mke2fs: clean up error handling in mke2fs_setup_tdb()

Avoid memory leaks on error paths, and make sure we issue the correct
error messages in the case of (highly) unlikely errors.

Original patch submitted by Namhyung Kim <namhyung@gmail.com>, but
highly rewritten since then.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index a437816..c07deba 100644 (file)
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -1915,8 +1915,8 @@ open_err_out:
 
 static int mke2fs_setup_tdb(const char *name, io_manager *io_ptr)
 {
-       errcode_t retval = 0;
-       char *tdb_dir, *tdb_file;
+       errcode_t retval = ENOMEM;
+       char *tdb_dir, *tdb_file = NULL;
        char *device_name, *tmp_name;
 
        /*
@@ -1934,38 +1934,40 @@ static int mke2fs_setup_tdb(const char *name, io_manager *io_ptr)
                return 0;
 
        tmp_name = strdup(name);
-       if (!tmp_name) {
-       alloc_fn_fail:
-               com_err(program_name, ENOMEM, 
-                       _("Couldn't allocate memory for tdb filename\n"));
-               return ENOMEM;
-       }
+       if (!tmp_name)
+               goto errout;
        device_name = basename(tmp_name);
        tdb_file = malloc(strlen(tdb_dir) + 8 + strlen(device_name) + 7 + 1);
-       if (!tdb_file)
-               goto alloc_fn_fail;
+       if (!tdb_file) {
+               free(tmp_name);
+               goto errout;
+       }
        sprintf(tdb_file, "%s/mke2fs-%s.e2undo", tdb_dir, device_name);
+       free(tmp_name);
 
        if (!access(tdb_file, F_OK)) {
                if (unlink(tdb_file) < 0) {
                        retval = errno;
-                       com_err(program_name, retval,
-                               _("while trying to delete %s"),
-                               tdb_file);
-                       free(tdb_file);
-                       return retval;
+                       goto errout;
                }
        }
 
        set_undo_io_backing_manager(*io_ptr);
        *io_ptr = undo_io_manager;
-       set_undo_io_backup_file(tdb_file);
+       retval = set_undo_io_backup_file(tdb_file);
+       if (retval)
+               goto errout;
        printf(_("Overwriting existing filesystem; this can be undone "
                 "using the command:\n"
                 "    e2undo %s %s\n\n"), tdb_file, name);
 
        free(tdb_file);
-       free(tmp_name);
+       return 0;
+
+errout:
+       free(tdb_file);
+       com_err(program_name, retval,
+               _("while trying to setup undo file\n"));
        return retval;
 }