Move mnt->mnt_node into the union with mnt->mnt_rcu and mnt->mnt_llist
instead of keeping it with mnt->mnt_list. This allows us to use
RB_CLEAR_NODE(&mnt->mnt_node) in umount_tree() as well as
list_empty(&mnt->mnt_node). That in turn allows us to remove MNT_ONRB.
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
fs/mount.h | 15 +++++++++------
fs/namespace.c | 14 ++++++--------
include/linux/mount.h | 3 +--
3 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/mount.h b/fs/mount.h
index 8cda387f47c5efd9af5e2e422569446c3d51986f..e9f48e563c0fe9c4af77369423db2cc8695fa808 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -42,6 +42,7 @@ struct mount {
struct dentry *mnt_mountpoint;
struct vfsmount mnt;
union {
+ struct rb_node mnt_node; /* node in the ns->mounts rbtree */
struct rcu_head mnt_rcu;
struct llist_node mnt_llist;
};
@@ -55,10 +56,7 @@ struct mount {
struct list_head mnt_child; /* and going through their mnt_child */
struct list_head mnt_instance; /* mount instance on sb->s_mounts */
const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
- union {
- struct rb_node mnt_node; /* Under ns->mounts */
- struct list_head mnt_list;
- };
+ struct list_head mnt_list;
struct list_head mnt_expire; /* link in fs-specific expiry list */
struct list_head mnt_share; /* circular list of shared mounts */
struct list_head mnt_slave_list;/* list of slave mounts */
@@ -149,11 +147,16 @@ static inline bool is_anon_ns(struct mnt_namespace *ns)
return ns->seq == 0;
}
+static inline bool mnt_ns_attached(const struct mount *mnt)
+{
+ return !RB_EMPTY_NODE(&mnt->mnt_node);
+}
+
static inline void move_from_ns(struct mount *mnt, struct list_head *dt_list)
{
- WARN_ON(!(mnt->mnt.mnt_flags & MNT_ONRB));
- mnt->mnt.mnt_flags &= ~MNT_ONRB;
+ WARN_ON(!mnt_ns_attached(mnt));
rb_erase(&mnt->mnt_node, &mnt->mnt_ns->mounts);
+ RB_CLEAR_NODE(&mnt->mnt_node);
list_add_tail(&mnt->mnt_list, dt_list);
}
diff --git a/fs/namespace.c b/fs/namespace.c
index 966dcd27c81cc877837eca747babe0bc31aaf922..d67df0fce4dcd1ee5ddf9ff5fbe005bcdcd626f1 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -378,6 +378,7 @@ static struct mount *alloc_vfsmnt(const char *name)
INIT_HLIST_NODE(&mnt->mnt_mp_list);
INIT_LIST_HEAD(&mnt->mnt_umounting);
INIT_HLIST_HEAD(&mnt->mnt_stuck_children);
+ RB_CLEAR_NODE(&mnt->mnt_node);
mnt->mnt.mnt_idmap = &nop_mnt_idmap;
}
return mnt;
@@ -1158,7 +1159,7 @@ static void mnt_add_to_ns(struct mnt_namespace *ns, struct mount *mnt)
struct rb_node **link = &ns->mounts.rb_node;
struct rb_node *parent = NULL;
- WARN_ON(mnt->mnt.mnt_flags & MNT_ONRB);
+ WARN_ON(mnt_ns_attached(mnt));
mnt->mnt_ns = ns;
while (*link) {
parent = *link;
@@ -1169,7 +1170,6 @@ static void mnt_add_to_ns(struct mnt_namespace *ns, struct mount *mnt)
}
rb_link_node(&mnt->mnt_node, parent, link);
rb_insert_color(&mnt->mnt_node, &ns->mounts);
- mnt->mnt.mnt_flags |= MNT_ONRB;
}
/*
@@ -1339,7 +1339,7 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
}
mnt->mnt.mnt_flags = old->mnt.mnt_flags;
- mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL|MNT_ONRB);
+ mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL);
atomic_inc(&sb->s_active);
mnt->mnt.mnt_idmap = mnt_idmap_get(mnt_idmap(&old->mnt));
@@ -1797,7 +1797,7 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
/* Gather the mounts to umount */
for (p = mnt; p; p = next_mnt(p, mnt)) {
p->mnt.mnt_flags |= MNT_UMOUNT;
- if (p->mnt.mnt_flags & MNT_ONRB)
+ if (mnt_ns_attached(p))
move_from_ns(p, &tmp_list);
else
list_move(&p->mnt_list, &tmp_list);
@@ -1946,16 +1946,14 @@ static int do_umount(struct mount *mnt, int flags)
event++;
if (flags & MNT_DETACH) {
- if (mnt->mnt.mnt_flags & MNT_ONRB ||
- !list_empty(&mnt->mnt_list))
+ if (mnt_ns_attached(mnt) || !list_empty(&mnt->mnt_list))
umount_tree(mnt, UMOUNT_PROPAGATE);
retval = 0;
} else {
shrink_submounts(mnt);
retval = -EBUSY;
if (!propagate_mount_busy(mnt, 2)) {
- if (mnt->mnt.mnt_flags & MNT_ONRB ||
- !list_empty(&mnt->mnt_list))
+ if (mnt_ns_attached(mnt) || !list_empty(&mnt->mnt_list))
umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
retval = 0;
}
diff --git a/include/linux/mount.h b/include/linux/mount.h
index c34c18b4e8f36f27775c4df624890eb8e6060965..04213d8ef8376d42d83b44d5a2ce1c35ad5a942e 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -50,7 +50,7 @@ struct path;
#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME )
#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \
- MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED | MNT_ONRB)
+ MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED)
#define MNT_INTERNAL 0x4000
@@ -64,7 +64,6 @@ struct path;
#define MNT_SYNC_UMOUNT 0x2000000
#define MNT_MARKED 0x4000000
#define MNT_UMOUNT 0x8000000
-#define MNT_ONRB 0x10000000
struct vfsmount {
struct dentry *mnt_root; /* root of the mounted tree */
--
2.45.2
