1 files changed, 49 insertions, 80 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 4bc3ca2cbd7d..84627cbd5b5b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -364,49 +364,6 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
 	return 0;
 }
 
-static struct extent_buffer *alloc_tree_block_no_bg_flush(
-					  struct btrfs_trans_handle *trans,
-					  struct btrfs_root *root,
-					  u64 parent_start,
-					  const struct btrfs_disk_key *disk_key,
-					  int level,
-					  u64 hint,
-					  u64 empty_size,
-					  enum btrfs_lock_nesting nest)
-{
-	struct btrfs_fs_info *fs_info = root->fs_info;
-	struct extent_buffer *ret;
-
-	/*
-	 * If we are COWing a node/leaf from the extent, chunk, device or free
-	 * space trees, make sure that we do not finish block group creation of
-	 * pending block groups. We do this to avoid a deadlock.
-	 * COWing can result in allocation of a new chunk, and flushing pending
-	 * block groups (btrfs_create_pending_block_groups()) can be triggered
-	 * when finishing allocation of a new chunk. Creation of a pending block
-	 * group modifies the extent, chunk, device and free space trees,
-	 * therefore we could deadlock with ourselves since we are holding a
-	 * lock on an extent buffer that btrfs_create_pending_block_groups() may
-	 * try to COW later.
-	 * For similar reasons, we also need to delay flushing pending block
-	 * groups when splitting a leaf or node, from one of those trees, since
-	 * we are holding a write lock on it and its parent or when inserting a
-	 * new root node for one of those trees.
-	 */
-	if (root == fs_info->extent_root ||
-	    root == fs_info->chunk_root ||
-	    root == fs_info->dev_root ||
-	    root == fs_info->free_space_root)
-		trans->can_flush_pending_bgs = false;
-
-	ret = btrfs_alloc_tree_block(trans, root, parent_start,
-				     root->root_key.objectid, disk_key, level,
-				     hint, empty_size, nest);
-	trans->can_flush_pending_bgs = true;
-
-	return ret;
-}
-
 /*
  * does the dirty work in cow of a single block.  The parent block (if
  * supplied) is updated to point to the new cow copy.  The new buffer is marked
@@ -455,8 +412,9 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent)
 		parent_start = parent->start;
 
-	cow = alloc_tree_block_no_bg_flush(trans, root, parent_start, &disk_key,
-					   level, search_start, empty_size, nest);
+	cow = btrfs_alloc_tree_block(trans, root, parent_start,
+				     root->root_key.objectid, &disk_key, level,
+				     search_start, empty_size, nest);
 	if (IS_ERR(cow))
 		return PTR_ERR(cow);
 
@@ -768,21 +726,21 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
 
 /*
  * search for key in the extent_buffer.  The items start at offset p,
- * and they are item_size apart.  There are 'max' items in p.
+ * and they are item_size apart.
  *
  * the slot in the array is returned via slot, and it points to
  * the place where you would insert key if it is not found in
  * the array.
  *
- * slot may point to max if the key is bigger than all of the keys
+ * Slot may point to total number of items if the key is bigger than
+ * all of the keys
  */
 static noinline int generic_bin_search(struct extent_buffer *eb,
 				       unsigned long p, int item_size,
-				       const struct btrfs_key *key,
-				       int max, int *slot)
+				       const struct btrfs_key *key, int *slot)
 {
 	int low = 0;
-	int high = max;
+	int high = btrfs_header_nritems(eb);
 	int ret;
 	const int key_size = sizeof(struct btrfs_disk_key);
 
