Orange Pi5 kernel

/*
 * Copyright (C) 2011 Red Hat, Inc.
 *
 * This file is released under the GPL.
 */
 
#include "dm-btree-internal.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"
 
#include <linux/export.h>
#include <linux/device-mapper.h>
 
#define DM_MSG_PREFIX "btree"
 
/*----------------------------------------------------------------
 * Array manipulation
 *--------------------------------------------------------------*/
static void memcpy_disk(void *dest, const void *src, size_t len)
<------>__dm_written_to_disk(src)
{
<------>memcpy(dest, src, len);
<------>__dm_unbless_for_disk(src);
}
 
static void array_insert(void *base, size_t elt_size, unsigned nr_elts,
<------><------><------> unsigned index, void *elt)
<------>__dm_written_to_disk(elt)
{
<------>if (index < nr_elts)
<------><------>memmove(base + (elt_size * (index + 1)),
<------><------><------>base + (elt_size * index),
<------><------><------>(nr_elts - index) * elt_size);
 
<------>memcpy_disk(base + (elt_size * index), elt, elt_size);
}
 
/*----------------------------------------------------------------*/
 
/* makes the assumption that no two keys are the same. */
static int bsearch(struct btree_node *n, uint64_t key, int want_hi)
{
<------>int lo = -1, hi = le32_to_cpu(n->header.nr_entries);
 
<------>while (hi - lo > 1) {
<------><------>int mid = lo + ((hi - lo) / 2);
<------><------>uint64_t mid_key = le64_to_cpu(n->keys[mid]);
 
<------><------>if (mid_key == key)
<------><------><------>return mid;
 
<------><------>if (mid_key < key)
<------><------><------>lo = mid;
<------><------>else
<------><------><------>hi = mid;
<------>}
 
<------>return want_hi ? hi : lo;
}
 
int lower_bound(struct btree_node *n, uint64_t key)
{
<------>return bsearch(n, key, 0);
}
 
static int upper_bound(struct btree_node *n, uint64_t key)
{
<------>return bsearch(n, key, 1);
}
 
void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
<------><------>  struct dm_btree_value_type *vt)
{
<------>unsigned i;
<------>uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
 
<------>if (le32_to_cpu(n->header.flags) & INTERNAL_NODE)
<------><------>for (i = 0; i < nr_entries; i++)
<------><------><------>dm_tm_inc(tm, value64(n, i));
<------>else if (vt->inc)
<------><------>for (i = 0; i < nr_entries; i++)
<------><------><------>vt->inc(vt->context, value_ptr(n, i));
}
 
static int insert_at(size_t value_size, struct btree_node *node, unsigned index,
<------><------>     uint64_t key, void *value)
<------>__dm_written_to_disk(value)
{
<------>uint32_t nr_entries = le32_to_cpu(node->header.nr_entries);
<------>uint32_t max_entries = le32_to_cpu(node->header.max_entries);
<------>__le64 key_le = cpu_to_le64(key);
 
<------>if (index > nr_entries ||
<------>    index >= max_entries ||
<------>    nr_entries >= max_entries) {
<------><------>DMERR("too many entries in btree node for insert");
<------><------>__dm_unbless_for_disk(value);
<------><------>return -ENOMEM;
<------>}
 
<------>__dm_bless_for_disk(&key_le);
 
<------>array_insert(node->keys, sizeof(*node->keys), nr_entries, index, &key_le);
<------>array_insert(value_base(node), value_size, nr_entries, index, value);
<------>node->header.nr_entries = cpu_to_le32(nr_entries + 1);
 
<------>return 0;
}
 
/*----------------------------------------------------------------*/
 
/*
 * We want 3n entries (for some n).  This works more nicely for repeated
 * insert remove loops than (2n + 1).
 */
static uint32_t calc_max_entries(size_t value_size, size_t block_size)
{
<------>uint32_t total, n;
<------>size_t elt_size = sizeof(uint64_t) + value_size; /* key + value */
 
<------>block_size -= sizeof(struct node_header);
<------>total = block_size / elt_size;
<------>n = total / 3;		/* rounds down */
 
<------>return 3 * n;
}
 
int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root)
{
<------>int r;
<------>struct dm_block *b;
<------>struct btree_node *n;
<------>size_t block_size;
<------>uint32_t max_entries;
 
<------>r = new_block(info, &b);
<------>if (r < 0)
<------><------>return r;
 
<------>block_size = dm_bm_block_size(dm_tm_get_bm(info->tm));
<------>max_entries = calc_max_entries(info->value_type.size, block_size);
 
