688 lines
17 KiB
C
688 lines
17 KiB
C
/*
|
|
* Copyright (C) 2011 Red Hat, Inc.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#include "dm-btree.h"
|
|
#include "dm-btree-internal.h"
|
|
#include "dm-transaction-manager.h"
|
|
|
|
#include <linux/export.h>
|
|
|
|
/*
|
|
* Removing an entry from a btree
|
|
* ==============================
|
|
*
|
|
* A very important constraint for our btree is that no node, except the
|
|
* root, may have fewer than a certain number of entries.
|
|
* (MIN_ENTRIES <= nr_entries <= MAX_ENTRIES).
|
|
*
|
|
* Ensuring this is complicated by the way we want to only ever hold the
|
|
* locks on 2 nodes concurrently, and only change nodes in a top to bottom
|
|
* fashion.
|
|
*
|
|
* Each node may have a left or right sibling. When decending the spine,
|
|
* if a node contains only MIN_ENTRIES then we try and increase this to at
|
|
* least MIN_ENTRIES + 1. We do this in the following ways:
|
|
*
|
|
* [A] No siblings => this can only happen if the node is the root, in which
|
|
* case we copy the childs contents over the root.
|
|
*
|
|
* [B] No left sibling
|
|
* ==> rebalance(node, right sibling)
|
|
*
|
|
* [C] No right sibling
|
|
* ==> rebalance(left sibling, node)
|
|
*
|
|
* [D] Both siblings, total_entries(left, node, right) <= DEL_THRESHOLD
|
|
* ==> delete node adding it's contents to left and right
|
|
*
|
|
* [E] Both siblings, total_entries(left, node, right) > DEL_THRESHOLD
|
|
* ==> rebalance(left, node, right)
|
|
*
|
|
* After these operations it's possible that the our original node no
|
|
* longer contains the desired sub tree. For this reason this rebalancing
|
|
* is performed on the children of the current node. This also avoids
|
|
* having a special case for the root.
|
|
*
|
|
* Once this rebalancing has occurred we can then step into the child node
|
|
* for internal nodes. Or delete the entry for leaf nodes.
|
|
*/
|
|
|
|
/*
|
|
* Some little utilities for moving node data around.
|
|
*/
|
|
static void node_shift(struct btree_node *n, int shift)
|
|
{
|
|
uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
|
|
uint32_t value_size = le32_to_cpu(n->header.value_size);
|
|
|
|
if (shift < 0) {
|
|
shift = -shift;
|
|
BUG_ON(shift > nr_entries);
|
|
BUG_ON((void *) key_ptr(n, shift) >= value_ptr(n, shift));
|
|
memmove(key_ptr(n, 0),
|
|
key_ptr(n, shift),
|
|
(nr_entries - shift) * sizeof(__le64));
|
|
memmove(value_ptr(n, 0),
|
|
value_ptr(n, shift),
|
|
(nr_entries - shift) * value_size);
|
|
} else {
|
|
BUG_ON(nr_entries + shift > le32_to_cpu(n->header.max_entries));
|
|
memmove(key_ptr(n, shift),
|
|
key_ptr(n, 0),
|
|
nr_entries * sizeof(__le64));
|
|
memmove(value_ptr(n, shift),
|
|
value_ptr(n, 0),
|
|
nr_entries * value_size);
|
|
}
|
|
}
|
|
|
|
static void node_copy(struct btree_node *left, struct btree_node *right, int shift)
|
|
{
|
|
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
|
|
uint32_t value_size = le32_to_cpu(left->header.value_size);
|
|
BUG_ON(value_size != le32_to_cpu(right->header.value_size));
|
|
|
|
if (shift < 0) {
|
|
shift = -shift;
|
|
BUG_ON(nr_left + shift > le32_to_cpu(left->header.max_entries));
|
|
memcpy(key_ptr(left, nr_left),
|
|
key_ptr(right, 0),
|
|
shift * sizeof(__le64));
|
|
memcpy(value_ptr(left, nr_left),
|
|
value_ptr(right, 0),
|
|
shift * value_size);
|
|
} else {
|
|
BUG_ON(shift > le32_to_cpu(right->header.max_entries));
|
|
memcpy(key_ptr(right, 0),
|
|
key_ptr(left, nr_left - shift),
|
|
shift * sizeof(__le64));
|
|
memcpy(value_ptr(right, 0),
|
|
value_ptr(left, nr_left - shift),
|
|
shift * value_size);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Delete a specific entry from a leaf node.
