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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/md/persistent-data/dm-btree-internal.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/md/persistent-data/dm-btree-internal.h')
-rw-r--r--drivers/md/persistent-data/dm-btree-internal.h160
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
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+/*
+ * Copyright (C) 2011 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_BTREE_INTERNAL_H
+#define DM_BTREE_INTERNAL_H
+
+#include "dm-btree.h"
+
+/*----------------------------------------------------------------*/
+
+/*
+ * We'll need 2 accessor functions for n->csum and n->blocknr
+ * to support dm-btree-spine.c in that case.
+ */
+
+enum node_flags {
+ INTERNAL_NODE = 1,
+ LEAF_NODE = 1 << 1
+};
+
+/*
+ * Every btree node begins with this structure. Make sure it's a multiple
+ * of 8-bytes in size, otherwise the 64bit keys will be mis-aligned.
+ */
+struct node_header {
+ __le32 csum;
+ __le32 flags;
+ __le64 blocknr; /* Block this node is supposed to live in. */
+
+ __le32 nr_entries;
+ __le32 max_entries;
+ __le32 value_size;
+ __le32 padding;
+} __attribute__((packed, aligned(8)));
+
+struct btree_node {
+ struct node_header header;
+ __le64 keys[];
+} __attribute__((packed, aligned(8)));
+
+
+/*
+ * Locks a block using the btree node validator.
+ */
+int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
+ struct dm_block **result);
+
+void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
+ struct dm_btree_value_type *vt);
+
+int new_block(struct dm_btree_info *info, struct dm_block **result);
+void unlock_block(struct dm_btree_info *info, struct dm_block *b);
+
+/*
+ * Spines keep track of the rolling locks. There are 2 variants, read-only
+ * and one that uses shadowing. These are separate structs to allow the
+ * type checker to spot misuse, for example accidentally calling read_lock
+ * on a shadow spine.
+ */
+struct ro_spine {
+ struct dm_btree_info *info;
+
+ int count;
+ struct dm_block *nodes[2];
+};
+
+void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info);
+void exit_ro_spine(struct ro_spine *s);
+int ro_step(struct ro_spine *s, dm_block_t new_child);
+void ro_pop(struct ro_spine *s);
+struct btree_node *ro_node(struct ro_spine *s);
+
+struct shadow_spine {
+ struct dm_btree_info *info;
+
+ int count;
+ struct dm_block *nodes[2];
+
+ dm_block_t root;
+};
+
+void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info);
+void exit_shadow_spine(struct shadow_spine *s);
+
+int shadow_step(struct shadow_spine *s, dm_block_t b,
+ struct dm_btree_value_type *vt);
+
+/*
+ * The spine must have at least one entry before calling this.
+ */
+struct dm_block *shadow_current(struct shadow_spine *s);
+
+/*
+ * The spine must have at least two entries before calling this.
+ */
+struct dm_block *shadow_parent(struct shadow_spine *s);
+
+int shadow_has_parent(struct shadow_spine *s);
+
+dm_block_t shadow_root(struct shadow_spine *s);
+
+/*
+ * Some inlines.
+ */
+static inline __le64 *key_ptr(struct btree_node *n, uint32_t index)
+{
+ return n->keys + index;
+}
+
+static inline void *value_base(struct btree_node *n)
+{
+ return &n->keys[le32_to_cpu(n->header.max_entries)];
+}
+
+static inline void *value_ptr(struct btree_node *n, uint32_t index)
+{
+ uint32_t value_size = le32_to_cpu(n->header.value_size);
+ return value_base(n) + (value_size * index);
+}
+
+/*
+ * Assumes the values are suitably-aligned and converts to core format.
+ */
+static inline uint64_t value64(struct btree_node *n, uint32_t index)
+{
+ __le64 *values_le = value_base(n);
+
+ return le64_to_cpu(values_le[index]);
+}
+
+/*
+ * Searching for a key within a single node.
+ */
+int lower_bound(struct btree_node *n, uint64_t key);
+
+extern struct dm_block_validator btree_node_validator;
+
+/*
+ * Value type for upper levels of multi-level btrees.
+ */
+extern void init_le64_type(struct dm_transaction_manager *tm,
+ struct dm_btree_value_type *vt);
+
+/*
+ * This returns a shadowed btree leaf that you may modify. In practise
+ * this means overwrites only, since an insert could cause a node to
+ * be split. Useful if you need access to the old value to calculate the
+ * new one.
+ *
+ * This only works with single level btrees. The given key must be present in
+ * the tree, otherwise -EINVAL will be returned.
+ */
+int btree_get_overwrite_leaf(struct dm_btree_info *info, dm_block_t root,
+ uint64_t key, int *index,
+ dm_block_t *new_root, struct dm_block **leaf);
+
+#endif /* DM_BTREE_INTERNAL_H */