erofs: get rid of {get,put}_page() for ztailpacking data

[ Upstream commit 96debe8 ]

The compressed data for the ztailpacking feature is fetched from
the metadata inode (e.g., bd_inode), which is folio-based.

Therefore, the folio interface should be used instead.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250626085459.339830-1-hsiangkao@linux.alibaba.com
Stable-dep-of: 131897c ("erofs: fix invalid algorithm for encoded extents")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: hsiangkao

fs/erofs/zdata.c

@@ -805,6 +805,7 @@ static int z_erofs_pcluster_begin(struct z_erofs_frontend *fe)
 	struct erofs_map_blocks *map = &fe->map;
 	struct super_block *sb = fe->inode->i_sb;
 	struct z_erofs_pcluster *pcl = NULL;
+	void *ptr;
 	int ret;
 
 	DBG_BUGON(fe->pcl);
@@ -854,15 +855,13 @@ static int z_erofs_pcluster_begin(struct z_erofs_frontend *fe)
 		/* bind cache first when cached decompression is preferred */
 		z_erofs_bind_cache(fe);
 	} else {
-		void *mptr;
-
-		mptr = erofs_read_metabuf(&map->buf, sb, map->m_pa, false);
-		if (IS_ERR(mptr)) {
-			ret = PTR_ERR(mptr);
+		ptr = erofs_read_metabuf(&map->buf, sb, map->m_pa, false);
+		if (IS_ERR(ptr)) {
+			ret = PTR_ERR(ptr);
 			erofs_err(sb, "failed to get inline data %d", ret);
 			return ret;
 		}
-		get_page(map->buf.page);
+		folio_get(page_folio(map->buf.page));
 		WRITE_ONCE(fe->pcl->compressed_bvecs[0].page, map->buf.page);
 		fe->pcl->pageofs_in = map->m_pa & ~PAGE_MASK;
 		fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE;
@@ -1325,9 +1324,8 @@ static int z_erofs_decompress_pcluster(struct z_erofs_backend *be, int err)
 
 	/* must handle all compressed pages before actual file pages */
 	if (pcl->from_meta) {
-		page = pcl->compressed_bvecs[0].page;
+		folio_put(page_folio(pcl->compressed_bvecs[0].page));
 		WRITE_ONCE(pcl->compressed_bvecs[0].page, NULL);
-		put_page(page);
 	} else {
 		/* managed folios are still left in compressed_bvecs[] */
 		for (i = 0; i < pclusterpages; ++i) {