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Commit 0714a533 authored by Al Viro's avatar Al Viro
Browse files

vfs: now it can be done - make mnt_parent point to struct mount 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3376f34f

fs/dcache.c

+4 −3
Original line number Diff line number Diff line
@@ -2452,6 +2452,7 @@ static int prepend_path(const struct path *path, 
{

	struct dentry *dentry = path->dentry;

	struct vfsmount *vfsmnt = path->mnt;

	struct mount *mnt = real_mount(vfsmnt);

	bool slash = false;

	int error = 0;
@@ -2460,12 +2461,12 @@ static int prepend_path(const struct path *path, 
		struct dentry * parent;



		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {

			struct mount *mnt = real_mount(vfsmnt);

			/* Global root? */

			if (!mnt_has_parent(mnt))

				goto global_root;

			dentry = vfsmnt->mnt_mountpoint;

			vfsmnt = mnt->mnt_parent;

			dentry = mnt->mnt.mnt_mountpoint;

			mnt = mnt->mnt_parent;

			vfsmnt = &mnt->mnt;

			continue;

		}

		parent = dentry->d_parent;

fs/mount.h

+2 −2
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 


struct mount {

	struct list_head mnt_hash;

	struct vfsmount *mnt_parent;

	struct mount *mnt_parent;

	struct vfsmount mnt;

};
@@ -13,7 +13,7 @@ static inline struct mount *real_mount(struct vfsmount *mnt) 


static inline int mnt_has_parent(struct mount *mnt)

{

	return &mnt->mnt != mnt->mnt_parent;

	return mnt != mnt->mnt_parent;

}



extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);

fs/namei.c

+13 −11
Original line number Diff line number Diff line
@@ -677,36 +677,38 @@ follow_link(struct path *link, struct nameidata *nd, void **p) 


static int follow_up_rcu(struct path *path)

{

	struct vfsmount *parent;

	struct mount *mnt = real_mount(path->mnt);

	struct mount *parent;

	struct dentry *mountpoint;



	parent = real_mount(path->mnt)->mnt_parent;

	if (parent == path->mnt)

	parent = mnt->mnt_parent;

	if (&parent->mnt == path->mnt)

		return 0;

	mountpoint = path->mnt->mnt_mountpoint;

	mountpoint = mnt->mnt.mnt_mountpoint;

	path->dentry = mountpoint;

	path->mnt = parent;

	path->mnt = &parent->mnt;

	return 1;

}



int follow_up(struct path *path)

{

	struct vfsmount *parent;

	struct mount *mnt = real_mount(path->mnt);

	struct mount *parent;

	struct dentry *mountpoint;



	br_read_lock(vfsmount_lock);

	parent = real_mount(path->mnt)->mnt_parent;

	if (parent == path->mnt) {

	parent = mnt->mnt_parent;

	if (&parent->mnt == path->mnt) {

		br_read_unlock(vfsmount_lock);

		return 0;

	}

	mntget(parent);

	mountpoint = dget(path->mnt->mnt_mountpoint);

	mntget(&parent->mnt);

	mountpoint = dget(mnt->mnt.mnt_mountpoint);

	br_read_unlock(vfsmount_lock);

	dput(path->dentry);

	path->dentry = mountpoint;

	mntput(path->mnt);

	path->mnt = parent;

	path->mnt = &parent->mnt;

	return 1;

}

fs/namespace.c

+26 −26
Original line number Diff line number Diff line
@@ -476,7 +476,7 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry, 
		if (tmp == head)

			break;

		p = list_entry(tmp, struct mount, mnt_hash);

		if (p->mnt_parent == mnt && p->mnt.mnt_mountpoint == dentry) {

		if (&p->mnt_parent->mnt == mnt && p->mnt.mnt_mountpoint == dentry) {

			found = p;

			break;

		}
@@ -558,8 +558,8 @@ static void dentry_reset_mounted(struct dentry *dentry) 
static void detach_mnt(struct mount *mnt, struct path *old_path)

{

	old_path->dentry = mnt->mnt.mnt_mountpoint;

	old_path->mnt = mnt->mnt_parent;

	mnt->mnt_parent = &mnt->mnt;

	old_path->mnt = &mnt->mnt_parent->mnt;

	mnt->mnt_parent = mnt;

	mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root;

	list_del_init(&mnt->mnt.mnt_child);

	list_del_init(&mnt->mnt_hash);
@@ -572,7 +572,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path) 
void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry,

			struct mount *child_mnt)

