[PATCH 2/7] follow_dotdot{,_rcu}(): change calling conventions

Al Viro
2022-07-04T23:14:51Z

Instead of returning NULL when we are in root, just make it return
the current position (and set *seqp and *inodep accordingly).
That collapses the calls of step_into() in handle_dots()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 4dbf55b37ec6..ecdb9ac21ece 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1909,7 +1909,9 @@ static struct dentry *follow_dotdot_rcu(struct nameidata *nd,
return ERR_PTR(-ECHILD);
if (unlikely(nd->flags & LOOKUP_BENEATH))
return ERR_PTR(-ECHILD);
- return NULL;
+ *seqp = nd->seq;
+ *inodep = nd->path.dentry->d_inode;
+ return nd->path.dentry;
}

static struct dentry *follow_dotdot(struct nameidata *nd,
@@ -1945,8 +1947,9 @@ static struct dentry *follow_dotdot(struct nameidata *nd,
in_root:
if (unlikely(nd->flags & LOOKUP_BENEATH))
return ERR_PTR(-EXDEV);
- dget(nd->path.dentry);
- return NULL;
+ *seqp = 0;
+ *inodep = nd->path.dentry->d_inode;
+ return dget(nd->path.dentry);
}

static const char *handle_dots(struct nameidata *nd, int type)
@@ -1968,12 +1971,7 @@ static const char *handle_dots(struct nameidata *nd, int type)
parent = follow_dotdot(nd, &inode, &seq);
if (IS_ERR(parent))
return ERR_CAST(parent);
- if (unlikely(!parent))
- error = step_into(nd, WALK_NOFOLLOW,
- nd->path.dentry, nd->inode, nd->seq);
- else
- error = step_into(nd, WALK_NOFOLLOW,
- parent, inode, seq);
+ error = step_into(nd, WALK_NOFOLLOW, parent, inode, seq);
if (unlikely(error))
return error;

--
2.30.2