Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 96 insertions, 46 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 82ef1405260e..1f4f9dac6e5a 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -632,14 +632,17 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry)
  */
 struct mount *__lookup_mnt_last(struct vfsmount *mnt, struct dentry *dentry)
 {
-	struct mount *p, *res;
-	res = p = __lookup_mnt(mnt, dentry);
+	struct mount *p, *res = NULL;
+	p = __lookup_mnt(mnt, dentry);
 	if (!p)
 		goto out;
+	if (!(p->mnt.mnt_flags & MNT_UMOUNT))
+		res = p;
 	hlist_for_each_entry_continue(p, mnt_hash) {
 		if (&p->mnt_parent->mnt != mnt || p->mnt_mountpoint != dentry)
 			break;
-		res = p;
+		if (!(p->mnt.mnt_flags & MNT_UMOUNT))
+			res = p;
 	}
 out:
 	return res;
@@ -795,10 +798,8 @@ static void __touch_mnt_namespace(struct mnt_namespace *ns)
 /*
  * vfsmount lock must be held for write
  */
-static void detach_mnt(struct mount *mnt, struct path *old_path)
+static void unhash_mnt(struct mount *mnt)
 {
-	old_path->dentry = mnt->mnt_mountpoint;
-	old_path->mnt = &mnt->mnt_parent->mnt;
 	mnt->mnt_parent = mnt;
 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
 	list_del_init(&mnt->mnt_child);
@@ -811,6 +812,26 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
 /*
  * vfsmount lock must be held for write
  */
+static void detach_mnt(struct mount *mnt, struct path *old_path)
+{
+	old_path->dentry = mnt->mnt_mountpoint;
+	old_path->mnt = &mnt->mnt_parent->mnt;
+	unhash_mnt(mnt);
+}
+
+/*
+ * vfsmount lock must be held for write
+ */
+static void umount_mnt(struct mount *mnt)
+{
+	/* old mountpoint will be dropped when we can do that */
+	mnt->mnt_ex_mountpoint = mnt->mnt_mountpoint;
+	unhash_mnt(mnt);
+}
+
+/*
+ * vfsmount lock must be held for write
+ */
 void mnt_set_mountpoint(struct mount *mnt,
 			struct mountpoint *mp,
 			struct mount *child_mnt)
@@ -1078,6 +1099,13 @@ static void mntput_no_expire(struct mount *mnt)
 	rcu_read_unlock();
 
 	list_del(&mnt->mnt_instance);
+
+	if (unlikely(!list_empty(&mnt->mnt_mounts))) {
+		struct mount *p, *tmp;
+		list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts,  mnt_child) {
+			umount_mnt(p);
+		}
+	}
 	unlock_mount_hash();
 
 	if (likely(!(mnt->mnt.mnt_flags & MNT_INTERNAL))) {
@@ -1298,17 +1326,15 @@ static HLIST_HEAD(unmounted);	/* protected by namespace_sem */
 
 static void namespace_unlock(void)
 {
-	struct hlist_head head = unmounted;
+	struct hlist_head head;
 
-	if (likely(hlist_empty(&head))) {
-		up_write(&namespace_sem);
-		return;
-	}
+	hlist_move_list(&unmounted, &head);
 
-	head.first->pprev = &head.first;
-	INIT_HLIST_HEAD(&unmounted);
 	up_write(&namespace_sem);
 
+	if (likely(hlist_empty(&head)))
+		return;
+
 	synchronize_rcu();
 
 	group_pin_kill(&head);
@@ -1319,49 +1345,63 @@ static inline void namespace_lock(void)
 	down_write(&namespace_sem);
 }
 
+enum umount_tree_flags {
+	UMOUNT_SYNC = 1,
+	UMOUNT_PROPAGATE = 2,
+	UMOUNT_CONNECTED = 4,
+};
 /*
  * mount_lock must be held
  * namespace_sem must be held for write
- * how = 0 => just this tree, don't propagate
- * how = 1 => propagate; we know that nobody else has reference to any victims
- * how = 2 => lazy umount
  */
-void umount_tree(struct mount *mnt, int how)
+static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
 {
-	HLIST_HEAD(tmp_list);
+	LIST_HEAD(tmp_list);
 	struct mount *p;
 
+	if (how & UMOUNT_PROPAGATE)
+		propagate_mount_unlock(mnt);
+
+	/* Gather the mounts to umount */
 	for (p = mnt; p; p = next_mnt(p, mnt)) {
-		hlist_del_init_rcu(&p->mnt_hash);
-		hlist_add_head(&p->mnt_hash, &tmp_list);
+		p->mnt.mnt_flags |= MNT_UMOUNT;
+		list_move(&p->mnt_list, &tmp_list);
 	}
 
-	hlist_for_each_entry(p, &tmp_list, mnt_hash)
+	/* Hide the mounts from mnt_mounts */
+	list_for_each_entry(p, &tmp_list, mnt_list) {
 		list_del_init(&p->mnt_child);
+	}
 
-	if (how)
+	/* 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)) {
+		bool disconnect;
+		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);
 		p->mnt_ns = NULL;
-		if (how < 2)
+		if (how & UMOUNT_SYNC)
 			p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
 