@@ -841,15 +799,11 @@ int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
 	if (btrfs_header_level(eb) == 0)
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_leaf, items),
-					  sizeof(struct btrfs_item),
-					  key, btrfs_header_nritems(eb),
-					  slot);
+					  sizeof(struct btrfs_item), key, slot);
 	else
 		return generic_bin_search(eb,
 					  offsetof(struct btrfs_node, ptrs),
-					  sizeof(struct btrfs_key_ptr),
-					  key, btrfs_header_nritems(eb),
-					  slot);
+					  sizeof(struct btrfs_key_ptr), key, slot);
 }
 
 static void root_add_used(struct btrfs_root *root, u32 size)
@@ -1279,7 +1233,6 @@ static void reada_for_search(struct btrfs_fs_info *fs_info,
 	u64 target;
 	u64 nread = 0;
 	u64 nread_max;
-	struct extent_buffer *eb;
 	u32 nr;
 	u32 blocksize;
 	u32 nscan = 0;
@@ -1308,10 +1261,14 @@ static void reada_for_search(struct btrfs_fs_info *fs_info,
 
 	search = btrfs_node_blockptr(node, slot);
 	blocksize = fs_info->nodesize;
-	eb = find_extent_buffer(fs_info, search);
-	if (eb) {
-		free_extent_buffer(eb);
-		return;
+	if (path->reada != READA_FORWARD_ALWAYS) {
+		struct extent_buffer *eb;
+
+		eb = find_extent_buffer(fs_info, search);
+		if (eb) {
+			free_extent_buffer(eb);
+			return;
+		}
 	}
 
 	target = search;
@@ -2145,6 +2102,27 @@ again:
 }
 
 /*
+ * Execute search and call btrfs_previous_item to traverse backwards if the item
+ * was not found.
+ *
+ * Return 0 if found, 1 if not found and < 0 if error.
+ */
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+			   struct btrfs_path *path)
+{
+	int ret;
+
+	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
+	if (ret > 0)
+		ret = btrfs_previous_item(root, path, key->objectid, key->type);
+
+	if (ret == 0)
+		btrfs_item_key_to_cpu(path->nodes[0], key, path->slots[0]);
+
+	return ret;
+}
+
+/*
  * adjust the pointers going up the tree, starting at level
  * making sure the right key of each node is points to 'key'.
  * This is used after shifting pointers to the left, so it stops
@@ -2458,9 +2436,9 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 	else
 		btrfs_node_key(lower, &lower_key, 0);
 
-	c = alloc_tree_block_no_bg_flush(trans, root, 0, &lower_key, level,
-					 root->node->start, 0,
-					 BTRFS_NESTING_NEW_ROOT);
+	c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+				   &lower_key, level, root->node->start, 0,
+				   BTRFS_NESTING_NEW_ROOT);
 	if (IS_ERR(c))
 		return PTR_ERR(c);
 
@@ -2589,8 +2567,9 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
 	mid = (c_nritems + 1) / 2;
 	btrfs_node_key(c, &disk_key, mid);
 
-	split = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, level,
-					     c->start, 0, BTRFS_NESTING_SPLIT);
+	split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+				       &disk_key, level, c->start, 0,
+				       BTRFS_NESTING_SPLIT);
 	if (IS_ERR(split))
 		return PTR_ERR(split);
 
@@ -3381,10 +3360,10 @@ again:
 	 * BTRFS_NESTING_SPLIT_THE_SPLITTENING if we need to, but for now just
 	 * use BTRFS_NESTING_NEW_ROOT.
 	 */
-	right = alloc_tree_block_no_bg_flush(trans, root, 0, &disk_key, 0,
-					     l->start, 0, num_doubles ?
-					     BTRFS_NESTING_NEW_ROOT :
-					     BTRFS_NESTING_SPLIT);
+	right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+				       &disk_key, 0, l->start, 0,
+				       num_doubles ? BTRFS_NESTING_NEW_ROOT :
+				       BTRFS_NESTING_SPLIT);
 	if (IS_ERR(right))
 		return PTR_ERR(right);
 
@@ -4399,16 +4378,6 @@ next:
 	return 1;
 }
 
-/*
- * search the tree again to find a leaf with greater keys
- * returns 0 if it found something or 1 if there are no greater leaves.
- * returns < 0 on io errors.
- */
-int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
-{
-	return btrfs_next_old_leaf(root, path, 0);
-}
-
 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 			u64 time_seq)
 {