|
|
*/
|
|
static void delete_at(struct btree_node *n, unsigned index)
|
|
{
|
|
unsigned nr_entries = le32_to_cpu(n->header.nr_entries);
|
|
unsigned nr_to_copy = nr_entries - (index + 1);
|
|
uint32_t value_size = le32_to_cpu(n->header.value_size);
|
|
BUG_ON(index >= nr_entries);
|
|
|
|
if (nr_to_copy) {
|
|
memmove(key_ptr(n, index),
|
|
key_ptr(n, index + 1),
|
|
nr_to_copy * sizeof(__le64));
|
|
|
|
memmove(value_ptr(n, index),
|
|
value_ptr(n, index + 1),
|
|
nr_to_copy * value_size);
|
|
}
|
|
|
|
n->header.nr_entries = cpu_to_le32(nr_entries - 1);
|
|
}
|
|
|
|
static unsigned merge_threshold(struct btree_node *n)
|
|
{
|
|
return le32_to_cpu(n->header.max_entries) / 3;
|
|
}
|
|
|
|
struct child {
|
|
unsigned index;
|
|
struct dm_block *block;
|
|
struct btree_node *n;
|
|
};
|
|
|
|
static int init_child(struct dm_btree_info *info, struct dm_btree_value_type *vt,
|
|
struct btree_node *parent,
|
|
unsigned index, struct child *result)
|
|
{
|
|
int r, inc;
|
|
dm_block_t root;
|
|
|
|
result->index = index;
|
|
root = value64(parent, index);
|
|
|
|
r = dm_tm_shadow_block(info->tm, root, &btree_node_validator,
|
|
&result->block, &inc);
|
|
if (r)
|
|
return r;
|
|
|
|
result->n = dm_block_data(result->block);
|
|
|
|
if (inc)
|
|
inc_children(info->tm, result->n, vt);
|
|
|
|
*((__le64 *) value_ptr(parent, index)) =
|
|
cpu_to_le64(dm_block_location(result->block));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void exit_child(struct dm_btree_info *info, struct child *c)
|
|
{
|
|
dm_tm_unlock(info->tm, c->block);
|
|
}
|
|
|
|
static void shift(struct btree_node *left, struct btree_node *right, int count)
|
|
{
|
|
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
|
|
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
|
|
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
|
|
uint32_t r_max_entries = le32_to_cpu(right->header.max_entries);
|
|
|
|
BUG_ON(max_entries != r_max_entries);
|
|
BUG_ON(nr_left - count > max_entries);
|
|
BUG_ON(nr_right + count > max_entries);
|
|
|
|
if (!count)
|
|
return;
|
|
|
|
if (count > 0) {
|
|
node_shift(right, count);
|
|
node_copy(left, right, count);
|
|
} else {
|
|
node_copy(left, right, count);
|
|
node_shift(right, count);
|
|
}
|
|
|
|
left->header.nr_entries = cpu_to_le32(nr_left - count);
|
|
right->header.nr_entries = cpu_to_le32(nr_right + count);
|
|
}
|
|
|
|
static void __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
|
|
struct child *l, struct child *r)
|
|
{
|
|
struct btree_node *left = l->n;
|
|
struct btree_node *right = r->n;
|
|
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
|
|
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
|
|
/*
|
|
* Ensure the number of entries in each child will be greater
|
|
* than or equal to (max_entries / 3 + 1), so no matter which
|
|
* child is used for removal, the number will still be not
|
|
* less than (max_entries / 3).
