From: Karel Zak <kzak@redhat.com>
Date: Thu, 24 Apr 2025 16:45:24 +0000 (+0200)
Subject: libmount: use and add has_listmount()
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=78ade43875b09436616421a6dd10d53673fde415;p=thirdparty%2Futil-linux.git

libmount: use and add has_listmount()

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

diff --git a/include/mount-api-utils.h b/include/mount-api-utils.h
index ea9aeb816..8dbe53467 100644
--- a/include/mount-api-utils.h
+++ b/include/mount-api-utils.h
@@ -437,6 +437,17 @@ static inline ssize_t ul_listmount(uint64_t mnt_id,
 
        return syscall(SYS_listmount, &req, list, num, flags);
 }
+
+static inline int has_listmount(void)
+{
+	uint64_t dummy;
+
+	errno = 0;
+
+	if (ul_listmount(LSMT_ROOT, 0, 0, &dummy, 1, LISTMOUNT_REVERSE) != 1)
+		return 0;
+	return 1;
+}
 #endif
 
 #endif /* HAVE_STATMOUNT_API */
diff --git a/libmount/src/tab_listmount.c b/libmount/src/tab_listmount.c
index c9725a23c..e4a1c2a52 100644
--- a/libmount/src/tab_listmount.c
+++ b/libmount/src/tab_listmount.c
@@ -91,18 +91,13 @@ static int table_init_listmount(struct libmnt_table *tb, size_t stepsiz)
 	ls = tb->lsmnt;
 
 	/* check if supported by current kernel */
-	if (!ls) {
-		uint64_t dummy;
-
-		errno = 0;
-		if (ul_listmount(LSMT_ROOT, 0, 0, &dummy, 1, LISTMOUNT_REVERSE) != 1) {
-			if (errno == ENOSYS)
-				DBG(TAB, ul_debugobj(tb, "listmount: unsuppported"));
-			if (errno == EINVAL)
-				DBG(TAB, ul_debugobj(tb, "listmount: reverse unsuppported"));
-			errno = ENOSYS;
-			return -ENOSYS;
-		}
+	if (!ls && !has_listmount()) {
+		if (errno == ENOSYS)
+			DBG(TAB, ul_debugobj(tb, "listmount: unsuppported"));
+		if (errno == EINVAL)
+			DBG(TAB, ul_debugobj(tb, "listmount: reverse unsuppported"));
+		errno = ENOSYS;
+		return -ENOSYS;
 	}
 
 	/* reset if allocated for a different size */
diff --git a/tests/helpers/test_sysinfo.c b/tests/helpers/test_sysinfo.c
index 00bf12727..b4a601e3b 100644
--- a/tests/helpers/test_sysinfo.c
+++ b/tests/helpers/test_sysinfo.c
@@ -157,14 +157,13 @@ static int hlp_statmount_ok(void)
 
 static int hlp_listmount_ok(void)
 {
+	printf("%d\n",
 #ifdef HAVE_STATMOUNT_API
-	uint64_t dummy;
-	errno = 0;
-	ul_listmount(LSMT_ROOT, 0, 0, &dummy, 1, LISTMOUNT_REVERSE);
+		has_listmount()
 #else
-	errno = ENOSYS;
+		0
 #endif
-	printf("%d\n", !(errno == ENOSYS || errno == EINVAL));
+	);
 	return 0;
 }