From: dengbo <dengbo@deepin.org>
Date: Thu, 25 Jun 2026 13:52:16 +0000 (+0800)
Subject: findmnt: skip shadowed entries when matching by --target
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6df11b009a950b317218df175575a2d8e1462bd1;p=thirdparty%2Futil-linux.git

findmnt: skip shadowed entries when matching by --target

The previous approach filtered shadowed entries in match_func() using
mnt_table_over_fs() with is_defined_match(COL_TARGET) as the trigger.
This was fragile because COL_TARGET matching is also enabled by other
code paths (source/target swap fallback in get_next_fs(), poll_match()
swap logic, and positional arguments).

Replace with the standard mountinfo iteration pattern: read
/proc/self/mountinfo backward (MNT_ITER_BACKWARD), stop at the first
match (FL_FIRSTONLY), and disable source/target swapping
(FL_NOSWAPMATCH). Since later mounts appear later in mountinfo,
backward iteration naturally finds the visible (topmost) filesystem
for the given target path.

Fixes https://github.com/util-linux/util-linux/issues/4424
---

diff --git a/misc-utils/findmnt.c b/misc-utils/findmnt.c
index c892bf299..eca6dc74b 100644
--- a/misc-utils/findmnt.c
+++ b/misc-utils/findmnt.c
@@ -1763,6 +1763,7 @@ int main(int argc, char *argv[])
 	char *outarg = NULL;
 	size_t i;
 	int force_tree = 0, istree = 0;
+	int force_target = 0;
 
 	struct libscols_table *table = NULL;
 
@@ -2001,7 +2002,7 @@ int main(int argc, char *argv[])
 			FALLTHROUGH;
 		case 'T':
 			set_match(COL_TARGET, optarg);
-			findmnt.flags |= FL_NOSWAPMATCH;
+			force_target = 1;
 			break;
 		case 'U':
 			findmnt.flags |= FL_UNIQ;
@@ -2143,6 +2144,11 @@ int main(int argc, char *argv[])
 			findmnt.flags |= FL_NOSWAPMATCH;
 	}
 
+	if (force_target) {
+		direction = MNT_ITER_BACKWARD;
+		findmnt.flags |= FL_NOSWAPMATCH | FL_FIRSTONLY;
+	}
+
 	/*
 	 * initialize libmount
 	 */