Commit 59158fde authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Add bch_btree_keys_u64s_remaining() 



Helper function to explicitly check how much space is free in a btree node

Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
parent a85e968e

drivers/md/bcache/bset.h

+15 −0
Original line number Diff line number Diff line
@@ -260,6 +260,21 @@ static inline bool btree_keys_expensive_checks(struct btree_keys *b) 
#define set_blocks(i, block_bytes)				\

	__set_blocks(i, (i)->keys, block_bytes)



static inline size_t bch_btree_keys_u64s_remaining(struct btree_keys *b)

{

	struct bset_tree *t = bset_tree_last(b);



	BUG_ON((PAGE_SIZE << b->page_order) <

	       (bset_byte_offset(b, t->data) + set_bytes(t->data)));



	if (!b->last_set_unwritten)

		return 0;



	return ((PAGE_SIZE << b->page_order) -

		(bset_byte_offset(b, t->data) + set_bytes(t->data))) /

		sizeof(u64);

}



static inline struct bset *bset_next_set(struct btree_keys *b,

					 unsigned block_bytes)

{

drivers/md/bcache/btree.c

+15 −13
Original line number Diff line number Diff line
@@ -179,14 +179,6 @@ static inline struct bset *write_block(struct btree *b) 
	return ((void *) btree_bset_first(b)) + b->written * block_bytes(b->c);

}



static inline bool should_split(struct btree *b)

{

	struct bset *i = write_block(b);

	return b->written >= btree_blocks(b) ||

		(b->written + __set_blocks(i, i->keys + 15, block_bytes(b->c))

		 > btree_blocks(b));

}



/* Btree key manipulation */



void bkey_put(struct cache_set *c, struct bkey *k)
@@ -2026,6 +2018,19 @@ copy: bkey_copy(m, k); 
	return true;

}



static size_t insert_u64s_remaining(struct btree *b)

{

	ssize_t ret = bch_btree_keys_u64s_remaining(&b->keys);



	/*

	 * Might land in the middle of an existing extent and have to split it

	 */

	if (b->keys.ops->is_extents)

		ret -= KEY_MAX_U64S;



	return max(ret, 0L);

}



static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op,

				  struct keylist *insert_keys,

				  struct bkey *replace_key)
@@ -2034,12 +2039,9 @@ static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op, 
	int oldsize = bch_count_data(b);



	while (!bch_keylist_empty(insert_keys)) {

		struct bset *i = write_block(b);

		struct bkey *k = insert_keys->keys;



		if (b->written +

		    __set_blocks(i, i->keys + bkey_u64s(k),

				 block_bytes(b->c)) > btree_blocks(b))

		if (bkey_u64s(k) > insert_u64s_remaining(b))

			break;



		if (bkey_cmp(k, &b->key) <= 0) {
@@ -2203,7 +2205,7 @@ static int bch_btree_insert_node(struct btree *b, struct btree_op *op, 
{

	BUG_ON(b->level && replace_key);



	if (should_split(b)) {

	if (bch_keylist_nkeys(insert_keys) > insert_u64s_remaining(b)) {

		if (current->bio_list) {

			op->lock = b->c->root->level + 1;

			return -EAGAIN;

include/uapi/linux/bcache.h

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ static inline void SET_##name(struct bkey *k, unsigned i, __u64 v) \ 
}



#define KEY_SIZE_BITS		16

#define KEY_MAX_U64S		8



KEY_FIELD(KEY_PTRS,	high, 60, 3)

KEY_FIELD(HEADER_SIZE,	high, 58, 2)