From ba4666388f1a69487e0a64e3626564d37feef2c0 Mon Sep 17 00:00:00 2001 From: "T.kabe" Date: Fri, 3 Mar 2017 14:29:26 +0900 Subject: [PATCH 1/4] get rid of propagate_umount() mistakenly treating slaves as busy. [upstream commit 88b368f27a094277143d8ecd5a056116f6a41520] Author: Al Viro Date: Mon Aug 18 15:09:26 2014 -0400 get rid of propagate_umount() mistakenly treating slaves as busy. The check in __propagate_umount() ("has somebody explicitly mounted something on that slave?") is done *before* taking the already doomed victims out of the child lists. Cc: stable@vger.kernel.org Signed-off-by: Al Viro --- fs/namespace.c | 4 +++- fs/pnode.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 9440b6a..0053bfc 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1195,6 +1195,9 @@ void umount_tree(struct mount *mnt, int propagate) for (p = mnt; p; p = next_mnt(p, mnt)) list_move(&p->mnt_hash, &tmp_list); + list_for_each_entry(p, &tmp_list, mnt_hash) + list_del_init(&p->mnt_child); + if (propagate) propagate_umount(&tmp_list); @@ -1203,7 +1206,6 @@ void umount_tree(struct mount *mnt, int propagate) list_del_init(&p->mnt_list); __touch_mnt_namespace(p->mnt_ns); p->mnt_ns = NULL; - list_del_init(&p->mnt_child); if (mnt_has_parent(p)) { p->mnt_parent->mnt_ghosts++; put_mountpoint(p->mnt_mp); diff --git a/fs/pnode.c b/fs/pnode.c index 54bd043..983cf93 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -390,8 +390,10 @@ static void __propagate_umount(struct mount *mnt) * umount the child only if the child has no * other children */ - if (child && list_empty(&child->mnt_mounts)) + if (child && list_empty(&child->mnt_mounts)) { + list_del_init(&child->mnt_child); list_move_tail(&child->mnt_hash, &mnt->mnt_hash); + } } } -- 1.8.3.1