-		pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, &unmounted);
+		disconnect = !(((how & UMOUNT_CONNECTED) &&
+				mnt_has_parent(p) &&
+				(p->mnt_parent->mnt.mnt_flags & MNT_UMOUNT)) ||
+			       IS_MNT_LOCKED_AND_LAZY(p));
+
+		pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt,
+				 disconnect ? &unmounted : NULL);
 		if (mnt_has_parent(p)) {
-			hlist_del_init(&p->mnt_mp_list);
-			put_mountpoint(p->mnt_mp);
 			mnt_add_count(p->mnt_parent, -1);
-			/* old mountpoint will be dropped when we can do that */
-			p->mnt_ex_mountpoint = p->mnt_mountpoint;
-			p->mnt_mountpoint = p->mnt.mnt_root;
-			p->mnt_parent = p;
-			p->mnt_mp = NULL;
+			if (!disconnect) {
+				/* Don't forget about p */
+				list_add_tail(&p->mnt_child, &p->mnt_parent->mnt_mounts);
+			} else {
+				umount_mnt(p);
+			}
 		}
 		change_mnt_propagation(p, MS_PRIVATE);
 	}
@@ -1447,14 +1487,14 @@ static int do_umount(struct mount *mnt, int flags)
 
 	if (flags & MNT_DETACH) {
 		if (!list_empty(&mnt->mnt_list))
-			umount_tree(mnt, 2);
+			umount_tree(mnt, UMOUNT_PROPAGATE);
 		retval = 0;
 	} else {
 		shrink_submounts(mnt);
 		retval = -EBUSY;
 		if (!propagate_mount_busy(mnt, 2)) {
 			if (!list_empty(&mnt->mnt_list))
-				umount_tree(mnt, 1);
+				umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 			retval = 0;
 		}
 	}
@@ -1480,13 +1520,20 @@ void __detach_mounts(struct dentry *dentry)
 
 	namespace_lock();
 	mp = lookup_mountpoint(dentry);
-	if (!mp)
+	if (IS_ERR_OR_NULL(mp))
 		goto out_unlock;
 
 	lock_mount_hash();
 	while (!hlist_empty(&mp->m_list)) {
 		mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
-		umount_tree(mnt, 2);
+		if (mnt->mnt.mnt_flags & MNT_UMOUNT) {
+			struct mount *p, *tmp;
+			list_for_each_entry_safe(p, tmp, &mnt->mnt_mounts,  mnt_child) {
+				hlist_add_head(&p->mnt_umount.s_list, &unmounted);
+				umount_mnt(p);
+			}
+		}
+		else umount_tree(mnt, UMOUNT_CONNECTED);
 	}
 	unlock_mount_hash();
 	put_mountpoint(mp);
@@ -1648,7 +1695,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
 out:
 	if (res) {
 		lock_mount_hash();
-		umount_tree(res, 0);
+		umount_tree(res, UMOUNT_SYNC);
 		unlock_mount_hash();
 	}
 	return q;
@@ -1660,8 +1707,11 @@ struct vfsmount *collect_mounts(struct path *path)
 {
 	struct mount *tree;
 	namespace_lock();
-	tree = copy_tree(real_mount(path->mnt), path->dentry,
-			 CL_COPY_ALL | CL_PRIVATE);
+	if (!check_mnt(real_mount(path->mnt)))
+		tree = ERR_PTR(-EINVAL);
+	else
+		tree = copy_tree(real_mount(path->mnt), path->dentry,
+				 CL_COPY_ALL | CL_PRIVATE);
 	namespace_unlock();
 	if (IS_ERR(tree))
 		return ERR_CAST(tree);
@@ -1672,7 +1722,7 @@ void drop_collected_mounts(struct vfsmount *mnt)
 {
 	namespace_lock();
 	lock_mount_hash();
-	umount_tree(real_mount(mnt), 0);
+	umount_tree(real_mount(mnt), UMOUNT_SYNC);
 	unlock_mount_hash();
 	namespace_unlock();
 }
@@ -1855,7 +1905,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
  out_cleanup_ids:
 	while (!hlist_empty(&tree_list)) {
 		child = hlist_entry(tree_list.first, struct mount, mnt_hash);
-		umount_tree(child, 0);
+		umount_tree(child, UMOUNT_SYNC);
 	}
 	unlock_mount_hash();
 	cleanup_group_ids(source_mnt, NULL);
@@ -2035,7 +2085,7 @@ static int do_loopback(struct path *path, const char *old_name,
 	err = graft_tree(mnt, parent, mp);
 	if (err) {
 		lock_mount_hash();
-		umount_tree(mnt, 0);
+		umount_tree(mnt, UMOUNT_SYNC);
 		unlock_mount_hash();
 	}
 out2:
@@ -2406,7 +2456,7 @@ void mark_mounts_for_expiry(struct list_head *mounts)
 	while (!list_empty(&graveyard)) {
 		mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
 		touch_mnt_namespace(mnt->mnt_ns);
-		umount_tree(mnt, 1);
+		umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 	}
 	unlock_mount_hash();
 	namespace_unlock();
@@ -2477,7 +2527,7 @@ static void shrink_submounts(struct mount *mnt)
 			m = list_first_entry(&graveyard, struct mount,
 						mnt_expire);
 			touch_mnt_namespace(m->mnt_ns);
-			umount_tree(m, 1);
+			umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC);
 		}
 	}
 }