bcache: Rename/shuffle various code around
More work to disentangle bset.c from the rest of the code:
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 9d9c2edd..e04e590 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -302,6 +302,115 @@
return true;
}
+/* Auxiliary search trees */
+
+/* 32 bits total: */
+#define BKEY_MID_BITS 3
+#define BKEY_EXPONENT_BITS 7
+#define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
+#define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
+
+struct bkey_float {
+ unsigned exponent:BKEY_EXPONENT_BITS;
+ unsigned m:BKEY_MID_BITS;
+ unsigned mantissa:BKEY_MANTISSA_BITS;
+} __packed;
+
+/*
+ * BSET_CACHELINE was originally intended to match the hardware cacheline size -
+ * it used to be 64, but I realized the lookup code would touch slightly less
+ * memory if it was 128.
+ *
+ * It definites the number of bytes (in struct bset) per struct bkey_float in
+ * the auxiliar search tree - when we're done searching the bset_float tree we
+ * have this many bytes left that we do a linear search over.
+ *
+ * Since (after level 5) every level of the bset_tree is on a new cacheline,
+ * we're touching one fewer cacheline in the bset tree in exchange for one more
+ * cacheline in the linear search - but the linear search might stop before it
+ * gets to the second cacheline.
+ */
+
+#define BSET_CACHELINE 128
+
+/* Space required for the btree node keys */
+static inline size_t btree_keys_bytes(struct btree *b)
+{
+ return PAGE_SIZE << b->page_order;
+}
+
+static inline size_t btree_keys_cachelines(struct btree *b)
+{
+ return btree_keys_bytes(b) / BSET_CACHELINE;
+}
+
+/* Space required for the auxiliary search trees */
+static inline size_t bset_tree_bytes(struct btree *b)
+{
+ return btree_keys_cachelines(b) * sizeof(struct bkey_float);
+}
+
+/* Space required for the prev pointers */
+static inline size_t bset_prev_bytes(struct btree *b)
+{
+ return btree_keys_cachelines(b) * sizeof(uint8_t);
+}
+
+/* Memory allocation */
+
+void bch_btree_keys_free(struct btree *b)
+{
+ struct bset_tree *t = b->sets;
+
+ if (bset_prev_bytes(b) < PAGE_SIZE)
+ kfree(t->prev);
+ else
+ free_pages((unsigned long) t->prev,
+ get_order(bset_prev_bytes(b)));
+
+ if (bset_tree_bytes(b) < PAGE_SIZE)
+ kfree(t->tree);
+ else
+ free_pages((unsigned long) t->tree,
+ get_order(bset_tree_bytes(b)));
+
+ free_pages((unsigned long) t->data, b->page_order);
+
+ t->prev = NULL;
+ t->tree = NULL;
+ t->data = NULL;
+}
+
+int bch_btree_keys_alloc(struct btree *b, unsigned page_order, gfp_t gfp)
+{
+ struct bset_tree *t = b->sets;
+
+ BUG_ON(t->data);
+
+ b->page_order = page_order;
+
+ t->data = (void *) __get_free_pages(gfp, b->page_order);
+ if (!t->data)
+ goto err;
+
+ t->tree = bset_tree_bytes(b) < PAGE_SIZE
+ ? kmalloc(bset_tree_bytes(b), gfp)
+ : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
+ if (!t->tree)
+ goto err;
+
+ t->prev = bset_prev_bytes(b) < PAGE_SIZE
+ ? kmalloc(bset_prev_bytes(b), gfp)
+ : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
+ if (!t->prev)
+ goto err;
+
+ return 0;
+err:
+ bch_btree_keys_free(b);
+ return -ENOMEM;
+}
+
/* Binary tree stuff for auxiliary search trees */
