Commit bd06bce1 authored by David Sterba's avatar David Sterba
Browse files

btrfs: use num_extent_folios() in for loop bounds 



As the helper num_extent_folios() is now __pure, we can use it in for
loop without storing its value in a variable explicitly, the compiler
will do this for us.

The effects on btrfs.ko is -200 bytes and there are stack space savings
too:

btrfs_clone_extent_buffer                               -8 (32 -> 24)
btrfs_clear_buffer_dirty                                -8 (48 -> 40)
clear_extent_buffer_uptodate                            -8 (40 -> 32)
set_extent_buffer_dirty                                 -8 (32 -> 24)
write_one_eb                                            -8 (88 -> 80)
set_extent_buffer_uptodate                              -8 (40 -> 32)
read_extent_buffer_pages_nowait                        -16 (64 -> 48)
find_extent_buffer                                      -8 (32 -> 24)

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6e7c2838

fs/btrfs/disk-io.c

+1 −2
Original line number Diff line number Diff line
@@ -182,13 +182,12 @@ static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, 
				      int mirror_num)

{

	struct btrfs_fs_info *fs_info = eb->fs_info;

	int num_folios = num_extent_folios(eb);

	int ret = 0;



	if (sb_rdonly(fs_info->sb))

		return -EROFS;



	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio = eb->folios[i];

		u64 start = max_t(u64, eb->start, folio_pos(folio));

		u64 end = min_t(u64, eb->start + eb->len,

fs/btrfs/extent_io.c

+18 −30
Original line number Diff line number Diff line
@@ -1779,7 +1779,6 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb, 
{

	struct btrfs_fs_info *fs_info = eb->fs_info;

	struct btrfs_bio *bbio;

	const int num_folios = num_extent_folios(eb);



	prepare_eb_write(eb);
@@ -1791,7 +1790,7 @@ static noinline_for_stack void write_one_eb(struct extent_buffer *eb, 
	wbc_init_bio(wbc, &bbio->bio);

	bbio->inode = BTRFS_I(eb->fs_info->btree_inode);

	bbio->file_offset = eb->start;

	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio = eb->folios[i];

		u64 range_start = max_t(u64, eb->start, folio_pos(folio));

		u32 range_len = min_t(u64, folio_pos(folio) + folio_size(folio),
@@ -2667,7 +2666,6 @@ static struct extent_buffer *__alloc_extent_buffer(struct btrfs_fs_info *fs_info 
struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)

{

	struct extent_buffer *new;

	int num_folios = num_extent_folios(src);

	int ret;



	new = __alloc_extent_buffer(src->fs_info, src->start);
@@ -2687,7 +2685,7 @@ struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src) 
		return NULL;

	}



	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(src); i++) {

		struct folio *folio = new->folios[i];



		ret = attach_extent_buffer_folio(new, folio, NULL);
@@ -2707,7 +2705,6 @@ struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 
						u64 start)

{

	struct extent_buffer *eb;

	int num_folios = 0;

	int ret;



	eb = __alloc_extent_buffer(fs_info, start);
@@ -2716,13 +2713,12 @@ struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 


	ret = alloc_eb_folio_array(eb, false);

	if (ret)

		goto err;

		goto out;



	num_folios = num_extent_folios(eb);

	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		ret = attach_extent_buffer_folio(eb, eb->folios[i], NULL);

		if (ret < 0)

			goto err;

			goto out_detach;

	}



	set_extent_buffer_uptodate(eb);
@@ -2730,13 +2726,15 @@ struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, 
	set_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);



	return eb;

err:

	for (int i = 0; i < num_folios; i++) {



out_detach:

	for (int i = 0; i < num_extent_folios(eb); i++) {

		if (eb->folios[i]) {

			detach_extent_buffer_folio(eb, eb->folios[i]);

			folio_put(eb->folios[i]);

		}

	}

out:

	kmem_cache_free(extent_buffer_cache, eb);

	return NULL;

}
@@ -2779,11 +2777,9 @@ static void check_buffer_tree_ref(struct extent_buffer *eb) 


static void mark_extent_buffer_accessed(struct extent_buffer *eb)

{

	int num_folios= num_extent_folios(eb);



	check_buffer_tree_ref(eb);



	for (int i = 0; i < num_folios; i++)

	for (int i = 0; i < num_extent_folios(eb); i++)

		folio_mark_accessed(eb->folios[i]);

