string: factorize skip_spaces and export it to be generally available
[safe/jmp/linux-2.6] / drivers / md / dm-table.c
index 9b1e2f5..1a6cb3c 100644 (file)
@@ -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.
  */
 #include <linux/ctype.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
 #include <asm/atomic.h>
 
+#define DM_MSG_PREFIX "table"
+
 #define MAX_DEPTH 16
 #define NODE_SIZE L1_CACHE_BYTES
 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
 
+/*
+ * The table has always exactly one reference from either mapped_device->map
+ * or hash_cell->new_map. This reference is not counted in table->holders.
+ * A pair of dm_create_table/dm_destroy_table functions is used for table
+ * creation/destruction.
+ *
+ * Temporary references from the other code increase table->holders. A pair
+ * of dm_table_get/dm_table_put functions is used to manipulate it.
+ *
+ * When the table is about to be destroyed, we wait for table->holders to
+ * drop to zero.
+ */
+
 struct dm_table {
+       struct mapped_device *md;
        atomic_t holders;
+       unsigned type;
 
        /* btree table */
        unsigned int depth;
@@ -39,20 +58,16 @@ struct dm_table {
         * 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;
 };
 
 /*
@@ -71,35 +86,6 @@ 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->seg_boundary_mask =
-               min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
-}
-
-/*
  * 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)
@@ -181,8 +167,10 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
 
        /*
         * Allocate both the target array and offset array at once.
+        * Append an empty entry to catch sectors beyond the end of
+        * the device.
         */
-       n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
+       n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
                                          sizeof(sector_t));
        if (!n_highs)
                return -ENOMEM;
@@ -204,16 +192,16 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
        return 0;
 }
 
-int dm_table_create(struct dm_table **result, int mode, unsigned num_targets)
+int dm_table_create(struct dm_table **result, fmode_t mode,
+                   unsigned num_targets, struct mapped_device *md)
 {
-       struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL);
+       struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 
        if (!t)
                return -ENOMEM;
 
-       memset(t, 0, sizeof(*t));
        INIT_LIST_HEAD(&t->devices);
-       atomic_set(&t->holders, 1);
+       atomic_set(&t->holders, 0);
 
        if (!num_targets)
                num_targets = KEYS_PER_NODE;
@@ -227,6 +215,7 @@ int dm_table_create(struct dm_table **result, int mode, unsigned num_targets)
        }
 
        t->mode = mode;
+       t->md = md;
        *result = t;
        return 0;
 }
@@ -235,17 +224,23 @@ static void free_devices(struct list_head *devices)
 {
        struct list_head *tmp, *next;
 
-       for (tmp = devices->next; tmp != devices; tmp = next) {
-               struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-               next = tmp->next;
+       list_for_each_safe(tmp, next, devices) {
+               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;
 
+       while (atomic_read(&t->holders))
+               msleep(1);
+       smp_mb();
+
        /* free the indexes (see dm_table_complete) */
        if (t->depth >= 2)
                vfree(t->index[t->depth - 2]);
@@ -263,12 +258,10 @@ 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");
-
+       if (t->devices.next != &t->devices)
                free_devices(&t->devices);
-       }
+
+       dm_free_md_mempools(t->mempools);
 
        kfree(t);
 }
@@ -283,8 +276,8 @@ void dm_table_put(struct dm_table *t)
        if (!t)
                return;
 
-       if (atomic_dec_and_test(&t->holders))
-               table_destroy(t);
+       smp_mb__before_atomic_dec();
+       atomic_dec(&t->holders);
 }
 
 /*
@@ -299,44 +292,14 @@ static inline int check_space(struct dm_table *t)
 }
 
 /*
- * 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.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_release(&nd);
-       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;
@@ -345,73 +308,116 @@ 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)
+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;
 
-       if (d->bdev)
-               BUG();
+       BUG_ON(d->dm_dev.bdev);
 
-       bdev = open_by_devnum(dev, d->mode);
+       bdev = open_by_devnum(dev, d->dm_dev.mode);
        if (IS_ERR(bdev))
                return PTR_ERR(bdev);
-       r = bd_claim(bdev, _claim_ptr);
+       r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
        if (r)
-               blkdev_put(bdev);
+               blkdev_put(bdev, d->dm_dev.mode);
        else
-               d->bdev = bdev;
+               d->dm_dev.bdev = bdev;
        return r;
 }
 
 /*
  * Close a device that we've been using.
  */
-static void close_dev(struct dm_dev *d)
+static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 {
-       if (!d->bdev)
+       if (!d->dm_dev.bdev)
                return;
 
