110 	struct dentry *upper;  in ovl_dentry_revalidate_common()  local
120 	upper = ovl_i_dentry_upper(inode);  in ovl_dentry_revalidate_common()
121 	if (upper)  in ovl_dentry_revalidate_common()
122 		ret = ovl_revalidate_real(upper, flags, weak);  in ovl_dentry_revalidate_common()
197 /* Sync real dirty inodes in upper filesystem (if it exists) */
243  * Get the filesystem statistics.  As writes always target the upper layer
244  * filesystem pass the statfs to the upper filesystem (if it exists)
337 		 * allowed as upper are limited to "normal" ones, where checking  in ovl_workdir_create()
548 		pr_err("upper fs is r/o, try multi-lower layers mount\n");  in ovl_get_upper()
728 	 * Upper should support d_type, else whiteouts are visible.  Given  in ovl_make_workdir()
729 	 * workdir and upper are on same fs, we can do iterate_dir() on  in ovl_make_workdir()
739 		pr_warn("upper fs needs to support d_type.\n");  in ovl_make_workdir()
741 	/* Check if upper/work fs supports O_TMPFILE */  in ovl_make_workdir()
747 		pr_warn("upper fs does not support tmpfile.\n");  in ovl_make_workdir()
750 	/* Check if upper/work fs supports RENAME_WHITEOUT */  in ovl_make_workdir()
757 		pr_warn("upper fs does not support RENAME_WHITEOUT.\n");  in ovl_make_workdir()
760 	 * Check if upper/work fs supports (trusted|user).overlay.* xattr  in ovl_make_workdir()
764 		pr_warn("failed to set xattr on upper\n");  in ovl_make_workdir()
798 	 * We allowed sub-optimal upper fs configuration and don't want to break  in ovl_make_workdir()
799 	 * users over kernel upgrade, but we never allowed remote upper fs, so  in ovl_make_workdir()
800 	 * we can enforce strict requirements for remote upper fs.  in ovl_make_workdir()
804 		pr_err("upper fs missing required features.\n");  in ovl_make_workdir()
821 	/* Check if upper/work fs supports file handles */  in ovl_make_workdir()
825 		pr_warn("upper fs does not support file handles, falling back to index=off.\n");  in ovl_make_workdir()
829 	/* Check if upper fs has 32bit inode numbers */  in ovl_make_workdir()
888 	/* Verify lower root is upper root origin */  in ovl_get_indexdir()
892 		pr_err("failed to verify upper root origin\n");  in ovl_get_indexdir()
914 		 * Verify upper root is exclusively associated with index dir.  in ovl_get_indexdir()
915 		 * Older kernels stored upper fh in ".overlay.origin"  in ovl_get_indexdir()
917 		 * upper dir file handle. In any case, verify or set xattr  in ovl_get_indexdir()
918 		 * ".overlay.upper" to indicate that index may have  in ovl_get_indexdir()
931 			pr_err("failed to verify index dir 'upper' xattr\n");  in ovl_get_indexdir()
958 	 * lower inode of non-dir upper.  in ovl_lower_uuid_ok()
1049 	 * idx/fsid 0 are reserved for upper fs even with lower only overlay  in ovl_get_layers()
1055 	 * All lower layers that share the same fs as upper layer, use the same  in ovl_get_layers()
1056 	 * pseudo_dev as upper layer.  Allocate fs[0].pseudo_dev even for lower  in ovl_get_layers()
1058 	 * is_lower will be set if upper fs is shared with a lower layer.  in ovl_get_layers()
1062 		pr_err("failed to get anonymous bdev for upper fs\n");  in ovl_get_layers()
1148 		 * fsid, where fsid 0 is reserved for upper fs (even with  in ovl_get_layers()
1158 		pr_info("\"xino\" feature enabled using %d upper inode bits.\n",  in ovl_get_layers()
1229  * - upper/work dir of any overlayfs instance
1317 		/* Root inode uses upper st_ino/i_ino */  in ovl_get_root()
1381 	 * Layer 0 is reserved for upper even if there's no upper.  in ovl_fill_super()
1413 		err = ovl_get_upper(sb, ofs, &layers[0], &ctx->upper);  in ovl_fill_super()
1427 		err = ovl_get_workdir(sb, ofs, &ctx->upper, &ctx->work);  in ovl_fill_super()
1442 	/* If the upper fs is nonexistent, we mark overlayfs r/o too */  in ovl_fill_super()
1447 		pr_warn("The uuid=off requires a single fs for lower and upper, falling back to uuid=null.\n");  in ovl_fill_super()
1451 		ovl_init_uuid_xattr(sb, ofs, &ctx->upper);  in ovl_fill_super()
1455 		err = ovl_get_indexdir(sb, ofs, oe, &ctx->upper);  in ovl_fill_super()
1503 	root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe);  in ovl_fill_super()