Commit 16068ec1 authored by David Sterba's avatar David Sterba
Browse files

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: default avatarDavid Sterba <dsterba@suse.cz>
parent e57cf21e

fs/btrfs/dev-replace.c

+3 −3
Original line number Diff line number Diff line
@@ -670,8 +670,8 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 
	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:

		srcdev = dev_replace->srcdev;

		args->status.progress_1000 = div64_u64(dev_replace->cursor_left,

			div64_u64(btrfs_device_get_total_bytes(srcdev), 1000));

		args->status.progress_1000 = div_u64(dev_replace->cursor_left,

			div_u64(btrfs_device_get_total_bytes(srcdev), 1000));

		break;

	}

	btrfs_dev_replace_unlock(dev_replace);
@@ -806,7 +806,7 @@ static int btrfs_dev_replace_kthread(void *data) 
		btrfs_dev_replace_status(fs_info, status_args);

		progress = status_args->status.progress_1000;

		kfree(status_args);

		do_div(progress, 10);

		progress = div_u64(progress, 10);

		printk_in_rcu(KERN_INFO

			"BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",

			dev_replace->srcdev->missing ? "<missing disk>" :

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -2277,7 +2277,7 @@ int open_ctree(struct super_block *sb, 
	fs_info->free_chunk_space = 0;

	fs_info->tree_mod_log = RB_ROOT;

	fs_info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;

	fs_info->avg_delayed_ref_runtime = div64_u64(NSEC_PER_SEC, 64);

	fs_info->avg_delayed_ref_runtime = NSEC_PER_SEC >> 6; /* div by 64 */

	/* readahead state */

	INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);

	spin_lock_init(&fs_info->reada_lock);

fs/btrfs/extent-tree.c

+7 −8
Original line number Diff line number Diff line
@@ -2561,8 +2561,7 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, 
		 */

		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 @@ static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads) 
	 * 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 @@ static int cache_save_setup(struct btrfs_block_group_cache *block_group, 
	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 @@ again: 
	 * 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 @@ static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info) 


	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 @@ static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes, 
	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);

fs/btrfs/free-space-cache.c

+4 −4
Original line number Diff line number Diff line
@@ -1537,7 +1537,7 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) 
		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 @@ static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) 
	}



	/*

	 * 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,

fs/btrfs/math.h

+2 −4
Original line number Diff line number Diff line
@@ -28,8 +28,7 @@ static inline u64 div_factor(u64 num, int factor) 
	if (factor == 10)

		return num;

	num *= factor;

	do_div(num, 10);

	return num;

	return div_u64(num, 10);

}



static inline u64 div_factor_fine(u64 num, int factor)
@@ -37,8 +36,7 @@ static inline u64 div_factor_fine(u64 num, int factor) 
	if (factor == 100)

		return num;

	num *= factor;

	do_div(num, 100);

	return num;

	return div_u64(num, 100);

}



#endif

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