}
@@ -3015,7 +3011,6 @@ static int attach_eb_folio_to_filemap(struct extent_buffer *eb, int i, 
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,

					  u64 start, u64 owner_root, int level)

{

	int num_folios;

	int attached = 0;

	struct extent_buffer *eb;

	struct extent_buffer *existing_eb = NULL;
@@ -3079,9 +3074,8 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 
		goto out;

	}



	num_folios = num_extent_folios(eb);

	/* Attach all pages to the filemap. */

	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio;



		ret = attach_eb_folio_to_filemap(eb, i, prealloc, &existing_eb);
@@ -3175,7 +3169,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, 
	 * btree_release_folio will correctly detect that a page belongs to a

	 * live buffer and won't free them prematurely.

	 */

	for (int i = 0; i < num_folios; i++)

	for (int i = 0; i < num_extent_folios(eb); i++)

		folio_unlock(eb->folios[i]);

	return eb;
@@ -3321,7 +3315,6 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 
			      struct extent_buffer *eb)

{

	struct btrfs_fs_info *fs_info = eb->fs_info;

	const int num_folios = num_extent_folios(eb);



	btrfs_assert_tree_write_locked(eb);
@@ -3348,7 +3341,7 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 
	percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -eb->len,

				 fs_info->dirty_metadata_batch);



	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio = eb->folios[i];

		bool last;
@@ -3365,14 +3358,12 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, 


void set_extent_buffer_dirty(struct extent_buffer *eb)

{

	int num_folios;

	bool was_dirty;



	check_buffer_tree_ref(eb);



	was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);



	num_folios = num_extent_folios(eb);

	WARN_ON(atomic_read(&eb->refs) == 0);

	WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags));

	WARN_ON(test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags));
@@ -3393,7 +3384,7 @@ void set_extent_buffer_dirty(struct extent_buffer *eb) 
		 */

		if (subpage)

			folio_lock(eb->folios[0]);

		for (int i = 0; i < num_folios; i++)

		for (int i = 0; i < num_extent_folios(eb); i++)

			btrfs_meta_folio_set_dirty(eb->folios[i], eb);

		if (subpage)

			folio_unlock(eb->folios[0]);
@@ -3402,17 +3393,16 @@ void set_extent_buffer_dirty(struct extent_buffer *eb) 
					 eb->fs_info->dirty_metadata_batch);

	}

#ifdef CONFIG_BTRFS_DEBUG

	for (int i = 0; i < num_folios; i++)

	for (int i = 0; i < num_extent_folios(eb); i++)

		ASSERT(folio_test_dirty(eb->folios[i]));

#endif

}



void clear_extent_buffer_uptodate(struct extent_buffer *eb)

{

	int num_folios = num_extent_folios(eb);



	clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);

	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio = eb->folios[i];



		if (!folio)
@@ -3424,10 +3414,9 @@ void clear_extent_buffer_uptodate(struct extent_buffer *eb) 


void set_extent_buffer_uptodate(struct extent_buffer *eb)

{

	int num_folios = num_extent_folios(eb);



	set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);

	for (int i = 0; i < num_folios; i++)

	for (int i = 0; i < num_extent_folios(eb); i++)

		btrfs_meta_folio_set_uptodate(eb->folios[i], eb);

}
@@ -3472,7 +3461,6 @@ static void end_bbio_meta_read(struct btrfs_bio *bbio) 
int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num,

				    const struct btrfs_tree_parent_check *check)

{

	const int num_folios = num_extent_folios(eb);

	struct btrfs_bio *bbio;



	if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))
@@ -3513,7 +3501,7 @@ int read_extent_buffer_pages_nowait(struct extent_buffer *eb, int mirror_num, 
	bbio->inode = BTRFS_I(eb->fs_info->btree_inode);

	bbio->file_offset = eb->start;

	memcpy(&bbio->parent_check, check, sizeof(*check));

	for (int i = 0; i < num_folios; i++) {

	for (int i = 0; i < num_extent_folios(eb); i++) {

		struct folio *folio = eb->folios[i];

		u64 range_start = max_t(u64, eb->start, folio_pos(folio));

		u32 range_len = min_t(u64, folio_pos(folio) + folio_size(folio),