-       bd_release(d->bdev);
-       blkdev_put(d->bdev);
-       d->bdev = NULL;
+       bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
+       blkdev_put(d->dm_dev.bdev, d->dm_dev.mode);
+       d->dm_dev.bdev = NULL;
 }
 
 /*
- * If possible (ie. blk_size[major] is set), 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;
-       dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT;
-       return ((start < dev_size) && (len <= (dev_size - start)));
+       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];
+
+       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;
+       }
+
+       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)
+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);
-       if (!r)
-               close_dev(&dd_copy);
-       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;
 }
 
 /*
@@ -420,15 +426,14 @@ static int upgrade_mode(struct dm_dev *dd, int new_mode)
  */
 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)
+                             fmode_t mode, struct dm_dev **result)
 {
        int r;
-       dev_t dev;
-       struct dm_dev *dd;
+       dev_t uninitialized_var(dev);
+       struct dm_dev_internal *dd;
        unsigned int major, minor;
 
-       if (!t)
-               BUG();
+       BUG_ON(!t);
 
        if (sscanf(path, "%u:%u", &major, &minor) == 2) {
                /* Extract the major/minor numbers */
@@ -437,8 +442,12 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
                        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);
@@ -447,96 +456,92 @@ 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))) {
+               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)) {
-               r = upgrade_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;
 }
 
+/*
+ * 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))
 
-int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
-                 sector_t len, int mode, struct dm_dev **result)
+int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
+                        sector_t start, sector_t len, void *data)
 {
-       int r = __table_get_device(ti->table, ti, path,
-                                  start, len, mode, result);
-       if (!r) {
-               request_queue_t *q = bdev_get_queue((*result)->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);
+       struct queue_limits *limits = data;
+       struct block_device *bdev = dev->bdev;
+       struct request_queue *q = bdev_get_queue(bdev);
+       char b[BDEVNAME_SIZE];
+
+       if (unlikely(!q)) {
+               DMWARN("%s: Cannot set limits for nonexistent device %s",
+                      dm_device_name(ti->table->md), bdevname(bdev, b));
+               return 0;
+       }
 
-               rs->max_hw_segments =
-                       min_not_zero(rs->max_hw_segments, q->max_hw_segments);
+       if (blk_stack_limits(limits, &q->limits, start << 9) < 0)
+               DMWARN("%s: target device %s is misaligned: "
+                      "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 << 9);
 
-               rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size);
 
-               rs->max_segment_size =
-                       min_not_zero(rs->max_segment_size, q->max_segment_size);
+       /*
+        * Check if merge fn is supported.
+        * If not we'll force DM to use PAGE_SIZE or
+        * smaller I/O, just to be safe.
+        */
 
-               rs->seg_boundary_mask =
-                       min_not_zero(rs->seg_boundary_mask,
-                                    q->seg_boundary_mask);
-       }
+       if (q->merge_bvec_fn && !ti->type->merge)
+               limits->max_sectors =
+                       min_not_zero(limits->max_sectors,
+                                    (unsigned int) (PAGE_SIZE >> 9));
+       return 0;
+}
+EXPORT_SYMBOL_GPL(dm_set_device_limits);
 
-       return r;
+int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
+                 sector_t len, fmode_t mode, struct dm_dev **result)
+{
+       return __table_get_device(ti->table, ti, path,
+                                 start, len, mode, result);
 }
 
+
 /*
  * Decrement a devices 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);
+               close_dev(dd, ti->table->md);
                list_del(&dd->list);
                kfree(dd);
        }
@@ -584,6 +589,12 @@ int dm_split_args(int *argc, char ***argvp, char *input)
        unsigned array_size = 0;
 
        *argc = 0;
+
+       if (!input) {
+               *argvp = NULL;
+               return 0;
+       }
+
        argv = realloc_argv(&array_size, argv);
        if (!argv)
                return -ENOMEM;
@@ -635,20 +646,78 @@ 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_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;
+       /*
+        * 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_default_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,
@@ -665,15 +734,14 @@ int dm_table_add_target(struct dm_table *t, const char *type,
        memset(tgt, 0, sizeof(*tgt));
 
        if (!len) {
-               tgt->error = "zero-length target";
-               DMERR("%s", tgt->error);
+               DMERR("%s: zero-length target", dm_device_name(t->md));
                return -EINVAL;
        }
 
        tgt->type = dm_get_target_type(type);
        if (!tgt->type) {
-               tgt->error = "unknown target type";
-               DMERR("%s", tgt->error);
+               DMERR("%s: %s: unknown target type", dm_device_name(t->md),
+                     type);
                return -EINVAL;
        }
 