<------>n = dm_block_data(b);
<------>memset(n, 0, block_size);
<------>n->header.flags = cpu_to_le32(LEAF_NODE);
<------>n->header.nr_entries = cpu_to_le32(0);
<------>n->header.max_entries = cpu_to_le32(max_entries);
<------>n->header.value_size = cpu_to_le32(info->value_type.size);
 
<------>*root = dm_block_location(b);
<------>unlock_block(info, b);
 
<------>return 0;
}
EXPORT_SYMBOL_GPL(dm_btree_empty);
 
/*----------------------------------------------------------------*/
 
/*
 * Deletion uses a recursive algorithm, since we have limited stack space
 * we explicitly manage our own stack on the heap.
 */
#define MAX_SPINE_DEPTH 64
struct frame {
<------>struct dm_block *b;
<------>struct btree_node *n;
<------>unsigned level;
<------>unsigned nr_children;
<------>unsigned current_child;
};
 
struct del_stack {
<------>struct dm_btree_info *info;
<------>struct dm_transaction_manager *tm;
<------>int top;
<------>struct frame spine[MAX_SPINE_DEPTH];
};
 
static int top_frame(struct del_stack *s, struct frame **f)
{
<------>if (s->top < 0) {
<------><------>DMERR("btree deletion stack empty");
<------><------>return -EINVAL;
<------>}
 
<------>*f = s->spine + s->top;
 
<------>return 0;
}
 
static int unprocessed_frames(struct del_stack *s)
{
<------>return s->top >= 0;
}
 
static void prefetch_children(struct del_stack *s, struct frame *f)
{
<------>unsigned i;
<------>struct dm_block_manager *bm = dm_tm_get_bm(s->tm);
 
<------>for (i = 0; i < f->nr_children; i++)
<------><------>dm_bm_prefetch(bm, value64(f->n, i));
}
 
static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
{
<------>return f->level < (info->levels - 1);
}
 
static int push_frame(struct del_stack *s, dm_block_t b, unsigned level)
{
<------>int r;
<------>uint32_t ref_count;
 
<------>if (s->top >= MAX_SPINE_DEPTH - 1) {
<------><------>DMERR("btree deletion stack out of memory");
<------><------>return -ENOMEM;
<------>}
 
<------>r = dm_tm_ref(s->tm, b, &ref_count);
<------>if (r)
<------><------>return r;
 
<------>if (ref_count > 1)
<------><------>/*
<------><------> * This is a shared node, so we can just decrement it's
<------><------> * reference counter and leave the children.
<------><------> */
<------><------>dm_tm_dec(s->tm, b);
 
<------>else {
<------><------>uint32_t flags;
<------><------>struct frame *f = s->spine + ++s->top;
 
<------><------>r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b);
<------><------>if (r) {
<------><------><------>s->top--;
<------><------><------>return r;
<------><------>}
 
<------><------>f->n = dm_block_data(f->b);
<------><------>f->level = level;
<------><------>f->nr_children = le32_to_cpu(f->n->header.nr_entries);
<------><------>f->current_child = 0;
 
<------><------>flags = le32_to_cpu(f->n->header.flags);
<------><------>if (flags & INTERNAL_NODE || is_internal_level(s->info, f))
<------><------><------>prefetch_children(s, f);
<------>}
 
<------>return 0;
}
 
static void pop_frame(struct del_stack *s)
{
<------>struct frame *f = s->spine + s->top--;
 
<------>dm_tm_dec(s->tm, dm_block_location(f->b));
<------>dm_tm_unlock(s->tm, f->b);
}
 
static void unlock_all_frames(struct del_stack *s)
{
<------>struct frame *f;
 
<------>while (unprocessed_frames(s)) {
<------><------>f = s->spine + s->top--;
<------><------>dm_tm_unlock(s->tm, f->b);
<------>}
}
 
int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
{
<------>int r;
<------>struct del_stack *s;
 
<------>/*
<------> * dm_btree_del() is called via an ioctl, as such should be
<------> * considered an FS op.  We can't recurse back into the FS, so we
<------> * allocate GFP_NOFS.
<------> */
<------>s = kmalloc(sizeof(*s), GFP_NOFS);
<------>if (!s)
<------><------>return -ENOMEM;
<------>s->info = info;
<------>s->tm = info->tm;
<------>s->top = -1;
 
<------>r = push_frame(s, root, 0);
<------>if (r)
<------><------>goto out;
 
<------>while (unprocessed_frames(s)) {
<------><------>uint32_t flags;
<------><------>struct frame *f;
<------><------>dm_block_t b;
 
<------><------>r = top_frame(s, &f);
<------><------>if (r)
<------><------><------>goto out;
 
<------><------>if (f->current_child >= f->nr_children) {
<------><------><------>pop_frame(s);
<------><------><------>continue;
<------><------>}
 
