Unverified Commit 8b45a4f4 authored by Luis Chamberlain's avatar Luis Chamberlain Committed by Christian Brauner
Browse files

fs/mpage: use blocks_per_folio instead of blocks_per_page 



Convert mpage to folios and adjust accounting for the number of blocks
within a folio instead of a single page. This also adjusts the number
of pages we should process to be the size of the folio to ensure we
always read a full folio.

Note that the page cache code already ensures do_mpage_readpage() will
work with folios respecting the address space min order, this ensures
that so long as folio_size() is used for our requirements mpage will
also now be able to process block sizes larger than the page size.

Originally-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20250221223823.1680616-5-mcgrof@kernel.org


Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 86c60efd

fs/mpage.c

+21 −21
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ static void map_buffer_to_folio(struct folio *folio, struct buffer_head *bh, 
		 * don't make any buffers if there is only one buffer on

		 * the folio and the folio just needs to be set up to date

		 */

		if (inode->i_blkbits == PAGE_SHIFT &&

		if (inode->i_blkbits == folio_shift(folio) &&

		    buffer_uptodate(bh)) {

			folio_mark_uptodate(folio);

			return;
@@ -153,7 +153,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
	struct folio *folio = args->folio;

	struct inode *inode = folio->mapping->host;

	const unsigned blkbits = inode->i_blkbits;

	const unsigned blocks_per_page = PAGE_SIZE >> blkbits;

	const unsigned blocks_per_folio = folio_size(folio) >> blkbits;

	const unsigned blocksize = 1 << blkbits;

	struct buffer_head *map_bh = &args->map_bh;

	sector_t block_in_file;
@@ -161,7 +161,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
	sector_t last_block_in_file;

	sector_t first_block;

	unsigned page_block;

	unsigned first_hole = blocks_per_page;

	unsigned first_hole = blocks_per_folio;

	struct block_device *bdev = NULL;

	int length;

	int fully_mapped = 1;
@@ -182,7 +182,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
		goto confused;



	block_in_file = folio_pos(folio) >> blkbits;

	last_block = block_in_file + args->nr_pages * blocks_per_page;

	last_block = block_in_file + ((args->nr_pages * PAGE_SIZE) >> blkbits);

	last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;

	if (last_block > last_block_in_file)

		last_block = last_block_in_file;
@@ -204,7 +204,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
				clear_buffer_mapped(map_bh);

				break;

			}

			if (page_block == blocks_per_page)

			if (page_block == blocks_per_folio)

				break;

			page_block++;

			block_in_file++;
@@ -216,7 +216,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
	 * Then do more get_blocks calls until we are done with this folio.

	 */

	map_bh->b_folio = folio;

	while (page_block < blocks_per_page) {

	while (page_block < blocks_per_folio) {

		map_bh->b_state = 0;

		map_bh->b_size = 0;
@@ -229,7 +229,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 


		if (!buffer_mapped(map_bh)) {

			fully_mapped = 0;

			if (first_hole == blocks_per_page)

			if (first_hole == blocks_per_folio)

				first_hole = page_block;

			page_block++;

			block_in_file++;
@@ -247,7 +247,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
			goto confused;

		}

	

		if (first_hole != blocks_per_page)

		if (first_hole != blocks_per_folio)

			goto confused;		/* hole -> non-hole */



		/* Contiguous blocks? */
@@ -260,7 +260,7 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
			if (relative_block == nblocks) {

				clear_buffer_mapped(map_bh);

				break;

			} else if (page_block == blocks_per_page)

			} else if (page_block == blocks_per_folio)

				break;

			page_block++;

			block_in_file++;
@@ -268,8 +268,8 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
		bdev = map_bh->b_bdev;

	}



	if (first_hole != blocks_per_page) {

		folio_zero_segment(folio, first_hole << blkbits, PAGE_SIZE);

	if (first_hole != blocks_per_folio) {

		folio_zero_segment(folio, first_hole << blkbits, folio_size(folio));

		if (first_hole == 0) {

			folio_mark_uptodate(folio);

			folio_unlock(folio);
@@ -303,10 +303,10 @@ static struct bio *do_mpage_readpage(struct mpage_readpage_args *args) 
	relative_block = block_in_file - args->first_logical_block;

	nblocks = map_bh->b_size >> blkbits;

	if ((buffer_boundary(map_bh) && relative_block == nblocks) ||

	    (first_hole != blocks_per_page))

	    (first_hole != blocks_per_folio))

		args->bio = mpage_bio_submit_read(args->bio);

	else

		args->last_block_in_bio = first_block + blocks_per_page - 1;

		args->last_block_in_bio = first_block + blocks_per_folio - 1;

out:

	return args->bio;
@@ -385,7 +385,7 @@ int mpage_read_folio(struct folio *folio, get_block_t get_block) 
{

	struct mpage_readpage_args args = {

		.folio = folio,

		.nr_pages = 1,

		.nr_pages = folio_nr_pages(folio),

		.get_block = get_block,

	};
@@ -456,12 +456,12 @@ static int __mpage_writepage(struct folio *folio, struct writeback_control *wbc, 
	struct address_space *mapping = folio->mapping;

	struct inode *inode = mapping->host;

	const unsigned blkbits = inode->i_blkbits;

	const unsigned blocks_per_page = PAGE_SIZE >> blkbits;

	const unsigned blocks_per_folio = folio_size(folio) >> blkbits;

	sector_t last_block;

	sector_t block_in_file;

	sector_t first_block;

	unsigned page_block;

	unsigned first_unmapped = blocks_per_page;

	unsigned first_unmapped = blocks_per_folio;

	struct block_device *bdev = NULL;

	int boundary = 0;

	sector_t boundary_block = 0;
@@ -486,12 +486,12 @@ static int __mpage_writepage(struct folio *folio, struct writeback_control *wbc, 
				 */

				if (buffer_dirty(bh))

					goto confused;

				if (first_unmapped == blocks_per_page)

				if (first_unmapped == blocks_per_folio)

					first_unmapped = page_block;

				continue;

			}



			if (first_unmapped != blocks_per_page)

			if (first_unmapped != blocks_per_folio)

				goto confused;	/* hole -> non-hole */



			if (!buffer_dirty(bh) || !buffer_uptodate(bh))
@@ -536,7 +536,7 @@ static int __mpage_writepage(struct folio *folio, struct writeback_control *wbc, 
		goto page_is_mapped;

	last_block = (i_size - 1) >> blkbits;

	map_bh.b_folio = folio;

	for (page_block = 0; page_block < blocks_per_page; ) {

	for (page_block = 0; page_block < blocks_per_folio; ) {



		map_bh.b_state = 0;

		map_bh.b_size = 1 << blkbits;
@@ -618,14 +618,14 @@ static int __mpage_writepage(struct folio *folio, struct writeback_control *wbc, 
	BUG_ON(folio_test_writeback(folio));

	folio_start_writeback(folio);

	folio_unlock(folio);

	if (boundary || (first_unmapped != blocks_per_page)) {

	if (boundary || (first_unmapped != blocks_per_folio)) {

		bio = mpage_bio_submit_write(bio);

		if (boundary_block) {

			write_boundary_block(boundary_bdev,

					boundary_block, 1 << blkbits);

		}

	} else {

		mpd->last_block_in_bio = first_block + blocks_per_page - 1;

		mpd->last_block_in_bio = first_block + blocks_per_folio - 1;

	}

	goto out;