btrfs: convert zlib_decompress() to take a folio

The old page API is being gradually replaced and converted to use folio
to improve code readability and avoid repeated conversion between page
and folio. And memcpy_to_page() can be replaced with memcpy_to_folio().
But there is no memzero_folio(), but it can be replaced equivalently by
folio_zero_range().

Signed-off-by: Li Zetao <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: Li Zetao

fs/btrfs/compression.c

@@ -142,7 +142,7 @@ static int compression_decompress(int type, struct list_head *ws,
 		unsigned long dest_pgoff, size_t srclen, size_t destlen)
 {
 	switch (type) {
-	case BTRFS_COMPRESS_ZLIB: return zlib_decompress(ws, data_in, dest_page,
+	case BTRFS_COMPRESS_ZLIB: return zlib_decompress(ws, data_in, page_folio(dest_page),
 						dest_pgoff, srclen, destlen);
 	case BTRFS_COMPRESS_LZO:  return lzo_decompress(ws, data_in, dest_page,
 						dest_pgoff, srclen, destlen);

fs/btrfs/compression.h

@@ -162,7 +162,7 @@ int zlib_compress_folios(struct list_head *ws, struct address_space *mapping,
 		unsigned long *total_in, unsigned long *total_out);
 int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
 int zlib_decompress(struct list_head *ws, const u8 *data_in,
-		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
+		struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
 		size_t destlen);
 struct list_head *zlib_alloc_workspace(unsigned int level);
 void zlib_free_workspace(struct list_head *ws);

fs/btrfs/zlib.c

@@ -393,7 +393,7 @@ int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb)
 }
 
 int zlib_decompress(struct list_head *ws, const u8 *data_in,
-		struct page *dest_page, unsigned long dest_pgoff, size_t srclen,
+		struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
 		size_t destlen)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
@@ -421,12 +421,12 @@ int zlib_decompress(struct list_head *ws, const u8 *data_in,
 
 	ret = zlib_inflateInit2(&workspace->strm, wbits);
 	if (unlikely(ret != Z_OK)) {
-		struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
+		struct btrfs_inode *inode = folio_to_inode(dest_folio);
 
 		btrfs_err(inode->root->fs_info,
 		"zlib decompression init failed, error %d root %llu inode %llu offset %llu",
 			  ret, btrfs_root_id(inode->root), btrfs_ino(inode),
-			  page_offset(dest_page));
+			  folio_pos(dest_folio));
 		return -EIO;
 	}
 
@@ -439,16 +439,16 @@ int zlib_decompress(struct list_head *ws, const u8 *data_in,
 	if (ret != Z_STREAM_END)
 		goto out;
 
-	memcpy_to_page(dest_page, dest_pgoff, workspace->buf, to_copy);
+	memcpy_to_folio(dest_folio, dest_pgoff, workspace->buf, to_copy);
 
 out:
 	if (unlikely(to_copy != destlen)) {
-		struct btrfs_inode *inode = BTRFS_I(dest_page->mapping->host);
+		struct btrfs_inode *inode = folio_to_inode(dest_folio);
 
 		btrfs_err(inode->root->fs_info,
 "zlib decompression failed, error %d root %llu inode %llu offset %llu decompressed %lu expected %zu",
 			  ret, btrfs_root_id(inode->root), btrfs_ino(inode),
-			  page_offset(dest_page), to_copy, destlen);
+			  folio_pos(dest_folio), to_copy, destlen);
 		ret = -EIO;
 	} else {
 		ret = 0;
@@ -457,7 +457,7 @@ int zlib_decompress(struct list_head *ws, const u8 *data_in,
 	zlib_inflateEnd(&workspace->strm);
 
 	if (unlikely(to_copy < destlen))
-		memzero_page(dest_page, dest_pgoff + to_copy, destlen - to_copy);
+		folio_zero_range(dest_folio, dest_pgoff + to_copy, destlen - to_copy);
 	return ret;
 }