1 files changed, 983 insertions, 344 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index e75b1437b58..5f59f1e3e5b 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2001 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
@@ -12,10 +12,12 @@
 #include <linux/blkdev.h>
 #include <linux/namei.h>
 #include <linux/ctype.h>
+#include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/mutex.h>
-#include <asm/atomic.h>
+#include <linux/delay.h>
+#include <linux/atomic.h>
 
 #define DM_MSG_PREFIX "table"
 
@@ -26,7 +28,7 @@
 
 struct dm_table {
 	struct mapped_device *md;
-	atomic_t holders;
+	unsigned type;
 
 	/* btree table */
 	unsigned int depth;
@@ -38,25 +40,27 @@ struct dm_table {
 	sector_t *highs;
 	struct dm_target *targets;
 
+	struct target_type *immutable_target_type;
+	unsigned integrity_supported:1;
+	unsigned singleton:1;
+
 	/*
 	 * Indicates the rw permissions for the new logical
 	 * device.  This should be a combination of FMODE_READ
 	 * and FMODE_WRITE.
 	 */
-	int mode;
+	fmode_t mode;
 
 	/* a list of devices used by this table */
 	struct list_head devices;
 
-	/*
-	 * These are optimistic limits taken from all the
-	 * targets, some targets will need smaller limits.
-	 */
-	struct io_restrictions limits;
-
 	/* events get handed up using this callback */
 	void (*event_fn)(void *);
 	void *event_context;
+
+	struct dm_md_mempools *mempools;
+
+	struct list_head target_callbacks;
 };
 
 /*
@@ -75,42 +79,6 @@ static unsigned int int_log(unsigned int n, unsigned int base)
 }
 
 /*
- * Returns the minimum that is _not_ zero, unless both are zero.
- */
-#define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r))
-
-/*
- * Combine two io_restrictions, always taking the lower value.
- */
-static void combine_restrictions_low(struct io_restrictions *lhs,
-				     struct io_restrictions *rhs)
-{
-	lhs->max_sectors =
-		min_not_zero(lhs->max_sectors, rhs->max_sectors);
-
-	lhs->max_phys_segments =
-		min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments);
-
-	lhs->max_hw_segments =
-		min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments);
-
-	lhs->hardsect_size = max(lhs->hardsect_size, rhs->hardsect_size);
-
-	lhs->max_segment_size =
-		min_not_zero(lhs->max_segment_size, rhs->max_segment_size);
-
-	lhs->max_hw_sectors =
-		min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors);
-
-	lhs->seg_boundary_mask =
-		min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
-
-	lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn);
-
-	lhs->no_cluster |= rhs->no_cluster;
-}
-
-/*
  * Calculate the index of the child node of the n'th node k'th key.
  */
 static inline unsigned int get_child(unsigned int n, unsigned int k)
@@ -173,12 +141,11 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 		return NULL;
 
 	size = nmemb * elem_size;
-	addr = vmalloc(size);
-	if (addr)
-		memset(addr, 0, size);
+	addr = vzalloc(size);
 
 	return addr;
 }
+EXPORT_SYMBOL(dm_vcalloc);
 
 /*
  * highs, and targets are managed as dynamic arrays during a
@@ -188,7 +155,6 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
 {
 	sector_t *n_highs;
 	struct dm_target *n_targets;
-	int n = t->num_targets;
 
 	/*
 	 * Allocate both the target array and offset array at once.
@@ -202,12 +168,7 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
 
 	n_targets = (struct dm_target *) (n_highs + num);
 
-	if (n) {
-		memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
-		memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
-	}
-
-	memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
+	memset(n_highs, -1, sizeof(*n_highs) * num);
 	vfree(t->highs);
 
 	t->num_allocated = num;
@@ -217,7 +178,7 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
 	return 0;
 }
 
-int dm_table_create(struct dm_table **result, int mode,
+int dm_table_create(struct dm_table **result, fmode_t mode,
 		    unsigned num_targets, struct mapped_device *md)
 {
 	struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
@@ -226,16 +187,20 @@ int dm_table_create(struct dm_table **result, int mode,
 		return -ENOMEM;
 
 	INIT_LIST_HEAD(&t->devices);
-	atomic_set(&t->holders, 1);
+	INIT_LIST_HEAD(&t->target_callbacks);
 
 	if (!num_targets)
 		num_targets = KEYS_PER_NODE;
 
 	num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 
+	if (!num_targets) {
+		kfree(t);
+		return -ENOMEM;
+	}
+
 	if (alloc_targets(t, num_targets)) {
 		kfree(t);
-		t = NULL;
 		return -ENOMEM;
 	}
 
@@ -245,59 +210,27 @@ int dm_table_create(struct dm_table **result, int mode,
 	return 0;
 }
 
-int dm_create_error_table(struct dm_table **result, struct mapped_device *md)
-{
-	struct dm_table *t;
-	sector_t dev_size = 1;
-	int r;
-
-	/*
-	 * Find current size of device.
-	 * Default to 1 sector if inactive.
-	 */
-	t = dm_get_table(md);
-	if (t) {
-		dev_size = dm_table_get_size(t);
-		dm_table_put(t);
-	}
-
-	r = dm_table_create(&t, FMODE_READ, 1, md);
-	if (r)
-		return r;
-
-	r = dm_table_add_target(t, "error", 0, dev_size, NULL);
-	if (r)
-		goto out;
-
-	r = dm_table_complete(t);
-	if (r)
-		goto out;
-
-	*result = t;
-
-out:
-	if (r)
-		dm_table_put(t);
-
-	return r;
-}
-EXPORT_SYMBOL_GPL(dm_create_error_table);
-
 static void free_devices(struct list_head *devices)
 {
 	struct list_head *tmp, *next;
 
 	list_for_each_safe(tmp, next, devices) {
-		struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
+		struct dm_dev_internal *dd =
+		    list_entry(tmp, struct dm_dev_internal, list);
+		DMWARN("dm_table_destroy: dm_put_device call missing for %s",
+		       dd->dm_dev.name);
 		kfree(dd);
 	}
 }
 
-static void table_destroy(struct dm_table *t)
+void dm_table_destroy(struct dm_table *t)
 {
 	unsigned int i;
 
