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authorEric W. Biederman <ebiederm@xmission.com>2014-12-18 22:10:48 +0300
committerEric W. Biederman <ebiederm@xmission.com>2015-04-03 04:34:18 +0300
commitc003b26ff98ca04a180ff34c38c007a3998d62f9 (patch)
tree0d48f9edeed164c03b02494cf129ef76a0ffb91c /fs/namespace.c
parent8318e667f176f7ea34451a1a530634e293f216ac (diff)
downloadlinux-c003b26ff98ca04a180ff34c38c007a3998d62f9.tar.xz
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>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c20
1 files changed, 11 insertions, 9 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);