fdisk: fix -t/--type when auto-creating a label on empty devices

fdisk_create_disklabel(cxt, NULL) always resolves to "dos" or "sun",
regardless of any restriction set via -t/--type. If -t disabled "dos"
(like in -t gpt) auto-creation on an empty device fails with -EINVAL.
As the return code was never checked, the failure was silent,
thus no label got created and no error was shown.

The requested label via -t is now passed to the auto-create call,
which warns if creation still fails.

There is no behavior change when -t is not used in the program.

Signed-off-by: Henrique Surian Stobbe <henriquesstobbe@gmail.com>

diff --git a/disk-utils/fdisk.8.adoc b/disk-utils/fdisk.8.adoc
index fcaaffc51c0537671db03f552b74bafe238d9a2d..95fe6c510c8d64c928cb48a3ed3fecda41fe1120 100644 (file)
--- a/disk-utils/fdisk.8.adoc
+++ b/disk-utils/fdisk.8.adoc
@@ -85,7 +85,7 @@ Print SIZE in bytes rather than in human readable format.
 Print the size in 512-byte sectors of each given block device. This option is DEPRECATED in favour of *blockdev*(8).
 
 *-t*, *--type* _type_::
-Enable support only for disklabels of the specified _type_, and disable support for all other types.
+Enable support only for disklabels of the specified _type_, and disable support for all other types. This also determines the disklabel type used when *fdisk* automatically creates a new disklabel on an empty device.
 
 *-u*, *--units*[**=**_unit_]::
 When listing partition tables, show sizes in 'sectors' or in 'cylinders'. The default is to show sizes in sectors. For backward compatibility, it is possible to use the option without the _unit_ argument -- then the default is used. Note that the optional _unit_ argument cannot be separated from the *-u* option by a space; the correct form is *-u=cylinders*, for example.

diff --git a/disk-utils/fdisk.c b/disk-utils/fdisk.c
index 02ffb964aea0bc5e98b3f93c565861f7a9f65f49..bd90d14d9ce577042e0854268b09105cbb7d7f2c 100644 (file)
--- a/disk-utils/fdisk.c
+++ b/disk-utils/fdisk.c
@@ -1149,6 +1149,7 @@ int main(int argc, char **argv)
        struct fdisk_context *cxt;
        char *outarg = NULL;
        const char *devname, *lockmode = NULL;
+       const char *wanted_label = NULL;
        enum {
                OPT_BYTES       = CHAR_MAX + 1,
                OPT_LOCK
@@ -1274,6 +1275,7 @@ int main(int argc, char **argv)
                        if (!lb)
                                errx(EXIT_FAILURE, _("unsupported disklabel: %s"), optarg);
                        fdisk_label_set_disabled(lb, 0);
+                       wanted_label = fdisk_label_get_name(lb);
                        break;
                }
                case 'u':
@@ -1401,8 +1403,11 @@ int main(int argc, char **argv)
 
                if (!fdisk_has_label(cxt)) {
                        fdisk_info(cxt, _("Device does not contain a recognized partition table."));
-                       if (!noauto_pt)
-                               fdisk_create_disklabel(cxt, NULL);
+                       if (!noauto_pt) {
+                               rc = fdisk_create_disklabel(cxt, wanted_label);
+                               if (rc)
+                                       fdisk_warn(cxt, _("Failed to create a disklabel."));
+                       }
 
                } else if (fdisk_is_label(cxt, GPT) && fdisk_gpt_is_hybrid(cxt))
                        fdisk_warnx(cxt, _(