{

	child_mnt->mnt_parent = mntget(mnt);

	child_mnt->mnt_parent = real_mount(mntget(mnt));

	child_mnt->mnt.mnt_mountpoint = dget(dentry);

	spin_lock(&dentry->d_lock);

	dentry->d_flags |= DCACHE_MOUNTED;
@@ -610,12 +610,12 @@ static inline void __mnt_make_shortterm(struct vfsmount *mnt) 
 */

static void commit_tree(struct mount *mnt)

{

	struct vfsmount *parent = mnt->mnt_parent;

	struct mount *parent = mnt->mnt_parent;

	struct vfsmount *m;

	LIST_HEAD(head);

	struct mnt_namespace *n = parent->mnt_ns;

	struct mnt_namespace *n = parent->mnt.mnt_ns;



	BUG_ON(parent == &mnt->mnt);

	BUG_ON(parent == mnt);



	list_add_tail(&head, &mnt->mnt.mnt_list);

	list_for_each_entry(m, &head, mnt_list) {
@@ -626,8 +626,8 @@ static void commit_tree(struct mount *mnt) 
	list_splice(&head, n->list.prev);



	list_add_tail(&mnt->mnt_hash, mount_hashtable +

				hash(parent, mnt->mnt.mnt_mountpoint));

	list_add_tail(&mnt->mnt.mnt_child, &parent->mnt_mounts);

				hash(&parent->mnt, mnt->mnt.mnt_mountpoint));

	list_add_tail(&mnt->mnt.mnt_child, &parent->mnt.mnt_mounts);

	touch_mnt_namespace(n);

}
@@ -639,9 +639,9 @@ static struct mount *next_mnt(struct mount *p, struct vfsmount *root) 
			if (&p->mnt == root)

				return NULL;

			next = p->mnt.mnt_child.next;

			if (next != &p->mnt_parent->mnt_mounts)

			if (next != &p->mnt_parent->mnt.mnt_mounts)

				break;

			p = real_mount(p->mnt_parent);

			p = p->mnt_parent;

		}

	}

	return list_entry(next, struct mount, mnt.mnt_child);
@@ -682,7 +682,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void 
	mnt->mnt.mnt_root = root;

	mnt->mnt.mnt_sb = root->d_sb;

	mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root;

	mnt->mnt_parent = &mnt->mnt;

	mnt->mnt_parent = mnt;

	return &mnt->mnt;

}

EXPORT_SYMBOL_GPL(vfs_kern_mount);
@@ -710,7 +710,7 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, 
		mnt->mnt.mnt_sb = sb;

		mnt->mnt.mnt_root = dget(root);

		mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root;

		mnt->mnt_parent = &mnt->mnt;

		mnt->mnt_parent = mnt;



		if (flag & CL_SLAVE) {

			list_add(&mnt->mnt.mnt_slave, &old->mnt.mnt_slave_list);
@@ -1027,7 +1027,7 @@ static int show_mountinfo(struct seq_file *m, void *v) 
	struct path root = p->root;

	int err = 0;



	seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, r->mnt_parent->mnt_id,

	seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, r->mnt_parent->mnt.mnt_id,

		   MAJOR(sb->s_dev), MINOR(sb->s_dev));

	if (sb->s_op->show_path)

		err = sb->s_op->show_path(m, mnt);
@@ -1202,9 +1202,9 @@ void release_mounts(struct list_head *head) 


			br_write_lock(vfsmount_lock);

			dentry = mnt->mnt.mnt_mountpoint;

			m = mnt->mnt_parent;

			m = &mnt->mnt_parent->mnt;

			mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root;

			mnt->mnt_parent = &mnt->mnt;

			mnt->mnt_parent = mnt;

			m->mnt_ghosts--;

			br_write_unlock(vfsmount_lock);

			dput(dentry);
@@ -1237,7 +1237,7 @@ void umount_tree(struct mount *mnt, int propagate, struct list_head *kill) 
		__mnt_make_shortterm(&p->mnt);

		list_del_init(&p->mnt.mnt_child);

		if (mnt_has_parent(p)) {

			p->mnt_parent->mnt_ghosts++;

			p->mnt_parent->mnt.mnt_ghosts++;

			dentry_reset_mounted(p->mnt.mnt_mountpoint);

