fs/namei.c: new helper - legitimize_root()

identical logics in unlazy_walk() and unlazy_child()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2019-07-16 21:05:36 -04:00
parent ce6595a28a
commit ee594bfff3

View File

@ -641,6 +641,13 @@ static bool legitimize_links(struct nameidata *nd)
return true;
}
static bool legitimize_root(struct nameidata *nd)
{
if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT))
return true;
return legitimize_path(nd, &nd->root, nd->root_seq);
}
/*
* Path walking has 2 modes, rcu-walk and ref-walk (see
* Documentation/filesystems/path-lookup.txt). In situations when we can't
@ -674,10 +681,8 @@ static int unlazy_walk(struct nameidata *nd)
goto out2;
if (unlikely(!legitimize_path(nd, &nd->path, nd->seq)))
goto out1;
if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq)))
goto out;
}
if (unlikely(!legitimize_root(nd)))
goto out;
rcu_read_unlock();
BUG_ON(nd->inode != parent->d_inode);
return 0;
@ -736,12 +741,10 @@ static int unlazy_child(struct nameidata *nd, struct dentry *dentry, unsigned se
* Sequence counts matched. Now make sure that the root is
* still valid and get it if required.
*/
if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq))) {
rcu_read_unlock();
dput(dentry);
return -ECHILD;
}
if (unlikely(!legitimize_root(nd))) {
rcu_read_unlock();
dput(dentry);
return -ECHILD;
}
rcu_read_unlock();