1 files changed, 950 insertions, 0 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
new file mode 100644
index 000000000000..ee175d4906c4
--- /dev/null
+++ b/drivers/md/dm-table.c
@@ -0,0 +1,950 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm.h"
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/blkdev.h>
+#include <linux/namei.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <asm/atomic.h>
+
+#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)
+
+struct dm_table {
+        atomic_t holders;
+
+        /* btree table */
+        unsigned int depth;
+        unsigned int counts[MAX_DEPTH]; /* in nodes */
+        sector_t *index[MAX_DEPTH];
+
+        unsigned int num_targets;
+        unsigned int num_allocated;
+        sector_t *highs;
+        struct dm_target *targets;
+
+        /*
+         * Indicates the rw permissions for the new logical
+         * device.  This should be a combination of FMODE_READ
+         * and FMODE_WRITE.
+         */
+        int 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;
+};
+
+/*
+ * Similar to ceiling(log_size(n))
+ */
+static unsigned int int_log(unsigned int n, unsigned int base)
+{
+        int result = 0;
+
+        while (n > 1) {
+                n = dm_div_up(n, base);
+                result++;
+        }
+
+        return result;
+}
+
+/*
+ * 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)
+{
+        return (n * CHILDREN_PER_NODE) + k;
+}
+
+/*
+ * Return the n'th node of level l from table t.
+ */
+static inline sector_t *get_node(struct dm_table *t,
+                                 unsigned int l, unsigned int n)
+{
+        return t->index[l] + (n * KEYS_PER_NODE);
+}
+
+/*
+ * Return the highest key that you could lookup from the n'th
+ * node on level l of the btree.
+ */
+static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
+{
+        for (; l < t->depth - 1; l++)
+                n = get_child(n, CHILDREN_PER_NODE - 1);
+
+        if (n >= t->counts[l])
+                return (sector_t) - 1;
+
+        return get_node(t, l, n)[KEYS_PER_NODE - 1];
+}
+
+/*
+ * Fills in a level of the btree based on the highs of the level
+ * below it.
+ */
+static int setup_btree_index(unsigned int l, struct dm_table *t)
+{
+        unsigned int n, k;
+        sector_t *node;
+
+        for (n = 0U; n < t->counts[l]; n++) {
+                node = get_node(t, l, n);
+
+                for (k = 0U; k < KEYS_PER_NODE; k++)
+                        node[k] = high(t, l + 1, get_child(n, k));
+        }
+
+        return 0;
+}
+
+void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
+{
+        unsigned long size;
+        void *addr;
+
+        /*
+         * Check that we're not going to overflow.
+         */
+        if (nmemb > (ULONG_MAX / elem_size))
+                return NULL;
+
+        size = nmemb * elem_size;
+        addr = vmalloc(size);
+        if (addr)
+                memset(addr, 0, size);
+
+        return addr;
+}
+
+/*
+ * highs, and targets are managed as dynamic arrays during a
+ * table load.
+ */
+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.
+         */
+        n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
+                                          sizeof(sector_t));
+        if (!n_highs)
+                return -ENOMEM;
+
+        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));
+        vfree(t->highs);
+
+        t->num_allocated = num;
+        t->highs = n_highs;
+        t->targets = n_targets;
+
+        return 0;
+}
+
+int dm_table_create(struct dm_table **result, int mode, unsigned num_targets)
+{
+        struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL);
+
+        if (!t)
+                return -ENOMEM;
+
+        memset(t, 0, sizeof(*t));
+        INIT_LIST_HEAD(&t->devices);
+        atomic_set(&t->holders, 1);
+
+        if (!num_targets)
+                num_targets = KEYS_PER_NODE;
+
+        num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
+
+        if (alloc_targets(t, num_targets)) {
+                kfree(t);
+                t = NULL;
+                return -ENOMEM;
+        }
+
+        t->mode = mode;
+        *result = t;
+        return 0;
+}
+
+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;
+                kfree(dd);
+        }
+}
+
+void table_destroy(struct dm_table *t)
+{
+        unsigned int i;
+
+        /* free the indexes (see dm_table_complete) */
+        if (t->depth >= 2)
+                vfree(t->index[t->depth - 2]);
+
+        /* free the targets */
+        for (i = 0; i < t->num_targets; i++) {
+                struct dm_target *tgt = t->targets + i;
+
+                if (tgt->type->dtr)
+                        tgt->type->dtr(tgt);
+
+                dm_put_target_type(tgt->type);
+        }
+
+        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);
+        }
+
+        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.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)
+{
+        struct dm_dev *dd;
+
+        list_for_each_entry (dd, l, list)
+                if (dd->bdev->bd_dev == dev)
+                        return dd;
+
+        return NULL;
+}
+
+/*
+ * Open a device so we can use it as a map destination.
