e2fsck: expand root dir if linking l+f fails

If there isn't space in the root directory to add the lost+found
entry, try expanding the root directory before failing the fsck.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

e2fsck/pass3.c

@@ -530,7 +530,15 @@ skip_new_block:
 	 * Finally, create the directory link
 	 */
 	pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
+	if (pctx.errcode == EXT2_ET_DIR_NO_SPACE) {
+		pctx.errcode = ext2fs_expand_dir(fs, EXT2_ROOT_INO);
+		if (pctx.errcode)
+			goto link_error;
+		pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino,
+					   EXT2_FT_DIR);
+	}
 	if (pctx.errcode) {
+link_error:
 		pctx.str = "ext2fs_link";
 		fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
 		return 0;

tests/f_expandroot_create_lnf/expect.1

@@ -0,0 +1,12 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+/lost+found not found.  Create? yes
+
+Pass 3A: Optimizing directories
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 16/64 files (0.0% non-contiguous), 33/1024 blocks
+Exit status is 1

tests/f_expandroot_create_lnf/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 16/64 files (6.3% non-contiguous), 33/1024 blocks
+Exit status is 0

tests/f_expandroot_create_lnf/name

@@ -0,0 +1 @@
+no space in root to create lost+found entry