-	/* free the indexes (see dm_table_complete) */
+	if (!t)
+		return;
+
+	/* free the indexes */
 	if (t->depth >= 2)
 		vfree(t->index[t->depth - 2]);
 
@@ -314,80 +247,22 @@ static void table_destroy(struct dm_table *t)
 	vfree(t->highs);
 
 	/* free the device list */
-	if (t->devices.next != &t->devices) {
-		DMWARN("devices still present during destroy: "
-		       "dm_table_remove_device calls missing");
+	free_devices(&t->devices);
 
-		free_devices(&t->devices);
-	}
+	dm_free_md_mempools(t->mempools);
 
 	kfree(t);
 }
 
-void dm_table_get(struct dm_table *t)
-{
-	atomic_inc(&t->holders);
-}
-
-void dm_table_put(struct dm_table *t)
-{
-	if (!t)
-		return;
-
-	if (atomic_dec_and_test(&t->holders))
-		table_destroy(t);
-}
-
-/*
- * Checks to see if we need to extend highs or targets.
- */
-static inline int check_space(struct dm_table *t)
-{
-	if (t->num_targets >= t->num_allocated)
-		return alloc_targets(t, t->num_allocated * 2);
-
-	return 0;
-}
-
-/*
- * Convert a device path to a dev_t.
- */
-static int lookup_device(const char *path, dev_t *dev)
-{
-	int r;
-	struct nameidata nd;
-	struct inode *inode;
-
-	if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd)))
-		return r;
-
-	inode = nd.path.dentry->d_inode;
-	if (!inode) {
-		r = -ENOENT;
-		goto out;
-	}
-
-	if (!S_ISBLK(inode->i_mode)) {
-		r = -ENOTBLK;
-		goto out;
-	}
-
-	*dev = inode->i_rdev;
-
- out:
-	path_put(&nd.path);
-	return r;
-}
-
 /*
  * See if we've already got a device in the list.
  */
-static struct dm_dev *find_device(struct list_head *l, dev_t dev)
+static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 {
-	struct dm_dev *dd;
+	struct dm_dev_internal *dd;
 
 	list_for_each_entry (dd, l, list)
-		if (dd->bdev->bd_dev == dev)
+		if (dd->dm_dev.bdev->bd_dev == dev)
 			return dd;
 
 	return NULL;
@@ -396,100 +271,167 @@ static struct dm_dev *find_device(struct list_head *l, dev_t dev)
 /*
  * Open a device so we can use it as a map destination.
  */
-static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md)
+static int open_dev(struct dm_dev_internal *d, dev_t dev,
+		    struct mapped_device *md)
 {
 	static char *_claim_ptr = "I belong to device-mapper";
 	struct block_device *bdev;
 
 	int r;
 
-	BUG_ON(d->bdev);
+	BUG_ON(d->dm_dev.bdev);
 
-	bdev = open_by_devnum(dev, d->mode);
+	bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
-	r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
-	if (r)
-		blkdev_put(bdev);
-	else
-		d->bdev = bdev;
-	return r;
+
+	r = bd_link_disk_holder(bdev, dm_disk(md));
+	if (r) {
+		blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
+		return r;
+	}
+
+	d->dm_dev.bdev = bdev;
+	return 0;
 }
 
 /*
  * Close a device that we've been using.
  */
-static void close_dev(struct dm_dev *d, struct mapped_device *md)
+static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 {
-	if (!d->bdev)
+	if (!d->dm_dev.bdev)
 		return;
 
-	bd_release_from_disk(d->bdev, dm_disk(md));
-	blkdev_put(d->bdev);
-	d->bdev = NULL;
+	bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
+	blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
+	d->dm_dev.bdev = NULL;
 }
 
 /*
- * If possible, this checks an area of a destination device is valid.
+ * If possible, this checks an area of a destination device is invalid.
  */
-static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len)
+static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
+				  sector_t start, sector_t len, void *data)
 {
-	sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT;
+	struct request_queue *q;
+	struct queue_limits *limits = data;
+	struct block_device *bdev = dev->bdev;
+	sector_t dev_size =
+		i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
+	unsigned short logical_block_size_sectors =
+		limits->logical_block_size >> SECTOR_SHIFT;
+	char b[BDEVNAME_SIZE];
+
+	/*
+	 * Some devices exist without request functions,
+	 * such as loop devices not yet bound to backing files.
+	 * Forbid the use of such devices.
+	 */
+	q = bdev_get_queue(bdev);
+	if (!q || !q->make_request_fn) {
+		DMWARN("%s: %s is not yet initialised: "
+		       "start=%llu, len=%llu, dev_size=%llu",
+		       dm_device_name(ti->table->md), bdevname(bdev, b),
+		       (unsigned long long)start,
+		       (unsigned long long)len,
+		       (unsigned long long)dev_size);
+		return 1;
+	}
 
 	if (!dev_size)
+		return 0;
+
+	if ((start >= dev_size) || (start + len > dev_size)) {
+		DMWARN("%s: %s too small for target: "
+		       "start=%llu, len=%llu, dev_size=%llu",
+		       dm_device_name(ti->table->md), bdevname(bdev, b),
+		       (unsigned long long)start,
+		       (unsigned long long)len,
+		       (unsigned long long)dev_size);
 		return 1;
+	}
 
-	return ((start < dev_size) && (len <= (dev_size - start)));
+	if (logical_block_size_sectors <= 1)
+		return 0;
+
+	if (start & (logical_block_size_sectors - 1)) {
+		DMWARN("%s: start=%llu not aligned to h/w "
+		       "logical block size %u of %s",
+		       dm_device_name(ti->table->md),
+		       (unsigned long long)start,
+		       limits->logical_block_size, bdevname(bdev, b));
+		return 1;
+	}
+
+	if (len & (logical_block_size_sectors - 1)) {
+		DMWARN("%s: len=%llu not aligned to h/w "
+		       "logical block size %u of %s",
+		       dm_device_name(ti->table->md),
+		       (unsigned long long)len,
+		       limits->logical_block_size, bdevname(bdev, b));
+		return 1;
+	}
+
+	return 0;
 }
 
