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

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-11-24 22:19:58 -05:00
parent 3376f34fff
commit 0714a53380
5 changed files with 53 additions and 50 deletions

View File

@ -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;

View File

@ -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);

View File

@ -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;
}

View File

@ -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 @@ static int select_submounts(struct mount *parent, struct list_head *graveyard)
*/
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;

View File

@ -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);