From 47a742fd977a7a8c39fea890712e9bfdf76f98f1 Mon Sep 17 00:00:00 2001 From: Jan Stancek Date: Thu, 10 Apr 2025 17:05:42 +0200 Subject: fs: use namespace_{lock,unlock} in dissolve_on_fput() In commit b73ec10a4587 ("fs: add fastpath for dissolve_on_fput()"), the namespace_{lock,unlock} has been replaced with scoped_guard using the namespace_sem. This however now also skips processing of 'unmounted' list in namespace_unlock(), and mount is not (immediately) cleaned up. For example, this causes LTP move_mount02 fail: ... move_mount02.c:80: TPASS: invalid-from-fd: move_mount() failed as expected: EBADF (9) move_mount02.c:80: TPASS: invalid-from-path: move_mount() failed as expected: ENOENT (2) move_mount02.c:80: TPASS: invalid-to-fd: move_mount() failed as expected: EBADF (9) move_mount02.c:80: TPASS: invalid-to-path: move_mount() failed as expected: ENOENT (2) move_mount02.c:80: TPASS: invalid-flags: move_mount() failed as expected: EINVAL (22) tst_test.c:1833: TINFO: === Testing on ext3 === tst_test.c:1170: TINFO: Formatting /dev/loop0 with ext3 opts='' extra opts='' mke2fs 1.47.2 (1-Jan-2025) /dev/loop0 is apparently in use by the system; will not make a filesystem here! tst_test.c:1170: TBROK: mkfs.ext3 failed with exit code 1 The test makes number of move_mount() calls but these are all designed to fail with specific errno. Even after test, 'losetup -d' can't detach loop device. Define a new guard for dissolve_on_fput, that will use namespace_{lock,unlock}. Fixes: b73ec10a4587 ("fs: add fastpath for dissolve_on_fput()") Signed-off-by: Jan Stancek Link: https://lore.kernel.org/cad2f042b886bf0ced3d8e3aff120ec5e0125d61.1744297468.git.jstancek@redhat.com Signed-off-by: Christian Brauner --- fs/namespace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 1eb76d6312de..d9ca80dcc544 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1830,6 +1830,8 @@ static inline void namespace_lock(void) down_write(&namespace_sem); } +DEFINE_GUARD(namespace_lock, struct rw_semaphore *, namespace_lock(), namespace_unlock()) + enum umount_tree_flags { UMOUNT_SYNC = 1, UMOUNT_PROPAGATE = 2, @@ -2383,7 +2385,7 @@ void dissolve_on_fput(struct vfsmount *mnt) return; } - scoped_guard(rwsem_write, &namespace_sem) { + scoped_guard(namespace_lock, &namespace_sem) { ns = m->mnt_ns; if (!must_dissolve(ns)) return; -- cgit