From 4ec331c3ea7ec94f28aa1c62a279cfa1cfe3c91b Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Mon, 13 Apr 2015 09:41:44 +0100 Subject: [PATCH] dm btree: add dm_btree_remove_leaves() Removes a range of leaf values from the tree. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/persistent-data/dm-btree-remove.c | 127 +++++++++++++++++++ drivers/md/persistent-data/dm-btree.h | 9 ++ 2 files changed, 136 insertions(+) diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c index b88757cd0d1d..e04cfd2d60ef 100644 --- a/drivers/md/persistent-data/dm-btree-remove.c +++ b/drivers/md/persistent-data/dm-btree-remove.c @@ -590,3 +590,130 @@ 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; + uint64_t k; + + init_shadow_spine(&spine, info); + for (level = 0; level < last_level; level++) { + r = remove_raw(&spine, info, &le64_type, + 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); + + } 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); diff --git a/drivers/md/persistent-data/dm-btree.h b/drivers/md/persistent-data/dm-btree.h index dacfc34180b4..11d8cf78621d 100644 --- a/drivers/md/persistent-data/dm-btree.h +++ b/drivers/md/persistent-data/dm-btree.h @@ -134,6 +134,15 @@ int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, int dm_btree_remove(struct dm_btree_info *info, dm_block_t root, uint64_t *keys, dm_block_t *new_root); +/* + * Removes values between 'keys' and keys2, where keys2 is keys with the + * final key replaced with 'end_key'. 'end_key' is the one-past-the-end + * value. 'keys' may be altered. + */ +int dm_btree_remove_leaves(struct dm_btree_info *info, dm_block_t root, + uint64_t *keys, uint64_t end_key, + dm_block_t *new_root, unsigned *nr_removed); + /* * Returns < 0 on failure. Otherwise the number of key entries that have * been filled out. Remember trees can have zero entries, and as such have -- 2.25.1