findmnt: add optional argument to --kernel

The number of methods for reading mount nodes from the kernel is
increasing. We need a way to specify the method on the findmnt(1)
command line.

Currently, findmnt only supports the "mountinfo" method. Another
method will be added in a separate commit.

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index 736c20e03811be2b3cc9aef1841c9e8e0af959ab..9a8cb0a3d0a45b27db3449d4ed8454edd2e7ab81 100644 (file)
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -92,7 +92,7 @@ enum {
 enum {
        TABTYPE_FSTAB = 1,
        TABTYPE_MTAB,
-       TABTYPE_KERNEL
+       TABTYPE_KERNEL_MOUNTINFO
 };
 
 /* column names */
@@ -1049,7 +1049,7 @@ static struct libmnt_table *parse_tabfiles(char **files,
                case TABTYPE_MTAB:
                        rc = mnt_table_parse_mtab(tb, path);
                        break;
-               case TABTYPE_KERNEL:
+               case TABTYPE_KERNEL_MOUNTINFO:
                        if (!path)
                                path = access(_PATH_PROC_MOUNTINFO, R_OK) == 0 ?
                                              _PATH_PROC_MOUNTINFO :
@@ -1057,6 +1057,9 @@ static struct libmnt_table *parse_tabfiles(char **files,
 
                        rc = mnt_table_parse_file(tb, path);
                        break;
+               default:
+                       rc = -EINVAL;
+                       break;
                }
                if (rc) {
                        mnt_unref_table(tb);
@@ -1714,7 +1717,7 @@ int main(int argc, char *argv[])
                { "help",           no_argument,       NULL, 'h'                 },
                { "invert",         no_argument,       NULL, 'i'                 },
                { "json",           no_argument,       NULL, 'J'                 },
-               { "kernel",         no_argument,       NULL, 'k'                 },
+               { "kernel",         optional_argument, NULL, 'k'                 },
                { "list",           no_argument,       NULL, 'l'                 },
                { "mountpoint",     required_argument, NULL, 'M'                 },
                { "mtab",           no_argument,       NULL, 'm'                 },
@@ -1775,7 +1778,7 @@ int main(int argc, char *argv[])
        findmnt.flags |= FL_TREE;
 
        while ((c = getopt_long(argc, argv,
-                               "AabCcDd:ehIiJfF:o:O:p::PQ:klmM:nN:rst:uvRS:T:Uw:VxyH",
+                               "AabCcDd:ehIiJfF:o:O:p::PQ:k::lmM:nN:rst:uvRS:T:Uw:VxyH",
                                longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
@@ -1871,8 +1874,14 @@ int main(int argc, char *argv[])
                        tabtype = TABTYPE_FSTAB;
                        findmnt.flags &= ~FL_TREE;
                        break;
-               case 'k':               /* kernel (mountinfo) */
-                       tabtype = TABTYPE_KERNEL;
+               case 'k':
+                       if (optarg) {
+                               if (strcmp(optarg, "mountinfo") == 0)
+                                       tabtype = TABTYPE_KERNEL_MOUNTINFO;
+                               else
+                                       errx(EXIT_FAILURE, _("invalid --kernel argument"));
+                       } else
+                               tabtype = TABTYPE_KERNEL_MOUNTINFO;
                        break;
                case 't':
                        set_match(COL_FSTYPE, optarg);
@@ -1888,7 +1897,7 @@ int main(int argc, char *argv[])
                        findmnt.flags |= FL_NOHEADINGS;
                        break;
                case 'N':
-                       tabtype = TABTYPE_KERNEL;
+                       tabtype = TABTYPE_KERNEL_MOUNTINFO;
                        tabfiles = append_pid_tabfile(tabfiles, &ntabfiles,
                                        strtou32_or_err(optarg,
                                                _("invalid TID argument")));
@@ -1993,7 +2002,7 @@ int main(int argc, char *argv[])
                return EXIT_FAILURE;
 
        if (!tabtype)
-               tabtype = verify ? TABTYPE_FSTAB : TABTYPE_KERNEL;
+               tabtype = verify ? TABTYPE_FSTAB : TABTYPE_KERNEL_MOUNTINFO;
 
        if ((findmnt.flags & FL_POLL) && ntabfiles > 1)
                errx(EXIT_FAILURE, _("--poll accepts only one file, but more specified by --tab-file"));
@@ -2042,7 +2051,7 @@ int main(int argc, char *argv[])
        mnt_table_set_userdata(tb, &findmnt);
 
        if (tabtype == TABTYPE_MTAB && tab_is_kernel(tb))
-               tabtype = TABTYPE_KERNEL;
+               tabtype = TABTYPE_KERNEL_MOUNTINFO;
 
        istree = tab_is_tree(tb);
        if (istree && force_tree)
@@ -2059,7 +2068,7 @@ int main(int argc, char *argv[])
                }
                mnt_table_set_cache(tb, findmnt.cache);
 
-               if (tabtype != TABTYPE_KERNEL)
+               if (tabtype != TABTYPE_KERNEL_MOUNTINFO)
                        cache_set_targets(findmnt.cache);
        }
 
@@ -2097,7 +2106,7 @@ int main(int argc, char *argv[])
                rc = add_matching_lines(tb, table, direction, &findmnt);
 
                if (rc != 0
-                   && tabtype == TABTYPE_KERNEL
+                   && tabtype == TABTYPE_KERNEL_MOUNTINFO
                    && (findmnt.flags & FL_NOSWAPMATCH)
                    && !(findmnt.flags & FL_STRICTTARGET)
                    && get_match(COL_TARGET)) {