Commit ed6078f7 authored by David Sterba's avatar David Sterba Committed by Chris Mason
Browse files

btrfs: use DIV_ROUND_UP instead of open-coded variants 



The form

  (value + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT

is equivalent to

  (value + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE

The rest is a simple subsitution, no difference in the generated
assembly code.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 4e54b17a

fs/btrfs/check-integrity.c

+1 −2
Original line number Diff line number Diff line
@@ -1251,8 +1251,7 @@ static void btrfsic_read_from_block_data( 


	while (len > 0) {

		cur = min(len, ((size_t)PAGE_CACHE_SIZE - offset_in_page));

		BUG_ON(i >= (block_ctx->len + PAGE_CACHE_SIZE - 1) >>

			    PAGE_CACHE_SHIFT);

		BUG_ON(i >= DIV_ROUND_UP(block_ctx->len, PAGE_CACHE_SIZE));

		kaddr = block_ctx->datav[i];

		memcpy(dst, kaddr + offset_in_page, cur);

fs/btrfs/compression.c

+4 −6
Original line number Diff line number Diff line
@@ -91,8 +91,7 @@ static inline int compressed_bio_size(struct btrfs_root *root, 
	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);



	return sizeof(struct compressed_bio) +

		((disk_size + root->sectorsize - 1) / root->sectorsize) *

		csum_size;

		(DIV_ROUND_UP(disk_size, root->sectorsize)) * csum_size;

}



static struct bio *compressed_bio_alloc(struct block_device *bdev,
@@ -615,8 +614,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
	cb->compress_type = extent_compress_type(bio_flags);

	cb->orig_bio = bio;



	nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /

				 PAGE_CACHE_SIZE;

	nr_pages = DIV_ROUND_UP(compressed_len, PAGE_CACHE_SIZE);

	cb->compressed_pages = kzalloc(sizeof(struct page *) * nr_pages,

				       GFP_NOFS);

	if (!cb->compressed_pages)
@@ -686,8 +684,8 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, 
							comp_bio, sums);

				BUG_ON(ret); /* -ENOMEM */

			}

			sums += (comp_bio->bi_iter.bi_size +

				 root->sectorsize - 1) / root->sectorsize;

			sums += DIV_ROUND_UP(comp_bio->bi_iter.bi_size,

					     root->sectorsize);



			ret = btrfs_map_bio(root, READ, comp_bio,

					    mirror_num, 0);

fs/btrfs/file.c

+8 −11
Original line number Diff line number Diff line
@@ -1481,9 +1481,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
	bool force_page_uptodate = false;

	bool need_unlock;



	nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /

		     PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /

		     (sizeof(struct page *)));

	nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_CACHE_SIZE),

			PAGE_CACHE_SIZE / (sizeof(struct page *)));

	nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);

	nrptrs = max(nrptrs, 8);

	pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
@@ -1497,8 +1496,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
		size_t write_bytes = min(iov_iter_count(i),

					 nrptrs * (size_t)PAGE_CACHE_SIZE -

					 offset);

		size_t num_pages = (write_bytes + offset +

				    PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;

		size_t num_pages = DIV_ROUND_UP(write_bytes + offset,

						PAGE_CACHE_SIZE);

		size_t reserve_bytes;

		size_t dirty_pages;

		size_t copied;
@@ -1526,9 +1525,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file, 
				 * our prealloc extent may be smaller than

				 * write_bytes, so scale down.

				 */

				num_pages = (write_bytes + offset +

					     PAGE_CACHE_SIZE - 1) >>

					PAGE_CACHE_SHIFT;

				num_pages = DIV_ROUND_UP(write_bytes + offset,

							 PAGE_CACHE_SIZE);

				reserve_bytes = num_pages << PAGE_CACHE_SHIFT;

				ret = 0;

			} else {
@@ -1590,9 +1588,8 @@ again: 
			dirty_pages = 0;

		} else {

			force_page_uptodate = false;

			dirty_pages = (copied + offset +

				       PAGE_CACHE_SIZE - 1) >>

				       PAGE_CACHE_SHIFT;

			dirty_pages = DIV_ROUND_UP(copied + offset,

						   PAGE_CACHE_SIZE);

		}



		/*

fs/btrfs/free-space-cache.c

+1 −2
Original line number Diff line number Diff line
@@ -279,8 +279,7 @@ static int io_ctl_init(struct io_ctl *io_ctl, struct inode *inode, 
	int num_pages;

	int check_crcs = 0;



	num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>

		    PAGE_CACHE_SHIFT;

	num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);



	if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)

		check_crcs = 1;

fs/btrfs/ioctl.c

+2 −3
Original line number Diff line number Diff line
@@ -1335,8 +1335,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, 
		inode->i_mapping->writeback_index = i;



	while (i <= last_index && defrag_count < max_to_defrag &&

	       (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>

		PAGE_CACHE_SHIFT)) {

	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE))) {

		/*

		 * make sure we stop running if someone unmounts

		 * the FS
@@ -1359,7 +1358,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, 
			 * the should_defrag function tells us how much to skip

			 * bump our counter by the suggested amount

			 */

			next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;

			next = DIV_ROUND_UP(skip, PAGE_CACHE_SIZE);

			i = max(i + 1, next);

			continue;

		}

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