@@ -704,17 +772,107 @@ 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);
        return 0;
 
  bad:
-       DMERR("%s", tgt->error);
+       DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
        dm_put_target_type(tgt->type);
        return r;
 }
 
+int dm_table_set_type(struct dm_table *t)
+{
+       unsigned i;
+       unsigned bio_based = 0, request_based = 0;
+       struct dm_target *tgt;
+       struct dm_dev_internal *dd;
+       struct list_head *devices;
+
+       for (i = 0; i < t->num_targets; i++) {
+               tgt = t->targets + i;
+               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 (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;
+}
+
+bool dm_table_request_based(struct dm_table *t)
+{
+       return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
+}
+
+int dm_table_alloc_md_mempools(struct dm_table *t)
+{
+       unsigned type = dm_table_get_type(t);
+
+       if (unlikely(type == DM_TYPE_NONE)) {
+               DMWARN("no table type is set, can't allocate mempools");
+               return -EINVAL;
+       }
+
+       t->mempools = dm_alloc_md_mempools(type);
+       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;
@@ -732,7 +890,7 @@ static int setup_indexes(struct dm_table *t)
                return -ENOMEM;
 
        /* set up internal nodes, bottom-up */
-       for (i = t->depth - 2, total = 0; i >= 0; i--) {
+       for (i = t->depth - 2; i >= 0; i--) {
                t->index[i] = indexes;
                indexes += (KEYS_PER_NODE * t->counts[i]);
                setup_btree_index(i, t);
@@ -749,8 +907,6 @@ int dm_table_complete(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);
@@ -765,14 +921,14 @@ int dm_table_complete(struct dm_table *t)
        return r;
 }
 
-static DECLARE_MUTEX(_event_lock);
+static DEFINE_MUTEX(_event_lock);
 void dm_table_event_callback(struct dm_table *t,
                             void (*fn)(void *), void *context)
 {
-       down(&_event_lock);
+       mutex_lock(&_event_lock);
        t->event_fn = fn;
        t->event_context = context;
-       up(&_event_lock);
+       mutex_unlock(&_event_lock);
 }
 
 void dm_table_event(struct dm_table *t)
@@ -783,10 +939,10 @@ void dm_table_event(struct dm_table *t)
         */
        BUG_ON(in_interrupt());
 
-       down(&_event_lock);
+       mutex_lock(&_event_lock);
        if (t->event_fn)
                t->event_fn(t->event_context);
-       up(&_event_lock);
+       mutex_unlock(&_event_lock);
 }
 
 sector_t dm_table_get_size(struct dm_table *t)
@@ -796,7 +952,7 @@ sector_t dm_table_get_size(struct dm_table *t)
 
 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
 {
-       if (index > t->num_targets)
+       if (index >= t->num_targets)
                return NULL;
 
        return t->targets + index;
@@ -804,6 +960,9 @@ struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
 
 /*
  * Search the btree for the correct target.
+ *
+ * Caller should check returned pointer with dm_target_is_valid()
+ * to trap I/O beyond end of device.
  */
 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
 {
@@ -822,18 +981,136 @@ 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)
+/*
+ * 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_default_limits(limits);
+
+       while (i < dm_table_get_num_targets(table)) {
+               blk_set_default_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: target device "
+                              "(start sect %llu len %llu) "
+                              "is misaligned",
+                              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.
+ */
+static void dm_table_set_integrity(struct dm_table *t)
+{
+       struct list_head *devices = dm_table_get_devices(t);
+       struct dm_dev_internal *prev = NULL, *dd = NULL;
+
+       if (!blk_get_integrity(dm_disk(t->md)))
+               return;
+
+       list_for_each_entry(dd, devices, list) {
+               if (prev &&
+                   blk_integrity_compare(prev->dm_dev.bdev->bd_disk,
+                                         dd->dm_dev.bdev->bd_disk) < 0) {
+                       DMWARN("%s: integrity not set: %s and %s mismatch",
+                              dm_device_name(t->md),
+                              prev->dm_dev.bdev->bd_disk->disk_name,
+                              dd->dm_dev.bdev->bd_disk->disk_name);
+                       goto no_integrity;
+               }
+               prev = dd;
+       }
+
+       if (!prev || !bdev_get_integrity(prev->dm_dev.bdev))
+               goto no_integrity;
+
+       blk_integrity_register(dm_disk(t->md),
+                              bdev_get_integrity(prev->dm_dev.bdev));
+
+       return;
+
+no_integrity:
+       blk_integrity_register(dm_disk(t->md), NULL);
+
+       return;
+}
+
+void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
+                              struct queue_limits *limits)
+{
+       /*
+        * Each target device in the table has a data area that should normally
+        * be aligned such that the DM device's alignment_offset is 0.
+        * FIXME: Propagate alignment_offsets up the stack and warn of
+        *        sub-optimal or inconsistent settings.
+        */
+       limits->alignment_offset = 0;
+       limits->misaligned = 0;
+
+       /*
+        * Copy table's limits to the DM device's request_queue
+        */
+       q->limits = *limits;
+
+       if (limits->no_cluster)
+               queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
+       else
+               queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
+
+       dm_table_set_integrity(t);
+
        /*
-        * Make sure we obey the optimistic sub devices
-        * restrictions.
+        * 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.
         */
-       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->seg_boundary_mask = t->limits.seg_boundary_mask;
+       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)
@@ -846,7 +1123,7 @@ 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;
 }
@@ -872,7 +1149,7 @@ 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)
@@ -880,12 +1157,23 @@ void dm_table_postsuspend_targets(struct dm_table *t)
        if (!t)
                return;
 
