From 29dae977ae9b01f429ae876743514da92ee8ecf4 Mon Sep 17 00:00:00 2001 From: Andrew Gierth Date: Mon, 10 Jul 2023 16:09:56 +0100 Subject: automount: check for mounted-over autofs instances on flush PR: 272446 (cherry picked from commit 21b8e363c4eb24c0a5659101603cc08a86d87759) --- usr.sbin/autofs/automount.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/usr.sbin/autofs/automount.c b/usr.sbin/autofs/automount.c index 188bbc3a040f..cee647cb4e2c 100644 --- a/usr.sbin/autofs/automount.c +++ b/usr.sbin/autofs/automount.c @@ -260,6 +260,7 @@ static void flush_caches(void) { struct statfs *mntbuf; + struct statfs statbuf; int i, nitems; nitems = getmntinfo(&mntbuf, MNT_WAIT); @@ -274,6 +275,21 @@ flush_caches(void) mntbuf[i].f_mntonname); continue; } + /* + * A direct map mountpoint may have been mounted over, in + * which case we can't MNT_UPDATE it. There's an obvious race + * condition remaining here, but that has to be fixed in the + * kernel. + */ + if (statfs(mntbuf[i].f_mntonname, &statbuf) != 0) { + log_err(1, "cannot statfs %s", mntbuf[i].f_mntonname); + continue; + } + if (strcmp(statbuf.f_fstypename, "autofs") != 0) { + log_debugx("skipping %s, filesystem type is not autofs", + mntbuf[i].f_mntonname); + continue; + } flush_autofs(mntbuf[i].f_mntonname); } -- cgit v1.3