Commit 27f0d9c9 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
Browse files

btrfs: refactor mergable_maps() for more readability 



At mergable_maps() instead of having a single if statement with many
ORed and ANDed conditions, refactor it with multiple if statements that
check a single condition and return immediately once a requirement fails.
This makes it easier to read.

Also change the return type from int to bool, make the arguments const
and rename the function from mergable_maps() to mergeable_maps().

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent b144cc04

fs/btrfs/extent_map.c

+14 −14
Original line number Diff line number Diff line
@@ -211,19 +211,19 @@ static bool can_merge_extent_map(const struct extent_map *em) 
}



/* Check to see if two extent_map structs are adjacent and safe to merge. */

static int mergable_maps(struct extent_map *prev, struct extent_map *next)

static bool mergeable_maps(const struct extent_map *prev, const struct extent_map *next)

{

	if (extent_map_end(prev) == next->start &&

	    prev->flags == next->flags &&

	    ((next->block_start == EXTENT_MAP_HOLE &&

	      prev->block_start == EXTENT_MAP_HOLE) ||

	     (next->block_start == EXTENT_MAP_INLINE &&

	      prev->block_start == EXTENT_MAP_INLINE) ||

	     (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&

	      next->block_start == extent_map_block_end(prev)))) {

		return 1;

	}

	return 0;

	if (extent_map_end(prev) != next->start)

		return false;



	if (prev->flags != next->flags)

		return false;



	if (next->block_start < EXTENT_MAP_LAST_BYTE - 1)

		return next->block_start == extent_map_block_end(prev);



	/* HOLES and INLINE extents. */

	return next->block_start == prev->block_start;

}



static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
@@ -249,7 +249,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) 
		rb = rb_prev(&em->rb_node);

		if (rb)

			merge = rb_entry(rb, struct extent_map, rb_node);

		if (rb && can_merge_extent_map(merge) && mergable_maps(merge, em)) {

		if (rb && can_merge_extent_map(merge) && mergeable_maps(merge, em)) {

			em->start = merge->start;

			em->orig_start = merge->orig_start;

			em->len += merge->len;
@@ -269,7 +269,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em) 
	rb = rb_next(&em->rb_node);

	if (rb)

		merge = rb_entry(rb, struct extent_map, rb_node);

	if (rb && can_merge_extent_map(merge) && mergable_maps(em, merge)) {

	if (rb && can_merge_extent_map(merge) && mergeable_maps(em, merge)) {

		em->len += merge->len;

		em->block_len += merge->block_len;

		rb_erase_cached(&merge->rb_node, &tree->map);