vfs: take mnt_child/mnt_mounts to struct mount

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/mount.h

@@ -17,6 +17,8 @@ struct mount {
 	int mnt_count;
 	int mnt_writers;
 #endif
+	struct list_head mnt_mounts;	/* list of children, anchored here */
+	struct list_head mnt_child;	/* and going through their mnt_child */
 };
 
 static inline struct mount *real_mount(struct vfsmount *mnt)

fs/namespace.c

@@ -200,8 +200,8 @@ static struct mount *alloc_vfsmnt(const char *name)
 #endif
 
 		INIT_LIST_HEAD(&p->mnt_hash);
-		INIT_LIST_HEAD(&mnt->mnt_child);
-		INIT_LIST_HEAD(&mnt->mnt_mounts);
+		INIT_LIST_HEAD(&p->mnt_child);
+		INIT_LIST_HEAD(&p->mnt_mounts);
 		INIT_LIST_HEAD(&mnt->mnt_list);
 		INIT_LIST_HEAD(&mnt->mnt_expire);
 		INIT_LIST_HEAD(&mnt->mnt_share);
@@ -562,7 +562,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
 	old_path->mnt = &mnt->mnt_parent->mnt;
 	mnt->mnt_parent = mnt;
 	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
-	list_del_init(&mnt->mnt.mnt_child);
+	list_del_init(&mnt->mnt_child);
 	list_del_init(&mnt->mnt_hash);
 	dentry_reset_mounted(old_path->dentry);
 }
@@ -588,7 +588,7 @@ static void attach_mnt(struct mount *mnt, struct path *path)
 	mnt_set_mountpoint(path->mnt, path->dentry, mnt);
 	list_add_tail(&mnt->mnt_hash, mount_hashtable +
 			hash(path->mnt, path->dentry));
-	list_add_tail(&mnt->mnt.mnt_child, &path->mnt->mnt_mounts);
+	list_add_tail(&mnt->mnt_child, &real_mount(path->mnt)->mnt_mounts);
 }
 
 static inline void __mnt_make_longterm(struct mount *mnt)
@@ -628,32 +628,32 @@ static void commit_tree(struct mount *mnt)
 
 	list_add_tail(&mnt->mnt_hash, mount_hashtable +
 				hash(&parent->mnt, mnt->mnt_mountpoint));
-	list_add_tail(&mnt->mnt.mnt_child, &parent->mnt.mnt_mounts);
+	list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
 	touch_mnt_namespace(n);
 }
 
 static struct mount *next_mnt(struct mount *p, struct vfsmount *root)
 {
-	struct list_head *next = p->mnt.mnt_mounts.next;
-	if (next == &p->mnt.mnt_mounts) {
+	struct list_head *next = p->mnt_mounts.next;
+	if (next == &p->mnt_mounts) {
 		while (1) {
 			if (&p->mnt == root)
 				return NULL;
-			next = p->mnt.mnt_child.next;
-			if (next != &p->mnt_parent->mnt.mnt_mounts)
+			next = p->mnt_child.next;
+			if (next != &p->mnt_parent->mnt_mounts)
 				break;
 			p = p->mnt_parent;
 		}
 	}
-	return list_entry(next, struct mount, mnt.mnt_child);
+	return list_entry(next, struct mount, mnt_child);
 }
 
 static struct mount *skip_mnt_tree(struct mount *p)
 {
-	struct list_head *prev = p->mnt.mnt_mounts.prev;
-	while (prev != &p->mnt.mnt_mounts) {
-		p = list_entry(prev, struct mount, mnt.mnt_child);
-		prev = p->mnt.mnt_mounts.prev;
+	struct list_head *prev = p->mnt_mounts.prev;
+	while (prev != &p->mnt_mounts) {
+		p = list_entry(prev, struct mount, mnt_child);
+		prev = p->mnt_mounts.prev;
 	}
 	return p;
 }
@@ -1238,7 +1238,7 @@ void umount_tree(struct mount *mnt, int propagate, struct list_head *kill)
 		__touch_mnt_namespace(p->mnt.mnt_ns);
 		p->mnt.mnt_ns = NULL;
 		__mnt_make_shortterm(p);
-		list_del_init(&p->mnt.mnt_child);
+		list_del_init(&p->mnt_child);
 		if (mnt_has_parent(p)) {
 			p->mnt_parent->mnt.mnt_ghosts++;
 			dentry_reset_mounted(p->mnt_mountpoint);
@@ -1427,7 +1427,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
 	q->mnt_mountpoint = mnt->mnt_mountpoint;
 
