From: Daniel Rosenberg <drosen@google.com>
Date: Sat, 12 Jan 2019 02:44:18 +0000 (-0800)
Subject: ANDROID: mnt: Propagate remount correctly
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=398001773b80e7acb29d1ee234c49b91c4e3f979;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

ANDROID: mnt: Propagate remount correctly

This switches over to propagation_next to respect
namepsace semantics.

Test: Remounting to change the options of a fs with mount based
      options should propagate to all shared copies of that mount,
      and the slaves/indirect slaves of those.
Bug: 122428178
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Change-Id: Ic35cd2782a646435689f5bedfa1f218fe4ab8254
---

diff --git a/fs/pnode.c b/fs/pnode.c
index 8702b2f3bce0..9a3811651cd5 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -687,44 +687,26 @@ int propagate_umount(struct list_head *list)
 	return 0;
 }
 
-/*
- *  Iterates over all slaves, and slaves of slaves.
- */
-static struct mount *next_descendent(struct mount *root, struct mount *cur)
-{
-	if (!IS_MNT_NEW(cur) && !list_empty(&cur->mnt_slave_list))
-		return first_slave(cur);
-	do {
-		struct mount *master = cur->mnt_master;
-
-		if (!master || cur->mnt_slave.next != &master->mnt_slave_list) {
-			struct mount *next = next_slave(cur);
-
-			return (next == root) ? NULL : next;
-		}
-		cur = master;
-	} while (cur != root);
-	return NULL;
-}
-
 void propagate_remount(struct mount *mnt)
 {
-	struct mount *m = mnt;
+	struct mount *parent = mnt->mnt_parent;
+	struct mount *p = mnt, *m;
 #ifdef CONFIG_RKP_NS_PROT
 	struct super_block *sb = mnt->mnt->mnt_sb;
 #else
 	struct super_block *sb = mnt->mnt.mnt_sb;
 #endif
 
-	if (sb->s_op->copy_mnt_data) {
-		m = next_descendent(mnt, m);
-		while (m) {
+	if (!sb->s_op->copy_mnt_data) 
+			return;
+	for (p = propagation_next(parent, parent); p;
+							p = propagation_next(p, parent)) {
+		m = __lookup_mnt(&p->mnt, mnt->mnt_mountpoint);
+		if (m)
 #ifdef CONFIG_RKP_NS_PROT
 			sb->s_op->copy_mnt_data(m->mnt->data, mnt->mnt->data);
 #else
 			sb->s_op->copy_mnt_data(m->mnt.data, mnt->mnt.data);
 #endif
-			m = next_descendent(mnt, m);
-		}
 	}
 }