vfs: more mnt_parent cleanups

a) mount --move is checking that ->mnt_parent is non-NULL before
looking if that parent happens to be shared; ->mnt_parent is never
NULL and it's not even an misspelled !mnt_has_parent()

b) pivot_root open-codes is_path_reachable(), poorly.

c) so does path_is_under(), while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-11-23 19:34:49 -05:00
parent b2dba1af3c
commit afac7cba7e
4 changed files with 29 additions and 55 deletions

View file

@ -28,21 +28,6 @@ static inline struct vfsmount *next_slave(struct vfsmount *p)
return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);
}
/*
* Return true if path is reachable from root
*
* namespace_sem is held, and mnt is attached
*/
static bool is_path_reachable(struct vfsmount *mnt, struct dentry *dentry,
const struct path *root)
{
while (mnt != root->mnt && mnt_has_parent(mnt)) {
dentry = mnt->mnt_mountpoint;
mnt = mnt->mnt_parent;
}
return mnt == root->mnt && is_subdir(dentry, root->dentry);
}
static struct vfsmount *get_peer_under_root(struct vfsmount *mnt,
struct mnt_namespace *ns,
const struct path *root)