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/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 96611fe..cb84923 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1537,7 +1537,7 @@
max_bytes = MAX_CACHE_BYTES_PER_GIG;
else
max_bytes = MAX_CACHE_BYTES_PER_GIG *
- div64_u64(size, 1024 * 1024 * 1024);
+ div_u64(size, 1024 * 1024 * 1024);
/*
* we want to account for 1 more bitmap than what we have so we can make
@@ -1552,14 +1552,14 @@
}
/*
- * we want the extent entry threshold to always be at most 1/2 the maxw
+ * we want the extent entry threshold to always be at most 1/2 the max
* bytes we can have, or whatever is less than that.
*/
extent_bytes = max_bytes - bitmap_bytes;
- extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
+ extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
ctl->extents_thresh =
- div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
+ div_u64(extent_bytes, sizeof(struct btrfs_free_space));
}
static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,