[LTP] [RFC] [PATCH] lib/tst_mkfs: Exit with TCONF on missing mkfs.foo

[Cyril Hrubis <chrubis@suse.cz>]

When mkfs.foo is not installed the tst_mkfs() exits the test with TBROK
which is not correct as the return should be TCONF instead.

To make it exit with TCONF we have to:

* Use mkfs.foo directly instead of the deprecated mkfs wrapper
  - since the wrapper always exits with 1 in case of any failure
  - we do that in the shell test.sh already anyway

* Check for the return value from tst_run_cmd()
  - when execvp() fails the child does _exit(-1)
    which sets the exit value to 255
  - this is not ideal as we should examine errno for ENOENT
    as well, but that would complicate the code since we would
    have to propagate the reason of the execvp() failure to the
    parent somehow

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 lib/tst_mkfs.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/tst_mkfs.c b/lib/tst_mkfs.c
index 7d9c924..c08b09e 100644
--- a/lib/tst_mkfs.c
+++ b/lib/tst_mkfs.c
@@ -25,8 +25,9 @@ void tst_mkfs(void (cleanup_fn)(void), const char *dev,
               const char *fs_type, const char *const fs_opts[],
               const char *extra_opt)
 {
-	int i, pos = 3;
-	const char *argv[OPTS_MAX] = {"mkfs", "-t", fs_type};
+	int i, pos = 1, ret;
+	char mkfs[64];
+	const char *argv[OPTS_MAX] = {mkfs};
 	char fs_opts_str[1024] = "";
 
 	if (!dev)
@@ -35,6 +36,8 @@ void tst_mkfs(void (cleanup_fn)(void), const char *dev,
 	if (!fs_type)
 		tst_brkm(TBROK, cleanup_fn, "No fs_type specified");
 
+	snprintf(mkfs, sizeof(mkfs), "mkfs.%s", mkfs);
+
 	if (fs_opts) {
 		for (i = 0; fs_opts[i]; i++) {
 			argv[pos++] = fs_opts[i];
@@ -65,7 +68,18 @@ void tst_mkfs(void (cleanup_fn)(void), const char *dev,
 
 	tst_resm(TINFO, "Formatting %s with %s opts='%s' extra opts='%s'",
 	         dev, fs_type, fs_opts_str, extra_opt ? extra_opt : "");
-	tst_run_cmd(cleanup_fn, argv, "/dev/null", NULL, 0);
+	ret = tst_run_cmd(cleanup_fn, argv, "/dev/null", NULL, 1);
+
+	switch (ret) {
+	case 0:
+	break;
+	case 255:
+		tst_brkm(TCONF, cleanup_fn,
+			 "%s not found in $PATH", mkfs);
+	default:
+		tst_brkm(TBROK, cleanup_fn,
+			 "%s failed with %i", mkfs, ret);
+	}
 }
 
 const char *tst_dev_fs_type(void)
-- 
2.7.3


-- 
Cyril Hrubis
chrubis@suse.cz