 /*
- * This upgrades the mode on an already open dm_dev.  Being
+ * This upgrades the mode on an already open dm_dev, being
  * careful to leave things as they were if we fail to reopen the
- * device.
+ * device and not to touch the existing bdev field in case
+ * it is accessed concurrently inside dm_table_any_congested().
  */
-static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md)
+static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
+			struct mapped_device *md)
 {
 	int r;
-	struct dm_dev dd_copy;
-	dev_t dev = dd->bdev->bd_dev;
+	struct dm_dev_internal dd_new, dd_old;
 
-	dd_copy = *dd;
+	dd_new = dd_old = *dd;
 
-	dd->mode |= new_mode;
-	dd->bdev = NULL;
-	r = open_dev(dd, dev, md);
-	if (!r)
-		close_dev(&dd_copy, md);
-	else
-		*dd = dd_copy;
+	dd_new.dm_dev.mode |= new_mode;
+	dd_new.dm_dev.bdev = NULL;
 
-	return r;
+	r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
+	if (r)
+		return r;
+
+	dd->dm_dev.mode |= new_mode;
+	close_dev(&dd_old, md);
+
+	return 0;
 }
 
 /*
  * Add a device to the list, or just increment the usage count if
  * it's already present.
  */
-static int __table_get_device(struct dm_table *t, struct dm_target *ti,
-			      const char *path, sector_t start, sector_t len,
-			      int mode, struct dm_dev **result)
+int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
+		  struct dm_dev **result)
 {
 	int r;
 	dev_t uninitialized_var(dev);
-	struct dm_dev *dd;
+	struct dm_dev_internal *dd;
 	unsigned int major, minor;
+	struct dm_table *t = ti->table;
+	char dummy;
 
 	BUG_ON(!t);
 
-	if (sscanf(path, "%u:%u", &major, &minor) == 2) {
+	if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 		/* Extract the major/minor numbers */
 		dev = MKDEV(major, minor);
 		if (MAJOR(dev) != major || MINOR(dev) != minor)
 			return -EOVERFLOW;
 	} else {
 		/* convert the path to a device */
-		if ((r = lookup_device(path, &dev)))
-			return r;
+		struct block_device *bdev = lookup_bdev(path);
+
+		if (IS_ERR(bdev))
+			return PTR_ERR(bdev);
+		dev = bdev->bd_dev;
+		bdput(bdev);
 	}
 
 	dd = find_device(&t->devices, dev);
@@ -498,112 +440,81 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
 		if (!dd)
 			return -ENOMEM;
 
-		dd->mode = mode;
-		dd->bdev = NULL;
+		dd->dm_dev.mode = mode;
+		dd->dm_dev.bdev = NULL;
 
 		if ((r = open_dev(dd, dev, t->md))) {
 			kfree(dd);
 			return r;
 		}
 
-		format_dev_t(dd->name, dev);
+		format_dev_t(dd->dm_dev.name, dev);
 
 		atomic_set(&dd->count, 0);
 		list_add(&dd->list, &t->devices);
 
-	} else if (dd->mode != (mode | dd->mode)) {
+	} else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
 		r = upgrade_mode(dd, mode, t->md);
 		if (r)
 			return r;
 	}
 	atomic_inc(&dd->count);
 
-	if (!check_device_area(dd, start, len)) {
-		DMWARN("device %s too small for target", path);
-		dm_put_device(ti, dd);
-		return -EINVAL;
-	}
-
-	*result = dd;
-
+	*result = &dd->dm_dev;
 	return 0;
 }
+EXPORT_SYMBOL(dm_get_device);
 
-void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev)
+static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
+				sector_t start, sector_t len, void *data)
 {
+	struct queue_limits *limits = data;
+	struct block_device *bdev = dev->bdev;
 	struct request_queue *q = bdev_get_queue(bdev);
-	struct io_restrictions *rs = &ti->limits;
-
-	/*
-	 * Combine the device limits low.
-	 *
-	 * FIXME: if we move an io_restriction struct
-	 *        into q this would just be a call to
-	 *        combine_restrictions_low()
-	 */
-	rs->max_sectors =
-		min_not_zero(rs->max_sectors, q->max_sectors);
-
-	/* FIXME: Device-Mapper on top of RAID-0 breaks because DM
-	 *        currently doesn't honor MD's merge_bvec_fn routine.
-	 *        In this case, we'll force DM to use PAGE_SIZE or
-	 *        smaller I/O, just to be safe. A better fix is in the
-	 *        works, but add this for the time being so it will at
-	 *        least operate correctly.
-	 */
-	if (q->merge_bvec_fn)
-		rs->max_sectors =
-			min_not_zero(rs->max_sectors,
-				     (unsigned int) (PAGE_SIZE >> 9));
-
-	rs->max_phys_segments =
-		min_not_zero(rs->max_phys_segments,
-			     q->max_phys_segments);
-
-	rs->max_hw_segments =
-		min_not_zero(rs->max_hw_segments, q->max_hw_segments);
-
-	rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size);
+	char b[BDEVNAME_SIZE];
 
-	rs->max_segment_size =
-		min_not_zero(rs->max_segment_size, q->max_segment_size);
-
-	rs->max_hw_sectors =
-		min_not_zero(rs->max_hw_sectors, q->max_hw_sectors);
-
-	rs->seg_boundary_mask =
-		min_not_zero(rs->seg_boundary_mask,
-			     q->seg_boundary_mask);
-
-	rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn);
-
-	rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
-}
-EXPORT_SYMBOL_GPL(dm_set_device_limits);
-
-int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
-		  sector_t len, int mode, struct dm_dev **result)
-{
-	int r = __table_get_device(ti->table, ti, path,
-				   start, len, mode, result);
+	if (unlikely(!q)) {
+		DMWARN("%s: Cannot set limits for nonexistent device %s",
+		       dm_device_name(ti->table->md), bdevname(bdev, b));
+		return 0;
+	}
 
-	if (!r)
-		dm_set_device_limits(ti, (*result)->bdev);
+	if (bdev_stack_limits(limits, bdev, start) < 0)
+		DMWARN("%s: adding target device %s caused an alignment inconsistency: "
+		       "physical_block_size=%u, logical_block_size=%u, "
+		       "alignment_offset=%u, start=%llu",
+		       dm_device_name(ti->table->md), bdevname(bdev, b),
+		       q->limits.physical_block_size,
+		       q->limits.logical_block_size,
+		       q->limits.alignment_offset,
+		       (unsigned long long) start << SECTOR_SHIFT);
 