-       return suspend_targets(t, 1);
+       suspend_targets(t, 1);
 }
 
-void dm_table_resume_targets(struct dm_table *t)
+int dm_table_resume_targets(struct dm_table *t)
 {
-       int i;
+       int i, r = 0;
+
+       for (i = 0; i < t->num_targets; i++) {
+               struct dm_target *ti = t->targets + i;
+
+               if (!ti->type->preresume)
+                       continue;
+
+               r = ti->type->preresume(ti);
+               if (r)
+                       return r;
+       }
 
        for (i = 0; i < t->num_targets; i++) {
                struct dm_target *ti = t->targets + i;
@@ -893,56 +1181,68 @@ void dm_table_resume_targets(struct dm_table *t)
                if (ti->type->resume)
                        ti->type->resume(ti);
        }
+
+       return 0;
 }
 
 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 {
-       struct list_head *d, *devices;
+       struct dm_dev_internal *dd;
+       struct list_head *devices = dm_table_get_devices(t);
        int r = 0;
 
-       devices = dm_table_get_devices(t);
-       for (d = devices->next; d != devices; d = d->next) {
-               struct dm_dev *dd = list_entry(d, struct dm_dev, list);
-               request_queue_t *q = bdev_get_queue(dd->bdev);
-               r |= bdi_congested(&q->backing_dev_info, bdi_bits);
+       list_for_each_entry(dd, devices, list) {
+               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));
        }
 
        return r;
 }
 
-void dm_table_unplug_all(struct dm_table *t)
+int dm_table_any_busy_target(struct dm_table *t)
 {
-       struct list_head *d, *devices = dm_table_get_devices(t);
-
-       for (d = devices->next; d != devices; d = d->next) {
-               struct dm_dev *dd = list_entry(d, struct dm_dev, list);
-               request_queue_t *q = bdev_get_queue(dd->bdev);
+       unsigned i;
+       struct dm_target *ti;
 
-               if (q->unplug_fn)
-                       q->unplug_fn(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;
 }
 
-int dm_table_flush_all(struct dm_table *t)
+void dm_table_unplug_all(struct dm_table *t)
 {
-       struct list_head *d, *devices = dm_table_get_devices(t);
-       int ret = 0;
+       struct dm_dev_internal *dd;
+       struct list_head *devices = dm_table_get_devices(t);
 
-       for (d = devices->next; d != devices; d = d->next) {
-               struct dm_dev *dd = list_entry(d, struct dm_dev, list);
-               request_queue_t *q = bdev_get_queue(dd->bdev);
-               int err;
+       list_for_each_entry(dd, devices, list) {
+               struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
+               char b[BDEVNAME_SIZE];
 
-               if (!q->issue_flush_fn)
-                       err = -EOPNOTSUPP;
+               if (likely(q))
+                       blk_unplug(q);
                else
-                       err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL);
-
-               if (!ret)
-                       ret = err;
+                       DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s",
+                                    dm_device_name(t->md),
+                                    bdevname(dd->dm_dev.bdev, b));
        }
+}
+
+struct mapped_device *dm_table_get_md(struct dm_table *t)
+{
+       dm_get(t->md);
 
-       return ret;
+       return t->md;
 }
 
 EXPORT_SYMBOL(dm_vcalloc);
@@ -951,7 +1251,7 @@ 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);
-EXPORT_SYMBOL(dm_table_flush_all);