<------><------>flags = le32_to_cpu(f->n->header.flags);
<------><------>if (flags & INTERNAL_NODE) {
<------><------><------>b = value64(f->n, f->current_child);
<------><------><------>f->current_child++;
<------><------><------>r = push_frame(s, b, f->level);
<------><------><------>if (r)
<------><------><------><------>goto out;
 
<------><------>} else if (is_internal_level(info, f)) {
<------><------><------>b = value64(f->n, f->current_child);
<------><------><------>f->current_child++;
<------><------><------>r = push_frame(s, b, f->level + 1);
<------><------><------>if (r)
<------><------><------><------>goto out;
 
<------><------>} else {
<------><------><------>if (info->value_type.dec) {
<------><------><------><------>unsigned i;
 
<------><------><------><------>for (i = 0; i < f->nr_children; i++)
<------><------><------><------><------>info->value_type.dec(info->value_type.context,
<------><------><------><------><------><------><------>     value_ptr(f->n, i));
<------><------><------>}
<------><------><------>pop_frame(s);
<------><------>}
<------>}
out:
<------>if (r) {
<------><------>/* cleanup all frames of del_stack */
<------><------>unlock_all_frames(s);
<------>}
<------>kfree(s);
 
<------>return r;
}
EXPORT_SYMBOL_GPL(dm_btree_del);
 
/*----------------------------------------------------------------*/
 
static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key,
<------><------><------>    int (*search_fn)(struct btree_node *, uint64_t),
<------><------><------>    uint64_t *result_key, void *v, size_t value_size)
{
<------>int i, r;
<------>uint32_t flags, nr_entries;
 
<------>do {
<------><------>r = ro_step(s, block);
<------><------>if (r < 0)
<------><------><------>return r;
 
<------><------>i = search_fn(ro_node(s), key);
 
<------><------>flags = le32_to_cpu(ro_node(s)->header.flags);
<------><------>nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries);
<------><------>if (i < 0 || i >= nr_entries)
<------><------><------>return -ENODATA;
 
<------><------>if (flags & INTERNAL_NODE)
<------><------><------>block = value64(ro_node(s), i);
 
<------>} while (!(flags & LEAF_NODE));
 
<------>*result_key = le64_to_cpu(ro_node(s)->keys[i]);
<------>if (v)
<------><------>memcpy(v, value_ptr(ro_node(s), i), value_size);
 
<------>return 0;
}
 
int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root,
<------><------>    uint64_t *keys, void *value_le)
{
<------>unsigned level, last_level = info->levels - 1;
<------>int r = -ENODATA;
<------>uint64_t rkey;
<------>__le64 internal_value_le;
<------>struct ro_spine spine;
 
<------>init_ro_spine(&spine, info);
<------>for (level = 0; level < info->levels; level++) {
<------><------>size_t size;
<------><------>void *value_p;
 
<------><------>if (level == last_level) {
<------><------><------>value_p = value_le;
<------><------><------>size = info->value_type.size;
 
<------><------>} else {
<------><------><------>value_p = &internal_value_le;
<------><------><------>size = sizeof(uint64_t);
<------><------>}
 
<------><------>r = btree_lookup_raw(&spine, root, keys[level],
<------><------><------><------>     lower_bound, &rkey,
<------><------><------><------>     value_p, size);
 
<------><------>if (!r) {
<------><------><------>if (rkey != keys[level]) {
<------><------><------><------>exit_ro_spine(&spine);
<------><------><------><------>return -ENODATA;
<------><------><------>}
<------><------>} else {
<------><------><------>exit_ro_spine(&spine);
<------><------><------>return r;
<------><------>}
 
<------><------>root = le64_to_cpu(internal_value_le);
<------>}
<------>exit_ro_spine(&spine);
 
<------>return r;
}
EXPORT_SYMBOL_GPL(dm_btree_lookup);
 
static int dm_btree_lookup_next_single(struct dm_btree_info *info, dm_block_t root,
<------><------><------><------>       uint64_t key, uint64_t *rkey, void *value_le)
{
<------>int r, i;
<------>uint32_t flags, nr_entries;
<------>struct dm_block *node;
<------>struct btree_node *n;
 
<------>r = bn_read_lock(info, root, &node);
<------>if (r)
<------><------>return r;
 
<------>n = dm_block_data(node);
<------>flags = le32_to_cpu(n->header.flags);
<------>nr_entries = le32_to_cpu(n->header.nr_entries);
 
<------>if (flags & INTERNAL_NODE) {
<------><------>i = lower_bound(n, key);
<------><------>if (i < 0) {
<------><------><------>/*
<------><------><------> * avoid early -ENODATA return when all entries are
<------><------><------> * higher than the search @key.
<------><------><------> */
<------><------><------>i = 0;
<------><------>}
<------><------>if (i >= nr_entries) {
<------><------><------>r = -ENODATA;
<------><------><------>goto out;
<------><------>}
 
<------><------>r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le);
<------><------>if (r == -ENODATA && i < (nr_entries - 1)) {
<------><------><------>i++;
<------><------><------>r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le);
<------><------>}
 
<------>} else {
<------><------>i = upper_bound(n, key);
<------><------>if (i < 0 || i >= nr_entries) {
<------><------><------>r = -ENODATA;
<------><------><------>goto out;
<------><------>}
 
<------><------>*rkey = le64_to_cpu(n->keys[i]);
<------><------>memcpy(value_le, value_ptr(n, i), info->value_type.size);
<------>}
out:
<------>dm_tm_unlock(info->tm, node);
<------>return r;
}
 
int dm_btree_lookup_next(struct dm_btree_info *info, dm_block_t root,
<------><------><------> uint64_t *keys, uint64_t *rkey, void *value_le)
{
<------>unsigned level;
<------>int r = -ENODATA;
<------>__le64 internal_value_le;
<------>struct ro_spine spine;
 
<------>init_ro_spine(&spine, info);
<------>for (level = 0; level < info->levels - 1u; level++) {
<------><------>r = btree_lookup_raw(&spine, root, keys[level],
<------><------><------><------>     lower_bound, rkey,
<------><------><------><------>     &internal_value_le, sizeof(uint64_t));
<------><------>if (r)
<------><------><------>goto out;
 
<------><------>if (*rkey != keys[level]) {
<------><------><------>r = -ENODATA;
<------><------><------>goto out;
<------><------>}
 
<------><------>root = le64_to_cpu(internal_value_le);
<------>}
 
<------>r = dm_btree_lookup_next_single(info, root, keys[level], rkey, value_le);
out:
<------>exit_ro_spine(&spine);
<------>return r;
}
 
EXPORT_SYMBOL_GPL(dm_btree_lookup_next);
 
/*
 * Splits a node by creating a sibling node and shifting half the nodes
 * contents across.  Assumes there is a parent node, and it has room for
 * another child.
 *
 * Before:
 *	  +--------+
 *	  | Parent |
 *	  +--------+
 *	     |
 *	     v
 *	+----------+
 *	| A ++++++ |
 *	+----------+
 *
 *
 * After:
 *		+--------+
 *		| Parent |
 *		+--------+
 *		  |	|
 *		  v	+------+
 *	    +---------+	       |
 *	    | A* +++  |	       v
 *	    +---------+	  +-------+
 *			  | B +++ |
 *			  +-------+
 *
 * Where A* is a shadow of A.
 */
static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index,
<------><------><------>       uint64_t key)
{
<------>int r;
<------>size_t size;
<------>unsigned nr_left, nr_right;
<------>struct dm_block *left, *right, *parent;
<------>struct btree_node *ln, *rn, *pn;
<------>__le64 location;
 
<------>left = shadow_current(s);
 
<------>r = new_block(s->info, &right);
<------>if (r < 0)
<------><------>return r;
 
<------>ln = dm_block_data(left);
<------>rn = dm_block_data(right);
 
<------>nr_left = le32_to_cpu(ln->header.nr_entries) / 2;
<------>nr_right = le32_to_cpu(ln->header.nr_entries) - nr_left;
 
<------>ln->header.nr_entries = cpu_to_le32(nr_left);
 
<------>rn->header.flags = ln->header.flags;
<------>rn->header.nr_entries = cpu_to_le32(nr_right);
<------>rn->header.max_entries = ln->header.max_entries;
<------>rn->header.value_size = ln->header.value_size;
<------>memcpy(rn->keys, ln->keys + nr_left, nr_right * sizeof(rn->keys[0]));
 
<------>size = le32_to_cpu(ln->header.flags) & INTERNAL_NODE ?
<------><------>sizeof(uint64_t) : s->info->value_type.size;
<------>memcpy(value_ptr(rn, 0), value_ptr(ln, nr_left),
<------>       size * nr_right);
 
<------>/*
<------> * Patch up the parent
<------> */
<------>parent = shadow_parent(s);
 
<------>pn = dm_block_data(parent);
<------>location = cpu_to_le64(dm_block_location(left));
<------>__dm_bless_for_disk(&location);
<------>memcpy_disk(value_ptr(pn, parent_index),
<------><------>    &location, sizeof(__le64));
 
<------>location = cpu_to_le64(dm_block_location(right));
<------>__dm_bless_for_disk(&location);
 
<------>r = insert_at(sizeof(__le64), pn, parent_index + 1,
<------><------>      le64_to_cpu(rn->keys[0]), &location);
<------>if (r) {
<------><------>unlock_block(s->info, right);
<------><------>return r;
<------>}
 
<------>if (key < le64_to_cpu(rn->keys[0])) {
<------><------>unlock_block(s->info, right);
<------><------>s->nodes[1] = left;
<------>} else {
<------><------>unlock_block(s->info, left);
<------><------>s->nodes[1] = right;
<------>}
 
<------>return 0;
}
 
/*
 * Splits a node by creating two new children beneath the given node.
 *
 * Before:
 *	  +----------+
 *	  | A ++++++ |
 *	  +----------+
 *
 *
 * After:
 *	+------------+
 *	| A (shadow) |
 *	+------------+
 *	    |	|
 *   +------+	+----+
 *   |		     |
 *   v		     v
 * +-------+	 +-------+
 * | B +++ |	 | C +++ |
 * +-------+	 +-------+
 */
static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
{
<------>int r;
<------>size_t size;
<------>unsigned nr_left, nr_right;
<------>struct dm_block *left, *right, *new_parent;
<------>struct btree_node *pn, *ln, *rn;
<------>__le64 val;
 
<------>new_parent = shadow_current(s);
 
<------>pn = dm_block_data(new_parent);
<------>size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
<------><------>sizeof(__le64) : s->info->value_type.size;
 
<------>/* create & init the left block */
<------>r = new_block(s->info, &left);
<------>if (r < 0)
<------><------>return r;
 
<------>ln = dm_block_data(left);
<------>nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
 
<------>ln->header.flags = pn->header.flags;
<------>ln->header.nr_entries = cpu_to_le32(nr_left);
<------>ln->header.max_entries = pn->header.max_entries;
<------>ln->header.value_size = pn->header.value_size;
<------>memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
<------>memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
 
<------>/* create & init the right block */
<------>r = new_block(s->info, &right);
<------>if (r < 0) {
<------><------>unlock_block(s->info, left);
<------><------>return r;
<------>}
 
<------>rn = dm_block_data(right);
<------>nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;
 
<------>rn->header.flags = pn->header.flags;
<------>rn->header.nr_entries = cpu_to_le32(nr_right);
<------>rn->header.max_entries = pn->header.max_entries;
<------>rn->header.value_size = pn->header.value_size;
<------>memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));
<------>memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
<------>       nr_right * size);
 
<------>/* new_parent should just point to l and r now */
<------>pn->header.flags = cpu_to_le32(INTERNAL_NODE);
<------>pn->header.nr_entries = cpu_to_le32(2);
<------>pn->header.max_entries = cpu_to_le32(
<------><------>calc_max_entries(sizeof(__le64),
<------><------><------><------> dm_bm_block_size(
<------><------><------><------><------> dm_tm_get_bm(s->info->tm))));
<------>pn->header.value_size = cpu_to_le32(sizeof(__le64));
 
<------>val = cpu_to_le64(dm_block_location(left));
<------>__dm_bless_for_disk(&val);
<------>pn->keys[0] = ln->keys[0];
<------>memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64));
 
<------>val = cpu_to_le64(dm_block_location(right));
<------>__dm_bless_for_disk(&val);
<------>pn->keys[1] = rn->keys[0];
<------>memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64));
 
<------>unlock_block(s->info, left);
<------>unlock_block(s->info, right);
<------>return 0;
}
 
static int btree_insert_raw(struct shadow_spine *s, dm_block_t root,
<------><------><------>    struct dm_btree_value_type *vt,
<------><------><------>    uint64_t key, unsigned *index)
{
<------>int r, i = *index, top = 1;
<------>struct btree_node *node;
 
<------>for (;;) {
<------><------>r = shadow_step(s, root, vt);
<------><------>if (r < 0)
<------><------><------>return r;
 
<------><------>node = dm_block_data(shadow_current(s));
 
<------><------>/*
<------><------> * 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) && i >= 0) { /* FIXME: second clause unness. */
<------><------><------>__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
 
<------><------><------>__dm_bless_for_disk(&location);
<------><------><------>memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
<------><------><------><------>    &location, sizeof(__le64));
<------><------>}
 
<------><------>node = dm_block_data(shadow_current(s));
 
<------><------>if (node->header.nr_entries == node->header.max_entries) {
<------><------><------>if (top)
<------><------><------><------>r = btree_split_beneath(s, key);
<------><------><------>else
<------><------><------><------>r = btree_split_sibling(s, i, key);
 
