[PATCH 03/16] cramfs: Convert cramfs_read_folio to use a folio

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

Remove the conversion back into a page and use the folio APIs throughout.
Remove the setting of PG_error instead of converting it; it is unused
by core code or by the rest of cramfs, so it serves no purpose here.
Use folio_end_read() to save an atomic operation and unify the two
exit paths.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 fs/cramfs/inode.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index d818ed1bb07e..b84d1747a020 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -811,19 +811,19 @@ static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, un
 
 static int cramfs_read_folio(struct file *file, struct folio *folio)
 {
-	struct page *page = &folio->page;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = folio->mapping->host;
 	u32 maxblock;
 	int bytes_filled;
 	void *pgdata;
+	bool success = false;
 
 	maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	bytes_filled = 0;
-	pgdata = kmap_local_page(page);
+	pgdata = kmap_local_folio(folio, 0);
 
-	if (page->index < maxblock) {
+	if (folio->index < maxblock) {
 		struct super_block *sb = inode->i_sb;
-		u32 blkptr_offset = OFFSET(inode) + page->index * 4;
+		u32 blkptr_offset = OFFSET(inode) + folio->index * 4;
 		u32 block_ptr, block_start, block_len;
 		bool uncompressed, direct;
 
@@ -844,7 +844,7 @@ static int cramfs_read_folio(struct file *file, struct folio *folio)
 			if (uncompressed) {
 				block_len = PAGE_SIZE;
 				/* if last block: cap to file length */
-				if (page->index == maxblock - 1)
+				if (folio->index == maxblock - 1)
 					block_len =
 						offset_in_page(inode->i_size);
 			} else {
@@ -861,7 +861,7 @@ static int cramfs_read_folio(struct file *file, struct folio *folio)
 			 * from the previous block's pointer.
 			 */
 			block_start = OFFSET(inode) + maxblock * 4;
-			if (page->index)
+			if (folio->index)
 				block_start = *(u32 *)
 					cramfs_read(sb, blkptr_offset - 4, 4);
 			/* Beware... previous ptr might be a direct ptr */
@@ -906,17 +906,12 @@ static int cramfs_read_folio(struct file *file, struct folio *folio)
 	}
 
 	memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled);
-	flush_dcache_page(page);
-	kunmap_local(pgdata);
-	SetPageUptodate(page);
-	unlock_page(page);
-	return 0;
+	flush_dcache_folio(folio);
 
+	success = true;
 err:
 	kunmap_local(pgdata);
-	ClearPageUptodate(page);
-	SetPageError(page);
-	unlock_page(page);
+	folio_end_read(folio, success);
 	return 0;
 }
 
-- 
2.43.0