Commit 21a4989d authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Hash in the offset and owner for file extent backref keys 



This makes searches for backrefs and backref insertion much more efficient
when there are many backrefs for a single extent

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 47e4bb98

fs/btrfs/extent-tree.c

+6 −7
Original line number Diff line number Diff line
@@ -397,13 +397,12 @@ static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation, 
	high_crc = crc32c(high_crc, &lenum, sizeof(lenum));

	lenum = cpu_to_le64(ref_generation);

	low_crc = crc32c(low_crc, &lenum, sizeof(lenum));



#if 0

	if (owner >= BTRFS_FIRST_FREE_OBJECTID) {

		lenum = cpu_to_le64(owner);

		low_crc = crc32c(low_crc, &lenum, sizeof(lenum));

		lenum = cpu_to_le64(owner_offset);

		low_crc = crc32c(low_crc, &lenum, sizeof(lenum));

#endif

	}

	return ((u64)high_crc << 32) | (u64)low_crc;

}