+ */
+static int open_dev(struct dm_dev *d, dev_t dev)
+{
+        static char *_claim_ptr = "I belong to device-mapper";
+        struct block_device *bdev;
+
+        int r;
+
+        if (d->bdev)
+                BUG();
+
+        bdev = open_by_devnum(dev, d->mode);
+        if (IS_ERR(bdev))
+                return PTR_ERR(bdev);
+        r = bd_claim(bdev, _claim_ptr);
+        if (r)
+                blkdev_put(bdev);
+        else
+                d->bdev = bdev;
+        return r;
+}
+
+/*
+ * Close a device that we've been using.
+ */
+static void close_dev(struct dm_dev *d)
+{
+        if (!d->bdev)
+                return;
+
+        bd_release(d->bdev);
+        blkdev_put(d->bdev);
+        d->bdev = NULL;
+}
+
+/*
+ * If possible (ie. blk_size[major] is set), this checks an area
+ * of a destination device is valid.
+ */
+static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len)
+{
+        sector_t dev_size;
+        dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT;
+        return ((start < dev_size) && (len <= (dev_size - start)));
+}
+
+/*
+ * 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.
+ */
+static int upgrade_mode(struct dm_dev *dd, int new_mode)
+{
+        int r;
+        struct dm_dev dd_copy;
+        dev_t dev = dd->bdev->bd_dev;
+
+        dd_copy = *dd;
+
+        dd->mode |= new_mode;
+        dd->bdev = NULL;
+        r = open_dev(dd, dev);
+        if (!r)
+                close_dev(&dd_copy);
+        else
+                *dd = dd_copy;
+
+        return r;
+}
+
+/*
+ * 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 r;
+        dev_t dev;
+        struct dm_dev *dd;
+        unsigned int major, minor;
+
+        if (!t)
+                BUG();
+
+        if (sscanf(path, "%u:%u", &major, &minor) == 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;
+        }
+
+        dd = find_device(&t->devices, dev);
+        if (!dd) {
+                dd = kmalloc(sizeof(*dd), GFP_KERNEL);
+                if (!dd)
+                        return -ENOMEM;
+
+                dd->mode = mode;
+                dd->bdev = NULL;
+
+                if ((r = open_dev(dd, dev))) {
+                        kfree(dd);
+                        return r;
+                }
+
+                format_dev_t(dd->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);
+                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;
+
+        return 0;
+}
+
+
+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 (!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 short)(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);
+
+                rs->max_segment_size =
+                        min_not_zero(rs->max_segment_size, q->max_segment_size);
+
+                rs->seg_boundary_mask =
+                        min_not_zero(rs->seg_boundary_mask,
+                                     q->seg_boundary_mask);
+        }
+
+        return r;
+}
+
+/*
+ * Decrement a devices use count and remove it if necessary.
+ */
+void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
+{
+        if (atomic_dec_and_test(&dd->count)) {
+                close_dev(dd);
+                list_del(&dd->list);
+                kfree(dd);
+        }
+}
+
+/*
+ * Checks to see if the target joins onto the end of the table.
+ */
+static int adjoin(struct dm_table *table, struct dm_target *ti)
+{
+        struct dm_target *prev;
+
+        if (!table->num_targets)
+                return !ti->begin;
+
+        prev = &table->targets[table->num_targets - 1];
+        return (ti->begin == (prev->begin + prev->len));
+}
+
+/*
+ * Used to dynamically allocate the arg array.