|
|
*/
|
|
unsigned int threshold = 2 * (merge_threshold(left) + 1);
|
|
|
|
if (nr_left + nr_right < threshold) {
|
|
/*
|
|
* Merge
|
|
*/
|
|
node_copy(left, right, -nr_right);
|
|
left->header.nr_entries = cpu_to_le32(nr_left + nr_right);
|
|
delete_at(parent, r->index);
|
|
|
|
/*
|
|
* We need to decrement the right block, but not it's
|
|
* children, since they're still referenced by left.
|
|
*/
|
|
dm_tm_dec(info->tm, dm_block_location(r->block));
|
|
} else {
|
|
/*
|
|
* Rebalance.
|
|
*/
|
|
unsigned target_left = (nr_left + nr_right) / 2;
|
|
shift(left, right, nr_left - target_left);
|
|
*key_ptr(parent, r->index) = right->keys[0];
|
|
}
|
|
}
|
|
|
|
static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
|
|
struct dm_btree_value_type *vt, unsigned left_index)
|
|
{
|
|
int r;
|
|
struct btree_node *parent;
|
|
struct child left, right;
|
|
|
|
parent = dm_block_data(shadow_current(s));
|
|
|
|
r = init_child(info, vt, parent, left_index, &left);
|
|
if (r)
|
|
return r;
|
|
|
|
r = init_child(info, vt, parent, left_index + 1, &right);
|
|
if (r) {
|
|
exit_child(info, &left);
|
|
return r;
|
|
}
|
|
|
|
__rebalance2(info, parent, &left, &right);
|
|
|
|
exit_child(info, &left);
|
|
exit_child(info, &right);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We dump as many entries from center as possible into left, then the rest
|
|
* in right, then rebalance2. This wastes some cpu, but I want something
|
|
* simple atm.
|
|
*/
|
|
static void delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
|
|
struct child *l, struct child *c, struct child *r,
|
|
struct btree_node *left, struct btree_node *center, struct btree_node *right,
|
|
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
|
|
{
|
|
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
|
|
unsigned shift = min(max_entries - nr_left, nr_center);
|
|
|
|
BUG_ON(nr_left + shift > max_entries);
|
|
node_copy(left, center, -shift);
|
|
left->header.nr_entries = cpu_to_le32(nr_left + shift);
|
|
|
|
if (shift != nr_center) {
|
|
shift = nr_center - shift;
|
|
BUG_ON((nr_right + shift) > max_entries);
|
|
node_shift(right, shift);
|
|
node_copy(center, right, shift);
|
|
right->header.nr_entries = cpu_to_le32(nr_right + shift);
|
|
}
|
|
*key_ptr(parent, r->index) = right->keys[0];
|
|
|
|
delete_at(parent, c->index);
|
|
r->index--;
|
|
|
|
dm_tm_dec(info->tm, dm_block_location(c->block));
|
|
__rebalance2(info, parent, l, r);
|
|
}
|
|
|
|
/*
|
|
* Redistributes entries among 3 sibling nodes.
|
|
*/
|
|
static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
|
|
struct child *l, struct child *c, struct child *r,
|
|
struct btree_node *left, struct btree_node *center, struct btree_node *right,
|
|
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
|
|
{
|
|
int s;
|
|
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
|
|
unsigned total = nr_left + nr_center + nr_right;
|
|
unsigned target_right = total / 3;
|
|
unsigned remainder = (target_right * 3) != total;
|
|
unsigned target_left = target_right + remainder;
|
|
|
|
BUG_ON(target_left > max_entries);
|
|
BUG_ON(target_right > max_entries);
|
|
|
|
if (nr_left < nr_right) {
|
|
s = nr_left - target_left;
|
|
|
|
if (s < 0 && nr_center < -s) {
|
|
/* not enough in central node */
|
|
shift(left, center, -nr_center);
|
|
s += nr_center;
|
|
shift(left, right, s);
|
|
nr_right += s;
|
|
} else
|
|
shift(left, center, s);
|
|
|
|
shift(center, right, target_right - nr_right);
|
|
|
|
} else {
|
|
s = target_right - nr_right;
|
|
if (s > 0 && nr_center < s) {
|
|
/* not enough in central node */
|
|
shift(center, right, nr_center);
|
|
s -= nr_center;
|
|
shift(left, right, s);
|
|
nr_left -= s;
|
|
} else
|
|
shift(center, right, s);
|
|
|
|
shift(left, center, nr_left - target_left);
|
|
}
|
|
|
|
*key_ptr(parent, c->index) = center->keys[0];
|
|
*key_ptr(parent, r->index) = right->keys[0];
|
|
}
|
|
|
|
static void __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
|
|
struct child *l, struct child *c, struct child *r)
|
|
{
|
|
struct btree_node *left = l->n;
|
|
struct btree_node *center = c->n;
|
|
struct btree_node *right = r->n;
|
|
|
|
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
|
|
uint32_t nr_center = le32_to_cpu(center->header.nr_entries);
|
|
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
|
|
|
|
unsigned threshold = merge_threshold(left) * 4 + 1;
|
|
|
|
BUG_ON(left->header.max_entries != center->header.max_entries);
|
|
BUG_ON(center->header.max_entries != right->header.max_entries);
|
|
|
|
if ((nr_left + nr_center + nr_right) < threshold)
|
|
delete_center_node(info, parent, l, c, r, left, center, right,
|
|
nr_left, nr_center, nr_right);
|
|
else
|
|
redistribute3(info, parent, l, c, r, left, center, right,
|
|
nr_left, nr_center, nr_right);
|
|
}
|
|
|
|
static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
|
|
struct dm_btree_value_type *vt, unsigned left_index)
|
|
{
|
|
int r;
|
|
struct btree_node *parent = dm_block_data(shadow_current(s));
|
|
struct child left, center, right;
|
|
|
|
/*
|
|
* FIXME: fill out an array?
|
|
*/
|
|
r = init_child(info, vt, parent, left_index, &left);
|
|
if (r)
|
|
return r;
|
|
|
|
r = init_child(info, vt, parent, left_index + 1, ¢er);
|
|
if (r) {
|
|
exit_child(info, &left);
|
|
return r;
|
|
}
|
|
|
|
r = init_child(info, vt, parent, left_index + 2, &right);
|
|
if (r) {
|
|
exit_child(info, &left);
|
|
exit_child(info, ¢er);
|
|
return r;
|
|
}
|
|
|
|
__rebalance3(info, parent, &left, ¢er, &right);
|
|
|
|
exit_child(info, &left);
|
|
exit_child(info, ¢er);
|
|
exit_child(info, &right);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rebalance_children(struct shadow_spine *s,
|
|
struct dm_btree_info *info,
|
|
struct dm_btree_value_type *vt, uint64_t key)
|
|
{
|
|
int i, r, has_left_sibling, has_right_sibling;
|
|
struct btree_node *n;
|
|
|
|
n = dm_block_data(shadow_current(s));
|
|
|
|
if (le32_to_cpu(n->header.nr_entries) == 1) {
|
|
struct dm_block *child;
|
|
dm_block_t b = value64(n, 0);
|
|
|
|
r = dm_tm_read_lock(info->tm, b, &btree_node_validator, &child);
|
|
if (r)
|
|
return r;
|
|
|
|
memcpy(n, dm_block_data(child),
|
|
dm_bm_block_size(dm_tm_get_bm(info->tm)));
|
|
dm_tm_unlock(info->tm, child);
|
|
|
|
dm_tm_dec(info->tm, dm_block_location(child));
|
|
return 0;
|
|
}
|
|
|
|
i = lower_bound(n, key);
|
|
if (i < 0)
|
|
return -ENODATA;
|
|
|
|
has_left_sibling = i > 0;
|
|
has_right_sibling = i < (le32_to_cpu(n->header.nr_entries) - 1);
|
|
|
|
if (!has_left_sibling)
|
|
r = rebalance2(s, info, vt, i);
|
|
|
|
else if (!has_right_sibling)
|
|
r = rebalance2(s, info, vt, i - 1);
|
|
|
|
else
|
|
r = rebalance3(s, info, vt, i - 1);
|
|
|
|
return r;
|
|
}
|
|
|
|
static int do_leaf(struct btree_node *n, uint64_t key, unsigned *index)
|
|
{
|
|
int i = lower_bound(n, key);
|
|
|
|
if ((i < 0) ||
|
|
(i >= le32_to_cpu(n->header.nr_entries)) ||
|
|
(le64_to_cpu(n->keys[i]) != key))
|
|
return -ENODATA;
|
|
|
|
*index = i;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Prepares for removal from one level of the hierarchy. The caller must
|
|
* call delete_at() to remove the entry at index.