-	return r;
+	/*
+	 * Check if merge fn is supported.
+	 * If not we'll force DM to use PAGE_SIZE or
+	 * smaller I/O, just to be safe.
+	 */
+	if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
+		blk_limits_max_hw_sectors(limits,
+					  (unsigned int) (PAGE_SIZE >> 9));
+	return 0;
 }
 
 /*
- * Decrement a devices use count and remove it if necessary.
+ * Decrement a device's use count and remove it if necessary.
  */
-void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
+void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 {
+	struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
+						  dm_dev);
+
 	if (atomic_dec_and_test(&dd->count)) {
 		close_dev(dd, ti->table->md);
 		list_del(&dd->list);
 		kfree(dd);
 	}
 }
+EXPORT_SYMBOL(dm_put_device);
 
 /*
  * Checks to see if the target joins onto the end of the table.
@@ -621,14 +532,28 @@ static int adjoin(struct dm_table *table, struct dm_target *ti)
 
 /*
  * Used to dynamically allocate the arg array.
+ *
+ * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
+ * process messages even if some device is suspended. These messages have a
+ * small fixed number of arguments.
+ *
+ * On the other hand, dm-switch needs to process bulk data using messages and
+ * excessive use of GFP_NOIO could cause trouble.
  */
 static char **realloc_argv(unsigned *array_size, char **old_argv)
 {
 	char **argv;
 	unsigned new_size;
+	gfp_t gfp;
 
-	new_size = *array_size ? *array_size * 2 : 64;
-	argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
+	if (*array_size) {
+		new_size = *array_size * 2;
+		gfp = GFP_KERNEL;
+	} else {
+		new_size = 8;
+		gfp = GFP_NOIO;
+	}
+	argv = kmalloc(new_size * sizeof(*argv), gfp);
 	if (argv) {
 		memcpy(argv, old_argv, *array_size * sizeof(*argv));
 		*array_size = new_size;
@@ -658,11 +583,8 @@ int dm_split_args(int *argc, char ***argvp, char *input)
 		return -ENOMEM;
 
 	while (1) {
-		start = end;
-
 		/* Skip whitespace */
-		while (*start && isspace(*start))
-			start++;
+		start = skip_spaces(end);
 
 		if (!*start)
 			break;	/* success, we hit the end */
@@ -704,24 +626,78 @@ int dm_split_args(int *argc, char ***argvp, char *input)
 	return 0;
 }
 
-static void check_for_valid_limits(struct io_restrictions *rs)
+/*
+ * Impose necessary and sufficient conditions on a devices's table such
+ * that any incoming bio which respects its logical_block_size can be
+ * processed successfully.  If it falls across the boundary between
+ * two or more targets, the size of each piece it gets split into must
+ * be compatible with the logical_block_size of the target processing it.
+ */
+static int validate_hardware_logical_block_alignment(struct dm_table *table,
+						 struct queue_limits *limits)
 {
-	if (!rs->max_sectors)
-		rs->max_sectors = SAFE_MAX_SECTORS;
-	if (!rs->max_hw_sectors)
-		rs->max_hw_sectors = SAFE_MAX_SECTORS;
-	if (!rs->max_phys_segments)
-		rs->max_phys_segments = MAX_PHYS_SEGMENTS;
-	if (!rs->max_hw_segments)
-		rs->max_hw_segments = MAX_HW_SEGMENTS;
-	if (!rs->hardsect_size)
-		rs->hardsect_size = 1 << SECTOR_SHIFT;
-	if (!rs->max_segment_size)
-		rs->max_segment_size = MAX_SEGMENT_SIZE;
-	if (!rs->seg_boundary_mask)
-		rs->seg_boundary_mask = -1;
-	if (!rs->bounce_pfn)
-		rs->bounce_pfn = -1;
+	/*
+	 * This function uses arithmetic modulo the logical_block_size
+	 * (in units of 512-byte sectors).
+	 */
+	unsigned short device_logical_block_size_sects =
+		limits->logical_block_size >> SECTOR_SHIFT;
+
+	/*
+	 * Offset of the start of the next table entry, mod logical_block_size.
+	 */
+	unsigned short next_target_start = 0;
+
+	/*
+	 * Given an aligned bio that extends beyond the end of a
+	 * target, how many sectors must the next target handle?
+	 */
+	unsigned short remaining = 0;
+
+	struct dm_target *uninitialized_var(ti);
+	struct queue_limits ti_limits;
+	unsigned i = 0;
+
+	/*
+	 * Check each entry in the table in turn.
+	 */
+	while (i < dm_table_get_num_targets(table)) {
+		ti = dm_table_get_target(table, i++);
+
+		blk_set_stacking_limits(&ti_limits);
+
+		/* combine all target devices' limits */
+		if (ti->type->iterate_devices)
+			ti->type->iterate_devices(ti, dm_set_device_limits,
+						  &ti_limits);
+
+		/*
+		 * If the remaining sectors fall entirely within this
+		 * table entry are they compatible with its logical_block_size?
+		 */
+		if (remaining < ti->len &&
+		    remaining & ((ti_limits.logical_block_size >>
+				  SECTOR_SHIFT) - 1))
+			break;	/* Error */
+
+		next_target_start =
+		    (unsigned short) ((next_target_start + ti->len) &
+				      (device_logical_block_size_sects - 1));
+		remaining = next_target_start ?
+		    device_logical_block_size_sects - next_target_start : 0;
+	}
+
+	if (remaining) {
+		DMWARN("%s: table line %u (start sect %llu len %llu) "
+		       "not aligned to h/w logical block size %u",
+		       dm_device_name(table->md), i,
+		       (unsigned long long) ti->begin,
+		       (unsigned long long) ti->len,
+		       limits->logical_block_size);
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 int dm_table_add_target(struct dm_table *t, const char *type,
@@ -731,8 +707,13 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 	char **argv;
 	struct dm_target *tgt;
 
-	if ((r = check_space(t)))
-		return r;
+	if (t->singleton) {
+		DMERR("%s: target type %s must appear alone in table",
+		      dm_device_name(t->md), t->targets->type->name);
+		return -EINVAL;
+	}
+
+	BUG_ON(t->num_targets >= t->num_allocated);
 
 	tgt = t->targets + t->num_targets;
 	memset(tgt, 0, sizeof(*tgt));
@@ -749,6 +730,36 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 		return -EINVAL;
 	}
 