<------><------><------>if (r < 0)
<------><------><------><------>return r;
<------><------>}
 
<------><------>node = dm_block_data(shadow_current(s));
 
<------><------>i = lower_bound(node, key);
 
<------><------>if (le32_to_cpu(node->header.flags) & LEAF_NODE)
<------><------><------>break;
 
<------><------>if (i < 0) {
<------><------><------>/* change the bounds on the lowest key */
<------><------><------>node->keys[0] = cpu_to_le64(key);
<------><------><------>i = 0;
<------><------>}
 
<------><------>root = value64(node, i);
<------><------>top = 0;
<------>}
 
<------>if (i < 0 || le64_to_cpu(node->keys[i]) != key)
<------><------>i++;
 
<------>*index = i;
<------>return 0;
}
 
static bool need_insert(struct btree_node *node, uint64_t *keys,
<------><------><------>unsigned level, unsigned index)
{
        return ((index >= le32_to_cpu(node->header.nr_entries)) ||
<------><------>(le64_to_cpu(node->keys[index]) != keys[level]));
}
 
static int insert(struct dm_btree_info *info, dm_block_t root,
<------><------>  uint64_t *keys, void *value, dm_block_t *new_root,
<------><------>  int *inserted)
<------><------>  __dm_written_to_disk(value)
{
<------>int r;
<------>unsigned level, index = -1, last_level = info->levels - 1;
<------>dm_block_t block = root;
<------>struct shadow_spine spine;
<------>struct btree_node *n;
<------>struct dm_btree_value_type le64_type;
 
<------>init_le64_type(info->tm, &le64_type);
<------>init_shadow_spine(&spine, info);
 
<------>for (level = 0; level < (info->levels - 1); level++) {
<------><------>r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index);
<------><------>if (r < 0)
<------><------><------>goto bad;
 
<------><------>n = dm_block_data(shadow_current(&spine));
 
<------><------>if (need_insert(n, keys, level, index)) {
<------><------><------>dm_block_t new_tree;
<------><------><------>__le64 new_le;
 
<------><------><------>r = dm_btree_empty(info, &new_tree);
<------><------><------>if (r < 0)
<------><------><------><------>goto bad;
 
<------><------><------>new_le = cpu_to_le64(new_tree);
<------><------><------>__dm_bless_for_disk(&new_le);
 
<------><------><------>r = insert_at(sizeof(uint64_t), n, index,
<------><------><------><------>      keys[level], &new_le);
<------><------><------>if (r)
<------><------><------><------>goto bad;
<------><------>}
 
<------><------>if (level < last_level)
<------><------><------>block = value64(n, index);
<------>}
 
<------>r = btree_insert_raw(&spine, block, &info->value_type,
<------><------><------>     keys[level], &index);
<------>if (r < 0)
<------><------>goto bad;
 
<------>n = dm_block_data(shadow_current(&spine));
 
<------>if (need_insert(n, keys, level, index)) {
<------><------>if (inserted)
<------><------><------>*inserted = 1;
 
<------><------>r = insert_at(info->value_type.size, n, index,
<------><------><------>      keys[level], value);
<------><------>if (r)
<------><------><------>goto bad_unblessed;
<------>} else {
<------><------>if (inserted)
<------><------><------>*inserted = 0;
 
<------><------>if (info->value_type.dec &&
<------><------>    (!info->value_type.equal ||
<------><------>     !info->value_type.equal(
<------><------><------>     info->value_type.context,
<------><------><------>     value_ptr(n, index),
<------><------><------>     value))) {
<------><------><------>info->value_type.dec(info->value_type.context,
<------><------><------><------><------>     value_ptr(n, index));
<------><------>}
<------><------>memcpy_disk(value_ptr(n, index),
<------><------><------>    value, info->value_type.size);
<------>}
 
<------>*new_root = shadow_root(&spine);
<------>exit_shadow_spine(&spine);
 
<------>return 0;
 
bad:
<------>__dm_unbless_for_disk(value);
bad_unblessed:
<------>exit_shadow_spine(&spine);
<------>return r;
}
 
int dm_btree_insert(struct dm_btree_info *info, dm_block_t root,
<------><------>    uint64_t *keys, void *value, dm_block_t *new_root)
<------><------>    __dm_written_to_disk(value)
{
<------>return insert(info, root, keys, value, new_root, NULL);
}
EXPORT_SYMBOL_GPL(dm_btree_insert);
 
int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root,
<------><------><------>   uint64_t *keys, void *value, dm_block_t *new_root,
<------><------><------>   int *inserted)
<------><------><------>   __dm_written_to_disk(value)
{
<------>return insert(info, root, keys, value, new_root, inserted);
}
EXPORT_SYMBOL_GPL(dm_btree_insert_notify);
 
