git: e59991206b14 - main - fts(3): be less strict when automount does its job under us walking autofs mount

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=e59991206b1463b7e85cc8aafde7f1dc03fcedcf

commit e59991206b1463b7e85cc8aafde7f1dc03fcedcf
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-02-21 13:07:43 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-02-25 07:09:29 +0000

    fts(3): be less strict when automount does its job under us walking autofs mount
    
    Namely, allow the file id change if the resulting file belongs to
    automounted filesystem.  If it is, remember the updated id.
    
    This allows the ids from the automounted volumes to change without
    restrictions, might be a further refinement would be to only allow such
    inconsistency once.
    
    PR:     284914
    Reported and tested by: Lexi Winter <lexi@hemlock.eden.le-fay.org>
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D49094
---
 lib/libc/gen/fts.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/libc/gen/fts.c b/lib/libc/gen/fts.c
index 770a7b2cc322..bd193c7c6cfc 100644
--- a/lib/libc/gen/fts.c
+++ b/lib/libc/gen/fts.c
@@ -1132,6 +1132,7 @@ fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
 {
 	int ret, oerrno, newfd;
 	struct stat sb;
+	struct statfs sf;
 
 	newfd = fd;
 	if (ISSET(FTS_NOCHDIR))
@@ -1144,9 +1145,15 @@ fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path)
 		goto bail;
 	}
 	if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) {
-		errno = ENOENT;		/* disinformation */
-		ret = -1;
-		goto bail;
+		if (_fstatfs(newfd, &sf) != 0 ||
+		    (sf.f_flags & MNT_AUTOMOUNTED) == 0) {
+			errno = ENOENT;		/* disinformation */
+			ret = -1;
+			goto bail;
+		}
+		/* autofs might did the mount under us, accept. */
+		p->fts_dev = sb.st_dev;
+		p->fts_ino == sb.st_ino;
 	}
 	ret = fchdir(newfd);
 bail: