[RFC][PATCH v4 42/69] path_parent_directory(): leave changing path->dentry to callers

Al Viro
2020-03-13T23:56:20Z

Instead of returning 0, return new dentry; instead of returning
-ENOENT, return NULL. Adjust the callers accordingly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/namei.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 2bf9f605c46f..49b2a08105c7 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1440,19 +1440,21 @@ static void follow_mount(struct path *path)
}
}

-static int path_parent_directory(struct path *path)
+static struct dentry *path_parent_directory(struct path *path)
{
- struct dentry *old = path->dentry;
/* rare case of legitimate dget_parent()... */
- path->dentry = dget_parent(path->dentry);
- dput(old);
- if (unlikely(!path_connected(path->mnt, path->dentry)))
- return -ENOENT;
- return 0;
+ struct dentry *parent = dget_parent(path->dentry);
+
+ if (unlikely(!path_connected(path->mnt, parent))) {
+ dput(parent);
+ parent = NULL;
+ }
+ return parent;
}

static int follow_dotdot(struct nameidata *nd)
{
+ struct dentry *parent;
while (1) {
if (path_equal(&nd->path, &nd->root)) {
if (unlikely(nd->flags & LOOKUP_BENEATH))
@@ -1460,9 +1462,11 @@ static int follow_dotdot(struct nameidata *nd)
break;
}
if (nd->path.dentry != nd->path.mnt->mnt_root) {
- int ret = path_parent_directory(&nd->path);
- if (ret)
- return ret;
+ parent = path_parent_directory(&nd->path);
+ if (!parent)
+ return -ENOENT;
+ dput(nd->path.dentry);
+ nd->path.dentry = parent;
break;
}
if (!follow_up(&nd->path))
@@ -2600,13 +2604,13 @@ int path_pts(struct path *path)
*/
struct dentry *child, *parent;
struct qstr this;
- int ret;

- ret = path_parent_directory(path);
- if (ret)
- return ret;
+ parent = path_parent_directory(path);
+ if (!parent)
+ return -ENOENT;

- parent = path->dentry;
+ dput(path->dentry);
+ path->dentry = parent;
this.name = "pts";
this.len = 3;
child = d_hash_and_lookup(parent, &this);
--
2.11.0