btrfs: cleanup 64bit/32bit divs, compile time constants
Switch to div_u64 if the divisor is a numeric constant or sum of
sizeof()s. We can remove a few instances of do_div that has the hidden
semtantics of changing the 1st argument.
Small power-of-two divisors are converted to bitshifts, large values are
kept intact for clarity.
Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 100a044..530a0ba 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1704,7 +1704,7 @@
avail_space = device->total_bytes - device->bytes_used;
/* align with stripe_len */
- do_div(avail_space, BTRFS_STRIPE_LEN);
+ avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN);
avail_space *= BTRFS_STRIPE_LEN;
/*