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/extent-tree.c b/fs/btrfs/extent-tree.c
index 28ce5c8..2cb32bc 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2561,8 +2561,7 @@
*/
spin_lock(&delayed_refs->lock);
avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
- avg = div64_u64(avg, 4);
- fs_info->avg_delayed_ref_runtime = avg;
+ fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
spin_unlock(&delayed_refs->lock);
}
return 0;
@@ -2624,7 +2623,7 @@
* We don't ever fill up leaves all the way so multiply by 2 just to be
* closer to what we're really going to want to ouse.
*/
- return div64_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
+ return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
}
int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
@@ -3193,7 +3192,7 @@
struct inode *inode = NULL;
u64 alloc_hint = 0;
int dcs = BTRFS_DC_ERROR;
- int num_pages = 0;
+ u64 num_pages = 0;
int retries = 0;
int ret = 0;
@@ -3277,7 +3276,7 @@
* taking up quite a bit since it's not folded into the other space
* cache.
*/
- num_pages = (int)div64_u64(block_group->key.offset, 256 * 1024 * 1024);
+ num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
if (!num_pages)
num_pages = 1;
@@ -4770,10 +4769,10 @@
num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
csum_size * 2;
- num_bytes += div64_u64(data_used + meta_used, 50);
+ num_bytes += div_u64(data_used + meta_used, 50);
if (num_bytes * 3 > meta_used)
- num_bytes = div64_u64(meta_used, 3);
+ num_bytes = div_u64(meta_used, 3);
return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
}
@@ -5039,7 +5038,7 @@
else
BTRFS_I(inode)->csum_bytes -= num_bytes;
csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
- num_csums_per_leaf = (int)div64_u64(csum_size,
+ num_csums_per_leaf = (int)div_u64(csum_size,
sizeof(struct btrfs_csum_item) +
sizeof(struct btrfs_disk_key));
num_csums = (int)div64_u64(BTRFS_I(inode)->csum_bytes, root->sectorsize);