|
|
*/
|
|
static int remove_raw(struct shadow_spine *s, struct dm_btree_info *info,
|
|
struct dm_btree_value_type *vt, dm_block_t root,
|
|
uint64_t key, unsigned *index)
|
|
{
|
|
int i = *index, r;
|
|
struct btree_node *n;
|
|
|
|
for (;;) {
|
|
r = shadow_step(s, root, vt);
|
|
if (r < 0)
|
|
break;
|
|
|
|
/*
|
|
* We have to patch up the parent node, ugly, but I don't
|
|
* see a way to do this automatically as part of the spine
|
|
* op.
|
|
*/
|
|
if (shadow_has_parent(s)) {
|
|
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
|
|
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
|
|
&location, sizeof(__le64));
|
|
}
|
|
|
|
n = dm_block_data(shadow_current(s));
|
|
|
|
if (le32_to_cpu(n->header.flags) & LEAF_NODE)
|
|
return do_leaf(n, key, index);
|
|
|
|
r = rebalance_children(s, info, vt, key);
|
|
if (r)
|
|
break;
|
|
|
|
n = dm_block_data(shadow_current(s));
|
|
if (le32_to_cpu(n->header.flags) & LEAF_NODE)
|
|
return do_leaf(n, key, index);
|
|
|
|
i = lower_bound(n, key);
|
|
|
|
/*
|
|
* We know the key is present, or else
|
|
* rebalance_children would have returned
|
|
* -ENODATA
|
|
*/
|
|
root = value64(n, i);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_btree_remove(struct dm_btree_info *info, dm_block_t root,
|
|
uint64_t *keys, dm_block_t *new_root)
|
|
{
|
|
unsigned level, last_level = info->levels - 1;
|
|
int index = 0, r = 0;
|
|
struct shadow_spine spine;
|
|
struct btree_node *n;
|
|
struct dm_btree_value_type le64_vt;
|
|
|
|
init_le64_type(info->tm, &le64_vt);
|
|
init_shadow_spine(&spine, info);
|
|
for (level = 0; level < info->levels; level++) {
|
|
r = remove_raw(&spine, info,
|
|
(level == last_level ?
|
|
&info->value_type : &le64_vt),
|
|
root, keys[level], (unsigned *)&index);
|
|
if (r < 0)
|
|
break;
|
|
|
|
n = dm_block_data(shadow_current(&spine));
|
|
if (level != last_level) {
|
|
root = value64(n, index);
|
|
continue;
|
|
}
|
|
|
|
BUG_ON(index < 0 || index >= le32_to_cpu(n->header.nr_entries));
|
|
|
|
if (info->value_type.dec)
|
|
info->value_type.dec(info->value_type.context,
|
|
value_ptr(n, index));
|
|
|
|
delete_at(n, index);
|
|
}
|
|
|
|
*new_root = shadow_root(&spine);
|
|
exit_shadow_spine(&spine);
|
|
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_btree_remove);
|
|
|
|
/*----------------------------------------------------------------*/
|
|
|
|
static int remove_nearest(struct shadow_spine *s, struct dm_btree_info *info,
|
|
struct dm_btree_value_type *vt, dm_block_t root,
|
|
uint64_t key, int *index)
|
|
{
|
|
int i = *index, r;
|
|
struct btree_node *n;
|
|
|
|
for (;;) {
|
|
r = shadow_step(s, root, vt);
|
|
if (r < 0)
|
|
break;
|
|
|
|
/*
|
|
* We have to patch up the parent node, ugly, but I don't
|
|
* see a way to do this automatically as part of the spine
|
|
* op.
