fs/btrfs/extent_map.c

31  * Initialize the extent tree @tree.  Should be called for each new inode or
34 void extent_map_tree_init(struct extent_map_tree *tree)
36 	tree->map = RB_ROOT_CACHED;
37 	INIT_LIST_HEAD(&tree->modified_extents);
38 	rwlock_init(&tree->lock);
136  * Search through the tree for an extent_map with a given offset.  If it can't
237 	struct extent_map_tree *tree = &inode->extent_tree;
242 	 * We can't modify an extent map that is in the tree and that is being
245 	 * the tree and 1 for this task (which is unpinning the extent map or
268 			rb_erase_cached(&merge->rb_node, &tree->map);
281 		rb_erase_cached(&merge->rb_node, &tree->map);
303  * 	    -ENOENT  when the extent is not found in the tree
309 	struct extent_map_tree *tree = &inode->extent_tree;
313 	write_lock(&tree->lock);
314 	em = lookup_extent_mapping(tree, start, len);
340 	write_unlock(&tree->lock);
370  * Add a new extent map to an inode's extent map tree.
377  * Insert @em into the @inode's extent map tree or perform a simple
379  * in will be inserted into the tree directly, with an additional reference
385 	struct extent_map_tree *tree = &inode->extent_tree;
390 	lockdep_assert_held_write(&tree->lock);
392 	ret = tree_insert(&tree->map, em);
405 __lookup_extent_mapping(struct extent_map_tree *tree,
413 	rb_node = __tree_search(&tree->map.rb_root, start, &prev_or_next);
433  * @tree:	tree to lookup in
437  * Find and return the first extent_map struct in @tree that intersects the
438  * [start, len] range.  There may be additional objects in the tree that
442 struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
445 	return __lookup_extent_mapping(tree, start, len, 1);
451  * @tree:	tree to lookup in
455  * Find and return the first extent_map struct in @tree that intersects the
460 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
463 	return __lookup_extent_mapping(tree, start, len, 0);
467  * Remove an extent_map from its inode's extent tree.
472  * Remove @em from the extent tree of @inode.  No reference counts are dropped,
477 	struct extent_map_tree *tree = &inode->extent_tree;
479 	lockdep_assert_held_write(&tree->lock);
482 	rb_erase_cached(&em->rb_node, &tree->map);
495 	struct extent_map_tree *tree = &inode->extent_tree;
497 	lockdep_assert_held_write(&tree->lock);
503 	rb_replace_node_cached(&cur->rb_node, &new->rb_node, &tree->map);
530  * Helper for btrfs_get_extent.  Given an existing extent in the tree,
533  * the best fitted new extent into the tree.
573  * Add extent mapping into an inode's extent map tree.
583  * Insert @em_in into the inode's extent map tree. In case there is an
607 	/* it is possible that someone inserted the extent into the tree
609 	 * an overlapping map exists in the tree
653  * Drop all extent maps from a tree in the fastest possible way, rescheduling
654  * if needed. This avoids searching the tree, from the root down to the first
659 	struct extent_map_tree *tree = &inode->extent_tree;
661 	write_lock(&tree->lock);
662 	while (!RB_EMPTY_ROOT(&tree->map.rb_root)) {
666 		node = rb_first_cached(&tree->map);
671 		cond_resched_rwlock_write(&tree->lock);
673 	write_unlock(&tree->lock);
688  * tree before calling this function.
856 			 * If the extent map is still in the tree it means that
869 			 * load it again from the subvolume tree's file extent
883 		 * Once for the tree reference (we replaced or removed the
884 		 * extent map from the tree).
901  * Replace a range in the inode's extent map tree with a new extent map.
904  * @new_em:     The new extent map to add to the inode's extent map tree.
908  * Drops all the extent maps in the inode's extent map tree that intersect the
909  * range of the new extent map and adds the new extent map to the tree.
911  * tree before calling this function.
918 	struct extent_map_tree *tree = &inode->extent_tree;
925 	 * tree, but getting -EEXIST when adding the new extent map can still
933 		write_lock(&tree->lock);
935 		write_unlock(&tree->lock);
1019 	/* Once for the tree */
1034 	struct extent_map_tree *tree = &inode->extent_tree;
1041 	 * in case we have to remove extent maps in the tree's list of modified
1045 	 * during inode logging it sees the flag set and uses the subvolume tree
1060 	write_lock(&tree->lock);
1061 	node = rb_first_cached(&tree->map);
1084 		/* Drop the reference for the tree. */
1096 		if (cond_resched_rwlock_write(&tree->lock))
1097 			node = rb_first_cached(&tree->map);
1099 	write_unlock(&tree->lock);