Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 4228 insertions, 0 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
new file mode 100644
index 000000000..597975831
--- /dev/null
+++ b/drivers/s390/block/dasd.c
@@ -0,0 +1,4228 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ *		    Horst Hummel <Horst.Hummel@de.ibm.com>
+ *		    Carsten Otte <Cotte@de.ibm.com>
+ *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ */
+
+#include <linux/export.h>
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ctype.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/hdreg.h>
+#include <linux/async.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+
+#include <asm/machine.h>
+#include <asm/ccwdev.h>
+#include <asm/ebcdic.h>
+#include <asm/idals.h>
+#include <asm/itcw.h>
+#include <asm/diag.h>
+
+#include "dasd_int.h"
+/*
+ * SECTION: Constant definitions to be used within this file
+ */
+#define DASD_CHANQ_MAX_SIZE 4
+
+#define DASD_DIAG_MOD		"dasd_diag_mod"
+
+/*
+ * SECTION: exported variables of dasd.c
+ */
+debug_info_t *dasd_debug_area;
+EXPORT_SYMBOL(dasd_debug_area);
+static struct dentry *dasd_debugfs_root_entry;
+struct dasd_discipline *dasd_diag_discipline_pointer;
+EXPORT_SYMBOL(dasd_diag_discipline_pointer);
+void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
+
+MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
+MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
+		   " Copyright IBM Corp. 2000");
+MODULE_LICENSE("GPL");
+
+/*
+ * SECTION: prototypes for static functions of dasd.c
+ */
+static int dasd_flush_block_queue(struct dasd_block *);
+static void dasd_device_tasklet(unsigned long);
+static void dasd_block_tasklet(unsigned long);
+static void do_kick_device(struct work_struct *);
+static void do_reload_device(struct work_struct *);
+static void do_requeue_requests(struct work_struct *);
+static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
+static void dasd_device_timeout(struct timer_list *);
+static void dasd_block_timeout(struct timer_list *);
+static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
+static void dasd_profile_init(struct dasd_profile *, struct dentry *);
+static void dasd_profile_exit(struct dasd_profile *);
+static void dasd_hosts_init(struct dentry *, struct dasd_device *);
+static void dasd_hosts_exit(struct dasd_device *);
+static int dasd_handle_autoquiesce(struct dasd_device *, struct dasd_ccw_req *,
+				   unsigned int);
+/*
+ * SECTION: Operations on the device structure.
+ */
+static wait_queue_head_t dasd_init_waitq;
+static wait_queue_head_t dasd_flush_wq;
+static wait_queue_head_t generic_waitq;
+static wait_queue_head_t shutdown_waitq;
+
+/*
+ * Allocate memory for a new device structure.
+ */
+struct dasd_device *dasd_alloc_device(void)
+{
+	struct dasd_device *device;
+
+	device = kzalloc_obj(struct dasd_device, GFP_KERNEL);
+	if (!device)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Four pages: a full-track ITCW is roughly twice the size of a plain
+	 * track-mode one, so this keeps two maximum-size requests in flight.
+	 */
+	device->ccw_mem = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA, 2);
+	if (!device->ccw_mem) {
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+	/* per-request track-filler buffers (R0 + count records) */
+	device->fill_mem = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA, 1);
+	if (!device->fill_mem) {
+		free_pages((unsigned long)device->ccw_mem, 2);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+	/* Get one page for error recovery. */
+	device->erp_mem = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!device->erp_mem) {
+		free_pages((unsigned long)device->fill_mem, 1);
+		free_pages((unsigned long)device->ccw_mem, 2);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+	/* sized like ccw_chunks: two max-size NRF format requests in flight */
+	device->ese_mem = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA, 2);
+	if (!device->ese_mem) {
+		free_page((unsigned long)device->erp_mem);
+		free_pages((unsigned long)device->fill_mem, 1);
+		free_pages((unsigned long)device->ccw_mem, 2);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+	device->nulldata = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!device->nulldata) {
+		free_page((unsigned long)device->erp_mem);
+		free_pages((unsigned long)device->fill_mem, 1);
+		free_pages((unsigned long)device->ccw_mem, 2);
+		free_pages((unsigned long)device->ese_mem, 2);
+		kfree(device);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE * 4);
+	dasd_init_chunklist(&device->fill_chunks, device->fill_mem, PAGE_SIZE * 2);
+	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
+	dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 4);
+	spin_lock_init(&device->mem_lock);
+	atomic_set(&device->tasklet_scheduled, 0);
+	tasklet_init(&device->tasklet, dasd_device_tasklet,
+		     (unsigned long) device);
+	INIT_LIST_HEAD(&device->ccw_queue);
+	timer_setup(&device->timer, dasd_device_timeout, 0);
+	INIT_WORK(&device->kick_work, do_kick_device);
+	INIT_WORK(&device->reload_device, do_reload_device);
+	INIT_WORK(&device->requeue_requests, do_requeue_requests);
+	device->state = DASD_STATE_NEW;
+	device->target = DASD_STATE_NEW;
+	mutex_init(&device->state_mutex);
+	spin_lock_init(&device->profile.lock);
+	return device;
+}
+
+/*
+ * Free memory of a device structure.
+ */
+void dasd_free_device(struct dasd_device *device)
+{
+	kfree(device->private);
+	free_pages((unsigned long)device->ese_mem, 2);
+	free_page((unsigned long)device->erp_mem);
+	free_pages((unsigned long)device->fill_mem, 1);
+	free_pages((unsigned long)device->ccw_mem, 2);
+	free_page((unsigned long)device->nulldata);
+	kfree(device);
+}
+
+/*
+ * Allocate memory for a new device structure.
+ */
+struct dasd_block *dasd_alloc_block(void)
+{
+	struct dasd_block *block;
+
+	block = kzalloc_obj(*block, GFP_ATOMIC);
+	if (!block)
+		return ERR_PTR(-ENOMEM);
+	/* open_count = 0 means device online but not in use */
+	atomic_set(&block->open_count, -1);
+
+	atomic_set(&block->tasklet_scheduled, 0);
+	tasklet_init(&block->tasklet, dasd_block_tasklet,
+		     (unsigned long) block);
+	INIT_LIST_HEAD(&block->ccw_queue);
+	spin_lock_init(&block->queue_lock);
+	INIT_LIST_HEAD(&block->format_list);
+	spin_lock_init(&block->format_lock);
+	INIT_LIST_HEAD(&block->ese_staging);
+	spin_lock_init(&block->ese_lock);
+	timer_setup(&block->timer, dasd_block_timeout, 0);
+	spin_lock_init(&block->profile.lock);
+
+	return block;
+}
+EXPORT_SYMBOL_GPL(dasd_alloc_block);
+
+/*
+ * Free memory of a device structure.
+ */
+void dasd_free_block(struct dasd_block *block)
+{
+	kfree(block);
+}
+EXPORT_SYMBOL_GPL(dasd_free_block);
+
+/*
+ * Make a new device known to the system.
+ */
+static int dasd_state_new_to_known(struct dasd_device *device)
+{
+	/*
+	 * As long as the device is not in state DASD_STATE_NEW we want to
+	 * keep the reference count > 0.
+	 */
+	dasd_get_device(device);
+	device->state = DASD_STATE_KNOWN;
+	return 0;
+}
+
+/*
+ * Let the system forget about a device.
+ */
+static int dasd_state_known_to_new(struct dasd_device *device)
+{
+	/* Disable extended error reporting for this device. */
+	dasd_eer_disable(device);
+	device->state = DASD_STATE_NEW;
+
+	/* Give up reference we took in dasd_state_new_to_known. */
+	dasd_put_device(device);
+	return 0;
+}
+
+/*
+ * Request the irq line for the device.
+ */
+static int dasd_state_known_to_basic(struct dasd_device *device)
+{
+	struct dasd_block *block = device->block;
+	int rc = 0;
+
+	/* Allocate and register gendisk structure. */
+	if (block) {
+		rc = dasd_gendisk_alloc(block);
+		if (rc)
+			return rc;
+		block->debugfs_dentry =
+			debugfs_create_dir(block->gdp->disk_name,
+					   dasd_debugfs_root_entry);
+		dasd_profile_init(&block->profile, block->debugfs_dentry);
+		if (dasd_global_profile_level == DASD_PROFILE_ON)
+			dasd_profile_on(&device->block->profile);
+	}
+	device->debugfs_dentry =
+		debugfs_create_dir(dev_name(&device->cdev->dev),
+				   dasd_debugfs_root_entry);
+	dasd_profile_init(&device->profile, device->debugfs_dentry);
+	dasd_hosts_init(device->debugfs_dentry, device);
+
+	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
+	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
+					    8 * sizeof(long));
+	debug_register_view(device->debug_area, &debug_sprintf_view);
+	debug_set_level(device->debug_area, DBF_WARNING);
+	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
+
+	device->state = DASD_STATE_BASIC;
+
+	return rc;
+}
+
+/*
+ * Release the irq line for the device. Terminate any running i/o.
+ */
+static int dasd_state_basic_to_known(struct dasd_device *device)
+{
+	int rc;
+
+	if (device->discipline->basic_to_known) {
+		rc = device->discipline->basic_to_known(device);
+		if (rc)
+			return rc;
+	}
+
+	if (device->block) {
+		dasd_profile_exit(&device->block->profile);
+		debugfs_remove(device->block->debugfs_dentry);
+		dasd_gendisk_free(device->block);
+		dasd_block_clear_timer(device->block);
+	}
+	rc = dasd_flush_device_queue(device);
+	if (rc)
+		return rc;
+	dasd_device_clear_timer(device);
+	dasd_profile_exit(&device->profile);
+	dasd_hosts_exit(device);
+	debugfs_remove(device->debugfs_dentry);
+	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
+	if (device->debug_area != NULL) {
+		debug_unregister(device->debug_area);
+		device->debug_area = NULL;
+	}
+	device->state = DASD_STATE_KNOWN;
+	return 0;
+}
+
+/*
+ * Do the initial analysis. The do_analysis function may return
+ * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
+ * until the discipline decides to continue the startup sequence
+ * by calling the function dasd_change_state. The eckd disciplines
+ * uses this to start a ccw that detects the format. The completion
+ * interrupt for this detection ccw uses the kernel event daemon to
+ * trigger the call to dasd_change_state. All this is done in the
+ * discipline code, see dasd_eckd.c.
+ * After the analysis ccw is done (do_analysis returned 0) the block
+ * device is setup.
+ * In case the analysis returns an error, the device setup is stopped
+ * (a fake disk was already added to allow formatting).
+ */
+static int dasd_state_basic_to_ready(struct dasd_device *device)
+{
+	struct dasd_block *block = device->block;
+	struct queue_limits lim;
+	int rc = 0;
+
+	/* make disk known with correct capacity */
+	if (!block) {
+		device->state = DASD_STATE_READY;
+		goto out;
+	}
+
+	if (block->base->discipline->do_analysis != NULL)
+		rc = block->base->discipline->do_analysis(block);
+	if (rc) {
+		if (rc == -EAGAIN)
+			return rc;
+		device->state = DASD_STATE_UNFMT;
+		kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
+			       KOBJ_CHANGE);
+		goto out;
+	}
+
+	lim = queue_limits_start_update(block->gdp->queue);
+	lim.max_dev_sectors = device->discipline->max_sectors(block);
+	lim.max_hw_sectors = lim.max_dev_sectors;
+	lim.logical_block_size = block->bp_block;
+	/*
+	 * Adjust dma_alignment to match block_size - 1
+	 * to ensure proper buffer alignment checks in the block layer.
+	 */
+	lim.dma_alignment = lim.logical_block_size - 1;
+
+	if (device->features & DASD_FEATURE_DISCARD) {
+		unsigned int max_bytes;
+
+		if (device->discipline->disc_limits) {
+			device->discipline->disc_limits(block, &lim);
+		} else {
+			lim.discard_granularity = block->bp_block;
+			/* Calculate max_discard_sectors and make it PAGE aligned */
+			max_bytes = USHRT_MAX * block->bp_block;
+			max_bytes = ALIGN_DOWN(max_bytes, PAGE_SIZE);
+			lim.max_hw_discard_sectors = max_bytes / block->bp_block;
+			lim.max_write_zeroes_sectors = lim.max_hw_discard_sectors;
+		}
+	}
+	rc = queue_limits_commit_update(block->gdp->queue, &lim);
+	if (rc)
+		return rc;
+
+	set_capacity(block->gdp, block->blocks << block->s2b_shift);
+	device->state = DASD_STATE_READY;
+
+	rc = dasd_scan_partitions(block);
+	if (rc) {
+		device->state = DASD_STATE_BASIC;
+		return rc;
+	}
+
+out:
+	if (device->discipline->basic_to_ready)
+		rc = device->discipline->basic_to_ready(device);
+	return rc;
+}
+
+static inline
+int _wait_for_empty_queues(struct dasd_device *device)
+{
+	if (device->block)
+		return list_empty(&device->ccw_queue) &&
+			list_empty(&device->block->ccw_queue) &&
+			list_empty(&device->block->ese_staging);
+	else
+		return list_empty(&device->ccw_queue);
+}
+
+/*
+ * Remove device from block device layer. Destroy dirty buffers.
+ * Forget format information. Check if the target level is basic
+ * and if it is create fake disk for formatting.
+ */
+static int dasd_state_ready_to_basic(struct dasd_device *device)
+{
+	int rc;
+
+	device->state = DASD_STATE_BASIC;
+	if (device->block) {
+		struct dasd_block *block = device->block;
+		rc = dasd_flush_block_queue(block);
+		if (rc) {
+			device->state = DASD_STATE_READY;
+			return rc;
+		}
+		dasd_destroy_partitions(block);
+		block->blocks = 0;
+		block->bp_block = 0;
+		block->s2b_shift = 0;
+	}
+	return 0;
+}
+
+/*
+ * Back to basic.
+ */
+static int dasd_state_unfmt_to_basic(struct dasd_device *device)
+{
+	device->state = DASD_STATE_BASIC;
+	return 0;
+}
+
+/*
+ * Make the device online and schedule the bottom half to start
+ * the requeueing of requests from the linux request queue to the
+ * ccw queue.
+ */
+static int
+dasd_state_ready_to_online(struct dasd_device * device)
+{
+	device->state = DASD_STATE_ONLINE;
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if ((device->features & DASD_FEATURE_USERAW)) {
+			kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
+					KOBJ_CHANGE);
+			return 0;
+		}
+		disk_uevent(file_bdev(device->block->bdev_file)->bd_disk,
+			    KOBJ_CHANGE);
+	}
+	return 0;
+}
+
+/*
+ * Stop the requeueing of requests again.
+ */
+static int dasd_state_online_to_ready(struct dasd_device *device)
+{
+	int rc;
+
+	if (device->discipline->online_to_ready) {
+		rc = device->discipline->online_to_ready(device);
+		if (rc)
+			return rc;
+	}
+
+	device->state = DASD_STATE_READY;
+	if (device->block && !(device->features & DASD_FEATURE_USERAW))
+		disk_uevent(file_bdev(device->block->bdev_file)->bd_disk,
+			    KOBJ_CHANGE);
+	return 0;
+}
+
+/*
+ * Device startup state changes.