static unsigned inorder_next(unsigned j, unsigned size)
@@ -538,21 +647,36 @@
t++->size = 0;
}
-static void bset_build_unwritten_tree(struct btree *b)
+static void bch_bset_build_unwritten_tree(struct btree *b)
{
- struct bset_tree *t = b->sets + b->nsets;
+ struct bset_tree *t = bset_tree_last(b);
bset_alloc_tree(b, t);
- if (t->tree != b->sets->tree + bset_tree_space(b)) {
+ if (t->tree != b->sets->tree + btree_keys_cachelines(b)) {
t->prev[0] = bkey_to_cacheline_offset(t->data->start);
t->size = 1;
}
}
+void bch_bset_init_next(struct btree *b, struct bset *i, uint64_t magic)
+{
+ if (i != b->sets->data) {
+ b->sets[++b->nsets].data = i;
+ i->seq = b->sets->data->seq;
+ } else
+ get_random_bytes(&i->seq, sizeof(uint64_t));
+
+ i->magic = magic;
+ i->version = 0;
+ i->keys = 0;
+
+ bch_bset_build_unwritten_tree(b);
+}
+
static void bset_build_written_tree(struct btree *b)
{
- struct bset_tree *t = b->sets + b->nsets;
+ struct bset_tree *t = bset_tree_last(b);
struct bkey *k = t->data->start;
unsigned j, cacheline = 1;
@@ -560,7 +684,7 @@
t->size = min_t(unsigned,
bkey_to_cacheline(t, bset_bkey_last(t->data)),
- b->sets->tree + bset_tree_space(b) - t->tree);
+ b->sets->tree + btree_keys_cachelines(b) - t->tree);
if (t->size < 2) {
t->size = 0;
@@ -599,7 +723,7 @@
struct bset_tree *t;
unsigned inorder, j = 1;
- for (t = b->sets; t <= &b->sets[b->nsets]; t++)
+ for (t = b->sets; t <= bset_tree_last(b); t++)
if (k < bset_bkey_last(t->data))
goto found_set;
@@ -639,9 +763,10 @@
} while (j < t->size);
}
-void bch_bset_fix_lookup_table(struct btree *b, struct bkey *k)
+static void bch_bset_fix_lookup_table(struct btree *b,
+ struct bset_tree *t,
+ struct bkey *k)
{
- struct bset_tree *t = &b->sets[b->nsets];
unsigned shift = bkey_u64s(k);
unsigned j = bkey_to_cacheline(t, k);
@@ -673,7 +798,7 @@
}
}
- if (t->size == b->sets->tree + bset_tree_space(b) - t->tree)
+ if (t->size == b->sets->tree + btree_keys_cachelines(b) - t->tree)
return;
/* Possibly add a new entry to the end of the lookup table */
@@ -687,21 +812,23 @@
}
}
-void bch_bset_init_next(struct btree *b)
+void bch_bset_insert(struct btree *b, struct bkey *where,
+ struct bkey *insert)
{
- struct bset *i = write_block(b);
+ struct bset_tree *t = bset_tree_last(b);
- if (i != b->sets[0].data) {
- b->sets[++b->nsets].data = i;
- i->seq = b->sets[0].data->seq;
- } else
- get_random_bytes(&i->seq, sizeof(uint64_t));
+ BUG_ON(t->data != write_block(b));
+ BUG_ON(bset_byte_offset(b, t->data) +
+ __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
+ PAGE_SIZE << b->page_order);
- i->magic = bset_magic(&b->c->sb);
- i->version = 0;
- i->keys = 0;
+ memmove((uint64_t *) where + bkey_u64s(insert),
+ where,
+ (void *) bset_bkey_last(t->data) - (void *) where);
- bset_build_unwritten_tree(b);
+ t->data->keys += bkey_u64s(insert);
+ bkey_copy(where, insert);
+ bch_bset_fix_lookup_table(b, t, where);
}
struct bset_search_iter {
@@ -1154,9 +1281,8 @@
__bch_btree_iter_init(b, &iter, NULL, &b->sets[start]);
- BUG_ON(b->sets[b->nsets].data == write_block(b) &&
- (b->sets[b->nsets].size || b->nsets));
-
+ BUG_ON(!bset_written(b, bset_tree_last(b)) &&
+ (bset_tree_last(b)->size || b->nsets));
if (start) {
unsigned i;