diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2014-12-18 13:10:48 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2015-04-02 20:34:18 -0500 |
| commit | c003b26ff98ca04a180ff34c38c007a3998d62f9 (patch) | |
| tree | 0d48f9edeed164c03b02494cf129ef76a0ffb91c | |
| parent | 8318e667f176f7ea34451a1a530634e293f216ac (diff) | |
mnt: In umount_tree reuse mnt_list instead of mnt_hash
umount_tree builds a list of mounts that need to be unmounted.
Utilize mnt_list for this purpose instead of mnt_hash. This begins to
allow keeping a mount on the mnt_hash after it is unmounted, which is
necessary for a properly functioning MNT_LOCKED implementation.
The fact that mnt_list is an ordinary list makding available list_move
is nice bonus.
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
| -rw-r--r-- | fs/namespace.c | 20 | ||||
| -rw-r--r-- | fs/pnode.c | 6 | ||||
| -rw-r--r-- | fs/pnode.h | 2 |
3 files changed, 15 insertions, 13 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index c68d9fc912e7..54cbef129f4a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1327,23 +1327,25 @@ enum umount_tree_flags { */ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) { - HLIST_HEAD(tmp_list); + LIST_HEAD(tmp_list); struct mount *p; - for (p = mnt; p; p = next_mnt(p, mnt)) { - hlist_del_init_rcu(&p->mnt_hash); - hlist_add_head(&p->mnt_hash, &tmp_list); - } + /* Gather the mounts to umount */ + for (p = mnt; p; p = next_mnt(p, mnt)) + list_move(&p->mnt_list, &tmp_list); - hlist_for_each_entry(p, &tmp_list, mnt_hash) + /* Hide the mounts from lookup_mnt and mnt_mounts */ + list_for_each_entry(p, &tmp_list, mnt_list) { + hlist_del_init_rcu(&p->mnt_hash); list_del_init(&p->mnt_child); + } + /* Add propogated mounts to the tmp_list */ if (how & UMOUNT_PROPAGATE) propagate_umount(&tmp_list); - while (!hlist_empty(&tmp_list)) { - p = hlist_entry(tmp_list.first, struct mount, mnt_hash); - hlist_del_init_rcu(&p->mnt_hash); + while (!list_empty(&tmp_list)) { + p = list_first_entry(&tmp_list, struct mount, mnt_list); list_del_init(&p->mnt_expire); list_del_init(&p->mnt_list); __touch_mnt_namespace(p->mnt_ns); diff --git a/fs/pnode.c b/fs/pnode.c index 260ac8f898a4..bf012af709dd 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -384,7 +384,7 @@ static void __propagate_umount(struct mount *mnt) if (child && list_empty(&child->mnt_mounts)) { list_del_init(&child->mnt_child); hlist_del_init_rcu(&child->mnt_hash); - hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash); + list_move_tail(&child->mnt_list, &mnt->mnt_list); } } } @@ -396,11 +396,11 @@ static void __propagate_umount(struct mount *mnt) * * vfsmount lock must be held for write */ -int propagate_umount(struct hlist_head *list) +int propagate_umount(struct list_head *list) { struct mount *mnt; - hlist_for_each_entry(mnt, list, mnt_hash) + list_for_each_entry(mnt, list, mnt_list) __propagate_umount(mnt); return 0; } diff --git a/fs/pnode.h b/fs/pnode.h index 16afc3d6d2f2..aa6d65df7204 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -40,7 +40,7 @@ static inline void set_mnt_shared(struct mount *mnt) void change_mnt_propagation(struct mount *, int); int propagate_mnt(struct mount *, struct mountpoint *, struct mount *, struct hlist_head *); -int propagate_umount(struct hlist_head *); +int propagate_umount(struct list_head *); int propagate_mount_busy(struct mount *, int); void mnt_release_group_id(struct mount *); int get_dominating_id(struct mount *mnt, const struct path *root); |