+ */
+static int dasd_increase_state(struct dasd_device *device)
+{
+	int rc;
+
+	rc = 0;
+	if (device->state == DASD_STATE_NEW &&
+	    device->target >= DASD_STATE_KNOWN)
+		rc = dasd_state_new_to_known(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_KNOWN &&
+	    device->target >= DASD_STATE_BASIC)
+		rc = dasd_state_known_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_BASIC &&
+	    device->target >= DASD_STATE_READY)
+		rc = dasd_state_basic_to_ready(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_UNFMT &&
+	    device->target > DASD_STATE_UNFMT)
+		rc = -EPERM;
+
+	if (!rc &&
+	    device->state == DASD_STATE_READY &&
+	    device->target >= DASD_STATE_ONLINE)
+		rc = dasd_state_ready_to_online(device);
+
+	return rc;
+}
+
+/*
+ * Device shutdown state changes.
+ */
+static int dasd_decrease_state(struct dasd_device *device)
+{
+	int rc;
+
+	rc = 0;
+	if (device->state == DASD_STATE_ONLINE &&
+	    device->target <= DASD_STATE_READY)
+		rc = dasd_state_online_to_ready(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_READY &&
+	    device->target <= DASD_STATE_BASIC)
+		rc = dasd_state_ready_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_UNFMT &&
+	    device->target <= DASD_STATE_BASIC)
+		rc = dasd_state_unfmt_to_basic(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_BASIC &&
+	    device->target <= DASD_STATE_KNOWN)
+		rc = dasd_state_basic_to_known(device);
+
+	if (!rc &&
+	    device->state == DASD_STATE_KNOWN &&
+	    device->target <= DASD_STATE_NEW)
+		rc = dasd_state_known_to_new(device);
+
+	return rc;
+}
+
+/*
+ * This is the main startup/shutdown routine.
+ */
+static void dasd_change_state(struct dasd_device *device)
+{
+	int rc;
+
+	if (device->state == device->target)
+		/* Already where we want to go today... */
+		return;
+	if (device->state < device->target)
+		rc = dasd_increase_state(device);
+	else
+		rc = dasd_decrease_state(device);
+	if (rc == -EAGAIN)
+		return;
+	if (rc)
+		device->target = device->state;
+
+	/* let user-space know that the device status changed */
+	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
+
+	if (device->state == device->target)
+		wake_up(&dasd_init_waitq);
+}
+
+/*
+ * Kick starter for devices that did not complete the startup/shutdown
+ * procedure or were sleeping because of a pending state.
+ * dasd_kick_device will schedule a call do do_kick_device to the kernel
+ * event daemon.
+ */
+static void do_kick_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
+	mutex_lock(&device->state_mutex);
+	dasd_change_state(device);
+	mutex_unlock(&device->state_mutex);
+	dasd_schedule_device_bh(device);
+	dasd_put_device(device);
+}
+
+void dasd_kick_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_kick_device to the kernel event daemon. */
+	if (!schedule_work(&device->kick_work))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_kick_device);
+
+/*
+ * dasd_reload_device will schedule a call do do_reload_device to the kernel
+ * event daemon.
+ */
+static void do_reload_device(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  reload_device);
+	device->discipline->reload(device);
+	dasd_put_device(device);
+}
+
+void dasd_reload_device(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_reload_device to the kernel event daemon. */
+	if (!schedule_work(&device->reload_device))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_reload_device);
+
+/*
+ * Set the target state for a device and starts the state change.
+ */
+void dasd_set_target_state(struct dasd_device *device, int target)
+{
+	dasd_get_device(device);
+	mutex_lock(&device->state_mutex);
+	/* If we are in probeonly mode stop at DASD_STATE_READY. */
+	if (dasd_probeonly && target > DASD_STATE_READY)
+		target = DASD_STATE_READY;
+	if (device->target != target) {
+		if (device->state == target)
+			wake_up(&dasd_init_waitq);
+		device->target = target;
+	}
+	if (device->state != device->target)
+		dasd_change_state(device);
+	mutex_unlock(&device->state_mutex);
+	dasd_put_device(device);
+}
+
+/*
+ * Enable devices with device numbers in [from..to].
+ */
+static inline int _wait_for_device(struct dasd_device *device)
+{
+	return (device->state == device->target);
+}
+
+void dasd_enable_device(struct dasd_device *device)
+{
+	dasd_set_target_state(device, DASD_STATE_ONLINE);
+	if (device->state <= DASD_STATE_KNOWN)
+		/* No discipline for device found. */
+		dasd_set_target_state(device, DASD_STATE_NEW);
+	/* Now wait for the devices to come up. */
+	wait_event(dasd_init_waitq, _wait_for_device(device));
+
+	dasd_reload_device(device);
+	if (device->discipline->kick_validate)
+		device->discipline->kick_validate(device);
+}
+EXPORT_SYMBOL(dasd_enable_device);
+
+/*
+ * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
+ */
+
+unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
+
+#ifdef CONFIG_DASD_PROFILE
+struct dasd_profile dasd_global_profile = {
+	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
+};
+static struct dentry *dasd_debugfs_global_entry;
+
+/*
+ * Add profiling information for cqr before execution.
+ */
+static void dasd_profile_start(struct dasd_block *block,
+			       struct dasd_ccw_req *cqr,
+			       struct request *req)
+{
+	struct list_head *l;
+	unsigned int counter;
+	struct dasd_device *device;
+
+	/* count the length of the chanq for statistics */
+	counter = 0;
+	if (dasd_global_profile_level || block->profile.data)
+		list_for_each(l, &block->ccw_queue)
+			if (++counter >= 31)
+				break;
+
+	spin_lock(&dasd_global_profile.lock);
+	if (dasd_global_profile.data) {
+		dasd_global_profile.data->dasd_io_nr_req[counter]++;
+		if (rq_data_dir(req) == READ)
+			dasd_global_profile.data->dasd_read_nr_req[counter]++;
+	}
+	spin_unlock(&dasd_global_profile.lock);
+
+	spin_lock(&block->profile.lock);
+	if (block->profile.data) {
+		block->profile.data->dasd_io_nr_req[counter]++;
+		if (rq_data_dir(req) == READ)
+			block->profile.data->dasd_read_nr_req[counter]++;
+	}
+	spin_unlock(&block->profile.lock);
+
+	/*
+	 * We count the request for the start device, even though it may run on
+	 * some other device due to error recovery. This way we make sure that
+	 * we count each request only once.
+	 */
+	device = cqr->startdev;
+	if (!device->profile.data)
+		return;
+
+	spin_lock(get_ccwdev_lock(device->cdev));
+	counter = 1; /* request is not yet queued on the start device */
+	list_for_each(l, &device->ccw_queue)
+		if (++counter >= 31)
+			break;
+	spin_unlock(get_ccwdev_lock(device->cdev));
+
+	spin_lock(&device->profile.lock);
+	device->profile.data->dasd_io_nr_req[counter]++;
+	if (rq_data_dir(req) == READ)
+		device->profile.data->dasd_read_nr_req[counter]++;
+	spin_unlock(&device->profile.lock);
+}
+
+/*
+ * Add profiling information for cqr after execution.
+ */
+
+#define dasd_profile_counter(value, index)			   \
+{								   \
+	for (index = 0; index < 31 && value >> (2+index); index++) \
+		;						   \
+}
+
+static void dasd_profile_end_add_data(struct dasd_profile_info *data,
+				      int is_alias,
+				      int is_tpm,
+				      int is_read,
+				      long sectors,
+				      int sectors_ind,
+				      int tottime_ind,
+				      int tottimeps_ind,
+				      int strtime_ind,
+				      int irqtime_ind,
+				      int irqtimeps_ind,
+				      int endtime_ind)
+{
+	/* in case of an overflow, reset the whole profile */
+	if (data->dasd_io_reqs == UINT_MAX) {
+			memset(data, 0, sizeof(*data));
+			ktime_get_real_ts64(&data->starttod);
+	}
+	data->dasd_io_reqs++;
+	data->dasd_io_sects += sectors;
+	if (is_alias)
+		data->dasd_io_alias++;
+	if (is_tpm)
+		data->dasd_io_tpm++;
+
+	data->dasd_io_secs[sectors_ind]++;
+	data->dasd_io_times[tottime_ind]++;
+	data->dasd_io_timps[tottimeps_ind]++;
+	data->dasd_io_time1[strtime_ind]++;
+	data->dasd_io_time2[irqtime_ind]++;
+	data->dasd_io_time2ps[irqtimeps_ind]++;
+	data->dasd_io_time3[endtime_ind]++;
+
+	if (is_read) {
+		data->dasd_read_reqs++;
+		data->dasd_read_sects += sectors;
+		if (is_alias)
+			data->dasd_read_alias++;
+		if (is_tpm)
+			data->dasd_read_tpm++;
+		data->dasd_read_secs[sectors_ind]++;
+		data->dasd_read_times[tottime_ind]++;
+		data->dasd_read_time1[strtime_ind]++;
+		data->dasd_read_time2[irqtime_ind]++;
+		data->dasd_read_time3[endtime_ind]++;
+	}
+}
+
+static void dasd_profile_end(struct dasd_block *block,
+			     struct dasd_ccw_req *cqr,
+			     struct request *req)
+{
+	unsigned long strtime, irqtime, endtime, tottime;
+	unsigned long tottimeps, sectors;
+	struct dasd_device *device;
+	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
+	int irqtime_ind, irqtimeps_ind, endtime_ind;
+	struct dasd_profile_info *data;
+
+	device = cqr->startdev;
+	if (!(dasd_global_profile_level ||
+	      block->profile.data ||
+	      device->profile.data))
+		return;
+
+	sectors = blk_rq_sectors(req);
+	if (!cqr->buildclk || !cqr->startclk ||
+	    !cqr->stopclk || !cqr->endclk ||
+	    !sectors)
+		return;
+
+	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
+	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
+	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
+	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
+	tottimeps = tottime / sectors;
+
+	dasd_profile_counter(sectors, sectors_ind);
+	dasd_profile_counter(tottime, tottime_ind);
+	dasd_profile_counter(tottimeps, tottimeps_ind);
+	dasd_profile_counter(strtime, strtime_ind);
+	dasd_profile_counter(irqtime, irqtime_ind);
+	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
+	dasd_profile_counter(endtime, endtime_ind);
+
+	spin_lock(&dasd_global_profile.lock);
+	if (dasd_global_profile.data) {
+		data = dasd_global_profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(dasd_global_profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&dasd_global_profile.lock);
+
+	spin_lock(&block->profile.lock);
+	if (block->profile.data) {
+		data = block->profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(block->profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&block->profile.lock);
+
+	spin_lock(&device->profile.lock);
+	if (device->profile.data) {
+		data = device->profile.data;
+		data->dasd_sum_times += tottime;
+		data->dasd_sum_time_str += strtime;
+		data->dasd_sum_time_irq += irqtime;
+		data->dasd_sum_time_end += endtime;
+		dasd_profile_end_add_data(device->profile.data,
+					  cqr->startdev != block->base,
+					  cqr->cpmode == 1,
+					  rq_data_dir(req) == READ,
+					  sectors, sectors_ind, tottime_ind,
+					  tottimeps_ind, strtime_ind,
+					  irqtime_ind, irqtimeps_ind,
+					  endtime_ind);
+	}
+	spin_unlock(&device->profile.lock);
+}
+
+void dasd_profile_reset(struct dasd_profile *profile)
+{
+	struct dasd_profile_info *data;
+
+	spin_lock_bh(&profile->lock);
+	data = profile->data;
+	if (!data) {
+		spin_unlock_bh(&profile->lock);
+		return;
+	}
+	memset(data, 0, sizeof(*data));
+	ktime_get_real_ts64(&data->starttod);
+	spin_unlock_bh(&profile->lock);
+}
+
+int dasd_profile_on(struct dasd_profile *profile)
+{
+	struct dasd_profile_info *data;
+
+	data = kzalloc_obj(*data);
+	if (!data)
+		return -ENOMEM;
+	spin_lock_bh(&profile->lock);
+	if (profile->data) {
+		spin_unlock_bh(&profile->lock);
+		kfree(data);
+		return 0;
+	}
+	ktime_get_real_ts64(&data->starttod);
+	profile->data = data;
+	spin_unlock_bh(&profile->lock);
+	return 0;
+}
+
+void dasd_profile_off(struct dasd_profile *profile)
+{
+	spin_lock_bh(&profile->lock);
+	kfree(profile->data);
+	profile->data = NULL;
+	spin_unlock_bh(&profile->lock);
+}
+
+char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
+{
+	char *buffer;
+
+	buffer = vmalloc(user_len + 1);
+	if (buffer == NULL)
+		return ERR_PTR(-ENOMEM);
+	if (copy_from_user(buffer, user_buf, user_len) != 0) {
+		vfree(buffer);
+		return ERR_PTR(-EFAULT);
+	}
+	/* got the string, now strip linefeed. */
+	if (buffer[user_len - 1] == '\n')
+		buffer[user_len - 1] = 0;
+	else
+		buffer[user_len] = 0;
+	return buffer;
+}
+
+static ssize_t dasd_stats_write(struct file *file,
+				const char __user *user_buf,
+				size_t user_len, loff_t *pos)
+{
+	char *buffer, *str;
+	int rc;
+	struct seq_file *m = (struct seq_file *)file->private_data;
+	struct dasd_profile *prof = m->private;
+
+	if (user_len > 65536)
+		user_len = 65536;
+	buffer = dasd_get_user_string(user_buf, user_len);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	str = skip_spaces(buffer);
+	rc = user_len;
+	if (strncmp(str, "reset", 5) == 0) {
+		dasd_profile_reset(prof);
+	} else if (strncmp(str, "on", 2) == 0) {
+		rc = dasd_profile_on(prof);
+		if (rc)
+			goto out;
+		rc = user_len;
+		if (prof == &dasd_global_profile) {
+			dasd_profile_reset(prof);
+			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
+		}
+	} else if (strncmp(str, "off", 3) == 0) {
+		if (prof == &dasd_global_profile)
+			dasd_global_profile_level = DASD_PROFILE_OFF;
+		dasd_profile_off(prof);
+	} else
+		rc = -EINVAL;
+out:
+	vfree(buffer);
+	return rc;
+}
+
+static void dasd_stats_array(struct seq_file *m, unsigned int *array)
+{
+	int i;
+
+	for (i = 0; i < 32; i++)
+		seq_printf(m, "%u ", array[i]);
+	seq_putc(m, '\n');
+}
+
+static void dasd_stats_seq_print(struct seq_file *m,
+				 struct dasd_profile_info *data)
+{
+	seq_printf(m, "start_time %ptSp\n", &data->starttod);
+	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
+	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
+	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
+	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
+	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
+	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
+		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
+	seq_puts(m, "histogram_sectors ");
+	dasd_stats_array(m, data->dasd_io_secs);
+	seq_puts(m, "histogram_io_times ");
+	dasd_stats_array(m, data->dasd_io_times);
+	seq_puts(m, "histogram_io_times_weighted ");
+	dasd_stats_array(m, data->dasd_io_timps);
+	seq_puts(m, "histogram_time_build_to_ssch ");
+	dasd_stats_array(m, data->dasd_io_time1);
+	seq_puts(m, "histogram_time_ssch_to_irq ");
+	dasd_stats_array(m, data->dasd_io_time2);
+	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
+	dasd_stats_array(m, data->dasd_io_time2ps);
+	seq_puts(m, "histogram_time_irq_to_end ");
+	dasd_stats_array(m, data->dasd_io_time3);
+	seq_puts(m, "histogram_ccw_queue_length ");
+	dasd_stats_array(m, data->dasd_io_nr_req);
+	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
+	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
+	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
+	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
+	seq_puts(m, "histogram_read_sectors ");
+	dasd_stats_array(m, data->dasd_read_secs);
+	seq_puts(m, "histogram_read_times ");
+	dasd_stats_array(m, data->dasd_read_times);
+	seq_puts(m, "histogram_read_time_build_to_ssch ");
+	dasd_stats_array(m, data->dasd_read_time1);