+ */
+static char **realloc_argv(unsigned *array_size, char **old_argv)
+{
+        char **argv;
+        unsigned new_size;
+
+        new_size = *array_size ? *array_size * 2 : 64;
+        argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL);
+        if (argv) {
+                memcpy(argv, old_argv, *array_size * sizeof(*argv));
+                *array_size = new_size;
+        }
+
+        kfree(old_argv);
+        return argv;
+}
+
+/*
+ * Destructively splits up the argument list to pass to ctr.
+ */
+int dm_split_args(int *argc, char ***argvp, char *input)
+{
+        char *start, *end = input, *out, **argv = NULL;
+        unsigned array_size = 0;
+
+        *argc = 0;
+        argv = realloc_argv(&array_size, argv);
+        if (!argv)
+                return -ENOMEM;
+
+        while (1) {
+                start = end;
+
+                /* Skip whitespace */
+                while (*start && isspace(*start))
+                        start++;
+
+                if (!*start)
+                        break;  /* success, we hit the end */
+
+                /* 'out' is used to remove any back-quotes */
+                end = out = start;
+                while (*end) {
+                        /* Everything apart from '\0' can be quoted */
+                        if (*end == '\\' && *(end + 1)) {
+                                *out++ = *(end + 1);
+                                end += 2;
+                                continue;
+                        }
+
+                        if (isspace(*end))
+                                break;  /* end of token */
+
+                        *out++ = *end++;
+                }
+
+                /* have we already filled the array ? */
+                if ((*argc + 1) > array_size) {
+                        argv = realloc_argv(&array_size, argv);
+                        if (!argv)
+                                return -ENOMEM;
+                }
+
+                /* we know this is whitespace */
+                if (*end)
+                        end++;
+
+                /* terminate the string and put it in the array */
+                *out = '\0';
+                argv[*argc] = start;
+                (*argc)++;
+        }
+
+        *argvp = argv;
+        return 0;
+}
+
+static void check_for_valid_limits(struct io_restrictions *rs)
+{
+        if (!rs->max_sectors)
+                rs->max_sectors = 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;
+}
+
+int dm_table_add_target(struct dm_table *t, const char *type,
+                        sector_t start, sector_t len, char *params)
+{
+        int r = -EINVAL, argc;
+        char **argv;
+        struct dm_target *tgt;
+
+        if ((r = check_space(t)))
+                return r;
+
+        tgt = t->targets + t->num_targets;
+        memset(tgt, 0, sizeof(*tgt));
+
+        if (!len) {
+                tgt->error = "zero-length target";
+                DMERR("%s", tgt->error);
+                return -EINVAL;
+        }
+
+        tgt->type = dm_get_target_type(type);
+        if (!tgt->type) {
+                tgt->error = "unknown target type";
+                DMERR("%s", tgt->error);
+                return -EINVAL;
+        }
+
+        tgt->table = t;
+        tgt->begin = start;
+        tgt->len = len;
+        tgt->error = "Unknown error";
+
+        /*
+         * Does this target adjoin the previous one ?
+         */
+        if (!adjoin(t, tgt)) {
+                tgt->error = "Gap in table";
+                r = -EINVAL;
+                goto bad;
+        }
+
+        r = dm_split_args(&argc, &argv, params);
+        if (r) {
+                tgt->error = "couldn't split parameters (insufficient memory)";
+                goto bad;
+        }
+
+        r = tgt->type->ctr(tgt, argc, argv);
+        kfree(argv);
+        if (r)
+                goto bad;
+
+        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);
+        dm_put_target_type(tgt->type);
+        return r;
+}
+
+static int setup_indexes(struct dm_table *t)
+{
+        int i;
+        unsigned int total = 0;
+        sector_t *indexes;
+
+        /* allocate the space for *all* the indexes */
+        for (i = t->depth - 2; i >= 0; i--) {
+                t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
+                total += t->counts[i];
+        }
+
+        indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
+        if (!indexes)
+                return -ENOMEM;
+
+        /* set up internal nodes, bottom-up */
+        for (i = t->depth - 2, total = 0; i >= 0; i--) {
+                t->index[i] = indexes;
+                indexes += (KEYS_PER_NODE * t->counts[i]);
+                setup_btree_index(i, t);
+        }
+
+        return 0;
+}
+
+/*
+ * Builds the btree to index the map.
