[PATCH v4 2/8] idmapped-mounts: switch to getopt_long_only()

[Christian Brauner <brauner@kernel.org>]

From: Christian Brauner <christian.brauner@ubuntu.com>

We're not using the shortopts anywhere anyway  and shouldn't encourage
using shortopts.  It's much more descriptive to see:

$here/src/idmapped-mounts/idmapped-mounts \
        --test-btrfs \
        --device "$TEST_DEV" \
        --mountpoint "$TEST_DIR" \
        --scratch-device "$SCRATCH_DEV" \
        --scratch-mountpoint "$SCRATCH_MNT"
        --fstype "$FSTYP"

in a test than it is to see:

$here/src/idmapped-mounts/idmapped-mounts \
        -b
        -d "$TEST_DEV" \
        -m "$TEST_DIR" \
        -s "$SCRATCH_DEV" \
        -a "$SCRATCH_MNT" \
        -f "$FSTYP"

In the second case one has to go consult the source code to make sure
that the correct option is passed. In the first case one can just see it
directly.

Cc: fstests@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v2 */
patch not present

/* v3 */
- Christoph Hellwig <hch@lst.de>:
  - Split into separate patch.

/* v4 */
- Christoph Hellwig <hch@lst.de>:
  - Pass empty string for optstring argument in getopt_long_only().
---
 src/idmapped-mounts/idmapped-mounts.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c
index 69dcc027..0e6698bd 100644
--- a/src/idmapped-mounts/idmapped-mounts.c
+++ b/src/idmapped-mounts/idmapped-mounts.c
@@ -8717,8 +8717,11 @@ static void usage(void)
 	fprintf(stderr, "    Run idmapped mount tests\n\n");
 
 	fprintf(stderr, "Arguments:\n");
-	fprintf(stderr, "-d --device        Device used in the tests\n");
-	fprintf(stderr, "-m --mountpoint    Mountpoint of device\n");
+	fprintf(stderr, "--device        Device used in the tests\n");
+	fprintf(stderr, "--fstype        Filesystem type used in the tests\n");
+	fprintf(stderr, "--help          Print help\n");
+	fprintf(stderr, "--mountpoint    Mountpoint of device\n");
+	fprintf(stderr, "--supported     Test whether idmapped mounts are supported on this filesystem\n");
 
 	_exit(EXIT_SUCCESS);
 }
@@ -8826,7 +8829,7 @@ int main(int argc, char *argv[])
 	int index = 0;
 	bool supported = false;
 
-	while ((ret = getopt_long(argc, argv, "", longopts, &index)) != -1) {
+	while ((ret = getopt_long_only(argc, argv, "", longopts, &index)) != -1) {
 		switch (ret) {
 		case 'd':
 			t_device = optarg;
-- 
2.30.2