Commit 5d3bb77e authored by Gao Xiang's avatar Gao Xiang
Browse files

erofs: support multi-page folios for erofs_bread() 

If the requested page is part of the previous multi-page folio, there
is no need to call read_mapping_folio() again.

Also, get rid of the remaining one of page->index [1] in our codebase.

[1] https://lore.kernel.org/r/Zp8fgUSIBGQ1TN0D@casper.infradead.org



Cc: Matthew Wilcox <willy@infradead.org>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240723073024.875290-1-hsiangkao@linux.alibaba.com
parent 684b290a

fs/erofs/data.c

+12 −18
Original line number Diff line number Diff line
@@ -21,38 +21,32 @@ void erofs_put_metabuf(struct erofs_buf *buf) 
	if (!buf->page)

		return;

	erofs_unmap_metabuf(buf);

	put_page(buf->page);

	folio_put(page_folio(buf->page));

	buf->page = NULL;

}



/*

 * Derive the block size from inode->i_blkbits to make compatible with

 * anonymous inode in fscache mode.

 */

void *erofs_bread(struct erofs_buf *buf, erofs_off_t offset,

		  enum erofs_kmap_type type)

{

	pgoff_t index = offset >> PAGE_SHIFT;

	struct page *page = buf->page;

	struct folio *folio;

	unsigned int nofs_flag;

	struct folio *folio = NULL;



	if (!page || page->index != index) {

	if (buf->page) {

		folio = page_folio(buf->page);

		if (folio_file_page(folio, index) != buf->page)

			erofs_unmap_metabuf(buf);

	}

	if (!folio || !folio_contains(folio, index)) {

		erofs_put_metabuf(buf);



		nofs_flag = memalloc_nofs_save();

		folio = read_cache_folio(buf->mapping, index, NULL, NULL);

		memalloc_nofs_restore(nofs_flag);

		folio = read_mapping_folio(buf->mapping, index, NULL);

		if (IS_ERR(folio))

			return folio;



		/* should already be PageUptodate, no need to lock page */

		page = folio_file_page(folio, index);

		buf->page = page;

	}

	buf->page = folio_file_page(folio, index);



	if (buf->kmap_type == EROFS_NO_KMAP) {

		if (type == EROFS_KMAP)

			buf->base = kmap_local_page(page);

			buf->base = kmap_local_page(buf->page);

		buf->kmap_type = type;

	} else if (buf->kmap_type != type) {

		DBG_BUGON(1);