+	seq_puts(m, "histogram_read_time_ssch_to_irq ");
+	dasd_stats_array(m, data->dasd_read_time2);
+	seq_puts(m, "histogram_read_time_irq_to_end ");
+	dasd_stats_array(m, data->dasd_read_time3);
+	seq_puts(m, "histogram_read_ccw_queue_length ");
+	dasd_stats_array(m, data->dasd_read_nr_req);
+}
+
+static int dasd_stats_show(struct seq_file *m, void *v)
+{
+	struct dasd_profile *profile;
+	struct dasd_profile_info *data;
+
+	profile = m->private;
+	spin_lock_bh(&profile->lock);
+	data = profile->data;
+	if (!data) {
+		spin_unlock_bh(&profile->lock);
+		seq_puts(m, "disabled\n");
+		return 0;
+	}
+	dasd_stats_seq_print(m, data);
+	spin_unlock_bh(&profile->lock);
+	return 0;
+}
+
+static int dasd_stats_open(struct inode *inode, struct file *file)
+{
+	struct dasd_profile *profile = inode->i_private;
+	return single_open(file, dasd_stats_show, profile);
+}
+
+static const struct file_operations dasd_stats_raw_fops = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.write		= dasd_stats_write,
+};
+
+static void dasd_profile_init(struct dasd_profile *profile,
+			      struct dentry *base_dentry)
+{
+	profile->data = NULL;
+	profile->dentry = debugfs_create_file("statistics", 0600, base_dentry,
+					      profile, &dasd_stats_raw_fops);
+}
+
+static void dasd_profile_exit(struct dasd_profile *profile)
+{
+	dasd_profile_off(profile);
+	debugfs_remove(profile->dentry);
+	profile->dentry = NULL;
+}
+
+static void dasd_statistics_removeroot(void)
+{
+	dasd_global_profile_level = DASD_PROFILE_OFF;
+	dasd_profile_exit(&dasd_global_profile);
+	debugfs_remove(dasd_debugfs_global_entry);
+	debugfs_remove(dasd_debugfs_root_entry);
+}
+
+static void dasd_statistics_createroot(void)
+{
+	dasd_debugfs_root_entry = debugfs_create_dir("dasd", NULL);
+	dasd_debugfs_global_entry = debugfs_create_dir("global", dasd_debugfs_root_entry);
+	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
+}
+
+#else
+#define dasd_profile_start(block, cqr, req) do {} while (0)
+#define dasd_profile_end(block, cqr, req) do {} while (0)
+
+static void dasd_statistics_createroot(void)
+{
+	return;
+}
+
+static void dasd_statistics_removeroot(void)
+{
+	return;
+}
+
+static void dasd_profile_init(struct dasd_profile *profile,
+			      struct dentry *base_dentry)
+{
+	return;
+}
+
+static void dasd_profile_exit(struct dasd_profile *profile)
+{
+	return;
+}
+
+int dasd_profile_on(struct dasd_profile *profile)
+{
+	return 0;
+}
+
+#endif				/* CONFIG_DASD_PROFILE */
+
+static int dasd_hosts_show(struct seq_file *m, void *v)
+{
+	struct dasd_device *device;
+	int rc = -EOPNOTSUPP;
+
+	device = m->private;
+	dasd_get_device(device);
+
+	if (device->discipline->hosts_print)
+		rc = device->discipline->hosts_print(device, m);
+
+	dasd_put_device(device);
+	return rc;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
+
+static void dasd_hosts_exit(struct dasd_device *device)
+{
+	debugfs_remove(device->hosts_dentry);
+	device->hosts_dentry = NULL;
+}
+
+static void dasd_hosts_init(struct dentry *base_dentry,
+			    struct dasd_device *device)
+{
+	device->hosts_dentry = debugfs_create_file("host_access_list", 0400, base_dentry,
+						   device, &dasd_hosts_fops);
+}
+
+struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
+					  struct dasd_device *device,
+					  struct dasd_ccw_req *cqr)
+{
+	unsigned long flags;
+	char *data, *chunk;
+	int size = 0;
+
+	if (cplength > 0)
+		size += cplength * sizeof(struct ccw1);
+	if (datasize > 0)
+		size += datasize;
+	if (!cqr)
+		size += (sizeof(*cqr) + 7L) & -8L;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	if (!chunk)
+		return ERR_PTR(-ENOMEM);
+	if (!cqr) {
+		cqr = (void *) data;
+		data += (sizeof(*cqr) + 7L) & -8L;
+	}
+	memset(cqr, 0, sizeof(*cqr));
+	cqr->mem_chunk = chunk;
+	if (cplength > 0) {
+		cqr->cpaddr = data;
+		data += cplength * sizeof(struct ccw1);
+		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
+	}
+	if (datasize > 0) {
+		cqr->data = data;
+ 		memset(cqr->data, 0, datasize);
+	}
+	cqr->magic = magic;
+	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	dasd_get_device(device);
+	return cqr;
+}
+EXPORT_SYMBOL(dasd_smalloc_request);
+
+struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
+					  int datasize,
+					  struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	unsigned long flags;
+	int size, cqr_size;
+	char *data;
+
+	cqr_size = (sizeof(*cqr) + 7L) & -8L;
+	size = cqr_size;
+	if (cplength > 0)
+		size += cplength * sizeof(struct ccw1);
+	if (datasize > 0)
+		size += datasize;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	cqr = dasd_alloc_chunk(&device->ese_chunks, size);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	if (!cqr)
+		return ERR_PTR(-ENOMEM);
+	memset(cqr, 0, sizeof(*cqr));
+	data = (char *)cqr + cqr_size;
+	cqr->cpaddr = NULL;
+	if (cplength > 0) {
+		cqr->cpaddr = data;
+		data += cplength * sizeof(struct ccw1);
+		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
+	}
+	cqr->data = NULL;
+	if (datasize > 0) {
+		cqr->data = data;
+		memset(cqr->data, 0, datasize);
+	}
+
+	cqr->magic = magic;
+	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+	dasd_get_device(device);
+
+	return cqr;
+}
+EXPORT_SYMBOL(dasd_fmalloc_request);
+
+void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	/*
+	 * Free the request block from the pool it came from: smalloc() sets
+	 * mem_chunk (ccw_chunks), fmalloc() leaves it NULL (ese_chunks). A
+	 * full-track request also frees its track-filler buffer.
+	 */
+	if (cqr->filldata)
+		dasd_free_chunk(&device->fill_chunks, cqr->filldata);
+	if (cqr->mem_chunk)
+		dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
+	else
+		dasd_free_chunk(&device->ese_chunks, cqr);
+
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_sfree_request);
+
+void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&device->mem_lock, flags);
+	if (cqr->filldata)
+		dasd_free_chunk(&device->fill_chunks, cqr->filldata);
+	dasd_free_chunk(&device->ese_chunks, cqr);
+	spin_unlock_irqrestore(&device->mem_lock, flags);
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_ffree_request);
+
+/*
+ * Check discipline magic in cqr.
+ */
+static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+
+	if (cqr == NULL)
+		return -EINVAL;
+	device = cqr->startdev;
+	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			    " dasd_ccw_req 0x%08x magic doesn't match"
+			    " discipline 0x%08x",
+			    cqr->magic,
+			    *(unsigned int *) device->discipline->name);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * Terminate the current i/o and set the request to clear_pending.
+ * Timer keeps device runnig.
+ * ccw_device_clear can fail if the i/o subsystem
+ * is in a bad mood.
+ */
+int dasd_term_IO(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int retries, rc;
+
+	/* Check the cqr */
+	rc = dasd_check_cqr(cqr);
+	if (rc)
+		return rc;
+	retries = 0;
+	device = (struct dasd_device *) cqr->startdev;
+	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
+		rc = ccw_device_clear(device->cdev, (long) cqr);
+		switch (rc) {
+		case 0:	/* termination successful */
+			cqr->status = DASD_CQR_CLEAR_PENDING;
+			cqr->stopclk = get_tod_clock();
+			cqr->starttime = 0;
+			DBF_DEV_EVENT(DBF_DEBUG, device,
+				      "terminate cqr %p successful",
+				      cqr);
+			break;
+		case -ENODEV:
+			DBF_DEV_EVENT(DBF_ERR, device, "%s",
+				      "device gone, retry");
+			break;
+		case -EINVAL:
+			/*
+			 * device not valid so no I/O could be running
+			 * handle CQR as termination successful
+			 */
+			cqr->status = DASD_CQR_CLEARED;
+			cqr->stopclk = get_tod_clock();
+			cqr->starttime = 0;
+			/* no retries for invalid devices */
+			cqr->retries = -1;
+			DBF_DEV_EVENT(DBF_ERR, device, "%s",
+				      "EINVAL, handle as terminated");
+			/* fake rc to success */
+			rc = 0;
+			break;
+		default:
+			dev_err(&device->cdev->dev,
+				"Unexpected error during request termination %d\n", rc);
+			BUG();
+			break;
+		}
+		retries++;
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+EXPORT_SYMBOL(dasd_term_IO);
+
+/*
+ * Start the i/o. This start_IO can fail if the channel is really busy.
+ * In that case set up a timer to start the request later.
+ */
+int dasd_start_IO(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+
+	/* Check the cqr */
+	rc = dasd_check_cqr(cqr);
+	if (rc) {
+		cqr->intrc = rc;
+		return rc;
+	}
+	device = (struct dasd_device *) cqr->startdev;
+	if (((cqr->block &&
+	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
+	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
+	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
+			      "because of stolen lock", cqr);
+		cqr->status = DASD_CQR_ERROR;
+		cqr->intrc = -EPERM;
+		return -EPERM;
+	}
+	if (cqr->retries < 0) {
+		dev_err(&device->cdev->dev,
+			"Start I/O ran out of retries\n");
+		cqr->status = DASD_CQR_ERROR;
+		return -EIO;
+	}
+	cqr->startclk = get_tod_clock();
+	cqr->starttime = jiffies;
+	cqr->retries--;
+	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+		cqr->lpm &= dasd_path_get_opm(device);
+		if (!cqr->lpm)
+			cqr->lpm = dasd_path_get_opm(device);
+	}
+	if (cqr->cpmode == 1) {
+		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
+					 (long) cqr, cqr->lpm);
+	} else {
+		rc = ccw_device_start(device->cdev, cqr->cpaddr,
+				      (long) cqr, cqr->lpm, 0);
+	}
+	switch (rc) {
+	case 0:
+		cqr->status = DASD_CQR_IN_IO;
+		break;
+	case -EBUSY:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: device busy, retry later");
+		break;
+	case -EACCES:
+		/* -EACCES indicates that the request used only a subset of the
+		 * available paths and all these paths are gone. If the lpm of
+		 * this request was only a subset of the opm (e.g. the ppm) then
+		 * we just do a retry with all available paths.
+		 * If we already use the full opm, something is amiss, and we
+		 * need a full path verification.
+		 */
+		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			DBF_DEV_EVENT(DBF_WARNING, device,
+				      "start_IO: selected paths gone (%x)",
+				      cqr->lpm);
+		} else if (cqr->lpm != dasd_path_get_opm(device)) {
+			cqr->lpm = dasd_path_get_opm(device);
+			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
+				      "start_IO: selected paths gone,"
+				      " retry on all paths");
+		} else {
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "start_IO: all paths in opm gone,"
+				      " do path verification");
+			dasd_generic_last_path_gone(device);
+			dasd_path_no_path(device);
+			dasd_path_set_tbvpm(device,
+					  ccw_device_get_path_mask(
+						  device->cdev));
+		}
+		break;
+	case -ENODEV:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -ENODEV device gone, retry");
+		/* this is equivalent to CC=3 for SSCH report this to EER */
+		dasd_handle_autoquiesce(device, cqr, DASD_EER_STARTIO);
+		break;
+	case -EIO:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -EIO device gone, retry");
+		break;
+	case -EINVAL:
+		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+			      "start_IO: -EINVAL device currently "
+			      "not accessible");
+		break;
+	default:
+		dev_err(&device->cdev->dev,
+			"Unexpected error during request start %d", rc);
+		BUG();
+		break;
+	}
+	cqr->intrc = rc;
+	return rc;
+}
+EXPORT_SYMBOL(dasd_start_IO);
+
+/*
+ * Timeout function for dasd devices. This is used for different purposes
+ *  1) missing interrupt handler for normal operation
+ *  2) delayed start of request where start_IO failed with -EBUSY
+ *  3) timeout for missing state change interrupts
+ * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
+ * DASD_CQR_QUEUED for 2) and 3).
+ */
+static void dasd_device_timeout(struct timer_list *t)
+{
+	unsigned long flags;
+	struct dasd_device *device;
+
+	device = timer_container_of(device, t, timer);
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	/* re-activate request queue */
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	dasd_schedule_device_bh(device);
+}
+
+/*
+ * Setup timeout for a device in jiffies.
+ */
+void dasd_device_set_timer(struct dasd_device *device, int expires)
+{
+	if (expires == 0)
+		timer_delete(&device->timer);
+	else
+		mod_timer(&device->timer, jiffies + expires);
+}
+EXPORT_SYMBOL(dasd_device_set_timer);
+
+/*
+ * Clear timeout for a device.
+ */
+void dasd_device_clear_timer(struct dasd_device *device)
+{
+	timer_delete(&device->timer);
+}
+EXPORT_SYMBOL(dasd_device_clear_timer);
+
+static void dasd_handle_killed_request(struct ccw_device *cdev,
+				       unsigned long intparm)
+{
+	struct dasd_ccw_req *cqr;
+	struct dasd_device *device;
+
+	if (!intparm)
+		return;
+	cqr = (struct dasd_ccw_req *) intparm;
+	if (cqr->status != DASD_CQR_IN_IO) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
+				"invalid status in handle_killed_request: "
+				"%02x", cqr->status);
+		return;
+	}
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"unable to get device from cdev");
+		return;
+	}
+
+	if (!cqr->startdev ||
+	    device != cqr->startdev ||
+	    strncmp(cqr->startdev->discipline->ebcname,
+		    (char *) &cqr->magic, 4)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"invalid device in request");
+		dasd_put_device(device);
+		return;
+	}
+
+	/* Schedule request to be retried. */
+	cqr->status = DASD_CQR_QUEUED;
+
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+	dasd_put_device(device);
+}
+
+void dasd_generic_handle_state_change(struct dasd_device *device)
+{
+	/* First of all start sense subsystem status request. */
+	dasd_eer_snss(device);
+
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
+	dasd_schedule_device_bh(device);
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->gdp)
+			blk_mq_run_hw_queues(device->block->gdp->queue, true);
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
+
+static int dasd_check_hpf_error(struct irb *irb)
+{
+	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
+	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
+	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
+}
+
+static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
+{
+	struct dasd_device *device = NULL;
+	u8 *sense = NULL;
+
+	if (!block)
+		return 0;
+	device = block->base;
+	if (!device || !device->discipline->is_ese)
+		return 0;
+	if (!device->discipline->is_ese(device))
+		return 0;
+
+	sense = dasd_get_sense(irb);
+	if (!sense)
+		return 0;
+
+	if (sense[1] & SNS1_NO_REC_FOUND)
+		return 1;
+
+	if ((sense[1] & SNS1_INV_TRACK_FORMAT) &&
+	    scsw_is_tm(&irb->scsw) &&
+	    !(sense[2] & SNS2_ENV_DATA_PRESENT))
+		return 1;
+
+	return 0;
+}
+
+static int dasd_ese_oos_cond(u8 *sense)
+{
+	return sense[0] & SNS0_EQUIPMENT_CHECK &&
+		sense[1] & SNS1_PERM_ERR &&
+		sense[1] & SNS1_WRITE_INHIBITED &&
+		sense[25] == 0x01;
+}
+
+/*
+ * Interrupt handler for "normal" ssch-io based dasd devices.
