Commit f525152a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Christian Brauner
Browse files

iomap: factor out a iomap_writepage_map_block helper 



Split the loop body that calls into the file system to map a block and
add it to the ioend into a separate helper to prefer for refactoring of
the surrounding code.

Note that this was the only place in iomap_writepage_map that could
return an error, so include the call to ->discard_folio into the new
helper as that will help to avoid code duplication in the future.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231207072710.176093-12-hch@lst.de


Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 6b865d65

fs/iomap/buffered-io.c

+43 −27
Original line number Diff line number Diff line
@@ -1712,6 +1712,45 @@ static void iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, 
	wbc_account_cgroup_owner(wbc, &folio->page, len);

}



static int iomap_writepage_map_blocks(struct iomap_writepage_ctx *wpc,

		struct writeback_control *wbc, struct folio *folio,

		struct inode *inode, u64 pos, unsigned *count,

		struct list_head *submit_list)

{

	int error;



	error = wpc->ops->map_blocks(wpc, inode, pos);

	if (error)

		goto fail;

	trace_iomap_writepage_map(inode, &wpc->iomap);



	switch (wpc->iomap.type) {

	case IOMAP_INLINE:

		WARN_ON_ONCE(1);

		error = -EIO;

		break;

	case IOMAP_HOLE:

		break;

	default:

		iomap_add_to_ioend(wpc, wbc, folio, inode, pos, submit_list);

		(*count)++;

	}



fail:

	/*

	 * We cannot cancel the ioend directly here on error.  We may have

	 * already set other pages under writeback and hence we have to run I/O

	 * completion to mark the error state of the pages under writeback

	 * appropriately.

	 *

	 * Just let the file system know what portion of the folio failed to

	 * map.

	 */

	if (error && wpc->ops->discard_folio)

		wpc->ops->discard_folio(folio, pos);

	return error;

}



/*

 * Check interaction of the folio with the file end.

 *
@@ -1796,7 +1835,8 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc, 
	unsigned nblocks = i_blocks_per_folio(inode, folio);

	u64 pos = folio_pos(folio);

	u64 end_pos = pos + folio_size(folio);

	int error = 0, count = 0, i;

	unsigned count = 0;

	int error = 0, i;

	LIST_HEAD(submit_list);



	trace_iomap_writepage(inode, pos, folio_size(folio));
@@ -1822,19 +1862,10 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc, 
	for (i = 0; i < nblocks && pos < end_pos; i++, pos += len) {

		if (ifs && !ifs_block_is_dirty(folio, ifs, i))

			continue;



		error = wpc->ops->map_blocks(wpc, inode, pos);

		error = iomap_writepage_map_blocks(wpc, wbc, folio, inode, pos,

				&count, &submit_list);

		if (error)

			break;

		trace_iomap_writepage_map(inode, &wpc->iomap);

		if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) {

			error = -EIO;

			break;

		}

		if (wpc->iomap.type == IOMAP_HOLE)

			continue;

		iomap_add_to_ioend(wpc, wbc, folio, inode, pos, &submit_list);

		count++;

	}

	if (count)

		wpc->nr_folios++;
@@ -1844,21 +1875,6 @@ static int iomap_writepage_map(struct iomap_writepage_ctx *wpc, 
	WARN_ON_ONCE(folio_test_writeback(folio));

	WARN_ON_ONCE(folio_test_dirty(folio));



	/*

	 * We cannot cancel the ioend directly here on error.  We may have

	 * already set other pages under writeback and hence we have to run I/O

	 * completion to mark the error state of the pages under writeback

	 * appropriately.

	 */

	if (unlikely(error)) {

		/*

		 * Let the filesystem know what portion of the current page

		 * failed to map.

		 */

		if (wpc->ops->discard_folio)

			wpc->ops->discard_folio(folio, pos);

	}



	/*

	 * We can have dirty bits set past end of file in page_mkwrite path

	 * while mapping the last partial folio. Hence it's better to clear