 	p = mnt;
-	list_for_each_entry(r, &mnt->mnt.mnt_mounts, mnt.mnt_child) {
+	list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
 		struct mount *s;
 		if (!is_subdir(r->mnt_mountpoint, dentry))
 			continue;
@@ -2134,11 +2134,11 @@ static int select_submounts(struct mount *parent, struct list_head *graveyard)
 	int found = 0;
 
 repeat:
-	next = this_parent->mnt.mnt_mounts.next;
+	next = this_parent->mnt_mounts.next;
 resume:
-	while (next != &this_parent->mnt.mnt_mounts) {
+	while (next != &this_parent->mnt_mounts) {
 		struct list_head *tmp = next;
-		struct mount *mnt = list_entry(tmp, struct mount, mnt.mnt_child);
+		struct mount *mnt = list_entry(tmp, struct mount, mnt_child);
 
 		next = tmp->next;
 		if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE))
@@ -2146,7 +2146,7 @@ static int select_submounts(struct mount *parent, struct list_head *graveyard)
 		/*
 		 * Descend a level if the d_mounts list is non-empty.
 		 */
-		if (!list_empty(&mnt->mnt.mnt_mounts)) {
+		if (!list_empty(&mnt->mnt_mounts)) {
 			this_parent = mnt;
 			goto repeat;
 		}
@@ -2160,7 +2160,7 @@ static int select_submounts(struct mount *parent, struct list_head *graveyard)
 	 * All done at this level ... ascend and resume the search
 	 */
 	if (this_parent != parent) {
-		next = this_parent->mnt.mnt_child.next;
+		next = this_parent->mnt_child.next;
 		this_parent = this_parent->mnt_parent;
 		goto resume;
 	}

fs/pnode.c

@@ -303,13 +303,13 @@ int propagate_mount_busy(struct mount *mnt, int refcnt)
 	 * If not, we don't have to go checking for all other
 	 * mounts
 	 */
-	if (!list_empty(&mnt->mnt.mnt_mounts) || do_refcount_check(mnt, refcnt))
+	if (!list_empty(&mnt->mnt_mounts) || do_refcount_check(mnt, refcnt))
 		return 1;
 
 	for (m = propagation_next(&parent->mnt, &parent->mnt); m;
 	     		m = propagation_next(m, &parent->mnt)) {
 		child = __lookup_mnt(m, mnt->mnt_mountpoint, 0);
-		if (child && list_empty(&child->mnt.mnt_mounts) &&
+		if (child && list_empty(&child->mnt_mounts) &&
 		    (ret = do_refcount_check(child, 1)))
 			break;
 	}
@@ -336,7 +336,7 @@ static void __propagate_umount(struct mount *mnt)
 		 * umount the child only if the child has no
 		 * other children
 		 */
-		if (child && list_empty(&child->mnt.mnt_mounts))
+		if (child && list_empty(&child->mnt_mounts))
 			list_move_tail(&child->mnt_hash, &mnt->mnt_hash);
 	}
 }

include/linux/mount.h

@@ -50,8 +50,6 @@ struct mnt_namespace;
 struct vfsmount {
 	struct dentry *mnt_root;	/* root of the mounted tree */
 	struct super_block *mnt_sb;	/* pointer to superblock */
-	struct list_head mnt_mounts;	/* list of children, anchored here */
-	struct list_head mnt_child;	/* and going through their mnt_child */
 	int mnt_flags;
 	/* 4 bytes hole on 64bits arches without fsnotify */
 #ifdef CONFIG_FSNOTIFY