f2fs: remove non-uptodate folio from the page cache in move_data_block

During data movement, move_data_block acquires file folio without
triggering a file read. Such folio are typically not uptodate, they need
to be removed from the page cache after gc complete. This patch marks
folio with the PG_dropbehind flag and uses folio_end_dropbehind to
remove folio from the page cache.

Signed-off-by: Yunlei He <[email protected]>
Signed-off-by: Yongpeng Yang <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

fs/f2fs/gc.c

@@ -1453,7 +1453,11 @@ up_out:
 put_out:
 	f2fs_put_dnode(&dn);
 out:
-	f2fs_folio_put(folio, true);
+	if (!folio_test_uptodate(folio))
+		__folio_set_dropbehind(folio);
+	folio_unlock(folio);
+	folio_end_dropbehind(folio);
+	folio_put(folio);
 	return err;
 }