+	if (dm_target_needs_singleton(tgt->type)) {
+		if (t->num_targets) {
+			DMERR("%s: target type %s must appear alone in table",
+			      dm_device_name(t->md), type);
+			return -EINVAL;
+		}
+		t->singleton = 1;
+	}
+
+	if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
+		DMERR("%s: target type %s may not be included in read-only tables",
+		      dm_device_name(t->md), type);
+		return -EINVAL;
+	}
+
+	if (t->immutable_target_type) {
+		if (t->immutable_target_type != tgt->type) {
+			DMERR("%s: immutable target type %s cannot be mixed with other target types",
+			      dm_device_name(t->md), t->immutable_target_type->name);
+			return -EINVAL;
+		}
+	} else if (dm_target_is_immutable(tgt->type)) {
+		if (t->num_targets) {
+			DMERR("%s: immutable target type %s cannot be mixed with other target types",
+			      dm_device_name(t->md), tgt->type->name);
+			return -EINVAL;
+		}
+		t->immutable_target_type = tgt->type;
+	}
+
 	tgt->table = t;
 	tgt->begin = start;
 	tgt->len = len;
@@ -776,9 +787,10 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 
 	t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 
-	/* FIXME: the plan is to combine high here and then have
-	 * the merge fn apply the target level restrictions. */
-	combine_restrictions_low(&t->limits, &tgt->limits);
+	if (!tgt->num_discard_bios && tgt->discards_supported)
+		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
+		       dm_device_name(t->md), type);
+
 	return 0;
 
  bad:
@@ -787,6 +799,187 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 	return r;
 }
 
+/*
+ * Target argument parsing helpers.
+ */
+static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
+			     unsigned *value, char **error, unsigned grouped)
+{
+	const char *arg_str = dm_shift_arg(arg_set);
+	char dummy;
+
+	if (!arg_str ||
+	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
+	    (*value < arg->min) ||
+	    (*value > arg->max) ||
+	    (grouped && arg_set->argc < *value)) {
+		*error = arg->error;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
+		unsigned *value, char **error)
+{
+	return validate_next_arg(arg, arg_set, value, error, 0);
+}
+EXPORT_SYMBOL(dm_read_arg);
+
+int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
+		      unsigned *value, char **error)
+{
+	return validate_next_arg(arg, arg_set, value, error, 1);
+}
+EXPORT_SYMBOL(dm_read_arg_group);
+
+const char *dm_shift_arg(struct dm_arg_set *as)
+{
+	char *r;
+
+	if (as->argc) {
+		as->argc--;
+		r = *as->argv;
+		as->argv++;
+		return r;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(dm_shift_arg);
+
+void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
+{
+	BUG_ON(as->argc < num_args);
+	as->argc -= num_args;
+	as->argv += num_args;
+}
+EXPORT_SYMBOL(dm_consume_args);
+
+static int dm_table_set_type(struct dm_table *t)
+{
+	unsigned i;
+	unsigned bio_based = 0, request_based = 0, hybrid = 0;
+	struct dm_target *tgt;
+	struct dm_dev_internal *dd;
+	struct list_head *devices;
+	unsigned live_md_type;
+
+	for (i = 0; i < t->num_targets; i++) {
+		tgt = t->targets + i;
+		if (dm_target_hybrid(tgt))
+			hybrid = 1;
+		else if (dm_target_request_based(tgt))
+			request_based = 1;
+		else
+			bio_based = 1;
+
+		if (bio_based && request_based) {
+			DMWARN("Inconsistent table: different target types"
+			       " can't be mixed up");
+			return -EINVAL;
+		}
+	}
+
+	if (hybrid && !bio_based && !request_based) {
+		/*
+		 * The targets can work either way.
+		 * Determine the type from the live device.
+		 * Default to bio-based if device is new.
+		 */
+		live_md_type = dm_get_md_type(t->md);
+		if (live_md_type == DM_TYPE_REQUEST_BASED)
+			request_based = 1;
+		else
+			bio_based = 1;
+	}
+
+	if (bio_based) {
+		/* We must use this table as bio-based */
+		t->type = DM_TYPE_BIO_BASED;
+		return 0;
+	}
+
+	BUG_ON(!request_based); /* No targets in this table */
+
+	/* Non-request-stackable devices can't be used for request-based dm */
+	devices = dm_table_get_devices(t);
+	list_for_each_entry(dd, devices, list) {
+		if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
+			DMWARN("table load rejected: including"
+			       " non-request-stackable devices");
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * Request-based dm supports only tables that have a single target now.
+	 * To support multiple targets, request splitting support is needed,
+	 * and that needs lots of changes in the block-layer.
+	 * (e.g. request completion process for partial completion.)
+	 */
+	if (t->num_targets > 1) {
+		DMWARN("Request-based dm doesn't support multiple targets yet");
+		return -EINVAL;
+	}
+
+	t->type = DM_TYPE_REQUEST_BASED;
+
+	return 0;
+}
+
+unsigned dm_table_get_type(struct dm_table *t)
+{
+	return t->type;
+}
+
+struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
+{
+	return t->immutable_target_type;
+}
+
+bool dm_table_request_based(struct dm_table *t)
+{
+	return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
+}
+
+static int dm_table_alloc_md_mempools(struct dm_table *t)
+{
+	unsigned type = dm_table_get_type(t);
+	unsigned per_bio_data_size = 0;
+	struct dm_target *tgt;
+	unsigned i;
+
+	if (unlikely(type == DM_TYPE_NONE)) {
+		DMWARN("no table type is set, can't allocate mempools");
+		return -EINVAL;
+	}
+
+	if (type == DM_TYPE_BIO_BASED)
+		for (i = 0; i < t->num_targets; i++) {
+			tgt = t->targets + i;
+			per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
+		}
+
+	t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
+	if (!t->mempools)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void dm_table_free_md_mempools(struct dm_table *t)
+{
+	dm_free_md_mempools(t->mempools);
+	t->mempools = NULL;
+}
+
+struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
+{
+	return t->mempools;
+}
+
 static int setup_indexes(struct dm_table *t)
 {
 	int i;
@@ -816,13 +1009,11 @@ static int setup_indexes(struct dm_table *t)
 /*
  * Builds the btree to index the map.
  */
-int dm_table_complete(struct dm_table *t)
+static int dm_table_build_index(struct dm_table *t)
 {
 	int r = 0;
 	unsigned int leaf_nodes;
 
-	check_for_valid_limits(&t->limits);
-
 	/* how many indexes will the btree have ? */
 	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
 	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
@@ -837,6 +1028,117 @@ int dm_table_complete(struct dm_table *t)
 	return r;
 }
 
+/*
+ * Get a disk whose integrity profile reflects the table's profile.
+ * If %match_all is true, all devices' profiles must match.
+ * If %match_all is false, all devices must at least have an
+ * allocated integrity profile; but uninitialized is ok.
+ * Returns NULL if integrity support was inconsistent or unavailable.
+ */
+static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
+						    bool match_all)
+{
+	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_dev_internal *dd = NULL;
+	struct gendisk *prev_disk = NULL, *template_disk = NULL;
+
+	list_for_each_entry(dd, devices, list) {
+		template_disk = dd->dm_dev.bdev->bd_disk;
+		if (!blk_get_integrity(template_disk))
+			goto no_integrity;
+		if (!match_all && !blk_integrity_is_initialized(template_disk))
+			continue; /* skip uninitialized profiles */
+		else if (prev_disk &&
+			 blk_integrity_compare(prev_disk, template_disk) < 0)
+			goto no_integrity;
+		prev_disk = template_disk;
+	}
+
+	return template_disk;
+
+no_integrity:
+	if (prev_disk)
+		DMWARN("%s: integrity not set: %s and %s profile mismatch",
+		       dm_device_name(t->md),
+		       prev_disk->disk_name,
+		       template_disk->disk_name);
+	return NULL;
+}
+
+/*
+ * Register the mapped device for blk_integrity support if
+ * the underlying devices have an integrity profile.  But all devices
+ * may not have matching profiles (checking all devices isn't reliable
+ * during table load because this table may use other DM device(s) which
+ * must be resumed before they will have an initialized integity profile).
+ * Stacked DM devices force a 2 stage integrity profile validation:
+ * 1 - during load, validate all initialized integrity profiles match
+ * 2 - during resume, validate all integrity profiles match
+ */
+static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
+{
+	struct gendisk *template_disk = NULL;
+
+	template_disk = dm_table_get_integrity_disk(t, false);
+	if (!template_disk)
+		return 0;
+
+	if (!blk_integrity_is_initialized(dm_disk(md))) {
+		t->integrity_supported = 1;
+		return blk_integrity_register(dm_disk(md), NULL);
+	}
+
+	/*
+	 * If DM device already has an initalized integrity
+	 * profile the new profile should not conflict.
+	 */
+	if (blk_integrity_is_initialized(template_disk) &&
+	    blk_integrity_compare(dm_disk(md), template_disk) < 0) {
+		DMWARN("%s: conflict with existing integrity profile: "
+		       "%s profile mismatch",
+		       dm_device_name(t->md),
+		       template_disk->disk_name);
+		return 1;
+	}
+
+	/* Preserve existing initialized integrity profile */
+	t->integrity_supported = 1;
+	return 0;
+}
+
+/*
+ * Prepares the table for use by building the indices,
+ * setting the type, and allocating mempools.
+ */
+int dm_table_complete(struct dm_table *t)
+{
+	int r;
+
+	r = dm_table_set_type(t);
+	if (r) {
+		DMERR("unable to set table type");
+		return r;
+	}
+
+	r = dm_table_build_index(t);
+	if (r) {
+		DMERR("unable to build btrees");
+		return r;
+	}
+
+	r = dm_table_prealloc_integrity(t, t->md);
+	if (r) {
+		DMERR("could not register integrity profile.");
+		return r;
+	}
+
+	r = dm_table_alloc_md_mempools(t);
+	if (r)
+		DMERR("unable to allocate mempools");
+
+	return r;
+}
+
 static DEFINE_MUTEX(_event_lock);
 void dm_table_event_callback(struct dm_table *t,
 			     void (*fn)(void *), void *context)
@@ -860,11 +1162,13 @@ void dm_table_event(struct dm_table *t)
 		t->event_fn(t->event_context);
 	mutex_unlock(&_event_lock);
 }
+EXPORT_SYMBOL(dm_table_event);
 
 sector_t dm_table_get_size(struct dm_table *t)
 {
 	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
 }
+EXPORT_SYMBOL(dm_table_get_size);
 
 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
 {
@@ -897,25 +1201,292 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 	return &t->targets[(KEYS_PER_NODE * n) + k];
 }
 
