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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/md/dm-table.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/md/dm-table.c')
-rw-r--r--drivers/md/dm-table.c950
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);