+ */
+void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
+		      struct irb *irb)
+{
+	struct dasd_ccw_req *cqr, *next;
+	struct dasd_device *device;
+	unsigned long now;
+	int nrf_suppressed = 0;
+	int it_suppressed = 0;
+	struct request *req;
+	u8 *sense = NULL;
+	int expires;
+
+	cqr = (struct dasd_ccw_req *) intparm;
+	if (IS_ERR(irb)) {
+		switch (PTR_ERR(irb)) {
+		case -EIO:
+			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
+				device = cqr->startdev;
+				cqr->status = DASD_CQR_CLEARED;
+				dasd_device_clear_timer(device);
+				wake_up(&dasd_flush_wq);
+				dasd_schedule_device_bh(device);
+				return;
+			}
+			break;
+		case -ETIMEDOUT:
+			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
+					"request timed out\n", __func__);
+			break;
+		default:
+			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
+					"unknown error %ld\n", __func__,
+					PTR_ERR(irb));
+		}
+		dasd_handle_killed_request(cdev, intparm);
+		return;
+	}
+
+	now = get_tod_clock();
+	/* check for conditions that should be handled immediately */
+	if (!cqr ||
+	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+	      scsw_cstat(&irb->scsw) == 0)) {
+		if (cqr)
+			memcpy(&cqr->irb, irb, sizeof(*irb));
+		device = dasd_device_from_cdev_locked(cdev);
+		if (IS_ERR(device))
+			return;
+		/* ignore unsolicited interrupts for DIAG discipline */
+		if (device->discipline == dasd_diag_discipline_pointer) {
+			dasd_put_device(device);
+			return;
+		}
+
+		/*
+		 * In some cases 'File Protected' or 'No Record Found' errors
+		 * might be expected and debug log messages for the
+		 * corresponding interrupts shouldn't be written then.
+		 * Check if either of the according suppress bits is set.
+		 */
+		sense = dasd_get_sense(irb);
+		if (sense) {
+			it_suppressed =	(sense[1] & SNS1_INV_TRACK_FORMAT) &&
+				!(sense[2] & SNS2_ENV_DATA_PRESENT) &&
+				test_bit(DASD_CQR_SUPPRESS_IT, &cqr->flags);
+			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
+				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
+
+			/*
+			 * Extent pool probably out-of-space.
+			 * Stop device and check exhaust level.
+			 */
+			if (dasd_ese_oos_cond(sense)) {
+				dasd_generic_space_exhaust(device, cqr);
+				device->discipline->ext_pool_exhaust(device, cqr);
+				dasd_put_device(device);
+				return;
+			}
+		}
+		if (!(it_suppressed || nrf_suppressed))
+			device->discipline->dump_sense_dbf(device, irb, "int");
+
+		if (device->features & DASD_FEATURE_ERPLOG)
+			device->discipline->dump_sense(device, cqr, irb);
+		device->discipline->check_for_device_change(device, cqr, irb);
+		dasd_put_device(device);
+	}
+
+	/* check for attention message */
+	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
+		device = dasd_device_from_cdev_locked(cdev);
+		if (!IS_ERR(device)) {
+			device->discipline->check_attention(device,
+							    irb->esw.esw1.lpum);
+			dasd_put_device(device);
+		}
+	}
+
+	if (!cqr)
+		return;
+
+	device = (struct dasd_device *) cqr->startdev;
+	if (!device ||
+	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
+				"invalid device in request");
+		return;
+	}
+
+	if (dasd_ese_needs_format(cqr->block, irb)) {
+		req = dasd_get_callback_data(cqr);
+		if (!req) {
+			cqr->status = DASD_CQR_ERROR;
+			return;
+		}
+		if (rq_data_dir(req) == READ) {
+			if (device->discipline->ese_read(cqr, irb))
+				cqr->status = DASD_CQR_ERROR;
+			else
+				cqr->status = DASD_CQR_SUCCESS;
+			cqr->stopclk = now;
+			dasd_device_clear_timer(device);
+			dasd_schedule_device_bh(device);
+			return;
+		}
+		if (cqr->filldata) {
+			/*
+			 * A WRITE_FULL_TRACK cqr carries the complete
+			 * track image; INV_TRACK_FORMAT here means the
+			 * generated image or the media itself is bad, not
+			 * that the track still needs formatting - retrying
+			 * via ese_format() would just resubmit the same
+			 * write. Let it fail instead.
+			 */
+			cqr->status = DASD_CQR_ERROR;
+			cqr->stopclk = now;
+			dasd_device_clear_timer(device);
+			dasd_schedule_device_bh(device);
+			return;
+		}
+		device->discipline->ese_format(device, cqr, irb);
+		return;
+	}
+
+	/* Check for clear pending */
+	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
+	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
+		cqr->status = DASD_CQR_CLEARED;
+		dasd_device_clear_timer(device);
+		wake_up(&dasd_flush_wq);
+		dasd_schedule_device_bh(device);
+		return;
+	}
+
+	/* check status - the request might have been killed by dyn detach */
+	if (cqr->status != DASD_CQR_IN_IO) {
+		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
+			      "status %02x", dev_name(&cdev->dev), cqr->status);
+		return;
+	}
+
+	next = NULL;
+	expires = 0;
+	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+	    scsw_cstat(&irb->scsw) == 0) {
+		/* request was completed successfully */
+		cqr->status = DASD_CQR_SUCCESS;
+		cqr->stopclk = now;
+		/* Start first request on queue if possible -> fast_io. */
+		if (cqr->devlist.next != &device->ccw_queue) {
+			next = list_entry(cqr->devlist.next,
+					  struct dasd_ccw_req, devlist);
+		}
+	} else {  /* error */
+		/* check for HPF error
+		 * call discipline function to requeue all requests
+		 * and disable HPF accordingly
+		 */
+		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
+		    device->discipline->handle_hpf_error)
+			device->discipline->handle_hpf_error(device, irb);
+		/*
+		 * If we don't want complex ERP for this request, then just
+		 * reset this and retry it in the fastpath
+		 */
+		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
+		    cqr->retries > 0) {
+			if (cqr->lpm == dasd_path_get_opm(device))
+				DBF_DEV_EVENT(DBF_DEBUG, device,
+					      "default ERP in fastpath "
+					      "(%i retries left)",
+					      cqr->retries);
+			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
+				cqr->lpm = dasd_path_get_opm(device);
+			cqr->status = DASD_CQR_QUEUED;
+			next = cqr;
+		} else
+			cqr->status = DASD_CQR_ERROR;
+	}
+	if (next && (next->status == DASD_CQR_QUEUED) &&
+	    (!device->stopped)) {
+		if (device->discipline->start_IO(next) == 0)
+			expires = next->expires;
+	}
+	if (expires != 0)
+		dasd_device_set_timer(device, expires);
+	else
+		dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+}
+EXPORT_SYMBOL(dasd_int_handler);
+
+enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
+{
+	struct dasd_device *device;
+
+	device = dasd_device_from_cdev_locked(cdev);
+
+	if (IS_ERR(device))
+		goto out;
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
+	   device->state != device->target ||
+	   !device->discipline->check_for_device_change){
+		dasd_put_device(device);
+		goto out;
+	}
+	if (device->discipline->dump_sense_dbf)
+		device->discipline->dump_sense_dbf(device, irb, "uc");
+	device->discipline->check_for_device_change(device, NULL, irb);
+	dasd_put_device(device);
+out:
+	return UC_TODO_RETRY;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
+
+/*
+ * If we have an error on a dasd_block layer request then we cancel
+ * and return all further requests from the same dasd_block as well.
+ */
+static void __dasd_device_recovery(struct dasd_device *device,
+				   struct dasd_ccw_req *ref_cqr)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+
+	/*
+	 * only requeue request that came from the dasd_block layer
+	 */
+	if (!ref_cqr->block)
+		return;
+
+	list_for_each_safe(l, n, &device->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+		if (cqr->status == DASD_CQR_QUEUED &&
+		    ref_cqr->block == cqr->block) {
+			cqr->status = DASD_CQR_CLEARED;
+		}
+	}
+};
+
+/*
+ * Remove those ccw requests from the queue that need to be returned
+ * to the upper layer.
+ */
+static void __dasd_device_process_ccw_queue(struct dasd_device *device,
+					    struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+
+	/* Process request with final status. */
+	list_for_each_safe(l, n, &device->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+
+		/* Skip any non-final request. */
+		if (cqr->status == DASD_CQR_QUEUED ||
+		    cqr->status == DASD_CQR_IN_IO ||
+		    cqr->status == DASD_CQR_CLEAR_PENDING)
+			continue;
+		if (cqr->status == DASD_CQR_ERROR) {
+			__dasd_device_recovery(device, cqr);
+		}
+		/* Rechain finished requests to final queue */
+		list_move_tail(&cqr->devlist, final_queue);
+	}
+}
+
+static void __dasd_process_cqr(struct dasd_device *device,
+			       struct dasd_ccw_req *cqr)
+{
+	switch (cqr->status) {
+	case DASD_CQR_SUCCESS:
+		cqr->status = DASD_CQR_DONE;
+		break;
+	case DASD_CQR_ERROR:
+		cqr->status = DASD_CQR_NEED_ERP;
+		break;
+	case DASD_CQR_CLEARED:
+		cqr->status = DASD_CQR_TERMINATED;
+		break;
+	case DASD_CQR_ABORT:
+		cqr->status = DASD_CQR_ABORTED;
+		/*
+		 * ABORT is only set on the block-layer origin write that a
+		 * full-track format replaces. Clear the callback so the request
+		 * is not completed here - the replacement completes it. Internal
+		 * requests never take this path, so no sleep_on waiter is left
+		 * without its wakeup.
+		 */
+		cqr->callback = NULL;
+		break;
+	default:
+		dev_err(&device->cdev->dev,
+			"Unexpected CQR status %02x", cqr->status);
+		BUG();
+	}
+	if (cqr->callback)
+		cqr->callback(cqr, cqr->callback_data);
+}
+
+/*
+ * the cqrs from the final queue are returned to the upper layer
+ * by setting a dasd_block state and calling the callback function
+ */
+static void __dasd_device_process_final_queue(struct dasd_device *device,
+					      struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	struct dasd_block *block;
+
+	list_for_each_safe(l, n, final_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, devlist);
+		list_del_init(&cqr->devlist);
+		block = cqr->block;
+		if (!block) {
+			__dasd_process_cqr(device, cqr);
+		} else {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_cqr(device, cqr);
+			spin_unlock_bh(&block->queue_lock);
+		}
+	}
+}
+
+/*
+ * check if device should be autoquiesced due to too many timeouts
+ */
+static void __dasd_device_check_autoquiesce_timeout(struct dasd_device *device,
+						    struct dasd_ccw_req *cqr)
+{
+	if ((device->default_retries - cqr->retries) >= device->aq_timeouts)
+		dasd_handle_autoquiesce(device, cqr, DASD_EER_TIMEOUTS);
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it reached its expire time. If so, terminate the IO.
+ */
+static void __dasd_device_check_expire(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+
+	if (list_empty(&device->ccw_queue))
+		return;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
+	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
+		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			/*
+			 * IO in safe offline processing should not
+			 * run out of retries
+			 */
+			cqr->retries++;
+		}
+		if (device->discipline->term_IO(cqr) != 0) {
+			/* Hmpf, try again in 5 sec */
+			dev_err(&device->cdev->dev,
+				"CQR timed out (%lus) but cannot be ended, retrying in 5s\n",
+				(cqr->expires / HZ));
+			cqr->expires += 5*HZ;
+			dasd_device_set_timer(device, 5*HZ);
+		} else {
+			dev_err(&device->cdev->dev,
+				"CQR timed out (%lus), %i retries remaining\n",
+				(cqr->expires / HZ), cqr->retries);
+		}
+		__dasd_device_check_autoquiesce_timeout(device, cqr);
+	}
+}
+
+/*
+ * return 1 when device is not eligible for IO
+ */
+static int __dasd_device_is_unusable(struct dasd_device *device,
+				     struct dasd_ccw_req *cqr)
+{
+	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
+
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
+	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/*
+		 * dasd is being set offline
+		 * but it is no safe offline where we have to allow I/O
+		 */
+		return 1;
+	}
+	if (device->stopped) {
+		if (device->stopped & mask) {
+			/* stopped and CQR will not change that. */
+			return 1;
+		}
+		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			/* CQR is not able to change device to
+			 * operational. */
+			return 1;
+		}
+		/* CQR required to get device operational. */
+	}
+	return 0;
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it needs to be started.
+ */
+static void __dasd_device_start_head(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+
+	if (list_empty(&device->ccw_queue))
+		return;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	if (cqr->status != DASD_CQR_QUEUED)
+		return;
+	/* if device is not usable return request to upper layer */
+	if (__dasd_device_is_unusable(device, cqr)) {
+		cqr->intrc = -EAGAIN;
+		cqr->status = DASD_CQR_CLEARED;
+		dasd_schedule_device_bh(device);
+		return;
+	}
+
+	rc = device->discipline->start_IO(cqr);
+	if (rc == 0)
+		dasd_device_set_timer(device, cqr->expires);
+	else if (rc == -EACCES) {
+		dasd_schedule_device_bh(device);
+	} else
+		/* Hmpf, try again in 1/2 sec */
+		dasd_device_set_timer(device, 50);
+}
+
+static void __dasd_device_check_path_events(struct dasd_device *device)
+{
+	__u8 tbvpm, fcsecpm;
+	int rc;
+
+	tbvpm = dasd_path_get_tbvpm(device);
+	fcsecpm = dasd_path_get_fcsecpm(device);
+
+	if (!tbvpm && !fcsecpm)
+		return;
+
+	if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
+		return;
+
+	dasd_path_clear_all_verify(device);
+	dasd_path_clear_all_fcsec(device);
+
+	rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
+	if (rc) {
+		dasd_path_add_tbvpm(device, tbvpm);
+		dasd_path_add_fcsecpm(device, fcsecpm);
+		dasd_device_set_timer(device, 50);
+	}
+};
+
+/*
+ * Go through all request on the dasd_device request queue,
+ * terminate them on the cdev if necessary, and return them to the
+ * submitting layer via callback.