/*----------------------------------------------------------------*/
 
static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest,
<------><------>    uint64_t *result_key, dm_block_t *next_block)
{
<------>int i, r;
<------>uint32_t flags;
 
<------>do {
<------><------>r = ro_step(s, block);
<------><------>if (r < 0)
<------><------><------>return r;
 
<------><------>flags = le32_to_cpu(ro_node(s)->header.flags);
<------><------>i = le32_to_cpu(ro_node(s)->header.nr_entries);
<------><------>if (!i)
<------><------><------>return -ENODATA;
<------><------>else
<------><------><------>i--;
 
<------><------>if (find_highest)
<------><------><------>*result_key = le64_to_cpu(ro_node(s)->keys[i]);
<------><------>else
<------><------><------>*result_key = le64_to_cpu(ro_node(s)->keys[0]);
 
<------><------>if (next_block || flags & INTERNAL_NODE) {
<------><------><------>if (find_highest)
<------><------><------><------>block = value64(ro_node(s), i);
<------><------><------>else
<------><------><------><------>block = value64(ro_node(s), 0);
<------><------>}
 
<------>} while (flags & INTERNAL_NODE);
 
<------>if (next_block)
<------><------>*next_block = block;
<------>return 0;
}
 
static int dm_btree_find_key(struct dm_btree_info *info, dm_block_t root,
<------><------><------>     bool find_highest, uint64_t *result_keys)
{
<------>int r = 0, count = 0, level;
<------>struct ro_spine spine;
 
<------>init_ro_spine(&spine, info);
<------>for (level = 0; level < info->levels; level++) {
<------><------>r = find_key(&spine, root, find_highest, result_keys + level,
<------><------><------>     level == info->levels - 1 ? NULL : &root);
<------><------>if (r == -ENODATA) {
<------><------><------>r = 0;
<------><------><------>break;
 
<------><------>} else if (r)
<------><------><------>break;
 
<------><------>count++;
<------>}
<------>exit_ro_spine(&spine);
 
<------>return r ? r : count;
}
 
int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root,
<------><------><------>      uint64_t *result_keys)
{
<------>return dm_btree_find_key(info, root, true, result_keys);
}
EXPORT_SYMBOL_GPL(dm_btree_find_highest_key);
 
int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root,
<------><------><------>     uint64_t *result_keys)
{
<------>return dm_btree_find_key(info, root, false, result_keys);
}
EXPORT_SYMBOL_GPL(dm_btree_find_lowest_key);
 
/*----------------------------------------------------------------*/
 
/*
 * FIXME: We shouldn't use a recursive algorithm when we have limited stack
 * space.  Also this only works for single level trees.
 */
static int walk_node(struct dm_btree_info *info, dm_block_t block,
<------><------>     int (*fn)(void *context, uint64_t *keys, void *leaf),
<------><------>     void *context)
{
<------>int r;
<------>unsigned i, nr;
<------>struct dm_block *node;
<------>struct btree_node *n;
<------>uint64_t keys;
 
<------>r = bn_read_lock(info, block, &node);
<------>if (r)
<------><------>return r;
 
<------>n = dm_block_data(node);
 
<------>nr = le32_to_cpu(n->header.nr_entries);
<------>for (i = 0; i < nr; i++) {
<------><------>if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) {
<------><------><------>r = walk_node(info, value64(n, i), fn, context);
<------><------><------>if (r)
<------><------><------><------>goto out;
<------><------>} else {
<------><------><------>keys = le64_to_cpu(*key_ptr(n, i));
<------><------><------>r = fn(context, &keys, value_ptr(n, i));
<------><------><------>if (r)
<------><------><------><------>goto out;
<------><------>}
<------>}
 
out:
<------>dm_tm_unlock(info->tm, node);
<------>return r;
}
 
int dm_btree_walk(struct dm_btree_info *info, dm_block_t root,
<------><------>  int (*fn)(void *context, uint64_t *keys, void *leaf),
<------><------>  void *context)
{
<------>BUG_ON(info->levels > 1);
<------>return walk_node(info, root, fn, context);
}
EXPORT_SYMBOL_GPL(dm_btree_walk);
 
/*----------------------------------------------------------------*/
 
static void prefetch_values(struct dm_btree_cursor *c)
{
<------>unsigned i, nr;
<------>__le64 value_le;
<------>struct cursor_node *n = c->nodes + c->depth - 1;
<------>struct btree_node *bn = dm_block_data(n->b);
<------>struct dm_block_manager *bm = dm_tm_get_bm(c->info->tm);
 
