From: Karel Zak <kzak@redhat.com>
Date: Mon, 16 Sep 2024 09:36:41 +0000 (+0200)
Subject: findmnt: add optional argument to --kernel
X-Git-Tag: v2.42-start~97^2~12
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=841d15e5d13dd0cc56e450c8dcc592211d66be27;p=thirdparty%2Futil-linux.git

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 736c20e03..9a8cb0a3d 100644
--- 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)) {