bcache: Move some stuff to btree.c

With the new btree_map() functions, we don't need to export the stuff
needed for traversing the btree anymore.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

1 files changed, 93 insertions, 2 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index cfbdcf349b7f..bfd60e6a2312 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -99,6 +99,13 @@ static const char *op_type(struct btree_op *op)
         return op_types[op->type];
 }
 
+enum {
+        BTREE_INSERT_STATUS_INSERT,
+        BTREE_INSERT_STATUS_BACK_MERGE,
+        BTREE_INSERT_STATUS_OVERWROTE,
+        BTREE_INSERT_STATUS_FRONT_MERGE,
+};
+
 #define MAX_NEED_GC             64
 #define MAX_SAVE_PRIO           72
 
@@ -116,6 +123,78 @@ void bch_btree_op_init_stack(struct btree_op *op)
         op->lock = -1;
 }
 
+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, b->c)
+                 > btree_blocks(b));
+}
+
+#define insert_lock(s, b)       ((b)->level <= (s)->lock)
+
+/*
+ * These macros are for recursing down the btree - they handle the details of
+ * locking and looking up nodes in the cache for you. They're best treated as
+ * mere syntax when reading code that uses them.
+ *
+ * op->lock determines whether we take a read or a write lock at a given depth.
+ * If you've got a read lock and find that you need a write lock (i.e. you're
+ * going to have to split), set op->lock and return -EINTR; btree_root() will
+ * call you again and you'll have the correct lock.
+ */
+
+/**
+ * btree - recurse down the btree on a specified key
+ * @fn:         function to call, which will be passed the child node
+ * @key:        key to recurse on
+ * @b:          parent btree node
+ * @op:         pointer to struct btree_op
+ */
+#define btree(fn, key, b, op, ...)                                      \
+({                                                                      \
+        int _r, l = (b)->level - 1;                                     \
+        bool _w = l <= (op)->lock;                                      \
+        struct btree *_child = bch_btree_node_get((b)->c, key, l, _w);  \
+        if (!IS_ERR(_child)) {                                          \
+                _child->parent = (b);                                   \
+                _r = bch_btree_ ## fn(_child, op, ##__VA_ARGS__);       \
+                rw_unlock(_w, _child);                                  \
+        } else                                                          \
+                _r = PTR_ERR(_child);                                   \
+        _r;                                                             \
+})
+
+/**
+ * btree_root - call a function on the root of the btree
+ * @fn:         function to call, which will be passed the child node
+ * @c:          cache set
+ * @op:         pointer to struct btree_op
+ */
+#define btree_root(fn, c, op, ...)                                      \
+({                                                                      \
+        int _r = -EINTR;                                                \
+        do {                                                            \
+                struct btree *_b = (c)->root;                           \
+                bool _w = insert_lock(op, _b);                          \
+                rw_lock(_w, _b, _b->level);                             \
+                if (_b == (c)->root &&                                  \
+                    _w == insert_lock(op, _b)) {                        \
+                        _b->parent = NULL;                              \
+                        _r = bch_btree_ ## fn(_b, op, ##__VA_ARGS__);   \
+                }                                                       \
+                rw_unlock(_w, _b);                                      \
+                bch_cannibalize_unlock(c);                              \
+                if (_r == -ENOSPC) {                                    \
+                        wait_event((c)->try_wait,                       \
+                                   !(c)->try_harder);                   \
+                        _r = -EINTR;                                    \
+                }                                                       \
+        } while (_r == -EINTR);                                         \
+                                                                        \
+        _r;                                                             \
+})
+
 /* Btree key manipulation */
 
 void __bkey_put(struct cache_set *c, struct bkey *k)
@@ -811,7 +890,7 @@ static struct btree *mca_cannibalize(struct cache_set *c, struct bkey *k)
  * cannibalize_bucket() will take. This means every time we unlock the root of
  * the btree, we need to release this lock if we have it held.
  */
-void bch_cannibalize_unlock(struct cache_set *c)
+static void bch_cannibalize_unlock(struct cache_set *c)
 {
         if (c->try_harder == current) {
                 bch_time_stats_update(&c->try_harder_time, c->try_harder_start);
@@ -2262,7 +2341,7 @@ static int submit_partial_cache_hit(struct btree *b, struct btree_op *op,
         return 0;
 }
 
-int bch_btree_search_recurse(struct btree *b, struct btree_op *op)
+static int bch_btree_search_recurse(struct btree *b, struct btree_op *op)
 {
         struct search *s = container_of(op, struct search, op);
         struct bio *bio = &s->bio.bio;
@@ -2296,6 +2375,18 @@ int bch_btree_search_recurse(struct btree *b, struct btree_op *op)
         return ret;
 }
 
+void bch_btree_search_async(struct closure *cl)
+{
+        struct btree_op *op = container_of(cl, struct btree_op, cl);
+
+        int ret = btree_root(search_recurse, op->c, op);
+
+        if (ret == -EAGAIN)
+                continue_at(cl, bch_btree_search_async, bcache_wq);
+
+        closure_return(cl);
+}
+
 /* Map across nodes or keys */
 
 static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op,