<------>BUG_ON(c->info->value_type.size != sizeof(value_le));
 
<------>nr = le32_to_cpu(bn->header.nr_entries);
<------>for (i = 0; i < nr; i++) {
<------><------>memcpy(&value_le, value_ptr(bn, i), sizeof(value_le));
<------><------>dm_bm_prefetch(bm, le64_to_cpu(value_le));
<------>}
}
 
static bool leaf_node(struct dm_btree_cursor *c)
{
<------>struct cursor_node *n = c->nodes + c->depth - 1;
<------>struct btree_node *bn = dm_block_data(n->b);
 
<------>return le32_to_cpu(bn->header.flags) & LEAF_NODE;
}
 
static int push_node(struct dm_btree_cursor *c, dm_block_t b)
{
<------>int r;
<------>struct cursor_node *n = c->nodes + c->depth;
 
<------>if (c->depth >= DM_BTREE_CURSOR_MAX_DEPTH - 1) {
<------><------>DMERR("couldn't push cursor node, stack depth too high");
<------><------>return -EINVAL;
<------>}
 
<------>r = bn_read_lock(c->info, b, &n->b);
<------>if (r)
<------><------>return r;
 
<------>n->index = 0;
<------>c->depth++;
 
<------>if (c->prefetch_leaves || !leaf_node(c))
<------><------>prefetch_values(c);
 
<------>return 0;
}
 
static void pop_node(struct dm_btree_cursor *c)
{
<------>c->depth--;
<------>unlock_block(c->info, c->nodes[c->depth].b);
}
 
static int inc_or_backtrack(struct dm_btree_cursor *c)
{
<------>struct cursor_node *n;
<------>struct btree_node *bn;
 
<------>for (;;) {
<------><------>if (!c->depth)
<------><------><------>return -ENODATA;
 
<------><------>n = c->nodes + c->depth - 1;
<------><------>bn = dm_block_data(n->b);
 
<------><------>n->index++;
<------><------>if (n->index < le32_to_cpu(bn->header.nr_entries))
<------><------><------>break;
 
<------><------>pop_node(c);
<------>}
 
<------>return 0;
}
 
static int find_leaf(struct dm_btree_cursor *c)
{
<------>int r = 0;
<------>struct cursor_node *n;
<------>struct btree_node *bn;
<------>__le64 value_le;
 
<------>for (;;) {
<------><------>n = c->nodes + c->depth - 1;
<------><------>bn = dm_block_data(n->b);
 
<------><------>if (le32_to_cpu(bn->header.flags) & LEAF_NODE)
<------><------><------>break;
 
<------><------>memcpy(&value_le, value_ptr(bn, n->index), sizeof(value_le));
<------><------>r = push_node(c, le64_to_cpu(value_le));
<------><------>if (r) {
<------><------><------>DMERR("push_node failed");
<------><------><------>break;
<------><------>}
<------>}
 
<------>if (!r && (le32_to_cpu(bn->header.nr_entries) == 0))
<------><------>return -ENODATA;
 
<------>return r;
}
 
int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root,
<------><------><------>  bool prefetch_leaves, struct dm_btree_cursor *c)
{
<------>int r;
 
<------>c->info = info;
<------>c->root = root;
<------>c->depth = 0;
<------>c->prefetch_leaves = prefetch_leaves;
 
<------>r = push_node(c, root);
<------>if (r)
<------><------>return r;
 
<------>return find_leaf(c);
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_begin);
 
void dm_btree_cursor_end(struct dm_btree_cursor *c)
{
<------>while (c->depth)
<------><------>pop_node(c);
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_end);
 
int dm_btree_cursor_next(struct dm_btree_cursor *c)
{
<------>int r = inc_or_backtrack(c);
<------>if (!r) {
<------><------>r = find_leaf(c);
<------><------>if (r)
<------><------><------>DMERR("find_leaf failed");
<------>}
 
<------>return r;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_next);
 
int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count)
{
<------>int r = 0;
 
<------>while (count-- && !r)
<------><------>r = dm_btree_cursor_next(c);
 
<------>return r;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_skip);
 
int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le)
{
<------>if (c->depth) {
<------><------>struct cursor_node *n = c->nodes + c->depth - 1;
<------><------>struct btree_node *bn = dm_block_data(n->b);
 
<------><------>if (le32_to_cpu(bn->header.flags) & INTERNAL_NODE)
<------><------><------>return -EINVAL;
 
<------><------>*key = le64_to_cpu(*key_ptr(bn, n->index));
<------><------>memcpy(value_le, value_ptr(bn, n->index), c->info->value_type.size);
<------><------>return 0;
 
<------>} else
<------><------>return -ENODATA;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_get_value);