+ */
+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);
+
+        /* leaf layer has already been set up */
+        t->counts[t->depth - 1] = leaf_nodes;
+        t->index[t->depth - 1] = t->highs;
+
+        if (t->depth >= 2)
+                r = setup_indexes(t);
+
+        return r;
+}
+
+static DECLARE_MUTEX(_event_lock);
+void dm_table_event_callback(struct dm_table *t,
+                             void (*fn)(void *), void *context)
+{
+        down(&_event_lock);
+        t->event_fn = fn;
+        t->event_context = context;
+        up(&_event_lock);
+}
+
+void dm_table_event(struct dm_table *t)
+{
+        /*
+         * You can no longer call dm_table_event() from interrupt
+         * context, use a bottom half instead.
+         */
+        BUG_ON(in_interrupt());
+
+        down(&_event_lock);
+        if (t->event_fn)
+                t->event_fn(t->event_context);
+        up(&_event_lock);
+}
+
+sector_t dm_table_get_size(struct dm_table *t)
+{
+        return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
+}
+
+struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
+{
+        if (index > t->num_targets)
+                return NULL;
+
+        return t->targets + index;
+}
+
+/*
+ * Search the btree for the correct target.
+ */
+struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
+{
+        unsigned int l, n = 0, k = 0;
+        sector_t *node;
+
+        for (l = 0; l < t->depth; l++) {
+                n = get_child(n, k);
+                node = get_node(t, l, n);
+
+                for (k = 0; k < KEYS_PER_NODE; k++)
+                        if (node[k] >= sector)
+                                break;
+        }
+
+        return &t->targets[(KEYS_PER_NODE * n) + k];
+}
+
+void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q)
+{
+        /*
+         * Make sure we obey the optimistic sub devices
+         * restrictions.
+         */
+        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;
+}
+
+unsigned int dm_table_get_num_targets(struct dm_table *t)
+{
+        return t->num_targets;
+}
+
+struct list_head *dm_table_get_devices(struct dm_table *t)
+{
+        return &t->devices;
+}
+
+int dm_table_get_mode(struct dm_table *t)
+{
+        return t->mode;
+}
+
+static void suspend_targets(struct dm_table *t, unsigned postsuspend)
+{
+        int i = t->num_targets;
+        struct dm_target *ti = t->targets;
+
+        while (i--) {
+                if (postsuspend) {
+                        if (ti->type->postsuspend)
+                                ti->type->postsuspend(ti);
+                } else if (ti->type->presuspend)
+                        ti->type->presuspend(ti);
+
+                ti++;
+        }
+}
+
+void dm_table_presuspend_targets(struct dm_table *t)
+{
+        return suspend_targets(t, 0);
+}
+
+void dm_table_postsuspend_targets(struct dm_table *t)
+{
+        return suspend_targets(t, 1);
+}
+
+void dm_table_resume_targets(struct dm_table *t)
+{
+        int i;
+
+        for (i = 0; i < t->num_targets; i++) {
+                struct dm_target *ti = t->targets + i;
+
+                if (ti->type->resume)
+                        ti->type->resume(ti);
+        }
+}
+
+int dm_table_any_congested(struct dm_table *t, int bdi_bits)
+{
+        struct list_head *d, *devices;
+        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);
+        }
+
+        return r;
+}
+
+void dm_table_unplug_all(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);
+
+                if (q->unplug_fn)
+                        q->unplug_fn(q);
+        }
+}
+
+int dm_table_flush_all(struct dm_table *t)
+{
+        struct list_head *d, *devices = dm_table_get_devices(t);
+        int ret = 0;
+
+        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;
+
+                if (!q->issue_flush_fn)
+                        err = -EOPNOTSUPP;
+                else
+                        err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL);
+
+                if (!ret)
+                        ret = err;
+        }
+
+        return ret;
+}
+
+EXPORT_SYMBOL(dm_vcalloc);
+EXPORT_SYMBOL(dm_get_device);
+EXPORT_SYMBOL(dm_put_device);
+EXPORT_SYMBOL(dm_table_event);
+EXPORT_SYMBOL(dm_table_get_mode);
+EXPORT_SYMBOL(dm_table_put);
+EXPORT_SYMBOL(dm_table_get);
+EXPORT_SYMBOL(dm_table_unplug_all);
+EXPORT_SYMBOL(dm_table_flush_all);