}
/* call under rcu_read_lock */
-bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+int __legitimize_mnt(struct vfsmount *bastard, unsigned seq)
{
struct mount *mnt;
if (read_seqretry(&mount_lock, seq))
- return false;
+ return 1;
if (bastard == NULL)
- return true;
+ return 0;
mnt = real_mount(bastard);
mnt_add_count(mnt, 1);
if (likely(!read_seqretry(&mount_lock, seq)))
- return true;
+ return 0;
if (bastard->mnt_flags & MNT_SYNC_UMOUNT) {
mnt_add_count(mnt, -1);
- return false;
+ return 1;
+ }
+ return -1;
+}
+
+/* call under rcu_read_lock */
+bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+{
+ int res = __legitimize_mnt(bastard, seq);
+ if (likely(!res))
+ return true;
+ if (unlikely(res < 0)) {
+ rcu_read_unlock();
+ mntput(bastard);
+ rcu_read_lock();
}
- rcu_read_unlock();
- mntput(bastard);
- rcu_read_lock();
return false;
}
/* iterator; we want it to have access to namespace_sem, thus here... */
static void *m_start(struct seq_file *m, loff_t *pos)
{
- struct proc_mounts *p = proc_mounts(m);
+ struct proc_mounts *p = m->private;
down_read(&namespace_sem);
if (p->cached_event == p->ns->event) {
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct proc_mounts *p = proc_mounts(m);
+ struct proc_mounts *p = m->private;
p->cached_mount = seq_list_next(v, &p->ns->list, pos);
p->cached_index = *pos;
static int m_show(struct seq_file *m, void *v)
{
- struct proc_mounts *p = proc_mounts(m);
+ struct proc_mounts *p = m->private;
struct mount *r = list_entry(v, struct mount, mnt_list);
return p->show(m, &r->mnt);
}
UMOUNT_PROPAGATE = 2,
UMOUNT_CONNECTED = 4,
};
+
+static bool disconnect_mount(struct mount *mnt, enum umount_tree_flags how)
+{
+ /* Leaving mounts connected is only valid for lazy umounts */
+ if (how & UMOUNT_SYNC)
+ return true;
+
+ /* A mount without a parent has nothing to be connected to */
+ if (!mnt_has_parent(mnt))
+ return true;
+
+ /* Because the reference counting rules change when mounts are
+ * unmounted and connected, umounted mounts may not be
+ * connected to mounted mounts.
+ */
+ if (!(mnt->mnt_parent->mnt.mnt_flags & MNT_UMOUNT))
+ return true;
+
+ /* Has it been requested that the mount remain connected? */
+ if (how & UMOUNT_CONNECTED)
+ return false;
+
+ /* Is the mount locked such that it needs to remain connected? */
+ if (IS_MNT_LOCKED(mnt))
+ return false;
+
+ /* By default disconnect the mount */
+ return true;
+}
+
/*
* mount_lock must be held
* namespace_sem must be held for write
if (how & UMOUNT_SYNC)
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
- disconnect = !(((how & UMOUNT_CONNECTED) &&
- mnt_has_parent(p) &&
- (p->mnt_parent->mnt.mnt_flags & MNT_UMOUNT)) ||
- IS_MNT_LOCKED_AND_LAZY(p));
+ disconnect = disconnect_mount(p, how);
pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt,
disconnect ? &unmounted : NULL);
while (!hlist_empty(&mp->m_list)) {
mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
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);
- }
+ hlist_add_head(&mnt->mnt_umount.s_list, &unmounted);
+ umount_mnt(mnt);
}
else umount_tree(mnt, UMOUNT_CONNECTED);
}
down_read(&namespace_sem);
list_for_each_entry(mnt, &ns->list, mnt_list) {
struct mount *child;
+ int mnt_flags;
+
if (mnt->mnt.mnt_sb->s_type != type)
continue;
if (mnt->mnt.mnt_root != mnt->mnt.mnt_sb->s_root)
continue;
+ /* Read the mount flags and filter out flags that
+ * may safely be ignored.
+ */
+ mnt_flags = mnt->mnt.mnt_flags;
+ if (mnt->mnt.mnt_sb->s_iflags & SB_I_NOEXEC)
+ mnt_flags &= ~(MNT_LOCK_NOSUID | MNT_LOCK_NOEXEC);
+
/* Verify the mount flags are equal to or more permissive
* than the proposed new mount.
*/
- if ((mnt->mnt.mnt_flags & MNT_LOCK_READONLY) &&
+ if ((mnt_flags & MNT_LOCK_READONLY) &&
!(new_flags & MNT_READONLY))
continue;
- if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) &&
+ if ((mnt_flags & MNT_LOCK_NODEV) &&
!(new_flags & MNT_NODEV))
continue;
- if ((mnt->mnt.mnt_flags & MNT_LOCK_ATIME) &&
- ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK)))
+ if ((mnt_flags & MNT_LOCK_NOSUID) &&
+ !(new_flags & MNT_NOSUID))
+ continue;
+ if ((mnt_flags & MNT_LOCK_NOEXEC) &&
+ !(new_flags & MNT_NOEXEC))
+ continue;
+ if ((mnt_flags & MNT_LOCK_ATIME) &&
+ ((mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK)))
continue;
/* This mount is not fully visible if there are any
list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) {
struct inode *inode = child->mnt_mountpoint->d_inode;
/* Only worry about locked mounts */
- if (!(mnt->mnt.mnt_flags & MNT_LOCKED))
+ if (!(mnt_flags & MNT_LOCKED))
continue;
/* Is the directory permanetly empty? */
if (!is_empty_dir_inode(inode))
goto next;
}
/* Preserve the locked attributes */
- *new_mnt_flags |= mnt->mnt.mnt_flags & (MNT_LOCK_READONLY | \
- MNT_LOCK_NODEV | \
- MNT_LOCK_ATIME);
+ *new_mnt_flags |= mnt_flags & (MNT_LOCK_READONLY | \
+ MNT_LOCK_NODEV | \
+ MNT_LOCK_NOSUID | \
+ MNT_LOCK_NOEXEC | \
+ MNT_LOCK_ATIME);
visible = true;
goto found;
next: ;
Code Review / kvmfornfv.git / blobdiff