diff options
Diffstat (limited to 'drivers/md/persistent-data/dm-btree-remove.c')
| -rw-r--r-- | drivers/md/persistent-data/dm-btree-remove.c | 142 |
1 files changed, 133 insertions, 9 deletions
diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c index a03178e91..4222f774c 100644 --- a/drivers/md/persistent-data/dm-btree-remove.c +++ b/drivers/md/persistent-data/dm-btree-remove.c @@ -544,14 +544,6 @@ static int remove_raw(struct shadow_spine *s, struct dm_btree_info *info, return r; } -static struct dm_btree_value_type le64_type = { - .context = NULL, - .size = sizeof(__le64), - .inc = NULL, - .dec = NULL, - .equal = NULL -}; - int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, uint64_t *keys, dm_block_t *new_root) { @@ -559,12 +551,14 @@ int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, 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_type), + &info->value_type : &le64_vt), root, keys[level], (unsigned *)&index); if (r < 0) break; @@ -590,3 +584,133 @@ int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, 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); |