-void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q)
+static int count_device(struct dm_target *ti, struct dm_dev *dev,
+			sector_t start, sector_t len, void *data)
+{
+	unsigned *num_devices = data;
+
+	(*num_devices)++;
+
+	return 0;
+}
+
+/*
+ * Check whether a table has no data devices attached using each
+ * target's iterate_devices method.
+ * Returns false if the result is unknown because a target doesn't
+ * support iterate_devices.
+ */
+bool dm_table_has_no_data_devices(struct dm_table *table)
+{
+	struct dm_target *uninitialized_var(ti);
+	unsigned i = 0, num_devices = 0;
+
+	while (i < dm_table_get_num_targets(table)) {
+		ti = dm_table_get_target(table, i++);
+
+		if (!ti->type->iterate_devices)
+			return false;
+
+		ti->type->iterate_devices(ti, count_device, &num_devices);
+		if (num_devices)
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ * Establish the new table's queue_limits and validate them.
+ */
+int dm_calculate_queue_limits(struct dm_table *table,
+			      struct queue_limits *limits)
+{
+	struct dm_target *uninitialized_var(ti);
+	struct queue_limits ti_limits;
+	unsigned i = 0;
+
+	blk_set_stacking_limits(limits);
+
+	while (i < dm_table_get_num_targets(table)) {
+		blk_set_stacking_limits(&ti_limits);
+
+		ti = dm_table_get_target(table, i++);
+
+		if (!ti->type->iterate_devices)
+			goto combine_limits;
+
+		/*
+		 * Combine queue limits of all the devices this target uses.
+		 */
+		ti->type->iterate_devices(ti, dm_set_device_limits,
+					  &ti_limits);
+
+		/* Set I/O hints portion of queue limits */
+		if (ti->type->io_hints)
+			ti->type->io_hints(ti, &ti_limits);
+
+		/*
+		 * Check each device area is consistent with the target's
+		 * overall queue limits.
+		 */
+		if (ti->type->iterate_devices(ti, device_area_is_invalid,
+					      &ti_limits))
+			return -EINVAL;
+
+combine_limits:
+		/*
+		 * Merge this target's queue limits into the overall limits
+		 * for the table.
+		 */
+		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
+			DMWARN("%s: adding target device "
+			       "(start sect %llu len %llu) "
+			       "caused an alignment inconsistency",
+			       dm_device_name(table->md),
+			       (unsigned long long) ti->begin,
+			       (unsigned long long) ti->len);
+	}
+
+	return validate_hardware_logical_block_alignment(table, limits);
+}
+
+/*
+ * Set the integrity profile for this device if all devices used have
+ * matching profiles.  We're quite deep in the resume path but still
+ * don't know if all devices (particularly DM devices this device
+ * may be stacked on) have matching profiles.  Even if the profiles
+ * don't match we have no way to fail (to resume) at this point.
+ */
+static void dm_table_set_integrity(struct dm_table *t)
+{
+	struct gendisk *template_disk = NULL;
+
+	if (!blk_get_integrity(dm_disk(t->md)))
+		return;
+
+	template_disk = dm_table_get_integrity_disk(t, true);
+	if (template_disk)
+		blk_integrity_register(dm_disk(t->md),
+				       blk_get_integrity(template_disk));
+	else if (blk_integrity_is_initialized(dm_disk(t->md)))
+		DMWARN("%s: device no longer has a valid integrity profile",
+		       dm_device_name(t->md));
+	else
+		DMWARN("%s: unable to establish an integrity profile",
+		       dm_device_name(t->md));
+}
+
+static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
+				sector_t start, sector_t len, void *data)
+{
+	unsigned flush = (*(unsigned *)data);
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && (q->flush_flags & flush);
+}
+
+static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
+{
+	struct dm_target *ti;
+	unsigned i = 0;
+
+	/*
+	 * Require at least one underlying device to support flushes.
+	 * t->devices includes internal dm devices such as mirror logs
+	 * so we need to use iterate_devices here, which targets
+	 * supporting flushes must provide.
+	 */
+	while (i < dm_table_get_num_targets(t)) {
+		ti = dm_table_get_target(t, i++);
+
+		if (!ti->num_flush_bios)
+			continue;
+
+		if (ti->flush_supported)
+			return 1;
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, device_flush_capable, &flush))
+			return 1;
+	}
+
+	return 0;
+}
+
+static bool dm_table_discard_zeroes_data(struct dm_table *t)
+{
+	struct dm_target *ti;
+	unsigned i = 0;
+
+	/* Ensure that all targets supports discard_zeroes_data. */
+	while (i < dm_table_get_num_targets(t)) {
+		ti = dm_table_get_target(t, i++);
+
+		if (ti->discard_zeroes_data_unsupported)
+			return 0;
+	}
+
+	return 1;
+}
+
+static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
+			    sector_t start, sector_t len, void *data)
 {
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && blk_queue_nonrot(q);
+}
+
+static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
+			     sector_t start, sector_t len, void *data)
+{
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && !blk_queue_add_random(q);
+}
+
+static bool dm_table_all_devices_attribute(struct dm_table *t,
+					   iterate_devices_callout_fn func)
+{
+	struct dm_target *ti;
+	unsigned i = 0;
+
+	while (i < dm_table_get_num_targets(t)) {
+		ti = dm_table_get_target(t, i++);
+
+		if (!ti->type->iterate_devices ||
+		    !ti->type->iterate_devices(ti, func, NULL))
+			return 0;
+	}
+
+	return 1;
+}
+
+static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
+					 sector_t start, sector_t len, void *data)
+{
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && !q->limits.max_write_same_sectors;
+}
+
+static bool dm_table_supports_write_same(struct dm_table *t)
+{
+	struct dm_target *ti;
+	unsigned i = 0;
+
+	while (i < dm_table_get_num_targets(t)) {
+		ti = dm_table_get_target(t, i++);
+
+		if (!ti->num_write_same_bios)
+			return false;
+
+		if (!ti->type->iterate_devices ||
+		    ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
+			return false;
+	}
+
+	return true;
+}
+
+void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
+			       struct queue_limits *limits)
+{
+	unsigned flush = 0;
+
 	/*
-	 * Make sure we obey the optimistic sub devices
-	 * restrictions.
+	 * Copy table's limits to the DM device's request_queue
 	 */
-	blk_queue_max_sectors(q, t->limits.max_sectors);
-	q->max_phys_segments = t->limits.max_phys_segments;
-	q->max_hw_segments = t->limits.max_hw_segments;
-	q->hardsect_size = t->limits.hardsect_size;
-	q->max_segment_size = t->limits.max_segment_size;
-	q->max_hw_sectors = t->limits.max_hw_sectors;
-	q->seg_boundary_mask = t->limits.seg_boundary_mask;
-	q->bounce_pfn = t->limits.bounce_pfn;
-	if (t->limits.no_cluster)
-		q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER);
+	q->limits = *limits;
+
+	if (!dm_table_supports_discards(t))
+		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
 	else
-		q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER);
+		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 
+	if (dm_table_supports_flush(t, REQ_FLUSH)) {
+		flush |= REQ_FLUSH;
+		if (dm_table_supports_flush(t, REQ_FUA))
+			flush |= REQ_FUA;
+	}
+	blk_queue_flush(q, flush);
+
+	if (!dm_table_discard_zeroes_data(t))
+		q->limits.discard_zeroes_data = 0;
+
+	/* Ensure that all underlying devices are non-rotational. */
+	if (dm_table_all_devices_attribute(t, device_is_nonrot))
+		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
+	else
+		queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
+
+	if (!dm_table_supports_write_same(t))
+		q->limits.max_write_same_sectors = 0;
+
+	dm_table_set_integrity(t);
+
+	/*
+	 * Determine whether or not this queue's I/O timings contribute
+	 * to the entropy pool, Only request-based targets use this.
+	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
+	 * have it set.
+	 */
+	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
+		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
+
+	/*
+	 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
+	 * visible to other CPUs because, once the flag is set, incoming bios
+	 * are processed by request-based dm, which refers to the queue
+	 * settings.
+	 * Until the flag set, bios are passed to bio-based dm and queued to
+	 * md->deferred where queue settings are not needed yet.
+	 * Those bios are passed to request-based dm at the resume time.
+	 */
+	smp_mb();
+	if (dm_table_request_based(t))
+		queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
 }
 
 unsigned int dm_table_get_num_targets(struct dm_table *t)
@@ -928,10 +1499,11 @@ struct list_head *dm_table_get_devices(struct dm_table *t)
 	return &t->devices;
 }
 