+ * Note:
+ * Make sure that all 'submitting layers' still exist when
+ * this function is called!. In other words, when 'device' is a base
+ * device then all block layer requests must have been removed before
+ * via dasd_flush_block_queue.
+ */
+int dasd_flush_device_queue(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr, *n;
+	int rc;
+	struct list_head flush_queue;
+
+	INIT_LIST_HEAD(&flush_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = 0;
+	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
+		/* Check status and move request to flush_queue */
+		switch (cqr->status) {
+		case DASD_CQR_IN_IO:
+			rc = device->discipline->term_IO(cqr);
+			if (rc) {
+				/* unable to terminate request */
+				dev_err(&device->cdev->dev,
+					"Flushing the DASD request queue failed\n");
+				/* stop flush processing */
+				goto finished;
+			}
+			break;
+		case DASD_CQR_QUEUED:
+			cqr->stopclk = get_tod_clock();
+			cqr->status = DASD_CQR_CLEARED;
+			break;
+		default: /* no need to modify the others */
+			break;
+		}
+		list_move_tail(&cqr->devlist, &flush_queue);
+	}
+finished:
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	/*
+	 * After this point all requests must be in state CLEAR_PENDING,
+	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
+	 * one of the others.
+	 */
+	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
+		wait_event(dasd_flush_wq,
+			   (cqr->status != DASD_CQR_CLEAR_PENDING));
+	/*
+	 * Now set each request back to TERMINATED, DONE or NEED_ERP
+	 * and call the callback function of flushed requests
+	 */
+	__dasd_device_process_final_queue(device, &flush_queue);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
+
+/*
+ * Acquire the device lock and process queues for the device.
+ */
+static void dasd_device_tasklet(unsigned long data)
+{
+	struct dasd_device *device = (struct dasd_device *) data;
+	struct list_head final_queue;
+
+	atomic_set (&device->tasklet_scheduled, 0);
+	INIT_LIST_HEAD(&final_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	/* Check expire time of first request on the ccw queue. */
+	__dasd_device_check_expire(device);
+	/* find final requests on ccw queue */
+	__dasd_device_process_ccw_queue(device, &final_queue);
+	__dasd_device_check_path_events(device);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	/* Now call the callback function of requests with final status */
+	__dasd_device_process_final_queue(device, &final_queue);
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	/* Now check if the head of the ccw queue needs to be started. */
+	__dasd_device_start_head(device);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	if (waitqueue_active(&shutdown_waitq))
+		wake_up(&shutdown_waitq);
+	dasd_put_device(device);
+}
+
+/*
+ * Schedules a call to dasd_tasklet over the device tasklet.
+ */
+void dasd_schedule_device_bh(struct dasd_device *device)
+{
+	/* Protect against rescheduling. */
+	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
+		return;
+	dasd_get_device(device);
+	tasklet_hi_schedule(&device->tasklet);
+}
+EXPORT_SYMBOL(dasd_schedule_device_bh);
+
+void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
+{
+	device->stopped |= bits;
+}
+EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
+
+void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
+{
+	device->stopped &= ~bits;
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
+
+/*
+ * Queue a request to the head of the device ccw_queue.
+ * Start the I/O if possible.
+ */
+void dasd_add_request_head(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+
+	device = cqr->startdev;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	cqr->status = DASD_CQR_QUEUED;
+	list_add(&cqr->devlist, &device->ccw_queue);
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+EXPORT_SYMBOL(dasd_add_request_head);
+
+/*
+ * Queue a request to the tail of the device ccw_queue.
+ * Start the I/O if possible.
+ */
+void dasd_add_request_tail(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	unsigned long flags;
+
+	device = cqr->startdev;
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	cqr->status = DASD_CQR_QUEUED;
+	list_add_tail(&cqr->devlist, &device->ccw_queue);
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+EXPORT_SYMBOL(dasd_add_request_tail);
+
+/*
+ * Wakeup helper for the 'sleep_on' functions.
+ */
+void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	cqr->endclk = get_tod_clock();
+	cqr->callback_data = DASD_SLEEPON_END_TAG;
+	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
+	wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
+
+static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+
+	device = cqr->startdev;
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+	return rc;
+}
+
+/*
+ * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
+ */
+static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	dasd_erp_fn_t erp_fn;
+
+	if (cqr->status == DASD_CQR_FILLED)
+		return 0;
+	device = cqr->startdev;
+	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
+		if (cqr->status == DASD_CQR_TERMINATED) {
+			device->discipline->handle_terminated_request(cqr);
+			return 1;
+		}
+		if (cqr->status == DASD_CQR_NEED_ERP) {
+			erp_fn = device->discipline->erp_action(cqr);
+			erp_fn(cqr);
+			return 1;
+		}
+		if (cqr->status == DASD_CQR_FAILED)
+			dasd_log_sense(cqr, &cqr->irb);
+		if (cqr->refers) {
+			__dasd_process_erp(device, cqr);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
+{
+	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
+		if (cqr->refers) /* erp is not done yet */
+			return 1;
+		return ((cqr->status != DASD_CQR_DONE) &&
+			(cqr->status != DASD_CQR_FAILED));
+	} else
+		return (cqr->status == DASD_CQR_FILLED);
+}
+
+static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
+{
+	struct dasd_device *device;
+	int rc;
+	struct list_head ccw_queue;
+	struct dasd_ccw_req *cqr;
+
+	INIT_LIST_HEAD(&ccw_queue);
+	maincqr->status = DASD_CQR_FILLED;
+	device = maincqr->startdev;
+	list_add(&maincqr->blocklist, &ccw_queue);
+	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
+	     cqr = list_first_entry(&ccw_queue,
+				    struct dasd_ccw_req, blocklist)) {
+
+		if (__dasd_sleep_on_erp(cqr))
+			continue;
+		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
+			continue;
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			continue;
+		}
+		/* Non-temporary stop condition will trigger fail fast */
+		if (device->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    !dasd_eer_enabled(device) && device->aq_mask == 0) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENOLINK;
+			continue;
+		}
+		/*
+		 * Don't try to start requests if device is in
+		 * offline processing, it might wait forever
+		 */
+		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENODEV;
+			continue;
+		}
+		/*
+		 * Don't try to start requests if device is stopped
+		 * except path verification requests
+		 */
+		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
+			if (interruptible) {
+				rc = wait_event_interruptible(
+					generic_waitq, !(device->stopped));
+				if (rc == -ERESTARTSYS) {
+					cqr->status = DASD_CQR_FAILED;
+					maincqr->intrc = rc;
+					continue;
+				}
+			} else
+				wait_event(generic_waitq, !(device->stopped));
+		}
+		if (!cqr->callback)
+			cqr->callback = dasd_wakeup_cb;
+
+		cqr->callback_data = DASD_SLEEPON_START_TAG;
+		dasd_add_request_tail(cqr);
+		if (interruptible) {
+			rc = wait_event_interruptible(
+				generic_waitq, _wait_for_wakeup(cqr));
+			if (rc == -ERESTARTSYS) {
+				dasd_cancel_req(cqr);
+				/* wait (non-interruptible) for final status */
+				wait_event(generic_waitq,
+					   _wait_for_wakeup(cqr));
+				cqr->status = DASD_CQR_FAILED;
+				maincqr->intrc = rc;
+				continue;
+			}
+		} else
+			wait_event(generic_waitq, _wait_for_wakeup(cqr));
+	}
+
+	maincqr->endclk = get_tod_clock();
+	if ((maincqr->status != DASD_CQR_DONE) &&
+	    (maincqr->intrc != -ERESTARTSYS))
+		dasd_log_sense(maincqr, &maincqr->irb);
+	if (maincqr->status == DASD_CQR_DONE)
+		rc = 0;
+	else if (maincqr->intrc)
+		rc = maincqr->intrc;
+	else
+		rc = -EIO;
+	return rc;
+}
+
+static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
+{
+	struct dasd_ccw_req *cqr;
+
+	list_for_each_entry(cqr, ccw_queue, blocklist) {
+		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
+			return 0;
+	}
+
+	return 1;
+}
+
+static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
+{
+	struct dasd_device *device;
+	struct dasd_ccw_req *cqr, *n;
+	u8 *sense = NULL;
+	int rc;
+
+retry:
+	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
+		device = cqr->startdev;
+		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
+			continue;
+
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			continue;
+		}
+		/*Non-temporary stop condition will trigger fail fast*/
+		if (device->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    !dasd_eer_enabled(device)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EAGAIN;
+			continue;
+		}
+
+		/*Don't try to start requests if device is stopped*/
+		if (interruptible) {
+			rc = wait_event_interruptible(
+				generic_waitq, !device->stopped);
+			if (rc == -ERESTARTSYS) {
+				cqr->status = DASD_CQR_FAILED;
+				cqr->intrc = rc;
+				continue;
+			}
+		} else
+			wait_event(generic_waitq, !(device->stopped));
+
+		if (!cqr->callback)
+			cqr->callback = dasd_wakeup_cb;
+		cqr->callback_data = DASD_SLEEPON_START_TAG;
+		dasd_add_request_tail(cqr);
+	}
+
+	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
+
+	rc = 0;
+	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
+		/*
+		 * In some cases certain errors might be expected and
+		 * error recovery would be unnecessary in these cases.
+		 * Check if the according suppress bit is set.
+		 */
+		sense = dasd_get_sense(&cqr->irb);
+		if (sense && (sense[1] & SNS1_INV_TRACK_FORMAT) &&
+		    !(sense[2] & SNS2_ENV_DATA_PRESENT) &&
+		    test_bit(DASD_CQR_SUPPRESS_IT, &cqr->flags))
+			continue;
+		if (sense && (sense[1] & SNS1_NO_REC_FOUND) &&
+		    test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags))
+			continue;
+		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
+		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
+			continue;
+
+		/*
+		 * for alias devices simplify error recovery and
+		 * return to upper layer
+		 * do not skip ERP requests
+		 */
+		if (cqr->startdev != cqr->basedev && !cqr->refers &&
+		    (cqr->status == DASD_CQR_TERMINATED ||
+		     cqr->status == DASD_CQR_NEED_ERP))
+			return -EAGAIN;
+
+		/* normal recovery for basedev IO */
+		if (__dasd_sleep_on_erp(cqr))
+			/* handle erp first */
+			goto retry;
+	}
+
+	return 0;
+}
+
+/*
+ * Queue a request to the tail of the device ccw_queue and wait for
+ * it's completion.
+ */
+int dasd_sleep_on(struct dasd_ccw_req *cqr)
+{
+	return _dasd_sleep_on(cqr, 0);
+}
+EXPORT_SYMBOL(dasd_sleep_on);
+
+/*
+ * Start requests from a ccw_queue and wait for their completion.
+ */
+int dasd_sleep_on_queue(struct list_head *ccw_queue)
+{
+	return _dasd_sleep_on_queue(ccw_queue, 0);
+}
+EXPORT_SYMBOL(dasd_sleep_on_queue);
+
+/*
+ * Start requests from a ccw_queue and wait interruptible for their completion.
+ */
+int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
+{
+	return _dasd_sleep_on_queue(ccw_queue, 1);
+}
+EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
+
+/*
+ * Queue a request to the tail of the device ccw_queue and wait
+ * interruptible for it's completion.
+ */
+int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
+{
+	return _dasd_sleep_on(cqr, 1);
+}
+EXPORT_SYMBOL(dasd_sleep_on_interruptible);
+
+/*
+ * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
+ * for eckd devices) the currently running request has to be terminated
+ * and be put back to status queued, before the special request is added
+ * to the head of the queue. Then the special request is waited on normally.
+ */
+static inline int _dasd_term_running_cqr(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+	int rc;
+
+	if (list_empty(&device->ccw_queue))
+		return 0;
+	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
+	/*
+	 * Path verification requests must not be terminated. They are critical
+	 * for bringing paths back online. Terminating them would cause rc=-EIO
+	 * because CLEARED requests skip the retry path.
+	 */
+	if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
+		return -EAGAIN;
+	rc = device->discipline->term_IO(cqr);
+	if (!rc)
+		/*
+		 * CQR terminated because a more important request is pending.
+		 * Undo decreasing of retry counter because this is
+		 * not an error case.
+		 */
+		cqr->retries++;
+	return rc;
+}
+
+int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device;
+	int rc;
+
+	device = cqr->startdev;
+	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
+	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+		cqr->status = DASD_CQR_FAILED;
+		cqr->intrc = -EPERM;
+		return -EIO;
+	}
+	spin_lock_irq(get_ccwdev_lock(device->cdev));
+	while ((rc = _dasd_term_running_cqr(device)) == -EAGAIN) {
+		spin_unlock_irq(get_ccwdev_lock(device->cdev));
+		msleep(1);
+		spin_lock_irq(get_ccwdev_lock(device->cdev));
+	}
+	if (rc) {
+		spin_unlock_irq(get_ccwdev_lock(device->cdev));
+		return rc;
+	}
+	cqr->callback = dasd_wakeup_cb;
+	cqr->callback_data = DASD_SLEEPON_START_TAG;
+	cqr->status = DASD_CQR_QUEUED;
+	/*
+	 * add new request as second
+	 * first the terminated cqr needs to be finished
+	 */
+	list_add(&cqr->devlist, device->ccw_queue.next);
+
+	/* let the bh start the request to keep them in order */
+	dasd_schedule_device_bh(device);
+
+	spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+	wait_event(generic_waitq, _wait_for_wakeup(cqr));
+
+	if (cqr->status == DASD_CQR_DONE)
+		rc = 0;
+	else if (cqr->intrc)
+		rc = cqr->intrc;
+	else
+		rc = -EIO;
+
+	/* kick tasklets */
+	dasd_schedule_device_bh(device);
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+
+	return rc;
+}
+EXPORT_SYMBOL(dasd_sleep_on_immediatly);
+
+/*
+ * Cancels a request that was started with dasd_sleep_on_req.
+ * This is useful to timeout requests. The request will be
+ * terminated if it is currently in i/o.
+ * Returns 0 if request termination was successful
+ *	   negative error code if termination failed
+ * Cancellation of a request is an asynchronous operation! The calling
+ * function has to wait until the request is properly returned via callback.
+ */
+static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device = cqr->startdev;
+	int rc = 0;
+
+	switch (cqr->status) {
+	case DASD_CQR_QUEUED:
+		/* request was not started - just set to cleared */
+		cqr->status = DASD_CQR_CLEARED;
+		break;
+	case DASD_CQR_IN_IO:
+		/* request in IO - terminate IO and release again */
+		rc = device->discipline->term_IO(cqr);
+		if (rc) {
+			dev_err(&device->cdev->dev,
+				"Cancelling request failed with rc=%d\n", rc);
+		} else {
+			cqr->stopclk = get_tod_clock();
+		}
+		break;
+	default: /* already finished or clear pending - do nothing */
+		break;
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+
+int dasd_cancel_req(struct dasd_ccw_req *cqr)
+{
+	struct dasd_device *device = cqr->startdev;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+	rc = __dasd_cancel_req(cqr);
+	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+	return rc;
+}
+
+/*
+ * SECTION: Operations of the dasd_block layer.
