/* 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)
{
	if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
		return 0;

	/*
	 * don't merge compressed extents, we need to know their
	 * actual size
	 */
	if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
		return 0;

	if (extent_map_end(prev) == next->start &&
	    prev->flags == next->flags &&
	    prev->bdev == next->bdev &&
	    ((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_DELALLOC &&
	      prev->block_start == EXTENT_MAP_DELALLOC) ||
	     (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
	      next->block_start == extent_map_block_end(prev)))) {
		return 1;
	}
	return 0;
}
Example #2
0
/* 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)
{
	if (test_bit(EXTENT_FLAG_PINNED, &prev->flags))
		return 0;

	/*
	 * don't merge compressed extents, we need to know their
	 * actual size
	 */
	if (test_bit(EXTENT_FLAG_COMPRESSED, &prev->flags))
		return 0;

	if (test_bit(EXTENT_FLAG_LOGGING, &prev->flags) ||
	    test_bit(EXTENT_FLAG_LOGGING, &next->flags))
		return 0;

	/*
	 * We don't want to merge stuff that hasn't been written to the log yet
	 * since it may not reflect exactly what is on disk, and that would be
	 * bad.
	 */
	if (!list_empty(&prev->list) || !list_empty(&next->list))
		return 0;

	if (extent_map_end(prev) == next->start &&
	    prev->flags == next->flags &&
	    prev->bdev == next->bdev &&
	    ((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_DELALLOC &&
	      prev->block_start == EXTENT_MAP_DELALLOC) ||
	     (next->block_start < EXTENT_MAP_LAST_BYTE - 1 &&
	      next->block_start == extent_map_block_end(prev)))) {
		return 1;
	}
	return 0;
}