-int dm_table_get_mode(struct dm_table *t)
+fmode_t dm_table_get_mode(struct dm_table *t)
 {
 	return t->mode;
 }
+EXPORT_SYMBOL(dm_table_get_mode);
 
 static void suspend_targets(struct dm_table *t, unsigned postsuspend)
 {
@@ -954,7 +1526,7 @@ void dm_table_presuspend_targets(struct dm_table *t)
 	if (!t)
 		return;
 
-	return suspend_targets(t, 0);
+	suspend_targets(t, 0);
 }
 
 void dm_table_postsuspend_targets(struct dm_table *t)
@@ -962,7 +1534,7 @@ void dm_table_postsuspend_targets(struct dm_table *t)
 	if (!t)
 		return;
 
-	return suspend_targets(t, 1);
+	suspend_targets(t, 1);
 }
 
 int dm_table_resume_targets(struct dm_table *t)
@@ -976,8 +1548,11 @@ int dm_table_resume_targets(struct dm_table *t)
 			continue;
 
 		r = ti->type->preresume(ti);
-		if (r)
+		if (r) {
+			DMERR("%s: %s: preresume failed, error = %d",
+			      dm_device_name(t->md), ti->type->name, r);
 			return r;
+		}
 	}
 
 	for (i = 0; i < t->num_targets; i++) {
@@ -990,46 +1565,110 @@ int dm_table_resume_targets(struct dm_table *t)
 	return 0;
 }
 
+void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
+{
+	list_add(&cb->list, &t->target_callbacks);
+}
+EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
+
 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 {
-	struct dm_dev *dd;
+	struct dm_dev_internal *dd;
 	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_target_callbacks *cb;
 	int r = 0;
 
 	list_for_each_entry(dd, devices, list) {
-		struct request_queue *q = bdev_get_queue(dd->bdev);
-		r |= bdi_congested(&q->backing_dev_info, bdi_bits);
+		struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
+		char b[BDEVNAME_SIZE];
+
+		if (likely(q))
+			r |= bdi_congested(&q->backing_dev_info, bdi_bits);
+		else
+			DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
+				     dm_device_name(t->md),
+				     bdevname(dd->dm_dev.bdev, b));
 	}
 
+	list_for_each_entry(cb, &t->target_callbacks, list)
+		if (cb->congested_fn)
+			r |= cb->congested_fn(cb, bdi_bits);
+
 	return r;
 }
 
-void dm_table_unplug_all(struct dm_table *t)
+int dm_table_any_busy_target(struct dm_table *t)
 {
-	struct dm_dev *dd;
-	struct list_head *devices = dm_table_get_devices(t);
-
-	list_for_each_entry(dd, devices, list) {
-		struct request_queue *q = bdev_get_queue(dd->bdev);
+	unsigned i;
+	struct dm_target *ti;
 
-		blk_unplug(q);
+	for (i = 0; i < t->num_targets; i++) {
+		ti = t->targets + i;
+		if (ti->type->busy && ti->type->busy(ti))
+			return 1;
 	}
+
+	return 0;
 }
 
 struct mapped_device *dm_table_get_md(struct dm_table *t)
 {
-	dm_get(t->md);
-
 	return t->md;
 }
-
-EXPORT_SYMBOL(dm_vcalloc);
-EXPORT_SYMBOL(dm_get_device);
-EXPORT_SYMBOL(dm_put_device);
-EXPORT_SYMBOL(dm_table_event);
-EXPORT_SYMBOL(dm_table_get_size);
-EXPORT_SYMBOL(dm_table_get_mode);
 EXPORT_SYMBOL(dm_table_get_md);
-EXPORT_SYMBOL(dm_table_put);
-EXPORT_SYMBOL(dm_table_get);
-EXPORT_SYMBOL(dm_table_unplug_all);
+
+void dm_table_run_md_queue_async(struct dm_table *t)
+{
+	struct mapped_device *md;
+	struct request_queue *queue;
+	unsigned long flags;
+
+	if (!dm_table_request_based(t))
+		return;
+
+	md = dm_table_get_md(t);
+	queue = dm_get_md_queue(md);
+	if (queue) {
+		spin_lock_irqsave(queue->queue_lock, flags);
+		blk_run_queue_async(queue);
+		spin_unlock_irqrestore(queue->queue_lock, flags);
+	}
+}
+EXPORT_SYMBOL(dm_table_run_md_queue_async);
+
+static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
+				  sector_t start, sector_t len, void *data)
+{
+	struct request_queue *q = bdev_get_queue(dev->bdev);
+
+	return q && blk_queue_discard(q);
+}
+
+bool dm_table_supports_discards(struct dm_table *t)
+{
+	struct dm_target *ti;
+	unsigned i = 0;
+
+	/*
+	 * Unless any target used by the table set discards_supported,
+	 * require at least one underlying device to support discards.
+	 * t->devices includes internal dm devices such as mirror logs
+	 * so we need to use iterate_devices here, which targets
+	 * supporting discard selectively must provide.
+	 */
+	while (i < dm_table_get_num_targets(t)) {
+		ti = dm_table_get_target(t, i++);
+
+		if (!ti->num_discard_bios)
+			continue;
+
+		if (ti->discards_supported)
+			return 1;
+
+		if (ti->type->iterate_devices &&
+		    ti->type->iterate_devices(ti, device_discard_capable, NULL))
+			return 1;
+	}
+
+	return 0;
+}