 #include "scsi_priv.h"
 #include "scsi_logging.h"
 
-
-struct kmem_cache *scsi_sdb_cache;
+static struct kmem_cache *scsi_sdb_cache;
 static struct kmem_cache *scsi_sense_cache;
 static struct kmem_cache *scsi_sense_isadma_cache;
 static DEFINE_MUTEX(scsi_sense_cache_mutex);
                scsi_sense_isadma_cache : scsi_sense_cache;
 }
 
-void scsi_free_sense_buffer(struct Scsi_Host *shost,
+static void scsi_free_sense_buffer(struct Scsi_Host *shost,
                unsigned char *sense_buffer)
 {
        kmem_cache_free(scsi_select_sense_cache(shost), sense_buffer);
 }
 
-unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost, gfp_t gfp_mask,
-               int numa_node)
+static unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost,
+       gfp_t gfp_mask, int numa_node)
 {
        return kmem_cache_alloc_node(scsi_select_sense_cache(shost), gfp_mask,
                        numa_node);
 
                if (bidi_bytes)
                        scsi_release_bidi_buffers(cmd);
+               scsi_release_buffers(cmd);
+               scsi_put_command(cmd);
 
                spin_lock_irqsave(q->queue_lock, flags);
                blk_finish_request(req, error);
                spin_unlock_irqrestore(q->queue_lock, flags);
 
-               scsi_release_buffers(cmd);
-
-               scsi_put_command(cmd);
                scsi_run_queue(q);
        }
 
 }
 EXPORT_SYMBOL(scsi_init_io);
 
-static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
-               struct request *req)
+void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 {
-       struct scsi_cmnd *cmd;
-
-       if (!req->special) {
-               /* Bail if we can't get a reference to the device */
-               if (!get_device(&sdev->sdev_gendev))
-                       return NULL;
-
-               cmd = scsi_get_command(sdev, GFP_ATOMIC);
-               if (unlikely(!cmd)) {
-                       put_device(&sdev->sdev_gendev);
-                       return NULL;
-               }
-               req->special = cmd;
-       } else {
-               cmd = req->special;
-       }
-
-       /* pull a tag out of the request if we have one */
-       cmd->tag = req->tag;
-       cmd->request = req;
+       void *buf = cmd->sense_buffer;
+       void *prot = cmd->prot_sdb;
+       unsigned long flags;
 
-       cmd->cmnd = req->cmd;
-       cmd->prot_op = SCSI_PROT_NORMAL;
+       memset(cmd, 0, sizeof(*cmd));
+       cmd->device = dev;
+       cmd->sense_buffer = buf;
+       cmd->prot_sdb = prot;
+       INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
+       cmd->jiffies_at_alloc = jiffies;
 
-       return cmd;
+       spin_lock_irqsave(&dev->list_lock, flags);
+       list_add_tail(&cmd->list, &dev->cmd_list);
+       spin_unlock_irqrestore(&dev->list_lock, flags);
 }
 
 static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 static int scsi_prep_fn(struct request_queue *q, struct request *req)
 {
        struct scsi_device *sdev = q->queuedata;
-       struct scsi_cmnd *cmd;
+       struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
        int ret;
 
        ret = scsi_prep_state_check(sdev, req);
        if (ret != BLKPREP_OK)
                goto out;
 
-       cmd = scsi_get_cmd_from_req(sdev, req);
-       if (unlikely(!cmd)) {
-               ret = BLKPREP_DEFER;
-               goto out;
+       if (!req->special) {
+               /* Bail if we can't get a reference to the device */
+               if (unlikely(!get_device(&sdev->sdev_gendev))) {
+                       ret = BLKPREP_DEFER;
+                       goto out;
+               }
+
+               scsi_init_command(sdev, cmd);
+               req->special = cmd;
        }
 
+       cmd->tag = req->tag;
+       cmd->request = req;
+       cmd->cmnd = req->cmd;
+       cmd->prot_op = SCSI_PROT_NORMAL;
+
        ret = scsi_setup_cmnd(sdev, req);
 out:
        return scsi_prep_return(q, req, ret);
 }
 EXPORT_SYMBOL_GPL(__scsi_init_queue);
 
+static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
+{
+       struct Scsi_Host *shost = q->rq_alloc_data;
+       struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
+
+       memset(cmd, 0, sizeof(*cmd));
+
+       cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp, NUMA_NO_NODE);
+       if (!cmd->sense_buffer)
+               goto fail;
+
+       if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
+               cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp);
+               if (!cmd->prot_sdb)
+                       goto fail_free_sense;
+       }
+
+       return 0;
+
+fail_free_sense:
+       scsi_free_sense_buffer(shost, cmd->sense_buffer);
+fail:
+       return -ENOMEM;
+}
+
+static void scsi_exit_rq(struct request_queue *q, struct request *rq)
+{
+       struct Scsi_Host *shost = q->rq_alloc_data;
+       struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
+
+       if (cmd->prot_sdb)
+               kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
+       scsi_free_sense_buffer(shost, cmd->sense_buffer);
+}
+
 struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
 {
+       struct Scsi_Host *shost = sdev->host;
        struct request_queue *q;
 
-       q = blk_init_queue(scsi_request_fn, NULL);
+       q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
        if (!q)
                return NULL;
+       q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
+       q->rq_alloc_data = shost;
+       q->request_fn = scsi_request_fn;
+       q->init_rq_fn = scsi_init_rq;
+       q->exit_rq_fn = scsi_exit_rq;
+
+       if (blk_init_allocated_queue(q) < 0) {
+               blk_cleanup_queue(q);
+               return NULL;
+       }
 
-       __scsi_init_queue(sdev->host, q);
+       __scsi_init_queue(shost, q);
        blk_queue_prep_rq(q, scsi_prep_fn);
        blk_queue_unprep_rq(q, scsi_unprep_fn);
        blk_queue_softirq_done(q, scsi_softirq_done);