findmnt: fix -k option parsing regression

It's a really bad idea to change any existing short option to support
optional arguments.

Fixes: https://github.com/util-linux/util-linux/issues/3512
References: 841d15e5d13dd0cc56e450c8dcc592211d66be27
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/findmnt.8.adoc b/misc-utils/findmnt.8.adoc
index 8a679153b498d171f9cdee0c6e2e1458a5be0167..9ac9316e340b77014262b59d0b8b835a969618b4 100644 (file)
--- a/misc-utils/findmnt.8.adoc
+++ b/misc-utils/findmnt.8.adoc
@@ -90,7 +90,7 @@ Use JSON output format.
 *-k*, *--kernel*[**=**_method_]::
 Reads information about filesystems from the kernel. This is the default output. The format is tree-like and only includes mount options managed by the kernel (see also *--mtab*).
 +
-The optional argument _method_ can be either:
+The optional argument _method_ is supported only for the long variant (--kernel). The short variant (-k) defaults to the mountinfo method for backward compatibility. The supported methods can be either:
 +
 * *mountinfo* - this is the default method and it reads data from the _/proc/self/mountinfo_ file.
 +

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index 46955fc2275949857cc77ec4a4c034bf79889f71..08903000f7b9cf0a1d8a18550b0dcd8d02b2f31e 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -1531,7 +1531,8 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_(" -F, --tab-file <path>  alternative file for -s, -m or -k options\n"), out);
        fputs(_(" -m, --mtab             search in table of mounted filesystems\n"
                "                          (includes user space mount options)\n"), out);
-       fputs(_(" -k, --kernel[=<method>] search in kernel mount table (default)\n"
+       fputs(_(" -k                     alias to '--kernel mountinfo'\n"), out);
+       fputs(_(" --kernel[=<method>]    search in kernel mount table (default)\n"
                "                          <method> is mountinfo or listmount\n"), out);
        fputs(_(" -N, --task <tid>       use alternative namespace (/proc/<tid>/mountinfo file)\n"), out);
        fputs(_(" -p, --poll[=<list>]    monitor changes in table of mounted filesystems\n"), out);
@@ -1764,7 +1765,8 @@ int main(int argc, char *argv[])
                FINDMNT_OPT_SHADOWED,
                FINDMNT_OPT_HYPERLINK,
                FINDMNT_OPT_ID,
-               FINDMNT_OPT_UNIQ_ID
+               FINDMNT_OPT_UNIQ_ID,
+               FINDMNT_OPT_KERNEL
        };
 
        static const struct option longopts[] = {
@@ -1781,7 +1783,7 @@ int main(int argc, char *argv[])
                { "help",           no_argument,       NULL, 'h'                 },
                { "invert",         no_argument,       NULL, 'i'                 },
                { "json",           no_argument,       NULL, 'J'                 },
-               { "kernel",         optional_argument, NULL, 'k'                 },
+               { "kernel",         optional_argument, NULL, FINDMNT_OPT_KERNEL  },
                { "list",           no_argument,       NULL, 'l'                 },
                { "mountpoint",     required_argument, NULL, 'M'                 },
                { "mtab",           no_argument,       NULL, 'm'                 },
@@ -1844,7 +1846,7 @@ int main(int argc, char *argv[])
        findmnt.flags |= FL_TREE;
 
        while ((c = getopt_long(argc, argv,
-                               "AabCcDd:ehIiJfF:o:O:p::PQ:k::lmM:nN:rst:uvRS:T:Uw:VxyH",
+                               "AabCcDd:ehIiJfF:o:O:p::PQ:klmM:nN:rst:uvRS:T:Uw:VxyH",
                                longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
@@ -1941,6 +1943,9 @@ int main(int argc, char *argv[])
                        findmnt.flags &= ~FL_TREE;
                        break;
                case 'k':
+                       tabtype = TABTYPE_KERNEL_MOUNTINFO;
+                       break;
+               case FINDMNT_OPT_KERNEL:
                        if (optarg) {
                                if (strcmp(optarg, "mountinfo") == 0)
                                        tabtype = TABTYPE_KERNEL_MOUNTINFO;