+ */
+
+/*
+ * Timeout function for dasd_block. This is used when the block layer
+ * is waiting for something that may not come reliably, (e.g. a state
+ * change interrupt)
+ */
+static void dasd_block_timeout(struct timer_list *t)
+{
+	unsigned long flags;
+	struct dasd_block *block;
+
+	block = timer_container_of(block, t, timer);
+	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
+	/* re-activate request queue */
+	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
+	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
+	dasd_schedule_block_bh(block);
+	blk_mq_run_hw_queues(block->gdp->queue, true);
+}
+
+/*
+ * Setup timeout for a dasd_block in jiffies.
+ */
+void dasd_block_set_timer(struct dasd_block *block, int expires)
+{
+	if (expires == 0)
+		timer_delete(&block->timer);
+	else
+		mod_timer(&block->timer, jiffies + expires);
+}
+EXPORT_SYMBOL(dasd_block_set_timer);
+
+/*
+ * Clear timeout for a dasd_block.
+ */
+void dasd_block_clear_timer(struct dasd_block *block)
+{
+	timer_delete(&block->timer);
+}
+EXPORT_SYMBOL(dasd_block_clear_timer);
+
+/*
+ * Process finished error recovery ccw.
+ */
+static void __dasd_process_erp(struct dasd_device *device,
+			       struct dasd_ccw_req *cqr)
+{
+	dasd_erp_fn_t erp_fn;
+
+	if (cqr->status == DASD_CQR_DONE)
+		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
+	else if (cqr->status == DASD_CQR_ABORTED)
+		/*
+		 * ESE format aborts the request and replaces it with a format
+		 * CQR - this is not an ERP failure.
+		 */
+		DBF_DEV_EVENT(DBF_NOTICE, device, "%s",
+			      "ERP request aborted, replaced by ESE format");
+	else
+		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
+	erp_fn = device->discipline->erp_postaction(cqr);
+	erp_fn(cqr);
+}
+
+static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
+{
+	struct request *req;
+	blk_status_t error = BLK_STS_OK;
+	unsigned int proc_bytes;
+	int status, intrc;
+
+	req = (struct request *) cqr->callback_data;
+	dasd_profile_end(cqr->block, cqr, req);
+
+	/*
+	 * free_cp() returns the request block to its memory pool, so snapshot
+	 * everything still needed from cqr before calling it - another CPU can
+	 * reallocate and overwrite the block right after.
+	 */
+	proc_bytes = cqr->proc_bytes;
+	intrc = cqr->intrc;
+	status = cqr->block->base->discipline->free_cp(cqr, req);
+	if (status < 0)
+		error = errno_to_blk_status(status);
+	else if (status == 0) {
+		switch (intrc) {
+		case -EPERM:
+			/*
+			 * DASD doesn't implement SCSI/NVMe reservations, but it
+			 * implements a locking scheme similar to them. We
+			 * return this error when we no longer have the lock.
+			 */
+			error = BLK_STS_RESV_CONFLICT;
+			break;
+		case -ENOLINK:
+			error = BLK_STS_TRANSPORT;
+			break;
+		case -ETIMEDOUT:
+			error = BLK_STS_TIMEOUT;
+			break;
+		default:
+			error = BLK_STS_IOERR;
+			break;
+		}
+	} else if (status == DASD_CQR_ABORTED) {
+		/* aborted requests are replaced with a new one so do not complete this */
+		return;
+	}
+
+	/*
+	 * We need to take care for ETIMEDOUT errors here since the
+	 * complete callback does not get called in this case.
+	 * Take care of all errors here and avoid additional code to
+	 * transfer the error value to the complete callback.
+	 */
+	if (error) {
+		blk_mq_end_request(req, error);
+		blk_mq_run_hw_queues(req->q, true);
+	} else {
+		/*
+		 * Partial completed requests can happen with ESE devices.
+		 * During read we might have gotten a NRF error and have to
+		 * complete a request partially.
+		 */
+		if (proc_bytes) {
+			blk_update_request(req, BLK_STS_OK, proc_bytes);
+			blk_mq_requeue_request(req, true);
+		} else if (likely(!blk_should_fake_timeout(req->q))) {
+			blk_mq_complete_request(req);
+		}
+	}
+}
+
+/*
+ * Process ccw request queue.
+ */
+static void __dasd_process_block_ccw_queue(struct dasd_block *block,
+					   struct list_head *final_queue)
+{
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	dasd_erp_fn_t erp_fn;
+	unsigned long flags;
+	struct dasd_device *base = block->base;
+
+restart:
+	/* Process request with final status. */
+	list_for_each_safe(l, n, &block->ccw_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
+		if (cqr->status != DASD_CQR_DONE &&
+		    cqr->status != DASD_CQR_FAILED &&
+		    cqr->status != DASD_CQR_NEED_ERP &&
+		    cqr->status != DASD_CQR_TERMINATED &&
+		    cqr->status != DASD_CQR_ABORTED)
+			continue;
+
+		if (cqr->status == DASD_CQR_TERMINATED) {
+			base->discipline->handle_terminated_request(cqr);
+			goto restart;
+		}
+
+		/*  Process requests that may be recovered */
+		if (cqr->status == DASD_CQR_NEED_ERP) {
+			erp_fn = base->discipline->erp_action(cqr);
+			if (IS_ERR(erp_fn(cqr)))
+				continue;
+			goto restart;
+		}
+
+		/* log sense for fatal error */
+		if (cqr->status == DASD_CQR_FAILED) {
+			dasd_log_sense(cqr, &cqr->irb);
+		}
+
+		/*
+		 * First call extended error reporting and check for autoquiesce
+		 */
+		spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
+		if (cqr->status == DASD_CQR_FAILED &&
+		    dasd_handle_autoquiesce(base, cqr, DASD_EER_FATALERROR)) {
+			cqr->status = DASD_CQR_FILLED;
+			cqr->retries = 255;
+			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
+			goto restart;
+		}
+		spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
+
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			__dasd_process_erp(base, cqr);
+			goto restart;
+		}
+
+		/* Rechain finished requests to final queue */
+		cqr->endclk = get_tod_clock();
+		list_move_tail(&cqr->blocklist, final_queue);
+	}
+}
+
+static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	struct dasd_ccw_req *temp_cqr;
+	struct dasd_block *block;
+
+	/* only format CQRs are candidates */
+	if (!cqr->block || unlikely(!cqr->format))
+		goto out;
+
+	block = cqr->block;
+	/*
+	 * Mark in-flight (IN_IO) CQRs that overlap this just-completed format
+	 * range so they re-check in test_and_set_format on completion; FILLED
+	 * or QUEUED CQRs re-check the format_list on their next round anyway.
+	 */
+	list_for_each_entry(temp_cqr, &block->ccw_queue, blocklist) {
+		if (temp_cqr != cqr &&
+		    temp_cqr->status != DASD_CQR_FILLED &&
+		    temp_cqr->status != DASD_CQR_QUEUED &&
+		    dasd_req_conflict(cqr, temp_cqr)) {
+			WRITE_ONCE(temp_cqr->collision, true);
+		}
+	}
+out:
+	dasd_schedule_block_bh(cqr->block);
+}
+
+static void __dasd_block_start_head(struct dasd_block *block)
+{
+	struct dasd_ccw_req *cqr;
+
+	if (list_empty(&block->ccw_queue))
+		return;
+	/* We allways begin with the first requests on the queue, as some
+	 * of previously started requests have to be enqueued on a
+	 * dasd_device again for error recovery.
+	 */
+	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
+		if (cqr->status != DASD_CQR_FILLED)
+			continue;
+		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
+		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -EPERM;
+			dasd_schedule_block_bh(block);
+			continue;
+		}
+		/* Non-temporary stop condition will trigger fail fast */
+		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
+		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
+		    !dasd_eer_enabled(block->base) && block->base->aq_mask == 0) {
+			cqr->status = DASD_CQR_FAILED;
+			cqr->intrc = -ENOLINK;
+			dasd_schedule_block_bh(block);
+			continue;
+		}
+		/* Don't try to start requests if device is stopped */
+		if (block->base->stopped)
+			return;
+
+		/* just a fail safe check, should not happen */
+		if (!cqr->startdev)
+			cqr->startdev = block->base;
+
+		/* make sure that the requests we submit find their way back */
+		cqr->callback = dasd_return_cqr_cb;
+
+		dasd_add_request_tail(cqr);
+	}
+}
+
+/*
+ * Central dasd_block layer routine. Takes requests from the generic
+ * block layer request queue, creates ccw requests, enqueues them on
+ * a dasd_device and processes ccw requests that have been returned.
+ */
+static void dasd_block_tasklet(unsigned long data)
+{
+	struct dasd_block *block = (struct dasd_block *) data;
+	struct list_head final_queue;
+	struct list_head *l, *n;
+	struct dasd_ccw_req *cqr;
+	struct dasd_queue *dq;
+
+	atomic_set(&block->tasklet_scheduled, 0);
+	INIT_LIST_HEAD(&final_queue);
+	spin_lock_irq(&block->queue_lock);
+	/*
+	 * Splice the hardirq-staged ESE format CQRs onto ccw_queue. Splice to
+	 * the tail so an aborted origin request (already on ccw_queue) is
+	 * retired before its format-CQR replacement completes and requeues it.
+	 */
+	spin_lock(&block->ese_lock);
+	list_splice_tail_init(&block->ese_staging, &block->ccw_queue);
+	spin_unlock(&block->ese_lock);
+	/* Finish off requests on ccw queue */
+	__dasd_process_block_ccw_queue(block, &final_queue);
+	spin_unlock_irq(&block->queue_lock);
+
+	/* Now call the callback function of requests with final status */
+	list_for_each_safe(l, n, &final_queue) {
+		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
+		dq = cqr->dq;
+		spin_lock_irq(&dq->lock);
+		list_del_init(&cqr->blocklist);
+		__dasd_cleanup_cqr(cqr);
+		spin_unlock_irq(&dq->lock);
+	}
+
+	spin_lock_irq(&block->queue_lock);
+	/* Now check if the head of the ccw queue needs to be started. */
+	__dasd_block_start_head(block);
+	spin_unlock_irq(&block->queue_lock);
+
+	if (waitqueue_active(&shutdown_waitq))
+		wake_up(&shutdown_waitq);
+	dasd_put_device(block->base);
+}
+
+static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
+{
+	wake_up(&dasd_flush_wq);
+}
+
+/*
+ * Requeue a request back to the block request queue
+ * only works for block requests
+ */
+static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
+{
+	struct request *req;
+
+	/*
+	 * If the request is an ERP request there is nothing to requeue.
+	 * This will be done with the remaining original request.
+	 */
+	if (cqr->refers)
+		return;
+	spin_lock_irq(&cqr->dq->lock);
+	req = (struct request *) cqr->callback_data;
+	blk_mq_requeue_request(req, true);
+	spin_unlock_irq(&cqr->dq->lock);
+
+	return;
+}
+
+static int _dasd_requests_to_flushqueue(struct dasd_block *block,
+					struct list_head *flush_queue)
+{
+	struct dasd_ccw_req *cqr, *n;
+	unsigned long flags;
+	int rc, i;
+
+	spin_lock_irqsave(&block->queue_lock, flags);
+	/*
+	 * Splice any hardirq-staged ESE format CQRs onto ccw_queue first so
+	 * they are seen and canceled by the walk below instead of being
+	 * orphaned across this flush / state transition. Mirrors the splice
+	 * in dasd_block_tasklet().
+	 */
+	spin_lock(&block->ese_lock);
+	list_splice_tail_init(&block->ese_staging, &block->ccw_queue);
+	spin_unlock(&block->ese_lock);
+	rc = 0;
+restart:
+	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
+		/* if this request currently owned by a dasd_device cancel it */
+		if (cqr->status >= DASD_CQR_QUEUED)
+			rc = dasd_cancel_req(cqr);
+		if (rc < 0)
+			break;
+		/* Rechain request (including erp chain) so it won't be
+		 * touched by the dasd_block_tasklet anymore.
+		 * Replace the callback so we notice when the request
+		 * is returned from the dasd_device layer.
+		 */
+		cqr->callback = _dasd_wake_block_flush_cb;
+		for (i = 0; cqr; cqr = cqr->refers, i++)
+			list_move_tail(&cqr->blocklist, flush_queue);
+		if (i > 1)
+			/* moved more than one request - need to restart */
+			goto restart;
+	}
+	spin_unlock_irqrestore(&block->queue_lock, flags);
+
+	return rc;
+}
+
+/*
+ * Go through all request on the dasd_block request queue, cancel them
+ * on the respective dasd_device, and return them to the generic
+ * block layer.
+ */
+static int dasd_flush_block_queue(struct dasd_block *block)
+{
+	struct dasd_ccw_req *cqr, *n;
+	struct list_head flush_queue;
+	unsigned long flags;
+	int rc;
+
+	INIT_LIST_HEAD(&flush_queue);
+	rc = _dasd_requests_to_flushqueue(block, &flush_queue);
+
+	/* Now call the callback function of flushed requests */
+restart_cb:
+	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
+		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_erp(block->base, cqr);
+			spin_unlock_bh(&block->queue_lock);
+			/* restart list_for_xx loop since dasd_process_erp
+			 * might remove multiple elements */
+			goto restart_cb;
+		}
+		/* call the callback function */
+		spin_lock_irqsave(&cqr->dq->lock, flags);
+		cqr->endclk = get_tod_clock();
+		list_del_init(&cqr->blocklist);
+		__dasd_cleanup_cqr(cqr);
+		spin_unlock_irqrestore(&cqr->dq->lock, flags);
+	}
+	return rc;
+}
+
+/*
+ * Schedules a call to dasd_tasklet over the device tasklet.
+ */
+void dasd_schedule_block_bh(struct dasd_block *block)
+{
+	/* Protect against rescheduling. */
+	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
+		return;
+	/* life cycle of block is bound to it's base device */
+	dasd_get_device(block->base);
+	tasklet_hi_schedule(&block->tasklet);
+}
+EXPORT_SYMBOL(dasd_schedule_block_bh);
+
+
+/*
+ * SECTION: external block device operations
+ * (request queue handling, open, release, etc.)
+ */
+
+/*
+ * Dasd request queue function. Called from ll_rw_blk.c
+ */
+static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
+				    const struct blk_mq_queue_data *qd)
+{
+	struct dasd_block *block = hctx->queue->queuedata;
+	struct dasd_queue *dq = hctx->driver_data;
+	struct request *req = qd->rq;
+	struct dasd_device *basedev;
+	struct dasd_ccw_req *cqr;
+	blk_status_t rc = BLK_STS_OK;
+	bool complete_noop = false;
+
+	basedev = block->base;
+	spin_lock_irq(&dq->lock);
+	if (basedev->state < DASD_STATE_READY ||
+	    test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "device not ready for request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	/*
+	 * if device is stopped do not fetch new requests
+	 * except failfast is active which will let requests fail
+	 * immediately in __dasd_block_start_head()
+	 */
+	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "device stopped request %p", req);
+		rc = BLK_STS_RESOURCE;
+		goto out;
+	}
+
+	if (basedev->features & DASD_FEATURE_READONLY &&
+	    rq_data_dir(req) == WRITE) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "Rejecting write request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
+	    (basedev->features & DASD_FEATURE_FAILFAST ||
+	     blk_noretry_request(req))) {
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "Rejecting failfast request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+
+	cqr = basedev->discipline->build_cp(basedev, block, req);
+	if (IS_ERR(cqr)) {
+		if (PTR_ERR(cqr) == -EBUSY ||
+		    PTR_ERR(cqr) == -ENOMEM ||
+		    PTR_ERR(cqr) == -EAGAIN) {
+			rc = BLK_STS_RESOURCE;
+		} else if (PTR_ERR(cqr) == -EINVAL) {
+			rc = BLK_STS_INVAL;
+		} else if (PTR_ERR(cqr) == -EOPNOTSUPP) {
+			/*
+			 * A discard that covers no whole extent releases
+			 * nothing. Discard is advisory, so complete it as a
+			 * benign no-op: the device does support discard, this
+			 * range just does not align to the large ESE extent
+			 * granularity.
