Commit 01af106a authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by David Sterba
Browse files

btrfs: fix two misuses of folio_shift() 



It is meaningless to shift a byte count by folio_shift().  The folio index
is in units of PAGE_SIZE, not folio_size().  We can use folio_contains()
to make this work for arbitrary-order folios, so remove the assertion
that the folios are of order 0.

Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent fdef89ce

fs/btrfs/extent_io.c

+5 −6
Original line number Diff line number Diff line
@@ -523,8 +523,6 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) 
		u64 end;

		u32 len;



		/* For now only order 0 folios are supported for data. */

		ASSERT(folio_order(folio) == 0);

		btrfs_debug(fs_info,

			"%s: bi_sector=%llu, err=%d, mirror=%u",

			__func__, bio->bi_iter.bi_sector, bio->bi_status,
@@ -552,7 +550,6 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) 


		if (likely(uptodate)) {

			loff_t i_size = i_size_read(inode);

			pgoff_t end_index = i_size >> folio_shift(folio);



			/*

			 * Zero out the remaining part if this range straddles
@@ -561,9 +558,11 @@ static void end_bbio_data_read(struct btrfs_bio *bbio) 
			 * Here we should only zero the range inside the folio,

			 * not touch anything else.

			 *

			 * NOTE: i_size is exclusive while end is inclusive.

			 * NOTE: i_size is exclusive while end is inclusive and

			 * folio_contains() takes PAGE_SIZE units.

			 */

			if (folio_index(folio) == end_index && i_size <= end) {

			if (folio_contains(folio, i_size >> PAGE_SHIFT) &&

			    i_size <= end) {

				u32 zero_start = max(offset_in_folio(folio, i_size),

						     offset_in_folio(folio, start));

				u32 zero_len = offset_in_folio(folio, end) + 1 -
@@ -956,7 +955,7 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached, 
		return ret;

	}



	if (folio->index == last_byte >> folio_shift(folio)) {

	if (folio_contains(folio, last_byte >> PAGE_SHIFT)) {

		size_t zero_offset = offset_in_folio(folio, last_byte);



		if (zero_offset) {