drivers/md/persistent-data/dm-btree-internal.h

Source file repositories/reference/linux-study-clean/drivers/md/persistent-data/dm-btree-internal.h

File Facts

System
Linux kernel
Corpus path
drivers/md/persistent-data/dm-btree-internal.h
Extension
.h
Size
4122 bytes
Lines
163
Domain
Driver Families
Bucket
drivers/md
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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;
} __packed __aligned(8);

struct btree_node {
	struct node_header header;
	__le64 keys[];
} __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)];
}

Annotation

Implementation Notes