+			 * Completed after the lock is dropped.
+			 */
+			rc = BLK_STS_OK;
+			complete_noop = true;
+		} else {
+			DBF_DEV_EVENT(DBF_ERR, basedev,
+				      "CCW creation failed (rc=%ld) on request %p",
+				      PTR_ERR(cqr), req);
+			rc = BLK_STS_IOERR;
+		}
+		goto out;
+	}
+	if (!cqr) {
+		/* build_cp may collapse a non-transient build error to NULL */
+		DBF_DEV_EVENT(DBF_ERR, basedev,
+			      "CCW creation returned NULL on request %p", req);
+		rc = BLK_STS_IOERR;
+		goto out;
+	}
+	/*
+	 *  Note: callback is set to dasd_return_cqr_cb in
+	 * __dasd_block_start_head to cover erp requests as well
+	 */
+	cqr->callback_data = req;
+	cqr->status = DASD_CQR_FILLED;
+	cqr->dq = dq;
+
+	blk_mq_start_request(req);
+	spin_lock(&block->queue_lock);
+	list_add_tail(&cqr->blocklist, &block->ccw_queue);
+	INIT_LIST_HEAD(&cqr->devlist);
+	dasd_profile_start(block, cqr, req);
+	dasd_schedule_block_bh(block);
+	spin_unlock(&block->queue_lock);
+
+out:
+	spin_unlock_irq(&dq->lock);
+	if (complete_noop)
+		blk_mq_end_request(req, BLK_STS_OK);
+	return rc;
+}
+
+/*
+ * Block timeout callback, called from the block layer
+ *
+ * Return values:
+ * BLK_EH_RESET_TIMER if the request should be left running
+ * BLK_EH_DONE if the request is handled or terminated
+ *		      by the driver.
+ */
+enum blk_eh_timer_return dasd_times_out(struct request *req)
+{
+	struct dasd_block *block = req->q->queuedata;
+	struct dasd_device *device;
+	struct dasd_ccw_req *cqr;
+	unsigned long flags;
+	int rc = 0;
+
+	cqr = blk_mq_rq_to_pdu(req);
+	if (!cqr)
+		return BLK_EH_DONE;
+
+	spin_lock_irqsave(&cqr->dq->lock, flags);
+	device = cqr->startdev ? cqr->startdev : block->base;
+	if (!device->blk_timeout) {
+		spin_unlock_irqrestore(&cqr->dq->lock, flags);
+		return BLK_EH_RESET_TIMER;
+	}
+	DBF_DEV_EVENT(DBF_WARNING, device,
+		      " dasd_times_out cqr %p status %x",
+		      cqr, cqr->status);
+
+	spin_lock(&block->queue_lock);
+	spin_lock(get_ccwdev_lock(device->cdev));
+	cqr->retries = -1;
+	cqr->intrc = -ETIMEDOUT;
+	if (cqr->status >= DASD_CQR_QUEUED) {
+		rc = __dasd_cancel_req(cqr);
+	} else if (cqr->status == DASD_CQR_FILLED ||
+		   cqr->status == DASD_CQR_NEED_ERP) {
+		cqr->status = DASD_CQR_TERMINATED;
+	} else if (cqr->status == DASD_CQR_IN_ERP) {
+		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
+
+		list_for_each_entry_safe(searchcqr, nextcqr,
+					 &block->ccw_queue, blocklist) {
+			tmpcqr = searchcqr;
+			while (tmpcqr->refers)
+				tmpcqr = tmpcqr->refers;
+			if (tmpcqr != cqr)
+				continue;
+			/* searchcqr is an ERP request for cqr */
+			searchcqr->retries = -1;
+			searchcqr->intrc = -ETIMEDOUT;
+			if (searchcqr->status >= DASD_CQR_QUEUED) {
+				rc = __dasd_cancel_req(searchcqr);
+			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
+				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
+				searchcqr->status = DASD_CQR_TERMINATED;
+				rc = 0;
+			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
+				/*
+				 * Shouldn't happen; most recent ERP
+				 * request is at the front of queue
+				 */
+				continue;
+			}
+			break;
+		}
+	}
+	spin_unlock(get_ccwdev_lock(device->cdev));
+	dasd_schedule_block_bh(block);
+	spin_unlock(&block->queue_lock);
+	spin_unlock_irqrestore(&cqr->dq->lock, flags);
+
+	return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
+}
+
+static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+			  unsigned int idx)
+{
+	struct dasd_queue *dq = kzalloc_obj(*dq);
+
+	if (!dq)
+		return -ENOMEM;
+
+	spin_lock_init(&dq->lock);
+	hctx->driver_data = dq;
+
+	return 0;
+}
+
+static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
+{
+	kfree(hctx->driver_data);
+	hctx->driver_data = NULL;
+}
+
+static void dasd_request_done(struct request *req)
+{
+	blk_mq_end_request(req, 0);
+	blk_mq_run_hw_queues(req->q, true);
+}
+
+struct blk_mq_ops dasd_mq_ops = {
+	.queue_rq = do_dasd_request,
+	.complete = dasd_request_done,
+	.timeout = dasd_times_out,
+	.init_hctx = dasd_init_hctx,
+	.exit_hctx = dasd_exit_hctx,
+};
+
+static int dasd_open(struct gendisk *disk, blk_mode_t mode)
+{
+	struct dasd_device *base;
+	int rc;
+
+	base = dasd_device_from_gendisk(disk);
+	if (!base)
+		return -ENODEV;
+
+	atomic_inc(&base->block->open_count);
+	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+
+	if (!try_module_get(base->discipline->owner)) {
+		rc = -EINVAL;
+		goto unlock;
+	}
+
+	if (dasd_probeonly) {
+		dev_info(&base->cdev->dev,
+			 "Accessing the DASD failed because it is in "
+			 "probeonly mode\n");
+		rc = -EPERM;
+		goto out;
+	}
+
+	if (base->state <= DASD_STATE_BASIC) {
+		DBF_DEV_EVENT(DBF_ERR, base, " %s",
+			      " Cannot open unrecognized device");
+		rc = -ENODEV;
+		goto out;
+	}
+	if ((mode & BLK_OPEN_WRITE) &&
+	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
+	     (base->features & DASD_FEATURE_READONLY))) {
+		rc = -EROFS;
+		goto out;
+	}
+	dasd_put_device(base);
+	return 0;
+
+out:
+	module_put(base->discipline->owner);
+unlock:
+	atomic_dec(&base->block->open_count);
+	dasd_put_device(base);
+	return rc;
+}
+
+static void dasd_release(struct gendisk *disk)
+{
+	struct dasd_device *base = dasd_device_from_gendisk(disk);
+	if (base) {
+		atomic_dec(&base->block->open_count);
+		module_put(base->discipline->owner);
+		dasd_put_device(base);
+	}
+}
+
+/*
+ * Return disk geometry.
+ */
+static int dasd_getgeo(struct gendisk *disk, struct hd_geometry *geo)
+{
+	struct dasd_device *base;
+
+	base = dasd_device_from_gendisk(disk);
+	if (!base)
+		return -ENODEV;
+
+	if (!base->discipline ||
+	    !base->discipline->fill_geometry) {
+		dasd_put_device(base);
+		return -EINVAL;
+	}
+	base->discipline->fill_geometry(base->block, geo);
+	// geo->start is left unchanged by the above
+	geo->start >>= base->block->s2b_shift;
+	dasd_put_device(base);
+	return 0;
+}
+
+const struct block_device_operations
+dasd_device_operations = {
+	.owner		= THIS_MODULE,
+	.open		= dasd_open,
+	.release	= dasd_release,
+	.ioctl		= dasd_ioctl,
+	.getgeo		= dasd_getgeo,
+	.set_read_only	= dasd_set_read_only,
+};
+
+/*******************************************************************************
+ * end of block device operations
+ */
+
+static void
+dasd_exit(void)
+{
+#ifdef CONFIG_PROC_FS
+	dasd_proc_exit();
+#endif
+	dasd_eer_exit();
+	kmem_cache_destroy(dasd_page_cache);
+	dasd_page_cache = NULL;
+	dasd_gendisk_exit();
+	dasd_devmap_exit();
+	if (dasd_debug_area != NULL) {
+		debug_unregister(dasd_debug_area);
+		dasd_debug_area = NULL;
+	}
+	dasd_statistics_removeroot();
+}
+
+/*
+ * SECTION: common functions for ccw_driver use
+ */
+
+/*
+ * Is the device read-only?
+ * Note that this function does not report the setting of the
+ * readonly device attribute, but how it is configured in z/VM.
+ */
+int dasd_device_is_ro(struct dasd_device *device)
+{
+	struct ccw_dev_id dev_id;
+	struct diag210 diag_data;
+	int rc;
+
+	if (!machine_is_vm())
+		return 0;
+	ccw_device_get_id(device->cdev, &dev_id);
+	memset(&diag_data, 0, sizeof(diag_data));
+	diag_data.vrdcdvno = dev_id.devno;
+	diag_data.vrdclen = sizeof(diag_data);
+	rc = diag210(&diag_data);
+	if (rc == 0 || rc == 2) {
+		return diag_data.vrdcvfla & 0x80;
+	} else {
+		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
+			  dev_id.devno, rc);
+		return 0;
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_device_is_ro);
+
+static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
+{
+	struct ccw_device *cdev = data;
+	int ret;
+
+	ret = ccw_device_set_online(cdev);
+	if (ret)
+		dev_warn(&cdev->dev, "Setting the DASD online failed with rc=%d\n", ret);
+}
+
+/*
+ * Initial attempt at a probe function. this can be simplified once
+ * the other detection code is gone.
+ */
+int dasd_generic_probe(struct ccw_device *cdev)
+{
+	cdev->handler = &dasd_int_handler;
+
+	/*
+	 * Automatically online either all dasd devices (dasd_autodetect)
+	 * or all devices specified with dasd= parameters during
+	 * initial probe.
+	 */
+	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
+	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
+		async_schedule(dasd_generic_auto_online, cdev);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_probe);
+
+void dasd_generic_free_discipline(struct dasd_device *device)
+{
+	/* Forget the discipline information. */
+	if (device->discipline) {
+		if (device->discipline->uncheck_device)
+			device->discipline->uncheck_device(device);
+		module_put(device->discipline->owner);
+		device->discipline = NULL;
+	}
+	if (device->base_discipline) {
+		module_put(device->base_discipline->owner);
+		device->base_discipline = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
+
+/*
+ * This will one day be called from a global not_oper handler.
+ * It is also used by driver_unregister during module unload.
+ */
+void dasd_generic_remove(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+	struct dasd_block *block;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device))
+		return;
+
+	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
+	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/* Already doing offline processing */
+		dasd_put_device(device);
+		return;
+	}
+	/*
+	 * This device is removed unconditionally. Set offline
+	 * flag to prevent dasd_open from opening it while it is
+	 * no quite down yet.
+	 */
+	dasd_set_target_state(device, DASD_STATE_NEW);
+	cdev->handler = NULL;
+	/* dasd_delete_device destroys the device reference. */
+	block = device->block;
+	dasd_delete_device(device);
+	/*
+	 * life cycle of block is bound to device, so delete it after
+	 * device was safely removed
+	 */
+	if (block)
+		dasd_free_block(block);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_remove);
+
+/*
+ * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
+ * the device is detected for the first time and is supposed to be used
+ * or the user has started activation through sysfs.
+ */
+int dasd_generic_set_online(struct ccw_device *cdev,
+			    struct dasd_discipline *base_discipline)
+{
+	struct dasd_discipline *discipline;
+	struct dasd_device *device;
+	struct device *dev;
+	int rc;
+
+	dev = &cdev->dev;
+
+	/* first online clears initial online feature flag */
+	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
+	device = dasd_create_device(cdev);
+	if (IS_ERR(device))
+		return PTR_ERR(device);
+
+	discipline = base_discipline;
+	if (device->features & DASD_FEATURE_USEDIAG) {
+	  	if (!dasd_diag_discipline_pointer) {
+			/* Try to load the required module. */
+			rc = request_module(DASD_DIAG_MOD);
+			if (rc) {
+				dev_warn(dev, "Setting the DASD online failed "
+					 "because the required module %s "
+					 "could not be loaded (rc=%d)\n",
+					 DASD_DIAG_MOD, rc);
+				dasd_delete_device(device);
+				return -ENODEV;
+			}
+		}
+		/* Module init could have failed, so check again here after
+		 * request_module(). */
+		if (!dasd_diag_discipline_pointer) {
+			dev_warn(dev, "Setting the DASD online failed because of missing DIAG discipline\n");
+			dasd_delete_device(device);
+			return -ENODEV;
+		}
+		discipline = dasd_diag_discipline_pointer;
+	}
+	if (!try_module_get(base_discipline->owner)) {
+		dasd_delete_device(device);
+		return -EINVAL;
+	}
+	device->base_discipline = base_discipline;
+	if (!try_module_get(discipline->owner)) {
+		dasd_delete_device(device);
+		return -EINVAL;
+	}
+	device->discipline = discipline;
+
+	/* check_device will allocate block device if necessary */
+	rc = discipline->check_device(device);
+	if (rc) {
+		dev_warn(dev, "Setting the DASD online with discipline %s failed with rc=%i\n",
+			 discipline->name, rc);
+		dasd_delete_device(device);
+		return rc;
+	}
+
+	dasd_set_target_state(device, DASD_STATE_ONLINE);
+	if (device->state <= DASD_STATE_KNOWN) {
+		dev_warn(dev, "Setting the DASD online failed because of a missing discipline\n");
+		rc = -ENODEV;
+		dasd_set_target_state(device, DASD_STATE_NEW);
+		if (device->block)
+			dasd_free_block(device->block);
+		dasd_delete_device(device);
+	} else {
+		dev_dbg(dev, "dasd_generic device found\n");
+	}
+
+	wait_event(dasd_init_waitq, _wait_for_device(device));
+
+	dasd_put_device(device);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_set_online);
+
+int dasd_generic_set_offline(struct ccw_device *cdev)
+{
+	int max_count, open_count, rc;
+	struct dasd_device *device;
+	struct dasd_block *block;
+	unsigned long flags;
+	struct device *dev;
+
+	dev = &cdev->dev;
+
+	rc = 0;
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device)) {
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		return PTR_ERR(device);
+	}
+
+	/*
+	 * We must make sure that this device is currently not in use.
+	 * The open_count is increased for every opener, that includes
+	 * the blkdev_get in dasd_scan_partitions. We are only interested
+	 * in the other openers.
