Commit 30835cd0 authored by Joern Engel's avatar Joern Engel
Browse files

[LogFS] Prevent 64bit divisions in hash_index 

Randy Dunlap caught this built error on i386:

fs/built-in.o: In function `hash_index':
dir.c:(.text+0x6c1f2): undefined reference to `__umoddi3'
parent ddfd1f04

fs/logfs/dir.c

+10 −5
Original line number Diff line number Diff line
@@ -133,17 +133,22 @@ static u32 hash_32(const char *s, int len, u32 seed) 
 */

static pgoff_t hash_index(u32 hash, int round)

{

	u32 i0_blocks = I0_BLOCKS;

	u32 i1_blocks = I1_BLOCKS;

	u32 i2_blocks = I2_BLOCKS;

	u32 i3_blocks = I3_BLOCKS;



	switch (round) {

	case 0:

		return hash % I0_BLOCKS;

		return hash % i0_blocks;

	case 1:

		return I0_BLOCKS + hash % (I1_BLOCKS - I0_BLOCKS);

		return i0_blocks + hash % (i1_blocks - i0_blocks);

	case 2:

		return I1_BLOCKS + hash % (I2_BLOCKS - I1_BLOCKS);

		return i1_blocks + hash % (i2_blocks - i1_blocks);

	case 3:

		return I2_BLOCKS + hash % (I3_BLOCKS - I2_BLOCKS);

		return i2_blocks + hash % (i3_blocks - i2_blocks);

	case 4 ... 19:

		return I3_BLOCKS + 16 * (hash % (((1<<31) - I3_BLOCKS) / 16))

		return i3_blocks + 16 * (hash % (((1<<31) - i3_blocks) / 16))

			+ round - 4;

	}

	BUG();