|
|
*/
|
|
if (shadow_has_parent(s)) {
|
|
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
|
|
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
|
|
&location, sizeof(__le64));
|
|
}
|
|
|
|
n = dm_block_data(shadow_current(s));
|
|
|
|
if (le32_to_cpu(n->header.flags) & LEAF_NODE) {
|
|
*index = lower_bound(n, key);
|
|
return 0;
|
|
}
|
|
|
|
r = rebalance_children(s, info, vt, key);
|
|
if (r)
|
|
break;
|
|
|
|
n = dm_block_data(shadow_current(s));
|
|
if (le32_to_cpu(n->header.flags) & LEAF_NODE) {
|
|
*index = lower_bound(n, key);
|
|
return 0;
|
|
}
|
|
|
|
i = lower_bound(n, key);
|
|
|
|
/*
|
|
* We know the key is present, or else
|
|
* rebalance_children would have returned
|
|
* -ENODATA
|
|
*/
|
|
root = value64(n, i);
|
|
}
|
|
|
|
return r;
|
|
}
|
|
|
|
static int remove_one(struct dm_btree_info *info, dm_block_t root,
|
|
uint64_t *keys, uint64_t end_key,
|
|
dm_block_t *new_root, unsigned *nr_removed)
|
|
{
|
|
unsigned level, last_level = info->levels - 1;
|
|
int index = 0, r = 0;
|
|
struct shadow_spine spine;
|
|
struct btree_node *n;
|
|
struct dm_btree_value_type le64_vt;
|
|
uint64_t k;
|
|
|
|
init_le64_type(info->tm, &le64_vt);
|
|
init_shadow_spine(&spine, info);
|
|
for (level = 0; level < last_level; level++) {
|
|
r = remove_raw(&spine, info, &le64_vt,
|
|
root, keys[level], (unsigned *) &index);
|
|
if (r < 0)
|
|
goto out;
|
|
|
|
n = dm_block_data(shadow_current(&spine));
|
|
root = value64(n, index);
|
|
}
|
|
|
|
r = remove_nearest(&spine, info, &info->value_type,
|
|
root, keys[last_level], &index);
|
|
if (r < 0)
|
|
goto out;
|
|
|
|
n = dm_block_data(shadow_current(&spine));
|
|
|
|
if (index < 0)
|
|
index = 0;
|
|
|
|
if (index >= le32_to_cpu(n->header.nr_entries)) {
|
|
r = -ENODATA;
|
|
goto out;
|
|
}
|
|
|
|
k = le64_to_cpu(n->keys[index]);
|
|
if (k >= keys[last_level] && k < end_key) {
|
|
if (info->value_type.dec)
|
|
info->value_type.dec(info->value_type.context,
|
|
value_ptr(n, index));
|
|
|
|
delete_at(n, index);
|
|
keys[last_level] = k + 1ull;
|
|
|
|
} else
|
|
r = -ENODATA;
|
|
|
|
out:
|
|
*new_root = shadow_root(&spine);
|
|
exit_shadow_spine(&spine);
|
|
|
|
return r;
|
|
}
|
|
|
|
int dm_btree_remove_leaves(struct dm_btree_info *info, dm_block_t root,
|
|
uint64_t *first_key, uint64_t end_key,
|
|
dm_block_t *new_root, unsigned *nr_removed)
|
|
{
|
|
int r;
|
|
|
|
*nr_removed = 0;
|
|
do {
|
|
r = remove_one(info, root, first_key, end_key, &root, nr_removed);
|
|
if (!r)
|
|
(*nr_removed)++;
|
|
} while (!r);
|
|
|
|
*new_root = root;
|
|
return r == -ENODATA ? 0 : r;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dm_btree_remove_leaves);
|