		}

		change_mnt_propagation(p, MS_PRIVATE);
@@ -1435,9 +1435,9 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, 
				s = skip_mnt_tree(s);

				continue;

			}

			while (p != real_mount(s->mnt_parent)) {

				p = real_mount(p->mnt_parent);

				q = real_mount(q->mnt_parent);

			while (p != s->mnt_parent) {

				p = p->mnt_parent;

				q = q->mnt_parent;

			}

			p = s;

			path.mnt = &q->mnt;
@@ -1899,7 +1899,7 @@ static int do_move_mount(struct path *path, char *old_name) 
	/*

	 * Don't move a mount residing in a shared parent.

	 */

	if (IS_MNT_SHARED(old->mnt_parent))

	if (IS_MNT_SHARED(&old->mnt_parent->mnt))

		goto out1;

	/*

	 * Don't move a mount tree containing unbindable mounts to a destination
@@ -1909,7 +1909,7 @@ static int do_move_mount(struct path *path, char *old_name) 
	    tree_contains_unbindable(old))

		goto out1;

	err = -ELOOP;

	for (p = real_mount(path->mnt); mnt_has_parent(p); p = real_mount(p->mnt_parent))

	for (p = real_mount(path->mnt); mnt_has_parent(p); p = p->mnt_parent)

		if (p == old)

			goto out1;
@@ -2159,7 +2159,7 @@ resume: 
	 */

	if (this_parent != parent) {

		next = this_parent->mnt.mnt_child.next;

		this_parent = real_mount(this_parent->mnt_parent);

		this_parent = this_parent->mnt_parent;

		goto resume;

	}

	return found;
@@ -2565,7 +2565,7 @@ bool is_path_reachable(struct mount *mnt, struct dentry *dentry, 
{

	while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {

		dentry = mnt->mnt.mnt_mountpoint;

		mnt = real_mount(mnt->mnt_parent);

		mnt = mnt->mnt_parent;

	}

	return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);

}
@@ -2636,8 +2636,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, 
	new_mnt = real_mount(new.mnt);

	root_mnt = real_mount(root.mnt);

	if (IS_MNT_SHARED(old.mnt) ||

		IS_MNT_SHARED(new_mnt->mnt_parent) ||

		IS_MNT_SHARED(root_mnt->mnt_parent))

		IS_MNT_SHARED(&new_mnt->mnt_parent->mnt) ||

		IS_MNT_SHARED(&root_mnt->mnt_parent->mnt))

		goto out4;

	if (!check_mnt(root.mnt) || !check_mnt(new.mnt))

		goto out4;

fs/pnode.c

+8 −8
Original line number Diff line number Diff line
@@ -292,10 +292,10 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 
{

	struct vfsmount *m;

	struct mount *child;

	struct vfsmount *parent = mnt->mnt_parent;

	struct mount *parent = mnt->mnt_parent;

	int ret = 0;



	if (&mnt->mnt == parent)

	if (mnt == parent)

		return do_refcount_check(mnt, refcnt);



	/*
@@ -306,8 +306,8 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 
	if (!list_empty(&mnt->mnt.mnt_mounts) || do_refcount_check(mnt, refcnt))

		return 1;



	for (m = propagation_next(parent, parent); m;

	     		m = propagation_next(m, parent)) {

	for (m = propagation_next(&parent->mnt, &parent->mnt); m;

	     		m = propagation_next(m, &parent->mnt)) {

		child = __lookup_mnt(m, mnt->mnt.mnt_mountpoint, 0);

		if (child && list_empty(&child->mnt.mnt_mounts) &&

		    (ret = do_refcount_check(child, 1)))
@@ -322,13 +322,13 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 
 */

static void __propagate_umount(struct mount *mnt)

{

	struct vfsmount *parent = mnt->mnt_parent;

	struct mount *parent = mnt->mnt_parent;

	struct vfsmount *m;



	BUG_ON(parent == &mnt->mnt);

	BUG_ON(parent == mnt);



	for (m = propagation_next(parent, parent); m;

			m = propagation_next(m, parent)) {

	for (m = propagation_next(&parent->mnt, &parent->mnt); m;

			m = propagation_next(m, &parent->mnt)) {



		struct mount *child = __lookup_mnt(m,

					mnt->mnt.mnt_mountpoint, 0);