+	 */
+	if (device->block) {
+		max_count = device->block->bdev_file ? 0 : -1;
+		open_count = atomic_read(&device->block->open_count);
+		if (open_count > max_count) {
+			if (open_count > 0)
+				dev_warn(dev, "The DASD cannot be set offline with open count %i\n",
+					 open_count);
+			else
+				dev_warn(dev, "The DASD cannot be set offline while it is in use\n");
+			rc = -EBUSY;
+			goto out_err;
+		}
+	}
+
+	/*
+	 * Test if the offline processing is already running and exit if so.
+	 * If a safe offline is being processed this could only be a normal
+	 * offline that should be able to overtake the safe offline and
+	 * cancel any I/O we do not want to wait for any longer
+	 */
+	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
+				  &device->flags);
+		} else {
+			rc = -EBUSY;
+			goto out_err;
+		}
+	}
+	set_bit(DASD_FLAG_OFFLINE, &device->flags);
+
+	/*
+	 * if safe_offline is called set safe_offline_running flag and
+	 * clear safe_offline so that a call to normal offline
+	 * can overrun safe_offline processing
+	 */
+	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
+	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+		/* need to unlock here to wait for outstanding I/O */
+		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+		/*
+		 * If we want to set the device safe offline all IO operations
+		 * should be finished before continuing the offline process
+		 * so sync bdev first and then wait for our queues to become
+		 * empty
+		 */
+		if (device->block && device->block->bdev_file)
+			bdev_mark_dead(file_bdev(device->block->bdev_file), false);
+		dasd_schedule_device_bh(device);
+		rc = wait_event_interruptible(shutdown_waitq,
+					      _wait_for_empty_queues(device));
+		if (rc != 0)
+			goto interrupted;
+
+		/*
+		 * check if a normal offline process overtook the offline
+		 * processing in this case simply do nothing beside returning
+		 * that we got interrupted
+		 * otherwise mark safe offline as not running any longer and
+		 * continue with normal offline
+		 */
+		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
+			rc = -ERESTARTSYS;
+			goto out_err;
+		}
+		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
+	}
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+
+	dasd_set_target_state(device, DASD_STATE_NEW);
+	/* dasd_delete_device destroys the device reference. */
+	block = device->block;
+	dasd_delete_device(device);
+	/*
+	 * life cycle of block is bound to device, so delete it after
+	 * device was safely removed
+	 */
+	if (block)
+		dasd_free_block(block);
+
+	return 0;
+
+interrupted:
+	/* interrupted by signal */
+	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
+	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
+out_err:
+	dasd_put_device(device);
+	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
+
+int dasd_generic_last_path_gone(struct dasd_device *device)
+{
+	struct dasd_ccw_req *cqr;
+
+	dev_warn(&device->cdev->dev, "No operational channel path is left "
+		 "for the device\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
+	/* First call extended error reporting and check for autoquiesce. */
+	dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
+
+	if (device->state < DASD_STATE_BASIC)
+		return 0;
+	/* Device is active. We want to keep it. */
+	list_for_each_entry(cqr, &device->ccw_queue, devlist)
+		if ((cqr->status == DASD_CQR_IN_IO) ||
+		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
+			cqr->status = DASD_CQR_QUEUED;
+			cqr->retries++;
+		}
+	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
+
+int dasd_generic_path_operational(struct dasd_device *device)
+{
+	dev_info(&device->cdev->dev, "A channel path to the device has become "
+		 "operational\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
+	dasd_schedule_device_bh(device);
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->gdp)
+			blk_mq_run_hw_queues(device->block->gdp->queue, true);
+	}
+
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
+
+int dasd_generic_notify(struct ccw_device *cdev, int event)
+{
+	struct dasd_device *device;
+	int ret;
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device))
+		return 0;
+	ret = 0;
+	switch (event) {
+	case CIO_GONE:
+	case CIO_BOXED:
+	case CIO_NO_PATH:
+		dasd_path_no_path(device);
+		ret = dasd_generic_last_path_gone(device);
+		break;
+	case CIO_OPER:
+		ret = 1;
+		if (dasd_path_get_opm(device))
+			ret = dasd_generic_path_operational(device);
+		break;
+	}
+	dasd_put_device(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_notify);
+
+void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
+{
+	struct dasd_device *device;
+	int chp, oldopm, hpfpm, ifccpm;
+
+	device = dasd_device_from_cdev_locked(cdev);
+	if (IS_ERR(device))
+		return;
+
+	oldopm = dasd_path_get_opm(device);
+	for (chp = 0; chp < 8; chp++) {
+		if (path_event[chp] & PE_PATH_GONE) {
+			dasd_path_notoper(device, chp);
+		}
+		if (path_event[chp] & PE_PATH_AVAILABLE) {
+			dasd_path_available(device, chp);
+			dasd_schedule_device_bh(device);
+		}
+		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
+			if (!dasd_path_is_operational(device, chp) &&
+			    !dasd_path_need_verify(device, chp)) {
+				/*
+				 * we can not establish a pathgroup on an
+				 * unavailable path, so trigger a path
+				 * verification first
+				 */
+			dasd_path_available(device, chp);
+			dasd_schedule_device_bh(device);
+			}
+			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
+				      "Pathgroup re-established\n");
+			if (device->discipline->kick_validate)
+				device->discipline->kick_validate(device);
+		}
+		if (path_event[chp] & PE_PATH_FCES_EVENT) {
+			dasd_path_fcsec_update(device, chp);
+			dasd_schedule_device_bh(device);
+		}
+	}
+	hpfpm = dasd_path_get_hpfpm(device);
+	ifccpm = dasd_path_get_ifccpm(device);
+	if (!dasd_path_get_opm(device) && hpfpm) {
+		/*
+		 * device has no operational paths but at least one path is
+		 * disabled due to HPF errors
+		 * disable HPF at all and use the path(s) again
+		 */
+		if (device->discipline->disable_hpf)
+			device->discipline->disable_hpf(device);
+		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
+		dasd_path_set_tbvpm(device, hpfpm);
+		dasd_schedule_device_bh(device);
+		dasd_schedule_requeue(device);
+	} else if (!dasd_path_get_opm(device) && ifccpm) {
+		/*
+		 * device has no operational paths but at least one path is
+		 * disabled due to IFCC errors
+		 * trigger path verification on paths with IFCC errors
+		 */
+		dasd_path_set_tbvpm(device, ifccpm);
+		dasd_schedule_device_bh(device);
+	}
+	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
+		dev_warn(&device->cdev->dev,
+			 "No verified channel paths remain for the device\n");
+		DBF_DEV_EVENT(DBF_WARNING, device,
+			      "%s", "last verified path gone");
+		/* First call extended error reporting and check for autoquiesce. */
+		dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
+		dasd_device_set_stop_bits(device,
+					  DASD_STOPPED_DC_WAIT);
+	}
+	dasd_put_device(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_path_event);
+
+int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
+{
+	if (!dasd_path_get_opm(device) && lpm) {
+		dasd_path_set_opm(device, lpm);
+		dasd_generic_path_operational(device);
+	} else
+		dasd_path_add_opm(device, lpm);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
+
+void dasd_generic_space_exhaust(struct dasd_device *device,
+				struct dasd_ccw_req *cqr)
+{
+	/* First call extended error reporting and check for autoquiesce. */
+	dasd_handle_autoquiesce(device, NULL, DASD_EER_NOSPC);
+
+	if (device->state < DASD_STATE_BASIC)
+		return;
+
+	if (cqr->status == DASD_CQR_IN_IO ||
+	    cqr->status == DASD_CQR_CLEAR_PENDING) {
+		cqr->status = DASD_CQR_QUEUED;
+		cqr->retries++;
+	}
+	dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
+	dasd_device_clear_timer(device);
+	dasd_schedule_device_bh(device);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
+
+void dasd_generic_space_avail(struct dasd_device *device)
+{
+	dev_info(&device->cdev->dev, "Extent pool space is available\n");
+	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
+
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
+	dasd_schedule_device_bh(device);
+
+	if (device->block) {
+		dasd_schedule_block_bh(device->block);
+		if (device->block->gdp)
+			blk_mq_run_hw_queues(device->block->gdp->queue, true);
+	}
+	if (!device->stopped)
+		wake_up(&generic_waitq);
+}
+EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
+
+/*
+ * clear active requests and requeue them to block layer if possible
+ */
+int dasd_generic_requeue_all_requests(struct dasd_device *device)
+{
+	struct dasd_block *block = device->block;
+	struct list_head requeue_queue;
+	struct dasd_ccw_req *cqr, *n;
+	int rc;
+
+	if (!block)
+		return 0;
+
+	INIT_LIST_HEAD(&requeue_queue);
+	rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
+
+	/* Now call the callback function of flushed requests */
+restart_cb:
+	list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
+		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
+		/* Process finished ERP request. */
+		if (cqr->refers) {
+			spin_lock_bh(&block->queue_lock);
+			__dasd_process_erp(block->base, cqr);
+			spin_unlock_bh(&block->queue_lock);
+			/* restart list_for_xx loop since dasd_process_erp
+			 * might remove multiple elements
+			 */
+			goto restart_cb;
+		}
+		/*
+		 * An aborted request was replaced by a full-track write and is
+		 * retired by that replacement; do not requeue it, just release
+		 * it (mirrors the DASD_CQR_ABORTED handling in
+		 * __dasd_cleanup_cqr()).
+		 */
+		if (cqr->status == DASD_CQR_ABORTED) {
+			struct request *req = cqr->callback_data;
+
+			list_del_init(&cqr->blocklist);
+			cqr->block->base->discipline->free_cp(cqr, req);
+			continue;
+		}
+		_dasd_requeue_request(cqr);
+		list_del_init(&cqr->blocklist);
+		cqr->block->base->discipline->free_cp(
+			cqr, (struct request *) cqr->callback_data);
+	}
+	dasd_schedule_device_bh(device);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_requeue_all_requests);
+
+static void do_requeue_requests(struct work_struct *work)
+{
+	struct dasd_device *device = container_of(work, struct dasd_device,
+						  requeue_requests);
+	dasd_generic_requeue_all_requests(device);
+	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+	dasd_put_device(device);
+}
+
+void dasd_schedule_requeue(struct dasd_device *device)
+{
+	dasd_get_device(device);
+	/* queue call to dasd_reload_device to the kernel event daemon. */
+	if (!schedule_work(&device->requeue_requests))
+		dasd_put_device(device);
+}
+EXPORT_SYMBOL(dasd_schedule_requeue);
+
+static int dasd_handle_autoquiesce(struct dasd_device *device,
+				   struct dasd_ccw_req *cqr,
+				   unsigned int reason)
+{
+	/* in any case write eer message with reason */
+	if (dasd_eer_enabled(device))
+		dasd_eer_write(device, cqr, reason);
+
+	if (!test_bit(reason, &device->aq_mask))
+		return 0;
+
+	/* notify eer about autoquiesce */
+	if (dasd_eer_enabled(device))
+		dasd_eer_write(device, NULL, DASD_EER_AUTOQUIESCE);
+
+	dev_info(&device->cdev->dev,
+		 "The DASD has been put in the quiesce state\n");
+	dasd_device_set_stop_bits(device, DASD_STOPPED_QUIESCE);
+
+	if (device->features & DASD_FEATURE_REQUEUEQUIESCE)
+		dasd_schedule_requeue(device);
+
+	return 1;
+}
+
+static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
+						   int rdc_buffer_size,
+						   int magic)
+{
+	struct dasd_ccw_req *cqr;
+	struct ccw1 *ccw;
+
+	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
+				   NULL);
+
+	if (IS_ERR(cqr)) {
+		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
+				"Could not allocate RDC request");
+		return cqr;
+	}
+
+	ccw = cqr->cpaddr;
+	ccw->cmd_code = CCW_CMD_RDC;
+	ccw->cda = virt_to_dma32(cqr->data);
+	ccw->flags = 0;
+	ccw->count = rdc_buffer_size;
+	cqr->startdev = device;
+	cqr->memdev = device;
+	cqr->expires = 10*HZ;
+	cqr->retries = 256;
+	cqr->buildclk = get_tod_clock();
+	cqr->status = DASD_CQR_FILLED;
+	return cqr;
+}
+
+
+int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
+				void *rdc_buffer, int rdc_buffer_size)
+{
+	int ret;
+	struct dasd_ccw_req *cqr;
+
+	cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
+	if (IS_ERR(cqr))
+		return PTR_ERR(cqr);
+
+	ret = dasd_sleep_on(cqr);
+	if (ret == 0)
+		memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
+	dasd_sfree_request(cqr, cqr->memdev);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
+
+/*
+ *   In command mode and transport mode we need to look for sense
+ *   data in different places. The sense data itself is allways
+ *   an array of 32 bytes, so we can unify the sense data access
+ *   for both modes.
+ */
+char *dasd_get_sense(struct irb *irb)
+{
+	struct tsb *tsb = NULL;
+	char *sense = NULL;
+
+	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
+		if (irb->scsw.tm.tcw)
+			tsb = tcw_get_tsb(dma32_to_virt(irb->scsw.tm.tcw));
+		if (tsb && tsb->length == 64 && tsb->flags)
+			switch (tsb->flags & 0x07) {
+			case 1:	/* tsa_iostat */
+				sense = tsb->tsa.iostat.sense;
+				break;
+			case 2: /* tsa_ddpc */
+				sense = tsb->tsa.ddpc.sense;
+				break;
+			default:
+				/* currently we don't use interrogate data */
+				break;
+			}
+	} else if (irb->esw.esw0.erw.cons) {
+		sense = irb->ecw;
+	}
+	return sense;
+}
+EXPORT_SYMBOL_GPL(dasd_get_sense);
+
+void dasd_generic_shutdown(struct ccw_device *cdev)
+{
+	struct dasd_device *device;
+
+	device = dasd_device_from_cdev(cdev);
+	if (IS_ERR(device))
+		return;
+
+	if (device->block)
+		dasd_schedule_block_bh(device->block);
+
+	dasd_schedule_device_bh(device);
+
+	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
+}
+EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
+
+static int __init dasd_init(void)
+{
+	int rc;
+
+	init_waitqueue_head(&dasd_init_waitq);
+	init_waitqueue_head(&dasd_flush_wq);
+	init_waitqueue_head(&generic_waitq);
+	init_waitqueue_head(&shutdown_waitq);
+
+	/* register 'common' DASD debug area, used for all DBF_XXX calls */
+	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
+	if (dasd_debug_area == NULL) {
+		rc = -ENOMEM;
+		goto failed;
+	}
+	debug_register_view(dasd_debug_area, &debug_sprintf_view);
+	debug_set_level(dasd_debug_area, DBF_WARNING);
+
+	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
+
+	dasd_diag_discipline_pointer = NULL;
+
+	dasd_statistics_createroot();
+
+	rc = dasd_devmap_init();
+	if (rc)
+		goto failed;
+	rc = dasd_gendisk_init();
+	if (rc)
+		goto failed;
+	rc = dasd_parse();
+	if (rc)
+		goto failed;
+	rc = dasd_eer_init();
+	if (rc)
+		goto failed;
+#ifdef CONFIG_PROC_FS
+	rc = dasd_proc_init();
+	if (rc)
+		goto failed;
+#endif
+
+	return 0;
+failed:
+	pr_info("The DASD device driver could not be initialized\n");
+	dasd_exit();
+	return rc;
+}
+
+module_init(dasd_init);
+module_exit(dasd_exit);